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EC-Lab Techniques and App Manual

1. 715 can IO 20 000 m Fig 31 SGEIS detailed diagram with a sinus amplitude h pA A sets the sinus amplitude to la Wait for pw period before each frequency measurement 46 Techniques and Applications Manual offers the possibility to add a delay before the measurement at each frequency This delay is defined as a part of the period Of course for low frequencies the delay may be long average Na mesure s per frequency repeats Na measure s and average values for each frequency o Drift correction corrects the drift of the system It needs to be used when the sytem has not reached its styeady state regime This feature is more specifically dedicated to low frequencies at which the impedance measurement can be pretty lengthy and for which the effect of the drift can be seen Note 1 If this option is selected the sinus frequencies are evaluated over 2 periods instead of 1 increasing the acquisition time by a factor of 2 2 Inthe bottom right corner of the block the approximate experiment duration is indicated as information for the user During the run several parameters remain accessible for modification such as the min and max frequencies and the number of points per decade For more information about the drift correction please refer to the Application Note 17 E Range enables the user to select the potential range and to adjust the potential res
2. dE ZO 7 100 py 4 600 0 me JEN 500 p Fig 165 Detailed diagram of the Generalized Corrosion technique e Rest potential or open circuit sequence See EVT technique above 186 Techniques and Applications Manual e Potential scan Scan Ewe with dE dt mV s defines the potential scan The software selects the smallest potential step according to the control potential resolution defined in the Advanced settings window see the EC Lab Soft ware User s Manual for more details From Ei V vs Ref Eoc Ectrl Emeas to E V vs Ref Eoc Ei from a potential Ei defined vs Ref the reference electrode potential or versus a previous open circuit potential Eoc previous controlled potential Ecti or previous measured potential Emeas to E vertex potential defined in absolute or versus Eoc or Ei Record lt I gt over the last of the step duration averaged N voltage steps I every dlp pA nA LA mA A or dtp S two different recording conditions on the current are available with the potentiodynamic mode either recording an averaged current lt I gt on each potential step or recording an instantaneous current with a time variation and or an instantaneous current variation dl and or charge var iation dQ E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab Software User s Manual for more details on t
3. Rest for H 5 voltage steps 500 ul AW dM Zant ten i 100 p 7 100 py 4 602 4 ms C reached go ta 6 SS SE nass C above o hp ma 10 0 pags Limit AT Ac lt dTq dty with di and di Record every dp dE R1 dp 1 00 I 0 h up mm 1 00 KE 00 rn O mm ooo00 ga ta 2 Stop controlling T C SeT 0 0 L Fig 172 Detailed diagram of the CPT technique 195 Techniques and Applications Manual The whole sequence can be described with the following figure IeasurED mm Time Fig 173 I Ewe and T vs time for the CPT experiment e First step set the initial temperature and turn to rest Set Ti C sets the temperature Ti Rest Until lt dT dt gt lt dTo C dto h mn or forto h mn turns to rest until the temperature is stabilized or during to time The first limit reached stops the rest period A 0 value devalidates a limit If dTo O or dto O then the rest duration will be to If only to is null the rest period will continue until the temperature is stabilized under dT o dto limit And if both dTo dto and to are null the rest is skipped but the temperature is also set to T value Record every dTpo C dEro mV and dtro MN S records on temperature dT Ro potential dEro and time dtro resolutions The first condition reached defines a recording A zero value disables a recording condition 196
4. for a charge when the positive electrode of the cell is connected to the working electrode cable red Set C N or CxN with N and I gt 0 or lt 0 for at most t h mn s sets the rate C N or CXN at which the battery will be charged I gt 0 or discharged l lt 0 The C value could be a noninteger value For instance if the capacity of a battery is 1800 mA h setting C N with N 3 and I gt 0 means that a current of 600 mA will be passed during 3h The total capacity of the battery will be reached in 3h 126 Techniques and Applications Manual Setting CxN with N 2 and I lt 0 means that a current of 3600 mA will be passed during 30 min The total capacity of the battery will be reached in half an hour There is still the possibility to set a time limit e First step galvanostatic period that can be followed by a potentiostatic period Limit Ece gt lt Em V sets the limit of the working electrode potential under charge discharge see warning 1 Record Ecei every dE mV and at least every dt S allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dE or and at least every dt time interval Sei v to Le for at most D Lint Ece gt EM Record even dE4 or dii Hold EM for tpg Limit Il lt le or dl dt lt dl dt Record every d o dtg Lirnit AG gt
5. Description of the error the error message mpr file picture of setting or any other useful information and of the context in which the error occurred Try to remember all steps you had performed immediately before the error oc curred The more information on the actual situation you can provide the easier it is to track the problem The serial number of the device located on the rear panel device Bio Logic SAS Model VMP3 sinn 0001 Power 110 240 Vac 50 60 Hz www bio logic info Fuses 10 AF Pmax 650 W CAUTION CE DO NOT OPEN ATTENTION RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR The software and hardware version you are currently using On the Help menu click About The displayed dialog box shows the version numbers The operating system on the connected computer The connection mode Ethernet LAN USB between computer and instru ment G eneral safety considerations H Class WARRANTY The instrument is safety ground to the Earth through the protective conductor of the AC power cable Use only the power cord supplied with the instrument and designed for the good current rating 10 A max and be sure to connect it to a power source provided with protective earth contact Any interruption of the protective earth grounding conductor outside the instrument could result in per sonal injury Guarantee and liability claims in the event of injury or mate rial damage are excluded when they ar
6. O OCY 0 Mode Galvanostatic 1 O Galvanodynamic 2 50 000 pA vvs lt Noner ei h A mn poog Limits Eq AG gt AQp Record every dEr dtp dqp E Range Range Bandwidth Go back to sequence Ma 0 NNN eat AAYY NRA for pe 0 time s Allene sean Fig 69 Modular Galvano Galvanostatic detailed diagram Set to l pA A vs lt None gt Ictrl Imeas for ts h mn S sets the Emer to a fixed value for ts time The current value can be defined in absolute or versus a previous controlled current or measured current Limits E V and AQ to AQw fA h A h pC kKC defines the potential and sequence charge limits The E limit is dependent on the charge sign the limit is Ewe gt EL if ls gt 0 Ewe lt EI otherwise To cancel the limits type p for pass in the Ex edition box and zero for AQm For the galvanostatic mode AQvy is not accessible and is calculated from ls and ts AQm Is ts Record every dE mV dtp s and dQ fA h A h pC kC defines the recording conditions A zero value cancels the corresponding recording criterion These values can be entered simultaneously If so the first condition that is reached determines the recording For the galvanostatic mode dQ is not accessible and is calculated from I and dtp dQp ls dtp 78 Techniques and Applications Manual E Range enables the user to selec
7. 002 V vs Eoo e Record EP e over the last 25 Z of the step duration average WN 5 voltage steps ERange 2NVM 2M Za gen Ad ar Range us e Bandwidth 7 e dE ot 100 py 602 4 me JEN 500 o Fig 155 Detailed diagram of the l V Characterization e First step rest potential or open circuit sequence Rest for tr h mn S sets a defined time duration tr for recording the rest potential Limit dEw dt lt dEr dt mV h gives the user the ability to shorten the open circuit period at the time when the decay of the potential is lower than a given value Record Ewe with dEr mV resolution and or dtr S allows the user to record the working electrode potential whenever the change in the potential is gt dEr or every dtr time interval Data recording with dEr resolution reduces the number of experimental points without losing any interesting changes in potential When there is no potential change only points according to the dtr value are recorded but if there is a sharp peak in potential the rate of the potential recording is governed by the potential recording resolution e Second step potential scan Scan Ewe with dE dt mV s defines the potential scan The software selects the smallest potential step according to the control potential resolution defined in the Advanced settings window see the corresponding section in the EC Lab Software User s Manual for
8. 61 Techniques and Applications Manual And the next variables are calculated from lt I gt or from the potential to save space on disk forward mA lt l gt values at the end of the pulses lp reverse mA lt l gt values before the pulses lbp delta UA difference between lt I gt values before and at the end of the pulse lp lbp E step V step potential value resulting from the potential sweep and used to plot the current 2 3 4 RNPV Reverse Normal Pulse Voltammetry The Reverse Normal Pulse Voltammetry is a derivative technique from the NPV The main difference is that the initial base potential E is placed in the diffusion limited region for elec trolysis of the species present in the bulk solution The pulses are made through the region where the species in solution is not electroactive The RNPV experiment involves a significant faradic current This method is a reversal experiment because of the detection of the product from a prior electrolysis Description e Initial potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas fort h mn s sets Ewe to the initial potential E This potential value can be set vs the reference electrode potential or according to the previous open circuit potential Eoc controlled potential Eei or measured potential Emeas Notice that only the last point of this period is recorded at the time 0 e Pulse waveform Scan Ewe from E to Ey V vs Ref
9. E Lg otg Lg pas V tg 0 000 0 dE wedt gt dEp dt pass mV s Record every du i D mi dtp 0 500 0 dap 0 000 mah E Range 2 2 Areca Fie Range 10 m Bandwidth F medium e Go back to sequence Net 0 NNN ene RYN AAA forme f timels Av est oo Fig 73 Special Modular Galvano Galvanodynamic detailed diagram The three modes of the Special Modular Galvano technique can be chained as sequences in the table in the order that the user wants Each of the parameters can be modified in its box But parameters like Range or Bandwidth must keep the same value for all the sequences Note that the first sequence has got the number Ns 0 To switch from a sequence to another one click on the desired row in the table Note in this technique the first and the last data points of each current steps are not recorded automatically 83 Techniques and Applications Manual 2 4 5 Tl and TO Trigger In and Trigger Out Selecting the triggers option allows the user to insert a trigger command before or after a tech nique The procedure is the same as for linked techniques Two options are available trigger in and trigger out The next table summarizes the different possibilities for trigger in and out Table 1 Triggers in and out stop start stop ALL A f JLIL lt d b lg Bist ing Edge Falling Edge tigger duration tq E h Ta mr 0 001
10. Fig 51 NPV waveform Fig 50 NPV detailed diagram average over the last of each step points selects the end part of the potential step for the current average lt I gt calculation to exclude the first points where the current may be disturbed by the step establishment A value of 100 will take all the step points for the average and a value of 0 will take only the last point Note that the current average lt I gt is recorded at the end of the potential step to the data file Scan rate mV s number of points these values are given as an indication and are calculated in the PC The scan rate is directly given by Py 0 001 Gr and the number of points is roughly 2 E Ei St for the forward scan E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth sets the current range and bandwidth values for the entire experiment Note It is highly recommended to avoid using the automatic current range with pulsed tech niques The resolution of each range is different and dynamic current range changes may lead to spikes on the plot NPV recorded and calculated variables The variables below are stored into the NPV raw files mpr state byte time s control V Ewe V lt l gt mA Q Qo mA h
11. designed originally for the WMP Itis a simple technique dedicated to TL Constant Voltage Lay l Ss TL Constant Current Lat fast chronoamperomety expenments This technique consists of fast Ag Corrosion loops on two potential steps This technique is reduced to basic 4 LC Custom Applications measurements in order to increase the acquisition rate Polarization Resistance PR Stepwise Potential Fast Chronoamperometry SPFC a Anodic stripping voltammetry ASV ae ADE rotating speed effect Le Special Applications Insert Technique Load from default Custom Applications Before J Advanced setting External devices a rn Alter Cell characteristics Rename Add REH Stack Cancel Fig 196 Custom Applications section in the Techniques window In this example two custom applications have been created Anodic stripping voltammetry and RDE rotating speed effect In the bottom of the technique window a frame with three buttons is dedicated to the custom applications The selected custom application can be renamed or removed The user can also add a custom application with the Add button 216 Techniques and Applications Manual 3 6 Special applications For each special application it is possible to stop the experiment with an external limit such as a temperature a speed Select Other Device Type in the External Device windows Fig 197 To record exte
12. s defines the recording conditions These values can be entered simultaneously The first con dition that is reached determines the recording A zero value disables the recording for each criterion I Range and Bandwidth sets the current range and bandwidth for this experiment e Rest period The rest period is an open circuit voltage period Refer to the OCV description for more details CAUTION Applying a constant power during a discharge experiment corresponds to an increase of the current in absolute value when the potential decreases The user must be careful to note the final current of the first constant power step For example let us consider a 30 watts power discharge applied to a battery with a 10 A booster We suppose that the potential limits of this experiment are 4 V and 2 5 V The initial current will be 7 5 A but the final current will be 12 A overload in current It will not be possible to go to the final current 3 3 4 CstV Constant Voltage The constant voltage CstV technique is especially dedicated to fuel cell s or photovoltaic cell s testing It is designed to apply successively several voltage steps to the cell s Between each voltage step an open circuit voltage period can be added e Rest period The rest period is an open circuit voltage period Refer to the OCV description for more details e Potential step with data recording conditions Apply Ei V vs Ref Eoc Ectrl Emeas the
13. C dEr mV and dtr mn S lf dI4 dt and t are set to 0 than the rest will not be executed but the temperature will be increased and the experiment will restart at the second step without the potential scan This 197 Techniques and Applications Manual means that the potential Ep will be applied continuously for the rest of the duration of the pitting experiment 3 4 8 MPP Multielectrode Potentiodynamic Pitting Pitting corrosion occurs when discrete areas of a material undergo rapid attack while the vast majority of the surface remains virtually unaffected The basic requirement for pitting is the existence of a passive state for the material in the environment of interest Pitting of a given material depends strongly upon the presence of an aggressive species in the environment and a sufficiently oxidizing potential This technique is designed to study pitting corrosion on one or several electrodes together in the electrochemical cell This technique corresponds to the pitting potential determination of a material using a potential sweep Begin Initial Rest Potential Sequence Potential Sweep with threshold pitting detection Disconnect the working electrode End Fig 174 General diagram of the Potentiodynamic Pitting technique First there is an open circuit sequence with recording of the working electrode potential for a given time or until its variation vs time is lower than a given limit
14. Note 3 The choice of the operating current range which is usually done in the Range menu of the Parameter settings window can also be obtained by double clicking on any cell of the corresponding column in the table associated to the detailed diagram window 114 Techniques and Applications Manual 3 1 2 2 Application The following figure shows the result of a GCPL experiment obtained with a Li ion battery 10 A h in an intermittent charge discharge cycling GITT mode 3e Ewe vs time 1S 5379_GCPL_3 12b 4 mpr e slk vs time TS 5379_GCPL_3 12b 4 mpri 3 000 2 500 A 000 7 1 500 1 000 sog 500 1 000 YU cl Ewe V 1 500 2 000 2500 D D LE i i i i i j 4 E H F 3000 3500 EC rr Am ha hk lh T 4 000 4500 5 O00 1 000 000 1 050 000 time s Fig 105 Example of GCPL experiment obtained with a Li ion battery 10 A h 3 1 2 3 GCPL Data processing 3 1 2 3 1 Compacting process for the apparent resistance determination Selecting Keep only values at the end of every open circuit period on period com presses the data resulting from the raw data file by keeping only one point for the whole open circuit period or the whole galvanostatic sequence This point is taken at the time correspond ing to the end of the period sequence Once selected the software calculates the ohmic drop Ri at the end of the galvanostatic sequences and the ohmic drop at th
15. Record every dl pA A dQ fA h A h pC kC and dtp S lt I gt every dts S You can record either an instantaneous current value or an averaged current value lt I gt The recording conditions during the potential step depend on the chosen current variable For the instantaneous current the recording values can be entered simultaneously then the first con dition is reached and determines the recording A zero value disables the recording for each criterion For the averaged current the user defines the time for the average calculation In that case the data points are recorded in the channel board memory every 200 us for VMP3 based instruments and for VMP300 based instruments E Range enables the user to select the potential range for adjusting the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range and Bandwidth sets the current range and the bandwidth for this experiment e Potentiodynamic Mode 2 Scan Ewe from E V vs Ref Eoc Ectrl Emeas to E V vs Ref Eoc Ectrl Emeas defines the initial potential Ei to a fixed value vs Ref or to the previous sequence final open circuit potential Eoc or controlled potential Ect or measured potential Emeas and defines the final potential E vs Ref or relatively to the open circuit potential Eoc or to the initial potential Ej With
16. Set Ewe to Ej V vs Ref Eoc Ectrl Emeas sets the starting potential vs reference electrode potential or vs the open circuit potential Eoc or the previous controlled potential Ecti or measured potential Emeas e First potential sweep with measurement and data recording conditions Scan Ewe with dE dt V s mV s mV mn allows the user to set the scan rate in V s mV s or mV mn The potential step height and its duration are optimized by the software in order to be as close as possible to an analogic scan Between brackets the potential step height and the duration are displayed according to the potential resolution defined by the user in the Advanced Settings window see the corre sponding section in the EC Lab Software User s Manual to vertex potential E V vs Ref Eoc Ei sets the first vertex potential value vs reference electrode potential or vs the open circuit potential Eoc or vs the potential of the previous experiment Ei e Reverse scan Reverse scan to vertex potential E2 Vve Ref Eoc Ei runs the reverse sweep towards a 2 limit potential The vertex potential value can be set vs reference electrode potential or according to the previous open circuit potential Eoc or ac cording to the potential of the previous experiment Ei e Repeat option for cycling 165 Techniques and Applications Manual Repeat ne times repeats the scan from Ei to E and to E2 ne time s Not
17. Techniques Representation and Applications Manual Nyquist Impedance wi Bode Impedance Nuoust Impedance Black Impedance El vs t Bode Admittance Nuoust Admittance Black Admittance Fig 34 Impedance graph plot se lector Among the available variables the Impedance Z is calculated using Fast Fourier Transform function and the admittance Y is determined as Y 1 Z For both variables Bode Nyquist and Black diagrams can be plotted according to the EC Lab software s predefined graph visuali zation modes e Bode diagram for both impedance and admittance The Bode diagram is the plot of log Z vs log f and Z phase vs log f for the impedance log Y vs log f and Y phase vs log f for the admittance On the first figure log Z and log Y have been overlaid on the same graph On the second one Phase Z and Phase Y have been over laid log Z Ohml Phase Z deg Fig 35 BODE 100 4 000 10 000 100 000 freq Hz log spacing 100 4 000 10 000 100 000 freq Hz log spacing diagrams for both im pedance blue and admittance red 49 Techniques and Applications Manual e Nyquist diagram The Nyquist diagram is the plot of Im Z vs Re Z for impedance Im Y vs Re Y for admittance Im Z Ohm The main difference between both visualiza tions is that the admittance diagram better rz S epp shows the high frequency semi circle SEH With th
18. Techniques and Applications Manual The pulse train is made of pulses of pulse height PH amplitude and pulse width Pw duration These steps are superimposed on a staircase of step height amplitude Sy and step duration 2 Pw Note that only one point is recorded at the end of the potential forward pulse and one point at the end of the potential reverse pulse making two points during the Sr period The settings below Fig 48 are given for a positive scan To perform a negative scan set Ey inferior to Ei and Sx to a negative value Set E ue to Ej 0500 V w Dei wll forty 0 hh mm 00000 3 Scan Ewe from E to Ey 0 500 V YG Dei with pulses height Py 275 0 DM pulses width Pay 50 0 m step height SH 10 0 mi Fig 49 SWV waveform average ower the last i oo ofeach step ASN mmia een n PR EE gee Anema OT D r 7 he ERange 2y 2 M B ena Fata Range 10 m vi Bandwidth 7 e Reverse scan to Ep 0 000 Y VE Ref Fig 48 SWV detailed diagram average I over the last of each step points Selects the end part of the potential step for the current average lt l gt calculation to exclude the first points where the current may be disturbed by the step establishment A value of 100 will take all the step points for the average and a value of 0 will take only the last point Note that the current average lt l gt is recorded at the end of the potential step into the data fi
19. The number of loops starts while the loop block is reached For example on Ns 3 if one enters goto Ns 2 for nc 1 time the sequence Ns 2 Ns 3 will be executed 2 times Nc 0 disables the loop and the execution continue to the next line Ns Ns 1 If there is no next line the execution stops 3 4 Corrosion Corrosion is the chemical or electrochemical reaction between a material usually a metal and its environment that produces a deterioration of the metal and its properties 3 4 1 EVT Econ versus Time This technique is the measurement of the corrosion potential when the circuit is open versus time During this measurement no potential or current is applied to the cell 180 Techniques and Applications Manual Be fo tp f b mp nmn 3 Limit ae dd lt dER dt Dn Mib Record every dEr 5 0 rei o dtg 300000 3 Fig 160 Ecorr vs time diagram Rest for te h MN S sets a defined time duration tr for recording the rest potential or until dEwe dt lt dEr dt mV h stops the rest sequence when the slope of the open circuit potential with time dER dt be comes lower than the set value value 0 invalidates the condition Record Ewe every dEr mV resolution and at least every die S allows the user to record the working electrode potential whenever the change in the potential is gt dEr with a minimum recording period in time dtr Data recording with dEr resolution c
20. The user is allowed to define the potential sweep by setting the potential step amplitude and duration It is also possible to go to the next potential step before the end of the potential steps if the charge or discharge currents are lower than a given value while it is still cycling with a minimum galvanostatic rate This is a direct technique for the determination of the incremental capacities dx dV of inser tion electrode materials The magnitude of the current transient can be used to provide a meas ure of the chemical diffusion flux of the mobile species as a function of time t The compacting function is used See 3 1 10 3 The quality of the determination is usually better than what is obtained by derivation of a titration curve made with chronopotentiometry under galvanostatic mode See 2 1 8 The main reason is the significant noise on the potential derivative with respect to the charge i e time References Wen C J Boukamp C A Huggins R A J Electrochem Soc 126 1979 2258 2266 Pantech Gabaron Acea Next Sweep Potential Swep with Galyanostatic Acceleration np est d Rest Potential Sequence Test Ewe vs Ey imit Nest Sweep or go ne tines to sequence Hs End Fig 116 General diagram of the PCGA application Pea i DIMEN End To Ne 3 1 10 1 Description of a potentiodynamic sequence See Fig 118 e First step stepwise potentiodynamic sweep Scan Ewe with dE
21. This technique is designed to study the discharge of a battery at constant power The control is made by checking the current to maintain an E l constant Corrosimetry application used in corrosion for the determination of Rp versus time by a rep etition of the polarization around the corrosion potential at fixed time intervals Cycle inside a technique this term is used to describe a Sequence repeated with time 229 Techniques and Applications Manual Cycle number processing function that allows the user to display on the graphic one or sev eral cycles chosen in the raw file The selected cycles are lightened and the others are hidden Cyclic Potentiodynamic Pitting CPP corrosion technique used to evaluate pitting suscep tibility and made with a potentiodynamic part and a conditional potentiostatic part which is taken into account if the pitting current is not reached during the potentiodynamic part Cyclic Voltammetry CV this technique consists in scanning the potential of the working electrode and measuring the current resulting from oxydo reduction reactions Cyclic voltam metry provides information on redox processes electron transfer reactions and adsorption processes Depassivation Potential DP corrosion technique composed with a potentiostatic part used to depassivate the electrode metal and with a potentiodynamic part used to study the corrosion pitting Differential Pulse Voltammetry DPV technique used in
22. Warning 1 When running a charge sequence I gt 0 the final value of the working electrode potential EL must be set at a lower value than the first limit value Eu This is due to the fact that at the end of the current on period charge the working electrode potential reaches a max imum and decreases during the open circuit period which follows If Ex is set at a higher value than Em the experiment will never reach the limiting condition test Ewe gt EL and the technique will always loop on the first step Similarly when running a discharge sequence I lt 0 the final value of the working electrode potential EL must be set at a higher value than the first limit value Ew At the end of the discharge the working electrode potential reaches a minimum and increases during the rest potential period If EL is set at a lower value than Em the experiment will never reach the limiting condition test Ewe lt EL and the technique will always loop on the first step Warning 2 When setting values in the diagram or the table s line the user must set variables to 0 instead of blank Otherwise the program will detect a blank cell and will end the technique Note 1 For the 1 sequence sweep Ns 0 the galvanostatic block is ignored This allows the user to run a 1 open circuit period before starting a charge or discharge sequence Note 2 If the AQwm limit is reached the Ewe vs Ex test is ignored and the next sequence is executed
23. current or the previous measured 39 Techniques and Applications Manual Instead of la one can consider the current peak to peak amplitude lpp related to la with Ipp 2 la or the Root Mean Square RMS voltage related to la with Iams la V2 2 2 3 SPEIS Staircase Potentio Electrochemical Impedance Spectroscopy The SPEIS and SGEIS powerful techniques are designed to perform successive impedance measurements on a whole frequency range during a potential scan SPEIS or during a cur rent scan SGEIS The main application of these techniques is to study electrochemical reac tion kinetics along voltamperometric E curves in analytical electrochemistry These tech niques find all their interest in studying the complexity of non stationary interfaces with faradic processes where the total AC response whole frequency range is required Another common application of such techniques is the study of semi conductor materials For these stationary systems only two or three frequencies for each potential step are required to determine the donor density and the flat band potential 2 2 3 1 Description The SPEIS technique consists in a staircase potential sweep potential limits and number of steps defined by the user An impedance measurement with an adjustable number of fre quencies is performed on each potential step For all these applications a Mott Schottky plot 1 C vs Ewe or 1 C vs Ewe can be displayed and a special linear f
24. jo ohio mn S0000 3 Limit Mei lt dEp_ dt 00 ik Record every dEp oO om or dtp o1000 Scan Ewe with dE fd i 00 000 miS from Ei 0 000 V wes Eoc to EL 2000 V vs Ref e Record TS over the last EN of the step duration average H 10 voltage steps ERange 254 25 J Arena TR ee Range lauto e Bandwidth 5 dE dt 100 py 21 0 me JEN 1 0 md Fig 11 Linear Sweep Voltammetry detailed diagram Record lt l gt over the last of the step duration selects the end part of the potential step from 1 to 100 for the current average lt I gt calcu lation to possibly exclude the first points where the current may be disturbed by the step es tablishment Note that the current average lt I gt is recorded at the end of the potential step into the data file average N voltage step s averages N current values over N potential steps in order to reduce the data file size and smooth the trace The potential step between two recording points is indicated between brack ets Once selected an estimation of the number of points per cycle is displayed into the diagram E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth enables the user to select the current range and the bandwidth
25. 193 3 points method n 2 reverse steps n 3 do not reverse steps 213 Techniques and Applications Manual The 4 points method gives more accuracy so it is proposed by default Nevertheless it is not always possible to make a reduction after an oxidation so then choose the 3 points method Note other methods can be performed with the Polarization Resistance technique but the process here accepts only the 3 and 4 points method If several points have been recorded for each potential step n gt 1 it is possible to exclude some points for the calculus For example selecting Calculate lt l gt for point 3 to 10 will exclude the first two points Chose the Rp unit Q cm or Q and click on Compute to calculate the next values C e C4 7 C3 DH t D SECH 7 Peathodic G po and Paveraged e D 27h l4 l3 H I l5 ie 3 points method with r and r 4r e de d Li D H 4 points method Lon Hem with e1 l1 being the potential and the average cur rent without excluded points on the potential step AE 2 l2 on 2AE e i on AE or 3AE according to the selected method and 4 i4 2AE Note if there are several loops n gt 0 then the en in values are averaged on the different loops before the calculus 3 5 2 SPFC Stepwise Potential Fast Chronoamperometry The Stepwise Potential Fast Chronoamperometry Begin is a simple technique designed to loop on two po tentia
26. E Range ov 10 Z nn NNN at Range 1A Bandwidth 7 wi 2 RestfortR b hfs mn foon s Limit ME we dl lt dEp dt 00 ri A Record even dep If DM or dtp 16 0000 dee Ger Za adi goi Fs 3 IE E we Ej pass V goto 1 4 Go back to seq Ne 0 ANN age EM for pe 0 time s Zi oa sez Fig 157 CPW detailed diagram e Choice of the power value Set P E l uW mW W for at most tu h mn S sets the cell power to P E I for tm duration With gt 0orl lt 0Oand keep lt Im pA A defines the charge I gt 0 or discharge I lt 0 mode and limits the current to a maximum value lu in order to preserve the cell and or the instrument Limits Ewe lt Em V AQ to AQm A h fA h kC pC lt gt Axu sets the limit of the working electrode potential Ewe to a maximum value if I gt 0 or to a minimum value if LO and the charge from the beginning of the sequence AO Ax for the whole 176 Techniques and Applications Manual step The maximum charge can be entered into mA h AQw or as a normalized charge re lated to intercalation electrodes Axm Once a limit is reached the experiment proceeds to the next step Rest even if the programmed time tm is not terminated These limits can be by passed by entering 0 values into the controls Record every dE mV dq A h fA h kC pC and dt
27. Fig 74 Trigger In and Out The Trigger In option puts the instrument in a waiting configuration until it receives a trigger with a rising edge or a falling edge depending on the instrument that generates the trigger signal The Trigger Out option sends a trigger to an external instrument with a rising edge or a falling edge before or after a technique It is possible to select the duration of the Trigger Out Inserting the trigger before or after the technique will start or stop the run These features can be set for every technique of the experiment The triggers are available on the DB9 connector as described below Cround Ext 1 TIL out Fig 75 DB9 Pin assignment when facing the instrument 84 Techniques and Applications Manual A special cable made with a DB9 connector on one side and 8 BNC plugs on the other side is provided with the instrument upon request 2 4 6 Wait The Wait technique has been designed for linked experiments This technique can be loaded only once another technique has been previously loaded Wal with previous control fortg 0 hu mm 00000 or from technique 1 begin untilthe 7 month 3 day 00g vear hi h n m Sp 4 Record even dE 0 00 DM d Dm IA e dt 0 1 Fig 76 Wait diagram Wait with previous control Forty h mn s O from technique begin It is possible to choose the wait duration ta In that case the duration can start at the end of the previous tech
28. Record Ewe every dE mV and at least every dts S limits the recordings conditions in voltage variation and or time variation Range Bandwidth sets the current range and the bandwidth for this experiment e Conditional test proposes to go to the next sequence or to loop on a previous sequence Ns Ns lt Ns 3 1 18 RPI Resistance Profile Importation This technique consists in applying various resistance values on a battery during a defined duration This technique is specially designed to fit the urban driving patterns designed to test EV batteries The particularity of this technique is the large number of sequences available and the fact that the experimental settings can be defined by importing a text file Note that experimental limits are not present in the settings it is highly recommended to use safety limits located in the Advanced Settings tab to avoid overcharge or overdischarge of the batteries The text file importation columns are time s differential or absolute and resistance Ohm 161 Techniques and Applications Manual Start discharge on A 10 kOhm vi forts p h ho mp fo 0000 S Record Ewe ever dE oz i mi and at least every dts i Oooo Ss Goback o seq Ns 10 RGIS aah facta for ne 0 time s d ne sat Head Hs o a Fig 147 RPI detailed diagram e Pulsed Resistance discharge Start discharge on R wOhms MOhms for ts h mN S defines the resi
29. Reverse scan to Ep 0 000 Wows Ref Fig 44 DPV detailed diagram average over the last of each step points selects the end part of the potential step for the current average lt I gt calculus to exclude the first points where the current may be perturbed by the step establishment A value of 100 will take all the step points for the average and a value of 0 will take only the last point Note that the current average lt I gt is recorded at the end of the potential step to the data file Scan rate mV s number of points these values are given as an indication and are calculated in the PC The scan rate is directly given by Gu 0 001S7 and the number of points is roughly 2 E Ei Su for the forward scan E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth sets the current range and bandwidth values for the whole experiment 56 Techniques and Applications Manual Note It is highly recommended to avoid using the automatic current range with pulsed tech niques The resolution of each range is different and dynamic current range changes may lead to spikes on the plot e Reverse scan definition O Reverse scan towards E V vs Ref Eoc Ei checks Reverse scan to perform a scan towards
30. S defines the recording conditions during the potential step 0 values disable the recording con dition and the corresponding box remains blue These values can be entered simultaneously and this is the first condition that is reached that determines the recording When lt Ewe gt is selected the number of averaged data points is displayed I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e RCA block e Potential step Apply E V vs Ref Eoc Ectrl Emeas the potential step is defined vs reference electrode potential or according to the previous open circuit potential Eoc controlled potential Ect or measured potential Emeas the potential step duration depend on the duration set on the disc channel E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation 2 7 3 CA RCA CA synchonized with CA The technique is composed of two CA one on the disc channel and another one on the ring channel Both protocols are displayed in the same technique The detailed flow diagram is made as follows 103 Techniques and Applicatio
31. Set power to P mW W fort h mn S define the restance pulse value and duration Record Ewe every dE mV and at least every dts S limits the recordings conditions in voltage variation and or time variation Range and Bandwidth sets the current range and bandwidth for this experiment e Conditional test which proposes to go to the next sequence or to loop on a previous sequence Ns Ns lt Ns 3 2 Super Capacitor This section is especially dedicated to supercapacities This section includes a cyclic vol tametry constant voltage constant current and current scan techniques 163 Techniques and Applications Manual Insert Techniques i Electrochemical Techniques ee Yolkamperometic Techniques Lu key Impedance Spectroscopy Lk Pulsed Techniques ES Technique Builder ey Ohmic Drop Determination Electrochemical Applications Es T Batteries Testing B Guter apachor ve Cycle Yoltammetry CY TL Constant Voltage Cat IL Constant Current Cat Current Scan CS Le Fhotovolktaic Fuel Cells E l Corrosion H gt Custom Applications H Special Applications 4 Insert Technique Load from default Custom Applications O Before Advanced setting External devices After Cell characteristics Fig 149 Supercapacity applications 3 2 1 Cyclic voltammetry The CV technique consists in scanning the potential of a stationary working electrode using a triangular
32. Techniques and Applications Manual e Second step potential scan Scan Ewe with dE dt mV s defines the potential scan The software selects the smallest potential step according to the control potential resolution defined in the Advanced settings window see the EC Lab Soft ware User s Manual for more details From EI V vs Ref Eoc Ectrl Emeas to E V vs Ref Eoc Ei from a potential Ei defined vs Ref the reference electrode potential or versus a previous open circuit potential Eoc previous controlled potential Ect or previous measured potential Emeas to Ep value difined in absolute or versus Eoc or Ei Hold E for tp h mn or until I gt h A pA for t gt ta S And A pA reached but no longer than te s after I gt k Hold the potential to Ep for tp time or until the critical pitting condition is reached The condition is first defined by h and ta If the current remains higher than the preset value during the time ta than the CPT is reached If it doesn t this condition can but does not have to pass be followed by a second condition set by le and te If the current continues to rise and reaches the value of le within a time te tc includes ta So must be gt ta then again the condition for pitting is reached Fig 173 illustrates these conditions Record lt l gt over the last of the step duration averaged N voltage steps I every
33. Then the instrument applies a potential sweep starting either from the potential reached at the end of the open circuit sequence plus a possible offset or from a given value The potential sweep goes on until its limit or until the current reaches a value defined as the pitting current limit value then the working electrode is disconnected For multi pitting i e if the same technique is applied on several channels in parallel the open circuit potential taken into account for applying the initial potential will be the average open circuit potential of the working electrodes The technique stops independently on each channel and the corresponding electrode is disconnected as soon as the pitting limit value of the cur rent is reached on the channel The EC Lab software uses a particular Process Data function Multi Pitting Statistics which gives the mean values and the mean quadratic deviations of the final rest potentials and pitting potentials obtained from all the channels used in the experiment 3 4 8 1 Description e First step a rest potential or open circuit sequence Rest for tr h MN S sets a defined time duration tr for recording the rest potential 198 Techniques and Applications Manual Limit dEw dt lt dEr dt mV h gives the user the ability to shorten the open circuit period at the time when the decay of the potential is lower than a given value Record Ewe with dEr mV resolution and at
34. damping factor of the potentiostat regulation 2 1 7 CA Chronoamperometry Chronocoulometry The basis of the controlled potential techniques is the measurement of the current response to an applied potential step In the Chronoamperometry technique a constant potential Ei is applied for a duration ti and the current is measured The current time response reflects the change of the concentration gra dient in the vicinity of the surface Chronoamperometry is often used to measure the diffusion 21 Techniques and Applications Manual coefficient of electroactive species or the surface area of the working electrode This technique can also be applied to the study of electrode processes mechanisms An alternative and very useful way of recording the electrochemical response is to integrate the current so that one obtains the charge passed as a function of time This is the chrono coulometric mode that is particularly used for measuring the quantity of adsorbed reactants co MAASIM SCAM ww Next Sequence or go ne times to sequence Ne to Ne or Ns OU e fen la ff oo dm ow Nest Sequence N or ga ne times to sequence Nes z Fig 12 Chronoamperometry Chronocoulometry general diagram The detailed diagram is composed of two blocks e potential step e loop e Potential step Apply Ej V vs Ref Eoc Ectrl Emeas the potential step is defined vs reference electrode potential or according to the previous open ci
35. gt gt button to display the list of scanned frequencies Note it is not possible to select Na points per decade in linear spacing For example a scan from fi 100 kHz to fr 1 kHz with Na 5 points per decade in logarithm spacing will perform measures at the following frequencies in kHz 100 63 1 39 8 25 1 15 8 10 6 31 3 98 2 51 1 58 1 and a scan from fi 100 kHz to f 1 KHz with N 11 total number of points in linear spacing will make measures at the following frequencies Hz 100 90 80 70 60 50 40 30 20 10 1 with amplitude Va mV sets sinus amplitude to Va Equivalence with Vous Is also given Note the following relationships between Va Vpp and Vrms Va Vop2 and Nous Vpp 2 V2 Wait for pw period before each frequency measurement offers the possibility to add a delay before the measurement at each frequency This delay is defined as a part of the period Of course for low frequencies the delay may be long average N mesure s per frequency repeats Na measure s and average values for each frequency o Drift correction corrects the drift of the system It needs to be used when the sytem has not reached its styeady state regime This feature is more specifically dedicated to low frequencies at which the impedance measurement can be pretty lengthy and for which the effect of the drift can be seen Note 1 If this option is selected the sinus frequencies are evaluated over
36. light This section includes five different applications the V characterization the constant load discharge the constant power voltage and current Insert Techniques E f Electrochemical Techniques H Voltamperometric Techniques tore Impedance Spectroscopy Lk Pulsed Techniques ES Technique Builder Lk Manual Control ey Ohmic Drop Determination 3 Lk Bipotentiostat f Electrochemical Applications T Batteries Testing E Le PhotovoltaicFuel Cells x4 IM characterization VC Constant Load Discharge CLD Constant Power CP FL Constant Voltage Cat JL Constant Current Lett E Led Corrosion E i Custom Applications Lk Special Applications Insert Technique Load from default Custom Applications Advanced setting External devices Cell characteristics Fig 154 Photovoltaic fuel cell applications 3 3 1 IVC l V Characterization l V characterization is intensively used to carry out investigations on Photovoltaic or Fuel cells The principle of this technique is to apply a linear potential sweep and to measure the corre sponding current and power Some characteristic parameters of the cell such as maximum current maximum potential and maximum power can be determined 172 Techniques and Applications Manual 3 3 1 1 Description Rest fort p o hu mm so Limit ME weil lt dEp dt D meh Record every dEp Oo m or dtp o1000 3 acan Ewe with dE Zdt 0 1 EE ms from Ei 0 025 V wv Eoc d to EL
37. lp lbp E step V step potential value resulting from the potential sweep and used to plot the current 2 3 3 NPV Normal Pulse Voltammetry Pulsed techniques have been introduced to increase the ratio between the faradaic and non faradaic currents in order to permit a quantification of a species at very low concentration lev els The Normal Pulse Voltammetry NPV is one of the first pulsed techniques elaborated for polarography needs An essential idea behind the NPV is the cyclic renewal of the diffusion layer With Dropping mercury Electrode DME this is achieved by the stirring that follows the fall of the mercury drop But at other electrodes renewal may not be so easily accomplished NPV consists in a series of pulses of linear increasing amplitude from E to Ey The potential pulse is ended by a return to the base value Ei The usual practice is to select Ei in a region where the electroactive species of interest does not react at the electrode The current is sam pled at a time t near to the end of the pulse and ata time t before the pulse The plotted current is the difference of both currents measured at the end of the pulse forward and at the end of the period previous to the pulse reverse Description e Initial potential Set Ewe to Ej V vs Ref Eoc Ectri Emeas fort h mn s sets Ewe to the initial potential Ei This potential value can be set vs reference electrode po tential or according to the pr
38. lt Ex after a discharge Note the user is allowed to bypass this test by entering p pass instead of a voltage value e Fourth step conditional test which proposes to go to the next sequence or to loop on a previous sequence Ns Ns lt Ns If Nc is set to 0 then the technique executes the next sequence If the user wants to loop to a previous sequence line the 2 last columns of the table Go to Ns and n cycles need to be filled The end of the technique is obtained by setting Ns and ne to 0 in the last sequence or setting Go back to sequence Ns 9999 at any sequence which then will be the last one executed even if the next sequence has its settings Such a complete sequence corresponds to one line of the table This line is composed of the columns which represent the successive variables encountered when setting the diagram the current range and the loop conditions all parameters which has to be set by the user Note that it is always possible to force the end of a technique while it is running at any se quence sweep using the Modify button and setting Go back to sequence Ns 9999 at the sequence one wants to stop 134 Techniques and Applications Manual 3 1 10 PCGA Potentiodynamic Cycling with Galvanostatic Acceleration This application corresponds to electrode cycling under stepwise potentiodynamic mode It is the technique to use to perform PITT Potential Intermittent Titration Technique experiment
39. 1 1 BCD Battery Capacity Determination This technique is used to determine the capacity of a battery and permits to utilize this value in the following techniques of the experiment adjust to the charge discharge rate C N or CxN in GCPL and Modulo Bat techniques This determination is made under galvanostatic mode i e the same current value is fixed in the charge and discharge regime The batteries are cycled between the potential limits Eu and Em2 The experiment can switch from galvanostatic mode to potentiostatic mode holding the potential of the working electrode at the limit potential while the limit in current or time is reached The capacity value is displayed and it could be used in the next techniques After this capacity determination the battery can be charged discharged to go back to the initial potential 3 1 1 1 Description of a galvanostatic sequence The detailed diagram of the BCD technique is shown in Fig 134 Set I to l pA A vs lt None gt Ictrl Imeas for at most ty h mn S sets the current as an absolute value or versus the previous controlled or measured current previous Sequence and the maximum duration of this period The sign of the current value is 107 Techniques and Applications Manual H H for a discharge and for a charge when the positive electrode of the cell is connected to the working electrode cable red Set to C N or CxN with N and I gt 0 or lt 0
40. 240 SP 200 SP 300 VSP 300 VMP 300 MPG 2XX Series Pulsed techniques EIS techniques Technique builder MP x x x x x SMP x x x x x MG x x x x x SMG x x x x x Trigger In x x x x x Trigger Out x x x x x Wait x x x x x TC x x x x x RDEC x x x x x EDC x x x x x Loop x x x x x Pause x x x x x 224 Techniques and Applications Manual EXTAPP x x x Email x x x VEERO aligo CMC PMC Ohmic Drop determination MIR ZIR CI Bipotentiostat techniques CV CA S VMP3 VSP CP CA s VMP3 VSP CA CA S VMP3 VSP VMP3 VSP SP 150 INSTRUMENTS VMP2 HCP 803 HCP 1005 CLB 500 CLB 2000 Batteries testing Photovoltaics Fuel cells I VC x x x MPG 2XX series SP VSP VMP300 SP VSP VSP300 SP VSP VSP300 SP 240 SP 200 SP 300 VSP 300 VMP 300 225 Techniques and Applications Manual CLD x x x x CPW x x x x CstC x x x x CstV x x x x Supercapacitors CV CstV CstC CS Custom Applications PR SPFC 226 Techniques and Applications Manual 6 List of abbreviations used in EC Lab software Abbreviations Description dEr Recording condition on a variation of the WE potential dEp dt Limit condition on a time variation of the WE potential dtr Recording condition on a variation of time tR Rest time E Initial potential Ref Reference electrode potential versus which WE potential will be applied Eoc Open circuit potential versus which WE pote
41. 3 if one enters go back to Ns 2 for n 1 time the sequence Ns 2 Ns 3 will be executed twice Nc 0 disables the loop and the execution continues to the next sequence Ns Ns 1 Second CA block e Potential step Apply E V vs Ref Eoc Ectrl Emeas the potential step is defined vs reference electrode potential or according to the previous open circuit potential Eoc controlled potential Ect or measured potential Emeas the potential step duration depend on the duration set on the disc channel E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation 106 Techniques and Applications Manual 3 Electrochemical applications 3 1 Batteries Testing In this application domain it is common to run successive charge and discharge sequences with possible open circuit periods varying the conditions for the cycles The techniques are defined on the basis of controlled mode and open circuit mode The con trolled variable is either the potential or the current A controlled current event is called a se quence whereas a controlled potential is labelled as a sweep Such a sweep or sequence appears as a
42. 693 7 1 159 6 3 036 7 17 24 3 002 2 AT A4 DONE Process Copy Close Fig 139 CPW process window This process window is made of a table containing the characteristic variables of each power step such as the time the energy and charge of the end of the step the working electrode potential and the current that crossed the cell at the beginning and the end of the step The 154 Techniques and Applications Manual Copy tab allows the user to paste the values of the table in graphic software in order to have a Ragone plot see figure below 10 Power W 0 2 2 5 3 3 5 4 Energy W h Fig 140 Ragone plot for a Li ion cell 1 35 A h 3 1 15 APGC Alternate Pulse Galvano Cycling The Alternate Pulse Galvano Cycling experiment has been designed to perform fast galvano steps between two values l and l2 with special recording conditions This gives the ability to follow fast phenomena on long periods The diagram is made of four blocks that can be linked with a parameters table Pulsed Galvano Charge Rest Potential Sequence Test Ewe vs E Next sequence 155 Techniques and Applications Manual Initial Rest Potential Sequence Ms UI Pulsed Galvano Charge Rest Potential Sequence Test Ewe vs Dn Next Sequence Fea s Oh CO 2 OD CD MA End To Ns Pulsed Galvano Charge Rest Potential Sequence Test Ewe vs EY Next Sequence or
43. An Hecond Ewe we every dE i 00 mi o dt 05000 E Range 10 10 sell feo ON GS Range 100 pts we Goback to sequence Ne 10 GG enge Heaney forme 0 time s Chasey Arr Fig 17 Chronopotentiometry detailed diagram Record Ewe or lt Ewe gt every dE mV and at least every dt S defines the recording conditions during the potential step 0 values disable the recording con dition and the corresponding box remains blue These values can be entered simultaneously and this is the first condition that is reached that determines the recording When lt Ewe gt is selected the number of averaged data points is displayed I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Loop Go back to sequence Ns for nc time s allows the experiment to go back to a previous sequence Ns lt Ns for ne times For example on N 3 if one enters go back to Ns 2 for n 1 time the sequence N 2 Ns 3 will be executed twice Nc O disables the loop and the execution continues to the next sequence Ns Ns 1 If there is no next sequence the execution stops In the current technique it is possible to loop to the first sequence Ns 0 and the current sequence Ns Ns This is different from battery experiments GCPL and PCGA Report to the battery techniques s
44. And pertorm impedance measurements from frequency F to F Fig 24 PEIS general diagram The potential of the working electrode follows the equation Ewe E Va sin 2 7 f t The detailed flow diagram is made of four blocks that can be separated into four parts single or multi sine mode initial potential frequency scan with recording conditions repeat sequence 35 Techniques and Applications Manual Single Sine C Multi Sine Mode SetEweto E hooo Y vs Eoo w forte g hilo ma 0000 s Record every d 0010 or dt 0 000 amp scan from Fy 200 000 kHz v to ff 100 000 mHz v nith Nq 6 points per decade or NT points from Fy to fr l Logarithmic spacing io l l Show frequencies gt gt Linear spacing sinus amplitude Ya 100 o mW rme 7 07 ml waitfor Pay 010 period before each frequency average Ha 1 meature s per frequency drift correction Repeat np m tirre 3 E Range 10 10W exc NN Range Auto we Bandwidth r he 1mn3Es scan Go back to seg Ha 0 GES erate RANAN for pr 0 time s ACL asf avec increment cycle number Fig 25 PEIS detailed diagram e Initial potential Set Eve to E V vs Ref Eoc Ectrl Emeas for te h mn S sets the fixed potential vs reference electrode potential or relatively to the previous OCV potenti
45. E either vs reference electrode potential or VS Eoc Or Ei Running the settings defined into Fig 44 will result in the following output 0 26 ne WW 0 24 Se roger tt 022 EE gn od i e gem 2 E iH a ee AA 018 e Geen ha olee Wi 017 perg E i eg GEN EE CR 015 An UA nia 4 7 i en 013 4 oun A 011 0 10 4 Ewe UU 0 5 1 0 1 5 20 25 AU timers Fig 46 DPV output Ewe vs time These variables are stored in the DPV raw files mpr state byte time s control V lt l gt mA Q Qo mA h And the next variables are calculated from lt I gt to save space on disk forward mA lt l gt values at the end of the pulses Ip on Fig 46 reverse mA lt l gt values before the pulses lbp delta UA difference between lt l gt values before and at the end of the pulse Ip lbp 57 Techniques and Applications Manual delta pA O02 DI D 0 1 0 2 A UA 0 5 Ewe V Fig 47 DPV measurement in a Fe II solution 2 3 2 SWV Square Wave Voltammetry Among the electroanalytical techniques the Square Wave Voltammetry SWV combines the background suppression the sensitivity of DPV and the diagnostic value of the Normal Pulse Voltammetry NPV c f 2 3 3 The SWV is a large amplitude differential technique in which a symmetrical square wave with one pulse in the forward direction and one in the reverse direc tion is Superimposed on a base staircase potent
46. Ei Ej2 on the next sequence Ns 1 with a loop on the first sequence goto Ns 0 will perform the next recording N 0 NA N 0 Nal q gt lt gt lt ka gt we Fig 14 Chronoamperometry Chronocoulometry example t In addition to the usual variables time control voltage measured working potential Ewe meas ured current and power P EC Lab calculates directly another variable dQ which is the total charge passed during a potential step Process chronocoulometry A process is associated with chronoamperometry chronocoulometry technique see Fig 14 The variable that can be processed are e Q charge the charge passed during the oxidation step where the current is positive Q discharge the charge passed during the reduction step where the current is negative Q Qo the total charge exchanged from the beginning of the experiment dl dt the time derivative of the current time cycle the time elapsed during one cycle one cycle being considered as one potential scan forward and one potential scan backward i e from OCP to E1 to E2 and then from E2 to E1 to E2 see Fig 6 The cycle time is reset each time the number of cycles is incremented see Fig 6 The step time is the time elapsed during one step Sequence or cycles In this technique the first and last data points of each potential steps are not automatically recorded 24 Techniques and Applications Manual Proce
47. Eoc Ei defines the vertex potential as Ey either vs reference electrode potential or vs Eoc or Ei with pulses height Pu mV pulses width Pw ms step time S ms The pulse train is made of pulses with a height of Puy amplitude that is added to the pulse height of the previous one and a width of Pw duration After each pulse the potential always comes back to the initial potential The scan increment is defined by a pseudo staircase made with steps of amplitude Py and duration Sr As mentioned above only one point is recorded at the end of the potential forward pulse and one point at the end of the potential reverse pulse making two points during the Gr period The settings above Fig 52 are given for a positive scan To perform a negative scan set Ey inferior to Ei and Sx to a negative value 62 Techniques and Applications Manual SetEweto Ej 0500 V vs De forty 0 hh mm poog 3 ScanEwe from Ejto Ey 0500 vs Ret sl with pulses height PH fog mm pulses width Pyy 250 ms step time ST 1000 me average over the last fog of each step Art pagr nae ANE AT EE as ALT A d er ne Fig 53 RNPV waveform ERange 2 2 recta Fae Range 10 mA Bandwidth 7 e Fig 52 RNPV detailed diagram average I over the last of each step points selects the end part of the potential step for the current average lt I gt calculation to exclude the first points where the curre
48. H 0 030 j 0 025 i 0 020 0 015 0 010 0 005 sna RCI re WT ey ee ee a IMA 0 000 SEN 0 005 0 010 4 1 D 1 D 1 H D 0 40 0 42 0 44 0 46 0 48 0 50 0 52 0 54 0 56 0 58 controli Fig 176 8 electrodes Potentiodynamic Pitting experiment Electrode Stainless steel in 0 02 M NaCl Scan rate 100 mV mn Recording resolution 0 2 pA or 20 ms 3 4 8 2 Data processing Data processing using Multi Pitting Statistics gives the mean values lt E gt and the mean quadratic deviations o of the final rest potentials Eoc and pitting potentials Ep obtained from all the channels used in the experiment Note that the Ep value corresponds to the potential measured for I lp 200 Techniques and Applications Manual Multi Pitting Statistics C Documents and Settings sebasten manips YMPI seb corrosion MPPSMPP4 1 2mptr C Documents and Settings sebastens manips VM seb corrosionshMPP MPP 1 d mp CA Documents and Settingssebastien manips VM seb corrosion MPP MPP4_ 1 Dmpr C Documents and Settings sebasten manips VM seb corrosion MPPSMPP4 1 bmpr C Documents and Settings sebasten manips VMPIl seb corasionk MPRSMPP4 1 Hotel Load Add Remove Statistics channel E init w 1 398 1 061 1 416 1 449 E ochNl 1 370 1 045 1 399 1 433 Ep f 0 529 0 567 0 530 0 533 lt E inite 1 065 CE init E ocy gt 1 055 CE oe lt Ep 0 435 Ep W Print Settings Copy Print Close Fig 177 Multi pitting statistics
49. IY CAFACTENI ZATION E 172 Sor lal Kl e e EE 173 eee EE e 174 So CLD Constant LOA DISC Le siege ete etd ce aad ces aaa ant 174 E E OPW Constant EE 175 3 3 4 Cen Constant Voltage 000no00nn0annoanenaneoannoannonnnrnnnrnnnrnnnrrnrernrernnernnernnernnee 177 30 0 CSE CONSAN GUM Ml seg eg Eege Eege 179 3 4 SOMO SOM EE 180 SAT EVT Beep VErSUS TINE EE 180 3 4 2 LP Linear Polarization ccccccceccseccecceeceeceeeceecceeceeeceeceeeceeseeeseesaeeseesaeesees 181 34 21 lt DESCHDUOM E 181 34 22 Pro ess and fits related te A EE 182 3 4 3 CM Corrosimetry Ap VS TIME cccccsccccesceceeeeecesceseueeceeeecesessueeeseasessaeeees 183 Sho al um Re e AE 183 3 4 3 2 Applications of the Corrosimetry application ccccccceseeeeeeeeesseeeeeeees 185 3 4 4 GC Generalized Corrosion cccccccsscecseeccseeseeecseeseusecseeceseesansecseesensensesseas 185 SAE Re die E 186 3 4 4 2 Process and fits related ioo 187 3 4 5 CPP Cyclic Potentiodynamic Polarization cccccceeccceeeeeeeeeeeeseeeseeeeseeeeaes 187 3 4 6 DP Depassivation Hoiental 190 3 4 7 CPT Critical Pitting Temperature 193 3 4 8 MPP Multielectrode Potentiodynamic Pitting ccccceeccseeeseeeeseeeseeeeneeeeaes 198 9481 Re e le A EEN 198 JAS 2 Dalal PlOCeSSING arcara 200 3 4 9 MPSP Multielectrode Potentiostatic Pttmg 201 3 4 10 ZRA Zero Resistance Ammeier 203 3 4 11 ZVC Zero VoltageCGurrent 206 3 4 12 VASP Variab
50. Potentiostatic 1 o Potentiodynamic 2 ScanEwe from Ej 0000 vs Ref gt to Ep numm 3 vs Ref gt o pm can Els ar 7 100 p 100 0 ms a Aoo b oo c 000 d 000 e 0000 Limits Imax pas m Imin pass m kO AQM 0 000 mah sl Analog ln gt Ko Lp fort Lp bes NV tp 30 0000 Record l gt e over the last 50 of the step duration average H i voltage steps 100 ul E Range 25W 25W m ena Arad Range Bandwidth Go back to sequence Ne 0 RGIS eat acta for pe 0 bmelel TAVA out Fig 66 Special Modular Potentio potentiodynamic detailed diagram And Analog In 1 Analog In2 lt gt Lp V for tp S sets limits of the sequence considering the value recorded with the analog input If the value reached Lp during t then the sequence is stopped and the next sequence is applied 2 4 3 MG Modular Galvano The Modular Galvano technique enables the user to perform combinations of OCV galvanos tatic and galvanodynamic periods It is possible to link these periods in any order and to per form loops It gives a lot of flexibility in creating galvano techniques The galvanodymamic mode can be used to study stepwise electron transfer reactions and multicomponent systems 76 Techniques and Applications Manual to Ns or Ms OC perod or Appl ls or Apply didt moiadimr om ow End Fig 67 Modular Galvano general diagram e Mod
51. Ref Eoc Ei With N potential steps sets the initial potential to a fixed value vs reference electrode potential or relatively to the previous OCV potential Eoc controlled potential Eet measured potential Emeas sets final potential to a fixed value vs reference electrode potential or relatively to the previous OCV potential Eoc initial potential Ej 41 Techniques and Applications Manual The number of potential steps is defined by user with the N value e Waiting period before EIS For each current step Wait fort h mN S O Record every dl pA nA A and dt S before the EIS measurement the user can apply an equilibration period with the ability to record the potential During this period no impedance measurement is done e Impedance scan Scan frequencies from fi MHz WHz to f MHZz wHz defines the initial fi and final d frequencies of the scan To have results more rapidly it is better to choice to scan from the highest frequencies to the lowest ones but it is possible to reverse the frequencies scan order with Ng points per decade N points from fi to f in Logarithm spacing Linear spacing defines the frequencies distribution between the scan bounds fi and f It is possible to select the number of points per decade Na or the total number of points Ni in linear or logarithm spacing Click on the Show frequencies
52. analytical electrochemistry to dis criminate faradic from capacitive current This technique consists in pulses superimposed on a potential sweep Differential Normal Pulse Voltammetry DNPV technique used in analytical electrochem istry to discriminate faradic from capacitive current This technique is made of increasing pre pulses with time and pulses superimposed on the prepulses Differential Pulse Amperometry DPA technique used in analytical electrochemistry to dis criminate faradic from capacitive current This technique consists in the repetition of a pulse sequences made with a prepulse and a superimposed pulse EC Lab software that drives the multichannel potentiostats galvanostat Galvanostatic Cycling with Potential Limitation GCPL battery testing technique corre sponding to battery cycling under galvanostatic mode with potential limitations and with the ability to hold a potentiostatic mode after the galvanostatic one Galvanostatic Cycling with Potential Limitation 2 GCPL2 battery testing technique simi lar to the GCPL but with two potential limitations on the working electrode and on the counter electrode potential The potential is not held after the current charge discharge Galvanostatic Cycling with Potential Limitation 3 GCPL3 battery testing technique simi lar to the GCPL2 with the ability to hold the working electrode potential after the galvanostatic phase Galvanostatic Cycling with Potential Limi
53. and bandwidth for the whole experiment The open circuit voltage is the standard block so report to the OCV technique chapter for more 205 Techniques and Applications Manual e Repeat Go to ne time s repeats the ZRA and the OCV blocks ne times If nc is set to 0 then these blocks will be done only once Nne 1 will execute the blocks twice Limit Q to Qr mA h limits the total charge from the beginning of the experiment to Qr Setting Qr to 0 cancel the test 3 4 11 ZVC Zero Voltage Current The ZVC technique is the same as the ZRA technique except that the control apply 0 V is done between the working electrode WE and the reference electrode REF rather than be tween the working electrode WE and the counter electrode CE Therefore report to the ZRA for more details on the ZVC technique ig mann Dm mh v ma 0 000 nh v cs lo timels 0 000 mah e Fig 184 ZVC detailed diagram 206 Techniques and Applications Manual 3 4 12 VASP Variable Amplitude Sinusoidal microPolarization This technique is a non linear EIS technique and can only be used for systems with tafelian behavior it is used as a corrosion technique to determine the corrosion current and corrosion coefficients In this technique a potential sinusoidal wave is applied around the corrosion po tential Ecorr with N amplitudes increasing from Va min and Va max At each amplitude the polarization resistance Rp is deter
54. averaged N voltage steps I every dlp pA nA LA mA A Two different recording conditions on the current are available with the potentiodynamic mode either recording an averaged current lt I gt on each potential step or recording an instantaneous current with a time variation and or an instantaneous current variation dl and or charge var iation dQ E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation Rp fit parameters dE mV Ba MV B mV allows the user to select the potential window around Ecor for the Rp fit and to set corrosion coefficients previously determined by a Tafel Fit e Rest potential or open circuit sequence Equivalent to the EVT technique described above e Repeat sequence Repeat n time s The potential sweep described in the second step will be repeated ne times Contrary to the MPP technique no current limitation is available with the linear polarization application 3 4 3 2 Applications of the Corrosimetry application When the experiment is running EC Lab software displays the polarization curve vs Ewe on a first graph and the processed value Rp versus time on a second gra
55. constant frequency fs is superimposed on a linear ramp between two vertex potentials E1 E2 The potential sweep is dE defined as follow E t E KEN Asin 2 7 f t Typically the linear ramp varies on a long t time scale compared to the superimposed AC variation Like the pulsed techniques ACV discriminates the faradaic current from the capacitive one Consequently ACV can be used for analytical purpose Moreover this technique can also be used for investigating electrochemical mechanisms for instance the fact that a forward and a backward scans are identical characterizes a reversible redox system 32 Techniques and Applications Manual Begin Set Initial Potential to E Ewe E A dE Potential sweep to E T with a sinusoid signal j D Reverse Potential sweep to E Repeat ng timels End Time 0 1 cycle Fig 22 General diagram for Alternating Current Voltammetry This technique corresponds to usual cyclic voltammetry with a superimposition of a sinusoid The technique is composed of e astarting potential setting block a 1 potential sweep with a final limit E and a sinusoid superimposed a 2 potential sweep in the opposite direction with a final limit E2 option the possibility to repeat ns times the 1 and the 2 potential sweeps Note that all the different sweeps have the same scan rate absolute value The detailed flow diagram on the following figure is made of three
56. constant power step For example let us consider a 30 W power discharge applied to a battery with a 10 A booster We suppose that the potential limits of this experiment are 4 V and 2 5 V The initial current will be 7 5 A but the final current will be 12 A overload in current It will not be possible to go to the final current 3 1 14 2 Application of the CPW technique The constant power technique is commonly used for a Ragone plot representation power vs energy The usual technique consists in a succession of Sequences made with Discharge to P 2 watts with n the number of the sequence no 0 Open circuit period after the discharge The discharge step is stopped when a minimum potential value is reached One can see the change of current and potential during a CPW experiment versus energy on the figure below For a constant power discharge the current decreases in the negative direc tion but it increases in absolute to compensate the fall of potential 2600 2400 2200 2000 1800 7600 1400 Ewen 1200 1000 DUU E C E S l m ei We SS RE ai i rr an ze ee 7 ai EE m rent ee Ta a ee Kies GAME ee wot Laem Sie Kl Ed LC eg a ST DEE Ei 0 0 0 5 1 0 La 25 3 0 4 5 40 2 0 Energy h Fig 137 E measured blue line and I adjusted red circles evolution vs energy dur ing a CPW experiment on a Li ion battery 1 35 A h
57. every dt time interval 2 Potentiostatic period Hold Em fort h mn s once Ew is reached it is held for a given time t4 Limit I lt Im A pA or dl dt lt dl dt A s JuA mn offers the possibility to stop the potentiostatic period when the limit current Im is reached or when the variation of the current is lower than given value dl dt Record AQ every dQ A h fA h kC pC and at least every dt s in the constant potential mode the system acts as a coulometer and a recording is performed every time the charge increment decrement since the previous recording is gt dQ and or every di time interval Limit AQ to AQmu A h fA h kC pC lt gt Axm sets the maximum charge change from the beginning of this sequence during the sequence This charge is equivalent to a Axm quantity which corresponds to a normalized charge related to intercalation electrodes E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab software user s manual for more details on the potential resolution ad justment Range Bandwidth sets the current range and bandwidth for this experiment e Second step open circuit period with monitoring of the electrode potentials turn to Rest for tr h mN S sets a maximum time tr to stay in open circuit mode Limit dEw dt lt dEr dt mV h 130 Techn
58. executed the number of the executed sequence is incremented Fig 77 Temparature control Set temperature to C on External Thermostat one can set a temperature and configure the temperature recording using the External ther mostat link Record every dE mV dl pA Aand dt S chooses one or several optional recording conditions E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment The sequences inthe TC RDEC and EDC technique The user can add several TC sequences Ns 0 to n These sequences are linked differently from the other techniques In other stand ard techniques one sequence is executed directly after the other For the TC RDEC and EDC technique each sequence corresponds to a loop of a linked technique Therefore only one sequence of the wait technique is executed at each loop of the linked experiment The se quences are considered successively at each loop This allows the user to increase tempera ture values at each sequence Loop lf the Loop number of increments is larger than the number of sequences in the TC technique then the TC technique starts all over again as long as the total number of Loop increments is not reached 2 4 8 RDEC Rotating Disk Electrode Control The Rotating Disk Electrode Control RDEC t
59. given value dl dt lf the limit potential Em is not reached within the time t or if tm is set to 0 the system skips to the next step Record Ewe every dE mV and at least every dti s allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dE or and at least every dt time interval 2 Potentiostatic period Hold Em fort h mn s once Ew Is reached it is held for a given time t If Em is not reached this step is skiped Limit I lt Im offers the possibility to stop the potentiostatic period when the limit current Im is reached 112 Techniques and Applications Manual Record AQ every dQ A h fA h kC pC and at least every dt in the constant potential mode the system acts as a coulometer and a recording is performed every time the charge increment decrement since the previous recording is gt dQ and or every di time interval Limit AQ to AQm A h fA h kKC pC lt gt Axm sets the maximum charge change from the beginning of this sequence during the sequence This charge is equivalent to a Axum quantity which corresponds to a normalized charge related to intercalation electrodes E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resol
60. go ne times to sequence Ns Hez u mio 23 m 1 CC OD Ob oF Ka te End Fig 141 APGC general diagram Similar to the other battery experiments the first sequence Ns 0 is forced to OCV and the other sequences are executed sequentially with the possibility to loop to a previous experi ment number from the third sequence Ns 2 The detailed diagram is described in Fig 123 e Pulsed Galvano Charge Set l to pA A fort h mn s Set l2 to pA A for t2 h MN S define the pulse currents values and durations Repeat for at most to h mN S sets the pulse period duration If te is set to zero then l2 and to and na are not used and the current is applied for t duration Limit on l Ewe between Emin V and Emax V limits the WE potential on I current steps and limit AQ E dQ dQ2 to AQm A h fA h kC pC limits the total charge of the galvano pulse for current sequence to AQw Record Ewe once over na l l2 alternances and over ns sequences limits the recordings with dE and dt resolutions one I1 l2 alternation for na if t2 gt 0 and one sequence for ns Zero values bypass the na and ns limitations 156 Techniques and Applications Manual setl to H B0000 mA forty o hid mal ooo thensetltola ooo n e forta o hu mn O50000 Repeat for at most g A hu mn pooo Limit on tq Ewel gt Emin 3 000 V a
61. is based both on the MPP and MPSP techniques except that the potentiody namic phase which is done before the potentiostatic one some phases are optional and there is an additional potentiodynamic phase 187 Techniques and Applications Manual Begin End WG Fig 166 CPP general diagram The detailed diagram is made of five blocks e Initial Rest Potential Sequence e Potential sweep with threshold pitting detection e Hold potential e Reverse scan e Rest potential or open circuit sequence See EVT technique above e Potential scan Scan Ewe with dE dt mV s defines the potential scan The software selects the smallest potential step according to the control potential resolution defined in the Advanced settings window see the EC Lab Soft ware User s Manual for more details From Ei V vs Ref Eoc Ectrl Emeas to E V vs Ref Eoc Ei from a potential E defined vs Ref the reference electrode potential or versus a previous open circuit potential Eoc previous controlled potential Ecti or previous measured potential Emeas to E vertex potential defined in absolute or versus Eoc or Ei Limit I gt Ip pA A after tb S sets the threshold pitting current Ip to detect Setting of a blanking time tp permits to eliminate a possible large peak of current when just applying the initial potential step in case of large AE value E Range enables the user to sele
62. lt Ns for ne times The number of loops starts while the loop block is reached For example on Ns 3 if one enters goto Ns 2 for Nc 1 time the sequence Ns 2 Ns 3 will be executed 2 times Nc 0 disables the loop and the execution continue to the next line Ns Ns 1 If there is no next line the execution stops Here it is possible to loop to the first instruction Ns 0 and the current instruction Ns Ns 168 Techniques and Applications Manual 3 2 3 CstC Constant Current The constant current CstC technique is especially dedicated to supercapacity testing It is designed to apply successively several current steps to the cell s Between each current step an open circuit voltage period can be added Res for tp 0 jh mn don Limit He dd lt dEqgfdt oun m7h Record even dn oun m o dtp 00000 Apply Ig 100 000 m s lt None gt fr t 9 ob amp mm fog zs Limits E we A EM pass V AG gt ANM 8333 m hi Record E we every dE i D ri o dtg 10000 3 E Range 0 5 Arena Fa Range 10 ma 7 Bandwidth D medium e Goback to sequence Net 0 POG agi Aaa for pe 0 Dmelsl d ne sie M e al Fig 152 Constant Current detailed diagram e Rest period The rest period is an open circuit voltage period Refer to the OCV description for more details e Current step Apply l pA A vs lt none gt Ictrl Imeas the current step
63. mV per dt h mn sets the potential scan rate choosing the step amplitude dEs and its duration dts independently According to the control potential resolution it might be necessary to adjust the experiment limit to have exactly the desired potential step amplitude The default resolution is near 300 uV 135 Techniques and Applications Manual for VMP3 based instrument and 333uV for VMP300 based instrument For example this reso lution cannot lead to exact 5 mV steps because 5 0 3 16 67 is not an integer In that case the user will receive the following warning message dE will be rounded to 5 100 mv according to the instrument AA resolution To set dEs to 5 000 m you should set the potential limits into the Advanced Settings tab to increase the potential control resolution Fig 117 PCGA warning message for the step amplitude If the user answers Yes the step will automatically be adjusted to 5 1 mV instead of 5 mV To perform exact 5 mV steps the potential control resolution must be adjusted report to the cor responding section in the EC Lab Software User s Manual for more details From E V vs Ref Eoc Ectrl Emeas sets the starting potential vs reference electrode potential or with respect to the final open circuit potential value of the previous sequence Eoc or the previous controlled potential value Ect or the previous measured potential value Emeas It allows the experiment to start at t
64. or previous measured potential Emeas to Ep value defined in absolute or versus Eoc or Ei Limit I gt Ip pA A after tb S sets the threshold pitting current Ip to detect Setting of a blanking time tp eliminates a possible large peak of current when just applying the initial potential step in case of large AE value 199 Techniques and Applications Manual Record lt l gt over the last of the step duration averaged N voltage steps I every dl pA Aordt s Two different recording conditions on the current are available with the potentiodynamic mode either recording an averaged current lt l gt on each potential step or recording an instantaneous current with a time variation and or an instantaneous current variation dl E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth The choice of the current range depends on the threshold pitting current value lp and is au tomatically fixed The bandwidth is selected by the user Once the threshold pitting current is reached the working electrode is disconnected The figure below Fig 176 shows the result of a potentiodynamic multi pitting experiment performed on 8 passivated stainless steel electrodes 0 060 0 055 0 050 0 045 l 0 040 0 035
65. or to loop on a previous sequence Ns Ns lt Ns Go back to seq Ns for ne If Nc is set to 0 then the technique executes the next sequence If the user wants to loop to a previous sequence the 2 last columns of the table have to be filled Go back to Ns and n cycles This table is visible using the following path View gt Settings with Flowcharts The end of the technique is obtained by setting Ns and ns to 0 in the last sequence or setting Go back to sequence Ns 9999 at any sequence which then will be the last one executed 113 Techniques and Applications Manual Such a complete sequence corresponds to one line of the table This line is composed of the columns which represent the successive variables encountered when setting the conditions see Warning 2 Note that it is always possible to force the end of a technique while it is running at any se quence using the Modify button and setting Go back to sequence Ns 9999 at the sequence one wants to stop The following table setting gives an example of the use of the loop conditions 1 0 0 0 1 000 3 000 1 000 1 0 2 000 0 0 1 000 1 0 3 500 1 000 1 0 A 500 2 Fig 104 Example of loop conditions With these loop conditions the technique will do the following set of sequences 2 times 3 times 3 times 3 times Ns 0121212123 12121212 3121212123 Thus after the initial sequence 0 there will be 4 cycles on steps 1 2 repeated 3 times
66. perturb the cell with an alternative signal and to observe how the systems follows the perturbation at the steady state the amplitude of perturbation should be small in order to assume the linear be haviour of the system A high precision is obtained with this method and it is frequently em ployed to evaluate the heterogeneous charge transfer parameters and to study the double layer structure EIS has uses in corrosion battery fuel cell development sensors and physical electrochemistry and can provide information on reaction parameters corrosion rates elec trode surfaces porosity coating mass transport and interfacial capacitance measurements The VMP2 Z VMP3 VSP SP 150 boards are designed to perform impedance measure ments independently or simultaneously from 10 WHz to 1 MHz 200 kHz for channel boards delivered before July 2005 For SP 300 SP 200 SP 240 VSP 300 and VMP 300 the maxi mum frequency is 7 MHz Refer to the application notes for more information on Impedance measurements using EC Lab Multisine measurements are also available and will be described at the end of this chapter 2 2 1 PEIS Potentiostatic Electrochemical Impedance Spectroscopy 2 2 1 1 Description The PEIS experiment performs impedance measurements into potentiostatic mode by apply ing a sinus around a potential E that can be set to a fixed value or relatively to the cell equilib rium potential Begin Appl a constant potential E
67. potential waveform During the potential sweep the potentiostat measures the cur rent answer of the system The cyclic voltammogram is a current response plotted as a function of the applied potential Traditionally this technique is performed using an analog ramp Due to the digital nature of the potentiostat the actual applied ramp consists in a series of small potential steps that approxi mate the targeted linear ramp see the control potential resolution part in the EC Lab Software User s Manual The technique is composed of Fig 150 e astarting potential setting block a 1 potential sweep with a final limit E4 a 2 potential sweep in the opposite direction with a final limit E2 the possibility to repeat ns times the 1 and the 2 potential sweeps a final conditional scan reverse to the previous one with its own limit Er Note that all the different sweeps have the same scan rate absolute value 164 Techniques and Applications Manual SetEwe to Es 0 000 Wows Scan Ewe with dE Zdt 20 000 to vertex potential Eq 1000 N vz erg Reverse scan to vertex E gt 13 000 V YS Bee Repeat ng D time s Measure dx over the last et 2 Of the step duration Record lt gt averaged over H 10 voltage steps E Range 25 Y LDW dE dt 100 py 6 0 mes dEM 1 0 mid 4000 points per cycle Fig 150 Cyclic Voltammetry detailed column diagram e Starting potential
68. software offers the user the ability to create his her own applications and save it as a Custom Application This new application built by the user is made with several linked tech niques The procedure to create linked experiments is described in the following section Once the experiment is built the user can save it in the custom applications Right click on the mouse and select Save as Custom Applications or in the experiment menu select Save as Custom Applications An experiment saved as custom application appears now in the Custom Applications section of the technique window in blue The blue color is used like the user s reference electrode to distinguish the standard EC Lab applications from the custom application The custom applications are available only for a new experiment not when one or several techniques are already loaded Insert Techniques Galvanostatic Cycling with Potential Limitation 6 GOPL6 Galvanostatic Cycling with Potential Limitation 7 GCPL Constant Load Discharge CLD Constant Power CPW Alternate Pulse Galvana Cycling SPGC ag Potentio Profile Importation PPI ag Galvano Profile Importation GP agt Resistance Profile Importation RPI a8 Power Profile Importation DAD SS Modula Bat MB 4 e PhotovoltaicFuel Cells nal oc Fee LN characterization IWE l i Constant Load Discharge CLD Constant Power CP The Stepwise Potential Fast Chronoamperometry has been
69. step from 1 to 100 for the current average lt I gt calcu lation It may be necessary to exclude the first points of the current response which may only be due to the capacitive rather than faradic behavior of the system Record lt l gt averaged over N voltage step s averages N current values on N potential steps in order to reduce the data file size and smooth the trace The potential step between two recording points Is indicated between brackets Once selected an estimation of the number of points per cycle is displayed in the diagram E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment Range Bandwidth sets the current range and bandwidth values for the entire experiment e Final potential End scan to E V vs Ref Eoc EI gives the possibility to end the potential sweep or to run a final sweep with a limit Ey Option Force E E2 During the experiment clicking on this button allows the user to stop the potential scan set the instantaneous running potential Ewe to E or E according to the scan direction and to start the reverse scan Thus E or and E2 are modified and adjusted in order to reduce the potential range Clicking on this button is equivalent to clicking on the Modify button setting the running po tential as E or E
70. tab Nyquist and Bode diagrams can be plotted for both the WE and the CE electrodes The working and counter electrode variables are displayed respectively as follows with the additional extension Re Z and Re Zce Im Z and Jm Zce 38 Techniques and Applications Manual 2 2 2 GEIS Galvanostatic Electrochemical Impedance Spectroscopy This technique Is very close to the Potentiostatic Impedance technique PEIS except that the current is controlled instead of the potential Please refer to the PEIS experiment section 2 2 1 for more details Ce Single Sine Co Multi Sine Setltole 300 mA zi WS for t 0 ho mn v Record even dE 0000 mV and d s i 200 000 kHz w to ff 100 000 mhe Scan fram f None gt v 0 000 3 points per decade 51 Logarithm spacing Linear spacing amplitude Las 100 000 Iw sl walt FOr Pyy average N drift correction 0 timefs Repeat ng E Range Range Bandwidth 1 m v Ei J Go back to seq Ne for my d Increment cycle number paints from F to F Show frequencies gt 0 10 pernod before each frequency 1 o measurele per frequency ov 10 sl mnb scar DD RR ende dere 0 time ls G ne seevaney Fig 26 GEIS detailed diagram Note that the current can be applied vs the previous control current previous sequence of a linked technique
71. than a given value and allow the user to fixe the current range and the bandwidth for this experiment Record Ewe every dE mV or every d S allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dE or and at least every dt time interval Potentiostatic period Hold Ewe Em V sets the limit of the working electrode potential under charge discharge See warning 1 fortu h mn s or until I lt Im DA JA allows the user to stand at the potential Ew for a given time or until the current reaches a low limit value Iv If the limit potential Em is not reached within the time t1 or if tu is set to 0 the system skips to the next step Record AQ every dQ mA h or every dt in the constant potential mode the system acts as a coulometer and a recording is performed every time the charge increment decrement since the previous recording is gt dQ and or every di time interval Limit AQ to AQu Ah JD lt gt Axm sets the maximum charge change from the beginning of this sequence during the sequence This charge is equivalent to a Axm quantity which corresponds to a normalized charge related to intercalation electrodes And Analog In 1 Analog In2 lt gt Lp V for tp S sets limits of the sequence considering the value recorded with the analog input If the value reached Lp during t
72. the potential step from 1 to 100 for the current average lt I gt calcu lation It may be necessary to exclude the first points of the current response which may only be due to the capacitive rather than faradic behavior of the system Record lt l gt averaged over N voltage step s averages N current values on N potential steps in order to reduce the data file size and smooth the trace The potential step between two recording points Is indicated between brackets Once selected an estimation of the number of points per cycle is displayed in the diagram e Repeat option for cycling Repeat n times repeats the scan Ei to E to E2 ne time s Note that the number of repetition does not include the first sequence if n 0 then the sequence will be done once if ne 1 the sequence will be done twice if n 2 the sequence will be done 3 times etc Record the first cycle and every n cycle s offers the ability for the user to store only one cycle every n cycle in case of many cycles in the experiment The first cycle is always stored E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Final p
73. the potential step depend on the chosen current variable For the instantaneous current the recording values can be entered simultaneously It is the first reached condition that determines the recording A zero value disables the recording for each condition For the averaged current the user defines the time for the calculation of the average In this case the data points are recorded in the channel board memory every 200 us for VMP3 based instruments and for VMP300 based instruments set dQ 0 for Chronoamperometry experiments and dl 0 for Chronocoulometry experiments 104 Techniques and Applications Manual Disk Channel 1 C a HE Ee 0 be be poo LR 5000 Dm 0 1000 A000 KEEN L Auto Go back to sequence Na D ANN ATE Maeva for pe lo imela Allan oa Ring Channel 6 ACA Ret ov aovo EE Fig 99 CA_RCA detailed setup E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation 105 Techniques and Applications Manual e Loop Go back to Ns for nc time s allows the experiment to go back to a previous sequence Ns lt Ns for ne times For example on N
74. to bypass this test by entering p pass instead of a voltage value e Fourth step repeat sequences The fourth step sets the next sweep by filling the Ns and ne variables as seen in tutorial 2 for the GCPL technique setting Ns to a previous sweep and ne to the number of repeats will loop Nc times to Ns Setting ne to 0 will go to the next sweep or will end the technique on the last sweep Setting Ns to 9999 will stop the technique at the end of this sweep A sweep corresponds to a line in the table The columns represent the successive values for variables of the diagram the current range the bandwidth settings and the loop conditions The current range and bandwidth settings are obtained either with a double click on any cell of the corresponding columns or directly in the cell characteristics window Warning see also GCPL Warnings 1 and 2 when running a charge cycle positive potential sweep the value of the electrode potential for the test EL must be set at a lower value than the sweep limit value Ey Similarly when running a discharge cycle negative potential sweep EL must be set ata more positive value than the sweep limit value Ey The cell characteristics window for battery testing applications has been previously described 138 Techniques and Applications Manual 3 1 10 2 Description of the cell characteristics window for batteries Cell Description Electrode material Initial state Electrolyte Comm
75. va Apply a sinusoidal potential scan with frequency Fg DI OO between vertex potential EJ 0 000 YO ys and vertex Ed 1 000 V w Repeat np 0 time s Hecod every dt D000 F and dl 0 000 E Range 25 We By k Zar aire Fae period 10 000 scan rate 0 200 Vis Fig 21 Large Amplitude Sinusoidal Voltammetry detailed diagram Repeat n times repeats the whole sequence ns time s Note that the number of repeat does not count the first sequence if n 0 then the sequence will be done 1 time nc 1 the sequence will be done 2 times Nc 2 the sequence will be 3 times Record every dt s and dl pA nA pA mA A offers the possibility to record with two conditions on the current variation dl and or on time variation E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation Note this technique includes sequences to link sines with different amplitude for example 2 1 11 ACV Alternating Current Voltammetry Alternating Current Voltammetry ACV is assimilated to a faradaic impedance technique With this technique a sinusoidal voltage of small amplitude A with a
76. 0 The test performed takes the conditional value gt or lt whether the open circuit sequence oc curs after a charge gt 0 or a discharge lt 0 The above 2 steps Galvanostatic and resting period will be repeated until the working elec trode potential reaches the limiting condition Ewe gt Ex after a charge or Ewe lt E after a dis charge Note the user can bypass this test by entering p pass instead of a voltage value e Loop Go back to sequence N nc time s loops to a previous sequence Ns lt Ns Nc time s Set Nc O to cancel the loop and go to the next sequence Ns 1 Note Ece and Ewe Ece recording are forced into the GCPL2 data files 3 1 4 GCPL3 Galvanostatic Cycling with Potential Limitation 3 The GCPL8 application is the same as the GCPL2 technique with the ability to hold the cell potential after the galvanostatic step The technique is by default composed of three sequences resting period i e OCV charge and discharge e Galvanostatic period Set I to Is pA A vs lt None gt Ictri Imeas for at most ti h mn S sets the current value in absolute versus the previous controlled current previous sequence or versus the previous measured current and the maximum duration of the imposed current period The sign of the current value is for a discharge and for a charge when the positive electrode of the cell is connected to the working elec
77. 0 pants per cycle Fig 5 Cyclic Voltammetry detailed column diagram e Starting potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas sets the starting potential vs reference electrode potential or vs the open circuit potential Eoc or the previous controlled potential Ecti or measured potential Emeas e First potential sweep with measurement and data recording conditions Scan Ewe with dE dt V s mV s mV mn allows the user to set the scan rate in V s mV s or mV mn The potential step height and its duration are optimized by the software in order to be as close as possible to an analogic scan Between brackets the potential step height and the duration are displayed according to the potential resolution defined by the user in the Advanced Settings window see the corre sponding section in the EC Lab Software User s Manual to vertex potential E V vs Ref Eoc Ei sets the first vertex potential value vs reference electrode potential or vs the open circuit potential Eoc or vs the potential of the previous experiment Ei e Reverse scan Reverse scan to vertex potential E2 Vve Ref Eoc Ei runs the reverse sweep towards a 2 limit potential The vertex potential value can be set vs reference electrode potential or according to the previous open circuit potential Eoc or ac cording to the potential of the previous experiment Ei Techniques and Applications Manual e Repeat option f
78. 2 228 Techniques and Applications Manual Peak to peak potential amplitude Final current value Number of current potential steps Final potential value Pulsed techniques Es ts Pulse Height Pulse Width Step Height Step Time Pre Pulse Width Pre Pulse Height Pulse period Period duration Technique Builder Step potential Time duration of Es Waiting duration Sequence to go back to with a loop Number of iterations of the experiment Techniques and Applications Manual Glossary This glossary is made to help the user understand most of the terms of the EC Lab software and the terms mentioned in the manual The terms are defined in alphabetical order Absolute value mathematical function that changes the negative values in positive ones Accept button in EC Lab software that switches to Modify when the user clicks on it Mod ify must be displayed to run the experiment Apparent resistance Rij conventional term defining the electrolytic resistance in a solid elec trochemical system such as a battery Ri is defined as the ratio dE dl when the potentiostat switches from an open circuit voltage mode to a galvanostatic mode or vice versa Bandwidth represents the frequency of the regulation loop of the potentiostat Choosing the Suitable one depends on the electrochemical cell impedance A cell with a high impedance and slow response will require a low bandwidth The bandwidth values go from 1 to 7 with
79. 2 Limit Ke dtl lt dep it Rest for tp Record ever dip or dtp 0 0 mm 0000 3 2 h mn pon s 50 000 n w 0 000 n ie m s gl 7 000 S0 0000 3 0 000 0 000 REN E Zant ft A ei 100 m gd 5 medum 1 blo m Wo0 e on meh oo mi 10 0000 PEG dar ade AG O Hy a a Goback to zen Ng for pe lt Ewe lt EL pass Y goto T 0 NNN ants fects 0 bmelsl Ad mr i savers Fig 110 GCPL5 detailed diagram 123 Techniques and Applications Manual e First step galvanostatic period that can be followed by a potentiostatic period 1 Galvanostatic period Set to Is pA A vs lt None gt Ictrl Imeas for at most ti h mn s sets the current value in absolute or versus the previous controlled current or previous meas ured current the sign for reduction and for oxidation and the maximum duration of the imposed current period Set C N or CxN with N and I gt 0 or lt 0 for at most t h mn s sets the rate C N or CXN at which the battery will be charged I gt 0 or discharged l lt 0 The C value could be a noninteger value For instance if the capacity of a battery is 1800 mA h setting C N with N 3 and I gt 0 means that a current of 600 mA will be passed during 3h The total capacity
80. 2 4 1 2 Potentiostatic Mode 1 C OC 0 Mode Potentiostatic 1 Potentiodynamic 2 setEweto Es 1 000 V vs forts 0 h io ma 30 0000 Limits l may pass Record lt l gt wi ever dt 0 1 oo 0 amp E Ranges 2 24 wel Zebra fi TOE Range Bandwidth Go back to sequence Ne 0 PTER E AAYAR for pe 0 times Gi An st oa Fig 61 Modular Potentio potentiostatic detailed diagram Set Ewe to Es V vs Ref Eoc Ectri Emeas sets the potential vs reference electrode potential or to the previous open circuit potential Eoc or to the previous controlled Eet or measured Emeas potential in linked experiments or linked sequences fort h mn S defines the potential step duration if not stopped on limits 70 Techniques and Applications Manual Limits to Imax D JA and to Imin pA JA And AQ to AQm fA h A h pC KC sets limits for the potential step If one limit is reached I gt Imax or lt Imin AQ gt Aw before the end of the step duration ts then the program proceeds to the next sequence A zero value disables the AQwy limit and typing p to enter pass disables the Imax and Imi limits Note the AQ value tested here versus AQw is the current sequence Ns integral charge Record I every dl pA A dQ fA h A h pC kC and dtp S lt I gt every dts S You can record either an inst
81. 2 and validating the modified parameters with the Accept button The Force E E2 button allows the user to perform the operation in a faster way in the case where the potential limits have not been properly estimated and to continue the scan without damaging the cell 100 Techniques and Applications Manual e RCA block e Potential step Apply Ej V vs Ref Eoc Ectrl Emeas the potential step is defined vs Ref the reference electrode potential or according to the pre vious open circuit potential Eoc controlled potential Eet or measured potential Emeas the potential step duration depend on the duration set on the disc channel E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation 2 7 2 CP RCA CP synchronized with CA The CP_RCA technique is composed of a CP on the disc channel and a CA on the ring channel Both protocols are displayed in the same technique CP block current step current sequences recording conditions repeat option Ewe instrument parameters configuration RCA block Fig 96 CP_RCA description e potential step e recording conditions e instrument parameters configur
82. 2 periods instead of 1 increasing the acquisition time by a factor of 2 42 Techniques and Applications Manual 2 Inthe bottom right corner of the block the approximate experiment duration is indicated as information for the user During the run several parameters remain accessible for modification such as the min and max frequencies and the number of points per decade For more information about the drift correction please refer to the Application Note 17 E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth sets the current range and bandwidth values for the whole experiment Graph tool Mott Schottky plot For the SPEIS technique particularly used in semi conductor materials study Mott Schottky experiments it is possible to display the 1 C vs Ewe plot when selecting Mott Schottky in the rapid selection scroll menu As capacitance values are automatically calculated during the experiment this representation is available during the run When the Mott Schottky plot is se lected the user must choose several frequencies among all the recorded frequencies Moreo ver a Special fit Mott Schottky fit has been built to determine the semi conductor param eters flatband potential donor density For more details
83. 50 ul Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Final potential End scan to E V vs Ref Eoc Ei gives the possibility to end the potential sweep or to run a final sweep with a limit Et Option Force E E2 During the experiment clicking on this button allows the user to stop the potential scan set the instantaneous running potential Ewe to E or E2 according to the scan direction and to start the reverse scan Thus E or and E2 are modified and adjusted in order to reduce the potential range Clicking on this button is equivalent to clicking on the Modify button setting the running po tential as E or E2 and validating the modified parameters with the Accept button The Force E E2 button allows the user to perform the operation in a faster way in the case where the potential limits have not been properly estimated and to continue the scan without damaging the cell Note it is highly recommended to adjust the potential resolution from 300 uV for 20 V of amplitude to 5 uV for 0 2 V of amplitude with a SP 150 VSP or VMP3 according to the 166 Techniques and Applications Manual experiment potential limits This will considerably reduce the noise level and increase the plot quality 3 2 2 CstV Constant Voltage The constant voltage CstV technique is especially dedicated to supercapacity testing It is designed
84. 999 at the se quence one wants to stop 3 1 8 GCPL7 Galvanostatic Cycling with Potential Limitation 7 This technique Is very similar to the GCPL technique see 3 1 1 The main and only difference is that the potential EM is held constant not by controlling the potential but by controlling the current By doing so the whole experiment charge discharge and EM maintained constant is performed under current control and not by current and then potential control as is done in GCPL With GCPL 7 the current glitch that occurs in GCPL and is associated to the switch from a potential to a current control is avoided Oa EES eT foratmostty ho hilo mn 0m00n Limit Ewe Ep 4 500 V Record ever dE D mu or dt 00000 Hold Epa for tpg hu mm foon Limit Ils Uppy DUU or JO lt dl dt O00 Record ever dQ 1 000 o dtg 120 000 Limit JAQ gt Al 0 000 lt gt Ey O00 ERange oy Bu wi ki Fenian Tee Range 1 A Ww Bandwidth 5 medium v 2 Bes op fo hip mn Aoo s Limit Me dtl lt dEp dt OT meh Record every dEp op ry o dtp 20 0000 d lew Ai A AEA o ie A 3 lt Ewe lt EL 4200 Y goto 1 4 Gobackto seq Mgt 0 ch Aacvainas fo ne 0 timels aoe reat meagre Fig 114 GCPL7 detailed diagram 129 Techniques and Applications Manual e First step galvanostatic period that can be followed by a pote
85. Al EEE EE bh E Range Range Bandwidth 2 e lt None gt we 10 hijo mh om0m0n 4 500 Y aood d 1 bio mn Aod EEN 000 m ie O00 mAh ze 200000 3 m h e a O00 O00 DEM sl Zant at Aen JE ed 1A a medium v Rest fo tp D hp mn 000 Limit IdE ey dtl lt dEg_ dt oui mi fh Record ever dp 00 DM o dp M20000 s dee Our At Au gota Fs D a Go back ta sen Ne lt Ecel EL 4 200 V go to 1 E NN ate da 28 Aal for pe E hires JE AV ost aan Fig 113 GCPL6 detailed diagram 127 Techniques and Applications Manual 2 Potentiostatic period Hold Ey for ty hh mn s and Limit I lt In pA A or dl dt lt dl dt A s JuA mn allows the user to stand at the potential Em for a given time or until the current reaches a low limit value Im or when the variation of the current is lower than given value dl dt If the limit potential Em is not reached within the time ti or if tu is set to 0 the system skips to the next step Record every dQ A h fA h kC pC and at least every dt s in the constant potential mode the system acts as a coulometer and a recording is performed every time the charge increment decrement since the previous recording is gt d
86. Amplitude Sinusoidal Voltammetry This technique is similar to usual cyclic voltammetry but using a frequency to define the scan speed The curve of the potential excitation can be compared to a large amplitude sinusoidal waveform The technique is composed of e a starting potential setting block e a frequency definition fs e a potential range definition from E to Es e the possibility to repeat nc times potential scan The detailed diagram see Fig 17 is made of two blocks e Starting potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas sets the starting potential vs reference electrode potential or according to the previous open circuit potential Eoc or controlled potential Ect or Measured potential Emeas e Frequency and Potential range definition with measurement and data recording conditions Apply a sinusoidal potential scan with frequency fs KHZ Hz mHz ypHz allows the user to set the value of frequency to define the scan rate between vertex potential E V vs Ref Eoc Ei Sets the first vertex potential value vs reference electrode potential or according to the previ ous Open circuit potential Eoc or previous potential Ei and vertex E2 V vs Ref Eoc Ei Sets the second vertex potential value vs reference electrode potential or according to the previous open circuit potential Eoc or previous potential Ei 31 Techniques and Applications Manual SetEwe ta Ey 0000 V
87. Circuit Potential Start ZAA Note for the ZRA technique the recording of Ece vs Eres is forced into the data file The ZRA technique is made of 4 blocks e Initial OCV e OCV e Repeat They are detailed below End Fig 182 ZRA general diagram e Initial OCV The open circuit voltage is the standard block so report to the OCV technique chapter for more information e ZRA Start ZRA for ti h mn S applies 0 V between the working electrode WE and the counter electrode CE for ti time Limits I gt Im pA A after tb S limits the ZRA duration if the current becomes greater than Im This test is performed only tp seconds after the beginning of the ZRA block to avoid exiting on the current perturbation that may occur when the 0 V potential is established Limit AQ to AQm A h pC limits the charge per nc loop to AQmu Setting AQm to 0 cancels the test Record E I or lt E gt lt I gt every dt S defines the recording conditions current and potential either instantaneous or average 204 Techniques and Applications Manual enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution Do hE m fooo00 D00 mAh v E Do0 mAh ow ic timels 0 000 Fig 183 ZRA detailed diagram Range Bandwidth sets range
88. EC Lab Software Techniques and Applications Version 10 38 August 2014 dk BioLogic science Instruments Equipment installation WARNING The instrument is safety ground to the Earth through the protective con ductor of the AC power cable Use only the power cord supplied with the instrument and designed for the good current rating 10 Amax and be sure to connect it to a power source provided with protective earth contact Any interruption of the protective earth grounding conductor outside the instrument could result in personal injury Please consult the installation manual for details on the installation of the instrument General description The equipment described in this manual has been designed in accordance with EN61010 and EN61326 and has been supplied in a safe condition The equipment is intended for electrical measurements only It shall not be used for any other purpose Intended use of the equipment This equipment is an electrical laboratory equipment intended for professional and intended to be used in laboratories commercial and light industrial environments Instrumentation and ac cessories shall not be connected to humans Instructions for use To avoid injury to an operator the safety precautions given below and throughout the manual must be strictly adhered to whenever the equipment is operated Only advanced user can use the instrument Bio Logic SAS accepts no responsibility for accide
89. External Devices windows The recordings are optional Record every dE mV dl pA A and dt S chooses one or several optional recording conditions E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment The EDC technique has a parameters table in the parameters settings window which can be related to the sequences selection The sequences in the TC RDEC and EDC technique The user can add several EDC se quences Ns 0 to n These sequences are linked differently from the other techniques In 88 Techniques and Applications Manual other standard techniques one sequence is executed directly after the other For the EDC RDEC and TC technique each sequence corresponds to a loop of a linked technique There fore only one sequence of the wait technique is executed at each loop of the linked experiment The sequences are considered successively at each loop This allows the user to increase temperature values at each sequence Loop If the Loop number of increments is larger than the number of sequences in the EDC technique then the EDC technique starts all over again as long as the total number of Loop increments is not reached 2 4 10 Loop As with the Wait technique the loop technique has been designed for linked experiments Th
90. G ye Fig 2 Special Open Circuit Voltage Technique Rest for tr h mn S sets a defined time duration tr for recording the rest potential Limit dEw dt lt dEr dt mV h stops the rest sequence when the slope of the open circuit potential with time dEp dt be comes lower than the set value value 0 invalidates the condition or Ewe lt Em mV for tb S stops the rest sequence when the potential of the working electrode reached Em during tp or until Analog In 1 Anolog In 2 lt gt Lim V for tp stops the rest sequence when the limit defines in the Lim box is reached during tp Record Ewe every dEr mV resolution and at least every dtr S allows the user to record the working electrode potential wnenever the change in the potential is gt dEr with a minimum recording period in time dtr Data recording with dEr resolution can reduce the number of experimental points without los ing any interesting changes in potential When there is no potential change only points ac cording to the dtr value are recorded but if there is a sharp peak in potential the rate of record ing increases 2 1 3 CV Cyclic Voltammetry Cyclic Voltammetry CV is the most widely used technique to acquire quantitative information about electrochemical reactions CV provides information on redox processes heterogeneous electron transfer reactions and adsorption processes It offers a rapid location of r
91. KC pC lt gt Axm sets the limit of the working electrode potential Ewe to a maximum value if I gt 0 or to a minimum value if LO and the charge from the beginning of the sequence IA Ax for the whole step The maximum charge can be entered into mA h AQwm or as a normalized charge related to intercalation electrodes Axm Once the limit is reached the experiment proceeds to the 152 Techniques and Applications Manual next step Rest even if the programmed time tm is not terminated These limits can be by passed by entering 0 values into the controls Note when the AQwy Axm limit is reached the E test is skipped This is due to the fact that the AQw limit is considered as the maximal charge that can be applied to the battery during the discharge Once reached the experiment must go to the next sequence Record every dE mV dq A h fA h kC pC and dt s defines the recording conditions These values can be entered simultaneously the first condi tion that is reached determines the recording A zero value disables the recording for each criterion Range Bandwidth sets the current range and bandwidth for this experiment The other blocks were already described above Note Applying a constant power during a discharge experiment corresponds to an increase of the current in absolute when the potential decreases The user must be careful to note the final current of the first
92. Linear Logarithm Exponential Polynomial scan defines the potential scan speed and its mathematical expression And a b C d defines the parameters of the mathematical expression E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment Range and Bandwidth sets the current range and the bandwidth for this experiment Record I lt I gt every dl pA uA A dQp fA h A h pC kKC and dtp S two different recording conditions on current are available with the potentiodynamic mode either recording an averaged current lt I gt on each potential step or recording an instantaneous current with an instantaneous current variation dl and or charge variation dQ and or a time variation Limit IAQI to AQm fA h A h pC kKC and I to Imax pA uA A and Imin PA UA A sets limits for the potential step If one limit is reached AO gt AQm gt Imax or lt Imin before the end of the step duration ts then the program goes to the next sequence A zero value disables the AQy limit and type p to enter pass to disable Imax and Imin limits Note the AQ value tested here versus AQw is the current sequence Ns integral charge 19 Techniques and Applications Manual ACW 0 Hode
93. Load Discharge CLD Time Constant Power CP l l l l l Altemate Pulse Galvano Cycling APGC This technique consists to apply various potential values on a ae battery during a defined duration This technique is specially sta Potentio Profile Importation PFI designed to fit with the urban driving patterns designed to test EM eg Galvano Profile Importation GFI batteries The particularity of this technique ts the large number of H ag Resistance Profile Importation RPI sequences available and the fact that the experimental settings can n Power Profile Importation PAP be defined by importation of a text file Note that experimental limits Tp Su it are not present in the setting it is highly recommended to use safety Geen eg a limits located in the Advanced Setting window to avoid P Jee Photovoltaic Fuel Cells overcharge for overdischarge of the batteries gt Led Corrosion Test file imporation columns timers differential or absolute arid gt Custom Applications potential Insert Technique Load from default Custom Applications Before Advanced setting _ Estermal devices a a J After Cell characteristics Rename Add Remove om Cancel Fig 143 Selection window for a profile importation Select the PPI application and click on OK The following window is displayed 158 Techniques and Applications Manual Zi Import Settings From Text File e s 3 A Developpe profil test batterie urb
94. MP300 based instruments Leave dl alone for Chronoamperometry experiments and dQ for Chronocoulometry experi ments nix Desiiotp o hg mafon 3 Limit IdEwedtl lt dER dt Dn mi Record every dER O00 mW o dp O00000 Apply Ej 2000 W vs Ref e forty 0 ho mn pogo Limits Imax pass mA min pass EN vd b AOM 0000 mah See every dl 9000 WA dd 0000 mh si dt 10000 3 E Range oy 5 L rena A ei Range Auto vi Bandwidth D medium e Goback to sequence Net 10 RGIS aoe Hees for pe E imela Allies neg Fig 158 Constant Voltage detailed diagram E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab software user s manual for more details on the potential resolution ad justment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Loop 178 Techniques and Applications Manual Go back to Ns for nc time s allows the experiment to loop to a previous line Ns lt Ns for ne times The number of loops starts while the loop block is reached For example on Ns 3 if one enters goto Ns 2 for Nc 1 time the sequence Ns 2 Ns 3 will be executed 2 times Nc 0 disables the loop and the execution continue to the next line Ns Ns 1 If there is no next line th
95. Manual for more details on the potential resolution ad justment I Range Bandwidth 148 Techniques and Applications Manual sets the current range and bandwidth for this experiment Discharge with the same rate set I ls The discharge charge period is preformed with the I ls e Loop Go back to sequence Ns nc time s loops to a sequence Ns lt Ns Nc time s Set Nc O to cancel the loop and go to the next sequence Ng 1 3 1 13 CLD Constant Load Discharge The Constant Load Discharge application has been designed to discharge a battery at a con stant resistance The potentiostat is seen as a constant resistor by the battery R Eil limit Eva Fig 133 CLD control I and measure Ewe sample vs time The constant resistance control is made by controlling the current to maintain the ratio EI constant 149 Techniques and Applications Manual 1 Start discharge on R EA 21 000 Ohm we for at most tay E h 0 rir 0 0000 amp Limit Ewel lt Em 3 500 V JAG gt Aw 1 354 994 m h wv lt gt AX h 0 550 Record every dE i OI DV dq dt 20 0000 s E Range 20 10 wll Glance NN Noel Range 100 m wi Bandwidth 7 2 Bea om ff ho mioon Limit dE edt dEp Zdt 1 0 ri Record ever dep i OI DV or dtp 120 000 0 dee Ger Go Au shi FV 3 lf Ewel EL pass W goto 1 Fig 134 CLD det
96. P 8 W 153 Techniques and Applications Manual The plotted current values are absolute values negative in reality In order to have a constant power the working electrode potential decreases when the current increases in absolute The power vs energy plot for a Li ion 1 35 A h battery is presented on the figure below Each constant power is separated with an OCV period limited with a potential variation dEr dt 2 mV h Farat 0 0 0 5 1 0 L 2 0 25 3 0 3 5 4 0 Energy A Fig 138 Power vs energy plot for a Li ion cell 1 35 A h P 8 W A process called Constant Power protocol summary has been specially designed for Ragone plot representation To use this data process click on process in the graphic window or choose Process data Constant Power technique summary in the Batteries Analysis menu Then the following processing window will be displayed Constant Power protocol summary Raw File C EC Lab Data Sampless CPw_RAGONE mp times Pa Energy h VU Uoldmg h Ewe initial ire initial Ewe final Vdm final 1185 7890 8 0006 2 6122 60 15 4 063 9 B24 7 3 001 3 2 665 8 2602 6217 3 9986 3 425 7 1 007 2 3 646 1 296 6 3 001 6 1 332 3526 4195 2 002 1 3 642 6 1 OF 32935 47 r93 3 001 4 bi Uh 4686 4659 17 0007 3 7544 1 113 6 3 171 223 45 3 002 1 333 35 5565 781 0 497 89 3 620 9 1 135 5 3 097 6 DO OD 3 001 4 165 58 6457 3199 0 250 27 3 562 6 1 145 4 3 056 1 18 914 3 001 7 83 376 Trl46683 0 124 41 3
97. Q and or every di time interval Limit AQ gt AQr A h fA h kC pC lt gt Axm sets the maximum charge change from the beginning of this sequence during the sequence This charge is equivalent to a Axm quantity which corresponds to a normalized charge related to intercalation electrodes E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution ad justment I Range Bandwidth sets the current range and bandwidth for this experiment e Second step open circuit period with monitoring of the electrode potentials Rest for tr h mn s sets a maximum time tr to stay in open circuit mode Limit dEcen dt lt dER dt mV h gives the user the ability to shorten the open circuit period when the decay of the potential is lower than a given value Record every dEr mV or dtr S allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dEr or and at least every dtr time interval Note the conditional test if tz 0 which bypasses the open circuit period e Third step test on the final open circuit potential If Ecel gt lt EL V The test is performed with the conditional value gt if the open circuit period just before the tes
98. RADED THE INSTRUMENT IS READY TO BE USED IT DOES NOT NEED TO BE UP GRADED WE ADVISE THE USERS TO READ AT LEAST THE SECOND AND THIRD CHAPTERS OF THIS DOCUMENT BEFORE STARTING AN EXPERIMENT Techniques and Applications Manual Electrochemical Techniques 2 1 Voltamperometric techniques Note that for all these techniques except OCV in addition to the time the potential and the current the charge Q Qp Is calculated and saved in the data file 2 1 1 OCV Open Circuit Voltage The Open Circuit Voltage OCV consists in a period during which no current can flow and no potential can be applied to the working electrode The cell is disconnected from the power amplifier On the cell the potential measurement is available Therefore the evolution of the rest potential can be recorded This period is commonly used as preconditioning time or for the system to reach a thermodynamic equilibrium Rest for tR 0 hig mp f300000 Limit Ke dl lt dEp d Mo mh Record ever dEr i D DM or dtp 0 5000 z E Range 25V 25V e end rena Ad ei Fig 1 Open Circuit Voltage Technique Rest for tr h MN S sets a defined duration tr for the recording of the rest potential or until dEwe dt lt dEr dt mV h stops the rest sequence when the slope of the open circuit potential with time dEp dt be comes lower than the set value value 0 invalidates the condition Record Ewe every dEr mV resolution and at least every
99. S two different recording conditions on the current are available with the potentiodynamic mode either recording an averaged current lt l gt on each potential step or recording an instantaneous current with a time variation and or an instantaneous current variation dl and or charge var iation dQ E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment Range Bandwidth sets the current range and bandwidth values for the entire experiment Go back to Ns for nc time s each one of the OCV potentiostatic and potentiodynamic periods is represented by a single line in the grid parameters If nc is set to 0 the sequence lines are executed one after another Then an OCV potentiodynamic and OCV sequence for example will be programmed by 3 lines in the parameters table Setting Nn gt 0 will loop to a previous line Ns lt Ns for ne times 71 Techniques and Applications Manual OC 0 Potentiostatic 1 Co Potentiodynamic 2 Mode Scan Ewe vith dE dk from Ey to Er 20 000 Dm ds 0 000 Wows 0 700 V va Bet Hef Limits Imax 4 mA F AOI gt Au Record over the last 50 Z ol the step duration average M 5 volta
100. SE a eee ee eee eee eee eee eee eee eee ee 89 Manual Porenta Conto ME 91 Modular Gavan IG EE 77 Gel ae Le Kiel Te 79 CAIN ue sprees eter ete oe in ea es ete a tera le ee atlas 78 234 Techniques and Applications Manual Se EEN 77 Modular POENTO MP E 7 69 73 81 OCV E ets eee ea eee 69 Batcieldleie dau e 71 Reiter 70 Viel Geo e EE 43 Multielectrode Potentiodynamic Pitting MP 198 Multielectrode Potentiostatic Pitting MPP 201 MUNISING WIGASUTCIMGMIS 22 ee 35 Normal Pulse Voltammetry NPV cc cccseccseeeneeeseeeseeeeeeeeeeeseeeseeeseeeseeeseeeseeseeeaeeeseeeaeeenaes 60 Ke HIER Leid DEE 50 Ohimi Drop GOMPESNSALION DEE 92 Open Circuit Voltage OG V EE 6 Pause e elle EE 89 90 BEE leie EC SIS LANG rca eared Siete adc ae ean iano ean eee eta 210 Potentio Electrochemical Impedance Spectroscopy DEI 35 FICC eige ei 50 Potentio Electrochemical Impedance Spectroscopy Wait DEIGW 47 Potentiodynamic Cycling with Galvanostatic Acceleration DCOGA 135 FAC OMNCATIO FAME scifi nc gece re at re Areal A ee Geiser eae aa ea 6 7 69 Process M t Single Te Stalis UCS E 200 POlANIZ AMON RESI Sla NCE EE 212 Process Daa EE 12 GMIFOMOCOUIOING IY EE 24 CMONODOENUOMNE IY EE 27 Constant Power Technique Summary ccccecccceccceeeeeceeeeeseeeeceecesseeeeseeeessaeeeseeeesseeeas 154 eebe 20 GYClO NUIMDEE ege 12 GP BEE 115 EE EB 141 Reverse Normal Pulse Voltammetry DNDV 62 Rotating electrode S asnata A N O 193 Spe
101. Schottky SPEI and ohmic drop compensation can be performed This allows 2 je Pobentio Electrochemical Impedance Spectroscopy Wat PEIS one to detect electroactive species with short lifetime in resistive Pulsed Techniques medium When the recording timebase dt is below 15 us the Instrument switches bo a fast acquisition mode allowing data points to be recorded at every 1 us In this specific mode averaging and auto ranging are disabled ei Technique Builder fe Manual Control 4 Ohmic Drop Determination Insert Technique Load from default Custom Applications Before Advanced setting External devices After C Cell characteristics EE KEE Cancel Fig 7 Technique windows when the LSG option is available 14 Techniques and Applications Manual The technique is composed of Fig 7 and Fig 8 e astarting potential setting block a 1 potential sweep with a final limit E4 a 2 potential sweep in the opposite direction with a final limit E2 the possibility to repeat ns times the 1 and the 2 potential sweeps a final conditional scan reverse to the initial potential Ei The detailed flow diagram in the Fig 8 below is made of five blocks it is also possible display the column diagram Fig 8 setEwe to E 0 000 Wows Scan E ue with dE dd 1 000 Mis to vertex potential Ey 0 001 V ve Ref v Record even dE Average dt o0000n E Range DV EM welt Range a
102. The potentiostatic period is recorded every dt time interval set in the galvanostatic period E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution ad justment I Range Bandwidth sets the current range and bandwidth for this experiment Discharge with the same rate set I ls The discharge charge period is preformed with the I ls Return to initial potential If this case is checked the system will be charged discharged l l to reach the initial poten tial Result Capacity mA h shows the obtained value o use Capacity value for the rest of experiment Selecting this option the obtained value can be used in the rest of experiment e g to set the rate C N or CxN in the GCPL s protocols 3 1 2 GCPL Galvanostatic Cycling with Potential Limitation This technique essentially corresponds to battery cycling under galvanostatic mode Le with an imposed current but with possible potential limitations under current for both charge and discharge and tests on potential values during open circuit period It can be used to perform GITT galvanostatic Intermittent Titration Technique experiment Similarly to PCGA GCPL can be used to have the chemical diffusion coefficient of the mobile species in the electrode since it is the current that is controlled the effect of the
103. Type Device Name Haake Phoenis seres Analog OUT Meslab ATE amp EX senes Julabo series Other 40 0 i 0 L UN E UU Analog IN 1 i 0 400 E 100 Analog IN S CH with E V zs 0 mas D Wee D mir Fig 170 Temperature configuration for the Haake Phoenix series 193 Techniques and Applications Manual Once the thermostat has been configured the CPT experiment can be loaded for a given channel the same way as the other experiments the CPT technique is located into the Corro sion section of the EC Lab techniques The next figures show the CPT diagram Begin Open Circuit Potential and apply initial temperature Open Circuit Potential and Increase temperature OCV OCV OCV Fig 171 General diagram of the CPT technique 194 set Tj Rest for ty Techniques and Applications Manual 200 E i h E mr Limit lt IdT dth lt dTg Z dtg with dig and dtg Record every dipg dpn ding 2 Scan ae m ih dE dt from Ej to En 3 Hold Ep for tp Limit M gt Ur fort ty and lg but no longer thant Record Lob 1 00 E 0 h up mm oso E 00 rn Oo om ono 0 166 DN de 0 100 V e Eoc 0 500 ove Bei O hun mp e000 ya _ D1000 pass m gt iz reached nass amp after I 21t over the last 25 of the step duration average H E Range Range Bandwidth 4 Jif pitting Il gt It Jor Te 5 Increase T with Tg below TL and L
104. UIC E 3 1 11 1 General Description of the Modulo Bat technique s nssensneneeeneenn SEET 3 1 11 2 1 CC Constant Current 3 1 11 2 2 CV Constant Voltage 3 1 11 2 3 CR Constant Resistance 3 1 11 2 4 CP Constant Power 3 1 11 2 5 CS Current Scan 3 1 11 2 6 VS Voltage Scan 3 1 11 2 7 Cl Current Interrupt WWWWWWWW a Ope er E E eck ch Ze OONDOARW 146 Techniques and Applications Manual 3 1 11 2 8 Other types 146 3 1 12 CED Coulombic Efficiency Determmmaton 147 3 1 12 1 Description of a galvanostatic seuence 147 3 1 13 CLD Constant Load Discharge 00nnn0nnnennoennonnnnennnnnnnnnnennnrnnrrnnrrnenreenee 149 Sdk GPW Constant POWGN oaser nena a a a A 151 3 1 14 1 DESCHPUOM EE 151 3 1 14 2 Application of the CPW technique cccccccceececeeeeeseeeeeaeeeeseeeesaeees 153 3 1 15 APGC Alternate Pulse Galvano Cycling ccccccseeceeeeeeeeeeeeseeeeseeeeseeeeens 155 3 1 16 PPI Potentio Profile Importaton 158 3 1 17 GPI Galvano Profile Importation ccccccceececeeeeeeeeeeeeeeesseeeeseeeeseeeesaeeess 160 3 1 18 RPI Resistance Profile Importation n snennnenennnennnnnnenensnrrnrrrerrenrrerrerrnene 161 3 1 19 PWPI Power Profile Importaton 162 3 2 SU EE O E A Gras N Grae to E EN A E E EA E EA 163 321 GVCHE VO eru nn re EE 164 32 2 CSIV CONSTANT Voltage eraai eege tee 167 32 9 CC Constant EEGENEN 169 Secs Co GUN CNL DC al EE 170 3 3 Pnotovoliaics Fuel EE 172 3 3 1 IWC
105. V amplitude with a SP 50 SP 150 VSP MPG 2 or VMP3 according to the experiment potential limit This will considerably reduce the noise level and increase the plot quality 3 Hold E While the experiment is running clicking in this button allows the user to hold the actual po tential Clicking again on this button the experiment will continue in the same direction 4 Table Sequence The CVA technique is equipped with a table the ability to add sequences This allows the user to link several sequences of CVA with different scan rates or different vertex potentials Graph tool Process Data When the CVA experiment is made the user can extract the charge quantities exchanged during the anodic step Q charge the cathodic step Q discharge and the total charge ex changed since the beginning of the experiment Q Qo 2 1 6 LSV Linear Sweep Voltammetry The linear sweep voltammetry technique is a standard electrochemical protocol Unlike the CV no backward scan is performed only the forward scan This technique is specially dedi cated to RDE Rotating Disk Electrode or RRDE Rotating Ring Disk Electrode investigations which allow user to carry out measurements in hydrodynamic steady state conditions This leads to the determination of redox potential and kinetic parameters The External Device Configuration of EC Lab menu makes it easy to control and measure the rotation rate of the R R DE device e Rest period Rest fo
106. about this plot refer to the EC Lab Software User s Manual Note It is possible to modify the settings of an impedance measurement during the experiment The user can Modify Pause Resume or Stop the experiment while it is running 2 2 3 2 Application The SPEIS technique is applied in this example to circuit 3 of Test Box 3 A potential sweep is made from Ei 0 V to E 2 1 V with 100 mV potential steps On each step an impedance measurement is performed for a whole frequency range 200 kHz to 1 Hz The user can plot 1 C vs Ewe of this data file either for few frequencies or the whole frequency range 43 Techniques and Applications Manual Channel 1 Graph M af gt sl vs Ewe staircase potElS 01 CAimpry j sl vs Ewe staircase potElIS_03_ CA impr 0 1 OU 2 000 3 O00 4 O00 Reiz Ohm Fig 29 Application of the SPEIS technique 2 2 4 SGEIS Staircase Galvano Electrochemical Impedance Spectroscopy With the SGEIS technique the potentiostat works as a galvanostat and applies a current scan staircase shape An impedance measurement whole frequency range can be performed on each current step The user can also select specific frequencies instead of the whole range The SGEIS experiment performs impedance measurements in galvano mode by applying a current sine around a current The impedance measurement is repeated on each current step 44 Techniques and Applications Manual Fig 30 SGEIS descript
107. ailed diagram Start discharge on R E I wOhm Mohm for at most tm h mn S sets the cell resistance to R E I for tw duration Limit Ewe lt Em V AQ gt AQm A hi fA h KCL Jo lt gt AXn sets the limit of the working electrode potential Ewe and the charge from the beginning of the sequence AQ Ax for the whole step The maximum charge can be entered into mA h AQm or aS a normalized charge related to intercalation electrodes Axm Once a limit is reached the experiment proceeds to the next step Rest even if the programmed time tm is not terminated These limits can be bypassed by entering 0 values into the controls Note when the AQwy Axm limit is reached the E test is skipped This is due to the fact that the AQw limit is considered as the maximal charge that can be applied to the battery during the discharge Once reached the experiment must go to the next sequence Record every dE mV dq A h fA h kC pC and dt s defines the recording conditions These values can be entered simultaneously the first condi tion that is reached determines the recording A zero value disables the recording for each criterion Range Bandwidth sets the current range and bandwidth for this experiment The other blocks were already described above 150 Techniques and Applications Manual 3 1 14 CPW Constant Power 3 1 14 1 Description The Constan
108. ain 4 Organiser e Nouveau dossier E UF Favoris Nom Modifi le BR Bureau application courant 20 10 2009 17 00 Emplacements re E urbain_Sminutes 03 09 2009 10 44 E T l chargement ay Biblioth ques Documents Images a Musique Be Vid os BS Ordinateur A Disque local C cow donnees D Get sys 192 109 206 u mep Nom du fichier Tert files TXT CH e Type Document tg Document te Fig 144 Text Import window The user has to select the text file to import with two columns time and potential in this case This technique is specially designed to fit the urban driving patterns designed to test EV bat teries The particularity of this technique is the large number of sequences available and the fact that the experimental settings can be defined by importing a text file Note that experi mental limits are not present in the settings it is consequently highly recommended to use safety limits located in the Advanced Settings tab to avoid overcharge or overdischarge of the batteries The text file importation columns are time s differential or absolute and cur rent A Apply Es 3 500 Y forts f h o mn 2 2000 S Record even dlg 00 dts 01000 ERange ON EM to Seanie Ane Range Gobackto seg Ns p HGS eagle face for pe m imela AAV ASE SANAS Ne dl DI 2 3 4 5 CAE 10 b Fig 145 PPI detailed diagram 159 Techniques and Applic
109. al Description e Initial potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas forti h mn S sets Ewe to the initial potential Ei This potential value can be vs Ref the reference electrode potential or according to the previous open circuit potential Eoc controlled potential Eeri or measured potential Emeas Notice that only the last point of this period is recorded at the time 0 e Pulse waveform Apply a waveform with Prepulse height PPu mV Prepulse width PPw ms Pulses height Pu mV Pulse width Pw MS Period P ms Time period tp ms Note that only one point is recorded at the end of the potential forward pulse and one point at the end of the potential reverse pulse making two points during the P period average over the last of each step points selects the end part of the potential step for the current average lt I gt calculation to exclude the first points where the current may be disturbed by the step establishment A value of 100 will take all the step points for the average and a value of 0 will take only the last point Note that the current average lt I gt is recorded at the end of the potential step into the data file number of points This value is given as an indication and is calculated in the PC The number of points is roughly 2 tp P for the forward scan E Range enables the user to select the potential range and to adjust t
110. al Eoc controlled potential Eetn measured potential Emeas forate sets te large enough to wait for the cell current stabilization in the case where the applied potential is different from the open circuit potential During this period no impedance meas urement is done 36 Techniques and Applications Manual Note if another experiment is defined before then it is possible to define the initial potential as a function of Ect and Emeas previous potential controlled and previous potential measured respectively If there is no experiment before it is not possible to use Ect and Emeas O Record every dl pA nA uyA mA A and dt e offers the possibility to record Ewe and during the DC period before the AC simulation with two conditions on the current variation dl and or on time variation dt e Impedance scan Scan from fi MHz uHZz to f MHZz us defines the initial fi and final d frequencies of the scan To have the first measured point more rapidly it is recommended to scan from the highest frequencies to the lowest ones but it is possible to reverse the frequencies scan order with Ng points per decade N points from fito fi in Logarithm spacing Linear spacing defines the frequencies distribution between the scan boundaries fi and fr It is possible to select the number of points per decade Na or the total number of points Ni in linear or logarithm spacing For
111. an be modified during a run without interrupting the experiment The channels can be interconnected and run synchronously for example to perform multi pitting experiments using a shared counter electrode in a single bath N Stat mode One computer or several for multichannel instruments connected to the instrument controls and monitors the system The computer is connected to the instrument through an Ethernet or USB connection With the Ethernet connection each one of the users is able to control his her own channel from his her computer More than multipotentiostats our instruments are modu lar versatile and flexible multi user instruments Once the techniques have been loaded and started from the PC the experiments are entirely controlled by the instrument s on board firmware Data are temporarily buffered in the instru ment and regularly transferred to the PC which is used for data storage on line visualization and off line data analysis and display This architecture ensures a very safe operation since a shutdown of the controlling PC does not affect the experiments in progress The application software package provides useful techniques separated into two categories Electrochemical Techniques and Electrochemical Applications The Electrochemical Techniques contain general voltamperometric Cyclic Voltammetry Chronopotentiometry techniques differential techniques impedance techniques and a tech nique builder including modular
112. an reduce the number of experimental points without los ing any interesting changes in potential When there is no potential change only points ac cording to the dtr value are recorded but if there is a sharp peak in potential the rate of record ing increases 3 4 2 LP Linear Polarization The linear polarization technique is used in corrosion monitoring This technique is especially designed for the determination of a polarization resistance Ap of a material and Lo through potential steps around the corrosion potential Ap is defined as the inverse of the slope of the current density vs potential curve at the free corrosion potential at which the overpotential dE 0 WI a dE R dE 0 Rp is determined using the Ho Fit graphic tool This technique is also used to plot polarization curves and determine corrosion rate and Tafel coefficients with the Tafel Fit tool 3 4 2 1 Description e Rest potential or open circuit sequence See EVT technique above e Potential scan Scan Ewe with dE dt mV s defines the potential scan The software selects the smallest potential step according to the control potential resolution defined in the Advanced settings window see the corresponding section in the EC Lab Software User s Manual for more details 181 Techniques and Applications Manual From Ei V vs Ref Eoc Ectrl Emeas to E V vs Ref Eoc Ei from a potential E defined vs Ref the reference electrod
113. antaneous current value or an averaged current value lt I gt The recording conditions during the potential step depend on the chosen current variable For the instantaneous current the recording values can be entered simultaneously The first condition reached determines the recording A zero value disables the recording for each criterion For the averaged current the user defines the time for the average calculation In that case the data points are recorded in the channel board memory every 200 us for VMP3 based instru ment and for VMP300 based instruments E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment Range Bandwidth sets the current range and bandwidth values for the entire experiment Go back to Ns for nc time s each one of the OCV potentiostatic and potentiodynamic periods is represented by a single line in the grid parameters If n is set to 0 the sequence lines are executed one after another Then an OCV potentiodynamic and OCV sequence for example will be programmed by 3 lines in the parameters table Setting n gt 0 will loop to a previous line Ns lt Ns for ne times 2 4 1 3 Potentiodynamic Mode 2 Record lt I gt over the last of the step duration averaged N voltage steps I every dlp pA or dtp
114. at each charge increment dg or at each time increment dt In the case where both conditions are chosen the faster of the two conditions will be taken into account A zero value skips the recording condition Limit AQ to AQy A h fA h kKC pC lt gt AXm sets the maximum charge change from the beginning of this sequence This charge is equiv alent to a Axm quantity which corresponds to a normalized charge related to intercalation electrodes I Range and Bandwidth sets the current range and bandwidth for this experiment e Open Circuit Voltage The open circuit voltage is the standard block so report to the OCV or GCPL techniques sec tions for more information e Potential test If Ewe Ece gt lt Et V The third step is the test on the open circuit final potential This test is skipped if there is no OCV period tr 0 The test performed takes the conditional value gt or lt whether the open circuit sequence oc curs after a charge gt 0 or a discharge lt 0 The above 2 steps Galvanostatic and resting period will be repeated until the working elec trode potential reaches the limiting condition Ewe gt Ex after a charge or Ewe lt E after a dis charge Note the user can bypass this test by entering p pass instead of a voltage value e Loop Go back to sequence N nc time s loops to a previous sequence Ns lt Ns Nc time s Set Nc O to cancel the l
115. at mg time s Reverse Potential Sweep to K End Fig 18 General diagram for Staircase Voltammetry The technique is composed of a starting potential setting block a 1 potential sweep with a final limit E4 a 2 potential sweep in the opposite direction with a final limit E2 the possibility to repeat ns times the 1 and the 2 potential sweeps e a final conditional scan reverse to the previous one with its own limit Er Note that all the different sweeps have the same scan rate absolute value The detailed diagram on the following figure is made of three blocks e Starting potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas sets the starting potential vs reference electrode potential or vs the open circuit potential Eoc or the previous controlled potential Ecti or measured potential Emeas e First potential sweep with measurement and data recording conditions Scan Ewe with dE dt mV s allows the user to set the scan rate in mV s The potential step height and its duration are optimized by the software in order to be as close as possible to an analogic scan Between 28 Techniques and Applications Manual brackets the potential step height and the duration are displayed according to the potential resolution defined by the user in the Advanced Settings window see the corresponding section in the EC Lab Software User s Manual to vertex potential E V vs Ref Eoc Ei sets
116. ated during an integration time of taera Record lt l gt every dt S I every dlp A pA or ts Two different recording conditions on the current are available with the potentiostatic mode either recording an averaged current lt I gt on given time duration or recording an instantaneous current with a time variation and or an instantaneous current variation dl E Range enables the user to select the potential range for adjusting the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth the current range depends on the Ip value and is automatically set The user makes the choice of the bandwidth Upon detection of the pitting limit in current or if the time for application of the potential has been reached the working electrode is disconnected In the case of multi pitting experiment the applied potential after the open circuit period will be the average potential of the working electrodes These electrodes will be disconnected one by one as and when they reach their pitting Current Data processing No data processing is available with the MPSP application 3 4 10 ZRA Zero Resistance Ammeter The Zero Resistance Ammeter is an application for the measurement of galvanic coupling current of dissimilar metals It is also made to perform electrochemical noise measurements lt consists in applying zero v
117. ation The detailed parameter setup is displayed on the following Fig 97 101 Techniques and Applications Manual Disk Channel 1 CP V forts g h Ho mmm Limits Ewe gt EM 0 200 V AO gt Au Record ever dE or dtg E Range Range 100 pA Bandwidth Go back to sequence Ng 0 RGIS erte jaca forme 0 imela Alliage ANANA Ring Channel 6 ACA Apply Ei E Range Range Bandwidth Fig 97 CP_RCA detailed setup CP block e Current step Apply l pA A vs lt none gt Ictrl Imeas the current step is set to a fixed value or relatively to the previous controlled current len that is the current of the previous sequence current step block or to the previous measured current Lues This option is not available on the first sequence Ns 0 To select the current step type check the option box for ts h MN S sets the current step duration 102 Techniques and Applications Manual Limits Ewe gt lt Em V curtails the step duration if the potential is reached If the limit is reached the loop condition go to Ns for nc times if set is not used and the program continues to the next sequence Ns 1 The AQ value is the integral charge for the current sequence This value is not reset if there is a loop on the same sequence Ns Ns O values disable the tests Record Ewe or lt Ewe gt every dE mV and at least every dts
118. ations Manual Automatically the number of Sequences corresponding to the number of rows in the table is displayed The maximum number of sequences is limited to 2500 on our standard boards lim ited by the memory size In the case where the software finds two lines with the same param eters they will be merged in only one line to save memory In the table to be imported the first column must be the time and the second one must be the other variable such as potential or current e Pulsed potentio Charge Apply E V forts h MN S defines the voltage pulse value and duration Record every dls pA A and or dts e limits the recordings conditions in current variuation and or time variation E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab software user s manual for more details on the potential resolution ad justment I Range Bandwidth sets the current range and the bandwidth for this experiment e Conditional test which proposes to go to the next sequence or to loop on a previous sequence Ns Ns lt Ns If Nc is set to 0 then the technique executes the next sequence If the user wants to loop to a previous sequence line the 2 last columns of the table needs to be filled Go to Ns and ne cycles The end of the technique is obtained by setting Ns and ns to 0 in the last sequence or setting Go back to sequ
119. be configured in the E Mail tab of the Options window Config menu Fig 85 Experiment i l windows 2 4 13 1 E Mail Configuration Before use the E Mail technique the email setting of the sender have to be configured One can set the e mail parameters in the E Mail tab of Option windows in menu Config Options default General Warming Text export Colors Reterences Tool bars menus E Mail SMTP Configuration SMTP Host 0 User Name fs Password fs Hot Fig 86 E Mail configuration tab 2 5 Manual Control 2 5 1 PC Potential Control This application enables the user to directly control the working electrode potential using the mouse to move a Sliding index 91 Techniques and Applications Manual E mal 110 000 Cell Potential WI 0 000 L gt E min DI 10 000 Fig 87 Manual Potential Control It contains a sliding index 2 boxes for setting the lower and upper limits of the potential one box for the current potential value and the possibility to select the bandwidth Potential setting once you have selected this menu you can set the potential limits and the controlled potential Then you need to accept the settings Application of the potential to the cell this is performed by using the Run button If you have already set a potential in the intermediate box this potential is applied to the cell If not it will be the value corresponding to the index position Moving the sliding inde
120. blocks Fig 19 e Starting potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas sets the starting potential vs reference electrode potential or according to the previous open circuit potential Eoc or controlled potential Ect or Measured potential Emeas e Potential sweep with superimposition of sinusoid signal and measurement and data recording conditions Scan Ewe with dE dt mV s allows the user to set the scan rate in mV s The potential step height and its duration are optimized by the software in order to be as close as possible from an analogic scan to vertex potential E V vs Ref Eoc Ei sets the first vertex potential value vs reference electrode potential or according to the previ ous Open circuit potential Eoc or previous potential Ei 33 Techniques and Applications Manual SetEwe to Ey 0 000 NV w Del w Scan Ewe with dE Zdt i 0 000 IM i s to vertex potential Eq 1 000 Wows Del Ww Add a sinusoidal signal to the potential scan and amplitude A Reverse scan to vertex Ep Repeat ne fo time s Record every dt 0 001 0 BR Range Auto v Reverse scan towards Ej Fig 23 Alternating Current Voltammetry detailed diagram Add a sinusoidal signal to the potential scan With frequency fs kHz Hz mHz uHz And amplitude A mV defines the properties frequency and amplitude of the sinusoidal signal o Reverse scan to ve
121. cess keep previous zoom Cancel Fig 38 EIS variable selection window with WE and CE PHS contre mpr s lm Z vs Re Z s Im Zce vs Re Zce 0 04 0 06 0 08 0 1 0 12 Re Zce Ohm Fig 39 PEIS data curves with WE and CE recording 51 Techniques and Applications Manual 2 2 6 3 Frequency vs time plot It is possible to perform impedance measurements at different time intervals to follow the evolution of Z or Im Z Re Z Phase Z vs time for each frequency value The user can repeat a PEIS experiment for which the potential Ewe Is fixed for a given time te for example 30 min After a run open the impedance file in a graphic window click on Selector and the file se lection window appears figure below Then select time s for the X axis and choose the pa rameter you want to represent on Y1 axis Z in our example File Selection Files CME C Lab D ata S amples 18650 POT_1 mpr Vattables Representation E vs t eo Relk hm M Jonke Hl Ohm iv Phasel deg time s e EDA cycle number Refi Ohmi M Imir Ohm MOhm Fhasef ideg W Same selection for all files Frequencies Hide Additional Variables J keep previous axes process keep previous zoom Load Add Remove Undo Clear Cancel Fig 40 File selection display Select Z t plot in the scroll menu Then the fol
122. chosen variable Click on Cus tom Units The figure below is displayed 217 Techniques and Applications Manual Custom Units custom unit sl Albums 143 E AN L1 H s a 1 s2 Ohm e 1 2 s4 Ohm s 1 2 d Fig 198 Custom Units window to define new variables To create a new variable with its unit click on Add and put the name and the unit of the new variable in the frame Then click on v to validate The new variable is displayed in the list in blue color as a custom variable and can now be selected as the recorded variable for the analog inputs The new selected variables for Analog In1 and for Analog In2 are automatically displayed on the Cell characteristics window and activated for recording In the Selector the created variables are displayed and can be plotted These auxiliary variables can be used in several techniques as conditional limits of an experiment Note The parameters set in Analog Ini and Analog In2 to define the linear slope can be inverted to have an opposite variation of the recorded value with the plotted value 218 Techniques and Applications Manual Linked experiments 4 1 Description and settings It is possible to link different techniques within the same run This allows the user to create and build complex experiments with up to 20 techniques Once they are created the linked experi ment settings can be saved either as a mps file or as a Custom Applicat
123. cial Galvanostatic Cycling with Potential Limitation SGOR E 131 Special Modular Potentio MP WEE 81 Special lee TEE ga Me RE Valo Special Open Circuit Voltage GOCN E 7 Staircase Galvano Electrochemical Impedance Spectroscopy GEI 44 Staircase Potentio Electrochemical Impedance Spectroscopy SPEIS nannnnnnennnnnnennennne 40 Staircase VoltammMetry SV ccccccccccccceecseeececceeescsecccoececcdececdecccoeeeecseceecenescuetecceeesceneescees 28 Stepwise Potential Fast Chronoamperometry SPFO nannannnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnne 214 REI 72 80 83 87 107 170 180 Techmigac E nl EE 219 AF dreet 84 Variable Amplitude Sinusoidal microPolarization VAN 207 ET EEN 85 Zo ONS OS TANG niana EE ees eae 52 Zero RESISTANCE Ammeter E EE 203 239
124. cna ana A 2 7 1 CV_RCA CV synchronized with CA 2d 2 CP RCA GP Synchronized WU E E 21 23 CA RCA CA Synchonzed WIO E Electrochemical applications ccccccescsesssesseeeseesseeseeeseeeseeesseesesseeeneoesesenseeseannees 3 1 Batteries Tee edd dE dE 3 1 1 BCD Battery Capacity Determination ccccccccccccseeeeseeeeceeesaeeeeseeeesseeeees 3 1 1 1 Description of a galvanostatic seguence 3 1 2 GCPL Galvanostatic Cycling with Potential Limitation cccccceeceeeeeeees 3 1 2 1 Description of a galvanostatic seguence E ee ee saa E e Eat 3 1 2 3 1 Compacting process for the apparent resistance determination GCPL2 Galvanostatic Cycling with Potential Limitation 2 GCPL3 Galvanostatic Cycling with Potential Limitation 3 GCPL4 Galvanostatic Cycling with Potential Limitation A GCPL5 Galvanostatic Cycling with Potential Limitation D GCPL6 Galvanostatic Cycling with Potential Lmtatonp GCPL 7 Galvanostatic Cycling with Potential Limitation 7 cccccceseeeeeees SGCPL Special Galvanostatic Cycling with Potential Limitation 0 PCGA Potentiodynamic Cycling with Galvanostatic Acceleration 3 1 10 1 Description of a potentiodynaMIC seguence 3 1 10 2 Description of the cell characteristics window for batteries 3 1103 GE Data DlOCeSSING EE 3 1 10 3 1 Compact function 3 1 10 3 2 Intercalation coefficient determination Sault MBENOG
125. corrosion poten tial or measurement of the charge transfer resistance Ra Ap is defined as the slope of the potential current density curve at the free corrosion potential Ap AE AI ag a In this appli cation the determination of Ap and kor is made only with three or four potential steps The detailed diagram is made of five blocks Initial open circuit voltage Potential step s Open circuit voltage Reverse potential step s Repeat Begin Initial Open Circuit Potential Pac n 2 4 steps reverse steps he 3 t Potential step s Ro at a initial LAE ODC DEM Open Circuit Potential IA IA Ab Fy Reverse Potential step s End Fig 189 Polarization Resistance general diagram 210 Techniques and Applications Manual Repeat all ng D tirne Fig 190 Polarization Resistance detailed diagram e Initial open circuit voltage The open circuit voltage is the standard block so report to the OCV technique chapter for more information e Potential step s From Eo Apply n potential step s with AE mV Keep potential level s for At s or until dl dt lt pA s applies n potential steps with AE amplitude and At duration from the potential of the previous OCV period Eoc If the current variation is small dl dt lt dl dt limit then the step is shortened set the dl dt limit to O to cancel the test Record n tim
126. cs Vill EE 141 Constant Amplitude Sinusoidal microPolarization CA 208 E ele E Lag Curent CSIC EE 169 179 Constant Load Discharge CID 149 174 Constant POWE GPW ER 151 175 Constant Voltage OST enesenn e n a S 167 177 COMMOSIMOMN Ee 183 Custom applications add Ree dere WEE 216 Cyclic Potentiodynamic Pitting CPP 187 Cyclic Voltammety GV EE 7 10 14 15 99 100 165 Cyclic Voltammetry Advanced CHA 17 18 Depassivation Potential DED POU E 190 Differential Normal Pulse Voltammetry ONDVT 64 Differential Pulse Amperometry RA 66 Differential Pulse Voltammetry ODDV 55 Eor VS IMO CE T Eug 180 External Rer Contos RE 88 Galvanostatic Cycling with Potential Limitation GC 109 Galvanostatic Cycling with Potential Limitation 2 GC 116 Galvanostatic Cycling with Potential Limitation 3 GCPL3 cc cceceecseseeeeeeeseeeeeaeeeenees 118 Galvanostatic Cycling with Potential Limitation 5 GC 123 Galvanostatic Cycling with Potential Limitation 6 GC 126 Galvanostatic Cycling with Potential Limitation 7 GC 129 Galvanostatic Impedance GEI 39 52 Generalized Corrosion GC 185 Ile ele EE 35 l VG AV ACTCMIZ ALON EE 172 Large Amplitude Sinusoidal Voltammetry AGV 30 Bis We EE Mea E hes 181 il Bel Eu S ariani i catevenu ness nena aetsieans bats gdismensacevanheetseaan ces mecdiaeeesaete 219 El AD DIC ANON EE 219 Iewen ie EE 219 Move TEE 220 MOVE e E 220 PIONEGICK TR EE 219 EEN 223 LOOD
127. ct the potential range and adjust the potential resolution to his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation 188 Techniques and Applications Manual Record lt l gt over the last of the step duration averaged N voltage steps every dl pA nA LA mA A or dtp S Two different recording conditions on the current are available with the potentiodynamic mode either recording an averaged current lt I gt on each potential step or recording an instantaneous current with a time variation and or an instantaneous current variation dl and or charge var iation dQ all foio D nn 25 B 4 4 4 dE JO 100 uv 4 10 0 me JEM 500 ul Fig 167 CPP detailed diagram e Hold potential Hold Ex Until I gt Ip if the current limit has not been reached during the previous phase I lt lp then the final potential of the scan EL is held until the current reaches the lp limit If the current limit has been reached during the previous phase I gt Ip then this block is skipped even if checked 189 Techniques and Applications Manual e Reverse scan End scan towards E V vs Ref Eoc Ei if checked then apply a potential scan from the current potential to E that can be set to a fix
128. ctive species 25 Techniques and Applications Manual ao Oho SB Db em ow yO to Ne or Ns D CO 2 ODC OD mm oF ev Sequence or go ne times to sequence Ms Fig 16 Chronopotentiometry general diagram This technique uses a sequence table also Each line of the table Ns corresponds to a rest and current step sequence The detailed diagram is made of two blocks e current step e loop e Current step Apply l pA A vs lt none gt Ictrl Imeas the current step is set to a fixed value or relatively to the previous controlled current len that is the current of the previous sequence current step block or to the previous measured current Lues This option is not available on the first sequence Ns 0 To select the current step type check the option box for ts h mn s sets the current step duration Limits Ewe gt Em V AQ gt Aw fA h A h pC kC curtails the step duration if the potential or charge limit is reached If the limit is reached the loop condition go to Ns for nc times if set is not used and the program continues to the next sequence Ng 1 The AQ value is the integral charge for the current sequence This value is not reset if there is a loop on the same sequence Ns Ns 0 values disable the tests 26 Techniques and Applications Manual poly Is 20 000 ua vs forte o bh fio mn powo Limits Ewe gt EW 0 200 W AO gt
129. current previous sequence or versus the previous measured current The sign of the current value is for a discharge 121 Techniques and Applications Manual and for a charge when the positive electrode of the cell is connected to the working elec trode cable red Set C N or CxN with N and I gt 0 or lt 0 sets the rate C N or CxN at which the battery will be charged I gt 0 or discharged l lt 0 The C value could be a noninteger value For instance if the capacity of a battery is 1800 mA h setting C N with N 3 and I gt 0 means that a current of 600 mA will be passed during 3h The total capacity of the battery will be reached in 3h Setting CxN with N 2 and I lt 0 means that a current of 3600 mA will be passed during 30 min The total capacity of the battery will be reached in half an hour There is still the possibility to set a time limit Record every dE mV and dt s defines the recording conditions during the galvano period These values can be entered sim ultaneously The first condition that is reached determines the recording A zero value disables the recording for each criterion Limit Ewe gt lt Em V sets the limit of the working electrode potential under charge discharge see warning 1 of GCPL technique This limit could be disabled by entering pass type p in the control e Potentiostatic period Hold Em once reached until 1 lt Im pA A next block on li
130. d The sign of the current value is for a discharge and for a charge when the positive electrode of the cell is connected to the working electrode cable red It is also possible to set the current relatively to the capacity of the battery entered in the cell characteristics see 3 1 10 2 io h a mn 4500 Y Record evem dEy 100 mv or dty 60 0000 Fig 103 setting the charge discharge using the capacity of the battery Set C N or CxN with N and I gt 0 or lt 0 for at most t h mn s sets the rate C N or CxN at which the battery will be charged I gt 0 or discharged l lt 0 The C value could be a noninteger value For instance if the capacity of a battery is 1800 mA h setting C N with N 3 and I gt 0 means that a current of 600 mA will be passed during 3h The total capacity of the battery will be reached in 3h Setting CxN with N 2 and I lt 0 means that a current of 3600 mA will be passed during 30 min The total capacity of the battery will be reached in half an hour There is still the possibility to set a time limit Limit Ewe gt lt Em V sets the limit of the working electrode potential under charge discharge see warning 1 fortw h mn s or until I lt Im pA A or dl dt lt dl dt Als uA mn allows the user to stand at the potential Ew for a given time or until the current reaches a low limit value Im or when the variation of the current is lower than
131. decade in logarithmic spacing Ns 1 average measures per Frequency drift correction Fig 132 GEIS control e TI Trigger In see 2 4 4 e TO Trigger Out see 2 4 4 3 1 12 CED Coulombic Efficiency Determination In the last years several researches were focused on the Coulombic Efficiency CE as a tool to study the battery lifetime Quantifying the influence on the battery lifetime by changes in the electrodes or electrolytes under classical testing conditions simply charge discharge condi tions requires extremely longtimes Contrarily to a simply cycle cells measurements until the cells reach the end of life CE measurements can be improved in short amount of time 3 4 weeks and also provide a tool to evaluate and compare the stability of different cells This technique is used to determine and follow the evolution of the coulombic efficiency of a battery during a charge discharge protocol This determination is made under galvanostatic mode i e the same current value is fixed in the charge and discharge regime The batteries are cycled between the potential limits Eu and Ewe 3 1 12 1 Description of a galvanostatic sequence The detailed diagram of the CED technique is shown in Fig 133 Set I tol pA A for t h mn s 147 Techniques and Applications Manual sets the cu
132. defined by the ratio of Laplace Transform of E and the Laplace Transform of I IR compensation in the electrochemical cell the resistance between the working and the reference electrode produces a potential drop that keeps the working electrode from being at the controlled potential IR compensation allows the user to set a resistance value to compen sate the solution resistance Linear Polarization LP technique that consists in a potential ramp around the corrosion potential It is often used to determine polarization resistance and corrosion current Linked experiments EC Lab offers the ability to link up to ten different experiments with the technique linker Linked experiment settings the user can save the settings of linked experiments as a mpls file This allows the user to easily load all the experiment settings Loop technique available in the linked experiments and used to repeat one or more experi ments It is different from the cycle in an experiment Manual Potential control application that enables the user to directly control the working electrode potential using the mouse to move a sliding index Modify button of EC Lab main window allowing the user to select a technique and change the experiment parameters before or during the experiment This button switches to Accept when the user clicks on Modulo Bat MB A technique specially dedicated to batteries that combines all the available control modes rec
133. ding conditions E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment The RDEC technique has a parameters table in the parameters settings window which can be related to the sequences selection The table view can be accessed with the following path View gt Settings With Flowcharts pply control Control Crp td td hrs date Imdd ul date Im sl 1000 0 0 00 17 0000 10 15 20 14 44 42 2000 0 0 00 1 0000 01701720 00 00 00 3000 0 0 00 1 0000 01701720 00 00 00 4000 0 0 00 1 0000 01701720 00 00 00 SU 0 00 1 0000 01701720 00 00 00 Fig 79 RDEC TC EDC table The sequences in the TC RDEC and EDC technique The user can add several RDEC se quences Ns 0 to n These sequences are linked differently from the other techniques In other standard techniques one sequence is executed directly after the other For the RDEC EDC and TC technique each sequence corresponds to a loop of a linked technique There fore only one sequence of the wait technique is executed at each loop of the linked experiment The sequences are considered successively at each loop This allows the user to increase temperature values at each sequence Loop 87 Techniques and Applications Manual If the Loop number of increments is larger than the number of sequence
134. ditioning steps either in OCV or at a particular potential preconcentration to Ns or Mes OC period or Appl Es potential or Appi dE Zdt potential scan DCD 3 ODC oO dm ow Fig 59 Modular Potentio general diagram e Mode selection Click on Mode OCV 0 Potentiostatic 1 or Potentiodynamic 2 to select the corresponding mode 2 4 1 1 Open Circuit Voltage Mode 0 OC D Mode Rest for tp Limit ldEwe dtl lt dE pR zdt Record even dep or dtp Go back to sequence Net Potentiostatic 1 Fotentiodynamic D 0 hip m om0 s 00 mh oo mm D n 0 ARES rer face Io nes f time s Gi aer seu Fig 60 Modular Potentio OCV detailed diagram The open circuit voltage is the standard block so report to the OCV technique section for more information 69 Techniques and Applications Manual Go back to N for ne time s each one of the OCV potentiostatic and potentiodynamic periods is represented by a single line in the grid parameters If nc is set to 0 the sequence lines are executed one after another Then an OCV potentiodynamic and OCV sequence for example will be programmed by 3 lines in the parameters table Setting Nn gt 0 will loop to a previous line Ns lt Ns for ne times Report to the battery techniques section 3 1 page 107 for more details on loop conditions It is possible to loop to Ns 0 but Ns must be lt Ns current sequence line number
135. dl A pA or dtp S Two different recording conditions on a current are available with the potentiodynamic mode either recording an averaged current lt I gt on each potential step or recording an instantaneous current with a time variation and or an instantaneous current variation dl and or charge var iation dQ E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment Range and Bandwidth defines the current range and bandwidth for the whole experiment Range is automatically set according to h and le values If Pitting I gt h fort gt ta or Te C reached Mi Stop Controlling T O Set T C If pitting or temperature Te is reached then it stops controlling temperature or applies a final temperature T and stops the experiment Otherwise go to the third step e Third step increase temperature and turn to rest Increase T with T C below T C and Ts2 C above Increases the temperature with Ts or Ts2 according to the TL value This allows for bigger steps in temperature with each cycle that pitting is not reached in order to speed up the exper iment s total duration Rest Until lt dT dt gt lt dT C dt h mn or fort h mn rest parameters see first step Record every dTr
136. dtr S allows the user to record the working electrode potential wnenever the change in the potential is gt dEr with a minimum recording period in time dtr Data recording with dEr resolution can reduce the number of experimental points without los ing any interesting changes in potential When there is no potential change only points ac cording to the dtr value are recorded but if there is a sharp peak in potential the rate of record ing increases E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment Techniques and Applications Manual 2 1 2 SOCV Special Open Circuit Voltage As the OCV period the Special Open Circuit Voltage OCV consists in a period during which no potential or current is applied to the working electrode The cell is disconnected from the power amplifier On the cell the potential measurement is available So the evolution of the rest potential can be recorded This period is commonly used as preconditioning time or for equilibration of the electrochemical cell An additional limit condition on Analog In1 or Analog In2 is added which makes it special RestfortR p hilo mm 300000 Limit Eed lt dEg dt Dn mi IEwel lt Ep th Lim 0 000 E Record ever dEr i 00 m or dtp 0 5000 5 E Range 10 104 scil rea NN G
137. e Nyquist visualization the axes are dis played orthonormally Iim Y Ohm 1 0 005 0 01 0 015 0 02 Re Ohm 1 Fig 36 NYQUIST diagrams for both impedance blue and admittance red e Black Diagram The Black diagram is the plot of log Z vs phase Z for impedance log Y vs phase Y for admittance 0E f log Ohm log Z 0 hm Su 20 Phase Z ideg Phase VY ideg Fig 37 BLACK diagrams for both impedance blue and admittance red 2 2 6 2 Counter electrode EIS data plot When the user selects Record Ece in the Cell characteristics window EIS measurement of the counter electrode is done and can be displayed 50 Im Zce Ohm 0 025 Techniques and Applications Manual Vanables Representation Custom T E 5 m freg Hz Re Ohm Im 4 Ohm ElOhm Phasel deg time s i i K SIICHT Ewer lt i gt ma cycle number Phasel ce ideg Fecel Ohm Re ce Ohm 7 Imf4ce Ohm V Same selection for all files Frequencies Hide Additional Variables KISISISIEISISISISIESIEIS Ka keep previous axes pro
138. e end of the rest periods Then the name of the compacted processed file is filename channel_cR mpp in the case where Ri is the only one processed variable 115 Techniques and Applications Manual Ri ve time 18650 GITT 170604 1_cRompp i Ewe vs time 18650_GITT_ 170604 1 mpr 0 18 0 16 0 14 0 12 Ui E wer LU Or la CO C C C io D D D Pa E OH OH CH D 20 000 40 000 60 000 time s Fig 106 Ri determination red circles after a GITT experiment blue crosses obtained with an 18650 Li ion battery 3 1 3 GCPL2 Galvanostatic Cycling with Potential Limitation 2 The GCPL2 application is similar to the GCPL one but was designed to limit both the working electrode WE and the counter electrode CE potential Additionally the cell potential after the current charge discharge is not held at a constant value The technique is by default composed of three sequences resting period i e OCV charge and discharge The GCPL2 technique is made of 4 blocks e QGalvanostatic e OCV e Potential test e Loop This is detailed Fig 107 e Galvanostatic period Set to Is pA A vs lt None gt Ictri Imeas for at most ti h mn S sets the current value in absolute versus the previous controlled current previous sequence or versus the previous measured current and the maximum duration of the imposed current period The sign of the current value is for a di
139. e execution stops Here it is possible to loop to the first instruction Ns 0 and the current instruction Ns Ns 3 3 5 CstC Constant Current The constant current CstC technique is especially dedicated to fuel cell s or photovoltaic cell s testing It is designed to apply successively several current steps to the cell s Between each current step an open circuit voltage period can be added RestfortR 0 hn mh pog 3 Limit IdEwe dtl lt dEp dt Dn meh Record even dER oun mv o dp 00000 Apply Ig 100 000 m s lt None gt forte D hb mh pomon 3 Limits Eye gt EM pass W AOI gt AQpy 6 3933 m A Record Ewe every dE i D mi or dt 1000 0 2 E Range OV DV Zaang A ag Range Om e Bandwidth 5 medium Go back to sequence Net 0 NNN erte fae for pe 0 Dmelsl d ne sie M e al Fig 159 Constant Current detailed diagram e Rest period The rest period is an open circuit voltage period Refer to the OCV description for more details e Current step Apply ls pA A vs lt none gt Ictrl Imeas 179 Techniques and Applications Manual the current step is set to a fixed value or relatively to the previous controlled current len that is the current of the previous sequence current step block or to the previous measured current Lues This option is not available on the first sequence Ns 0 To select the current step type check the option box fo
140. e medium The data sampling could be made every us When the recording timebase dt is below 15 us the instruments switches to a fast acquisition mode In this mode auto ranging are disabled pe d zm Insert Techniques alc Electrochemical Techniques 4 eo Molkemperomeinc Techniques o Open Circuit Voltage OC Special Open Circuit Voltage SOC ve Cyclic Volkarnmetry CY ee Cyclic Voltammetny Linear CL v gt Cyclic Yoltanmety Advanced CYA l Linear Sweep WYolktammetry LEM TL Chronoampernometry Chronocoulormetry CA TL Chronopotentionetry CF 2 Staircase Voltammetry SY g Large Amplitude Sinusoidal Yoltammetry LASY The UV Linear technique allows the user to perform a voltage J scan using the analog scan generator option of the potentiostat a AC Voltammetiy ACY When this technique and this option are used a tre analog A Ka Impedance Spectroscopy voltage scan not a staircase scan between two vertex neo Galvano Electrochemical Impedance Spectroscopy GEIS potentials E1 and E2 iz applied to the system This analog cow Potentia Electrochemical Impedance Spectroscopy PEIS characteristic of the voltage scan avoids any transient currents of Staircase Galvano Electrochemical Impedance Spectroscopy SGEIS to the system This option can be coupled with the hardware d ohmic drop compensation So expenments with fast scan rate Stanrcase Potentio Electrochemical Impedance Spectroscopy Mott
141. e passed during the oxidation step where the current is positive Q discharge the charge passed during the reduction step where the current is negative Q Qo the total charge exchanged from the beginning of the experiment dl dt the time derivative of the current time cycle is the time elapsed during one cycle The definition of a cycle is chosen in the process window cf Fig 5 One cycle being considered as one potential scan forward and one potential scan backward i e from OCP to E1 to E2 and then from E2 to E1 to E2 The time cycle is reset each time the number of cycles is incremented e time charge and time discharge are the total duration of the charge positive current or discharge negative current e time step is the time elapsed during one sequence which can be different from the time elapsed during one cycle 2 1 4 CVL Cyclic Voltammetry Linear The Cyclic Voltammetry Linear is available only for the SP300 based see Voltamperometric Technique menu Fig 6 instruments when the LSG option is installed see section 8 1 Linear Scan Generator LSG in the installation and configuration Manual This technique allows the user to apply a true analog voltage scan not a staircase scan between two vertexes of po tential This option can be coupled with fast scan rate and the hardware ohmic drop compensation could be made This technique could be used to detect e g electroactive species with a short lifetime in a resistiv
142. e potential or versus a previous open circuit potential Eoc previous controlled potential Eet or previous measured potential Emeas to Ep value defined in absolute or versus Eoc or Ei RestfortR lo hilo mn foomo amp Limit Me dit lt dEp dt Dn mveh Record every dp oO mV or dtp o1000 can Ewe with dE dt 0 1 EE rays from Ey 0025 V w Eoc to EL a05 Y vs Eoc el Record ER over the last 25 Of the step duration average H 5 voltage steps ERange 2W 2W ania Ao a Range lato e Bandwidth 7 dE ZO 7 100 p 4 602 4 me IEN 500 py Fig 161 Detailed diagram of the Linear Polarization application Record lt l gt over the last of the step duration averaged N voltage steps l every dlp pA nA pA mA A Two different recording conditions on the current are available with the potentiodynamic mode either recording an averaged current lt I gt on each potential step or recording an instantaneous current with a time variation and or an instantaneous current variation dl and or charge var iation dQ E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation Contrary to the MPP t
143. e pulses lbp delta UA difference between lt I gt values before and at the end of the pulse lp lbp E step V step potential value resulting from the potential sweep and used to plot the current 2 3 5 DNPV Differential Normal Pulse Voltammetry Originally introduced as a polarographic technique performed at a Dropping Mercury Elec trode DME the Differential Normal Pulse Voltammetry is a sensitive electroanalytical technique very similar to the DPV technique with a pulsed potential sweep The potential pulse is swept from an initial potential E to a final potential Ev There are two main differences with the DPV technique first the pulse waveform is made with a prepulse SH amplitude with PPw duration before the pulse Du amplitude with Pw duration and second the potential always comes back to the initial potential Ei after the pulsed sequence Eiis assumed to be the po tential where no faradic reaction occurs The plotted current is the difference of both currents measured at the end of the pulse I forward and the end of the prepulse I reverse This technique is often used in polarography and by biologists to define the most appropriate potential for the electrochemical detection to a fixed potential with the DPA technique Description e Initial potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas forti h mn s sets Ewe to the initial potential E This potential value can be set vs the reference elect
144. e selection Click on Mode OCV 0 Potentiostatic 1 or Potentiodynamic 2 to select the corresponding mode Then the detailed diagram appears To select the second sequence Ns 1 click on the corresponding row in the Modular galvano table see below By default the technique contains 3 sequences OCV Galvanostatic and Galvanodynamic 2 4 3 1 Open Circuit Voltage Mode 0 Go OLY IO Mode Galvanostatic 1 O Galvanodynarnic 2 Fest fortp o h mfg s Limit IdEwe dl lt dEp dt Bo mh Record every dp oo mm o dp jo5000 3 Go back to sequence NM 0 ANN erer facta for pe 0 time s Ai nr aas Seed Fig 68 MG OCH detailed diagram The open circuit voltage is the standard block So report to the OCV technique section 2 1 1 page 6 for more details Go back to Ns for nc time s each one of the OCV potentiostatic and potentiodynamic periods is represented by a single line in the grid parameters If nc is set to 0 the sequence lines are executed one after another Then an OCV potentiodynamic and OCV sequence for example will be programmed by 3 lines in the parameters table Setting Nn gt 0 will loop to a previous line Ns lt Ns for ne times 11 Techniques and Applications Manual Go to the battery protocols section 3 1 page 107 for more details on loops conditions It is possible to loop to Ns 0 but Ns must be lt Ns current sequence line number 2 4 3 2 Galvanostatic Mode 1
145. e selection window Insert Technique C Before e After Fig 200 Insert before after option of the technique selection window 219 Techniques and Applications Manual If the technique is not in the correct position in the experiment the user can easily move it up or down using the Move Technique Before and Move Technique After options 4 2 Example of linked experiment Let us program the following experiment that could be used for a Levich plot 1 Trigger In wait for a trigger to start 2 MP mode 0 OCV period 5 s mode 2 potential sweep from 0 V to 1 V with 10 mV s 3 Wait 1 s with modification of the RRDE rotation speed no recording 4 Loop to MP technique five times To build the experiment click on Modify and select New Experiment on the right click menu In the technique selection window choose TI Trigger In The instrument will wait for a trigger to start On the parameter settings window right click with the mouse Select Insert New Technique Choose the Modular Potentio technique and click OK check that the technique will be inserted after the trigger Report to section 2 4 1 page 69 for more details about the Modular Potentio technique For sequence N 0 select mode 0 OCV and for sequence Ns 1 select mode 2 potential sweep and set parameters for every sequence To add a wait and a LOOP technique repeat the same operation Insert New Technique and set parameters The WAIT
146. e that the number of repetition does not include the first sequence if nc O then the sequence will be done once if nc 1 the sequence will be done twice if nc 2 the sequence will be done 3 times etc e Data recording conditions Measure lt l gt over the last of the step duration selects the end part of the potential step from 1 to 100 for the current average lt I gt calcu lation It may be necessary to exclude the first points of the current response which may only be due to the capacitive rather than faradic behavior of the system Record lt l gt averaged over N voltage step s averages N current values on N potential steps in order to reduce the data file size and smooth the trace The potential step between two recording points Is indicated between brackets Once selected an estimation of the number of points per cycle is displayed in the diagram E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment ERange 25 25 e some potential ranges are defined by de e fault but the user can customize the Edit Potential Range E Range in agreement to the system by E range min Vomax 1 000 W clicking on hall Information on the resolution is given simul taneously to the change of minimum and oct pn maximum potentials resolution
147. e the result of one of the following Improper use of the device Improper installation operation or maintenance of the device Operating the device when the safety and protective devices are defective and or inoperable Non observance of the instructions in the manual with regard to transport storage installation Unauthorized structural alterations to the device Unauthorized modifications to the system settings Inadequate monitoring of device components subject to wear Improperly executed and unauthorized repairs Unauthorized opening of the device or its components Catastrophic events due to the effect of foreign bodies ONLY QUALIFIED PERSONNEL should operate or ser vice this equipment 1 Techniques and Applications Manual Table of contents Ji ge tee en BEE 5 Electrochemical Techniques Suguer ees 6 2 1 Voltamperometric techniques n nnennenoennaeoenonrrnnrnrnnrrnrrnrrnrrnrrnrrrernrrnrrnrrnrrnernerne 6 2 1 1 OCH Open Circuit Voltage c cc cecccceececeeeecseeeeceeeeeseeeeseeeeseaeeeseusessaeeeseeesaaees 6 2 1 2 SOCV Special Open Circuit Voltage c cc cccecccseececeeeesseeeseecesseeeeseeeesseeeesaees 7 Selen oletieetitieat stereos E ities alk 7 2 1 4 CVL Cyclic Voltammetry mear 14 2 1 5 CVA Cyclic Voltammetry Advanced sannnennnnnnennennnnnnennnnnnnrrsnrrnrnsnrnrrrsrreenne 17 2 1 6 LSV Linear Sweep Voltammetm 20 2 1 7 CA Chronoamperometry Chro
148. e to 0 in the last sequence or setting Go back to sequence Ns 9999 at any sequence which then will be the last one executed even if the next sequence has its settings Such a complete sequence corresponds to one line of the table This line is composed of the columns which represent the successive variables encountered when setting the diagram the current range and the loop conditions all parameters which must be set by the user see Warning 2 Note that it is always possible to force the end of a technique while it is running at any se quence sweep using the Modify button and setting Goto sequence Ns 9999 at the se quence one wants to stop 3 1 9 SGCPL Special Galvanostatic Cycling with Potential Limitation This technique such as the GCPL technique corresponds to battery cycling under galvanos tatic mode essentially i e with an imposed current but with possible potential limitations under current for both charge and discharge and test on potential values during open circuit period Additionally to the GCPL technique it is possible to limit the under current period by considering the value recorded with the analog input The main characteristics of this technique are the same as those of the GCPL one 131 132 for at most D Limits Ewe gt Epa Record ever dE or dt Hold Epg for tpg Limit ll lt Uppy Record even dQ or do Limits AGI gt Aw lt gt AXE Lg th E Range Range Bandw
149. eas sets the current value in absolute value vs Ictrl the previous controlled current from the pre vious Sequence or technique or vs Imeas the previous measured current For a charge a positive value must be entered and for a discharge a negative value 3 1 11 2 2 CV Constant Voltage Type Constant Voltage Apply 000 vs Number 41 gt Fig 125 Constant Voltage control 144 Techniques and Applications Manual Apply V mV vs Ref Eoc Ectrl Emeas Applies a constant potential value defined vs Ref the reference electrode potential vs Eoc the open circuit potential vs Eet the previous controlled potential from the previous se quence or technique or vs Emeas the previous measured potential 3 1 11 2 3 CR Constant Resistance a Constant Resistance Fig 126 Constant Resistance control Apply MOhm kOhm Ohm mOhm Ohm Applies a constant load on the system A constant load means that the battery is being dis charged The value of the load is maintained constant by controlling the current such that the ratio E I is constant 3 1 11 2 4 CP Constant Power Type CF se Constant Power Apply 3 000 Fig 127 Constant Power control Apply W mW pW A constant power is applied to the system The current is controlled to maintain the product E constant so if the potential decreases the current increases CAUTION Applying a constant power during a discharge ex
150. eation investigations Three couple of techniques are pro posed in EC Lab CV RCA CP RCA and CA RCA Note Both channels are totally independent but the first technique controls the sampling rate and the total duration of the experiment The first channel board is called disk channel and the second channel is the ring channel The two channels have to be selected and defined in the Select the bipotentiostat ring and disc channels window Fig 81 The bipotentiostat techniques are not linkable with other technique in EC Lab software Insert Techniques Eee Electrochemical Techniques Voltamperometic Techniques H ken Impedance Spectroscopy ey Pulsed Techniques ES ES Technique Builder Lk Manual Control ey Ohmic Drop Determination z Electrochemical Applications Insert Technique Load from default Custom Applications Advanced setting External devices Cell characteristics Fig 92 Bipotentiostat techniques 97 Techniques and Applications Manual Select the bipotentistat ring and disk channels Group SP 300 238 device channel 1 in mode with Devices Channels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 YSP 300 238 a Disk channel q4 f b Ring channel b Fig 93 Select the bipotentiostat ring and disk channels window 2 7 1 CV_RCA CV synchronized with CA The technique is composed of two blocks CV on the disk channel and a RCA on the Ring channel CV block a starting potentia
151. echnique see 3 4 8 no current limitation is available with the linear polarization application 3 4 2 2 Process and fits related to LP The LP application can be used for Rp and Lon determination using the Rp fit see EC Lab software manual for more details It can also be used to determine the corrosion rate with the Tafel fit see EC Lab Software User s Manual for more details 182 Techniques and Applications Manual 3 4 3 CM Corrosimetry Rp vs Time This application is advanced in corrosion tests It is designed to follow the corrosion standard values Ap Ecorr kor evolution versus time for a very long time several months It consists in applying periodic linear potential sweeps around the corrosion potential Ecorr The current is measured during the potential scan According to the recording conditions on the current either one point is plotted as an average on each potential step or several points are plotted as instantaneous values An automatic linear fit is performed around Ecor to determine the polarization resistance Rp One Ap value is obtained for each sweep and the Rp evolution is plotted versus time on another graph The user can define the anodic and cathodic corrosion constants in the settings for more accurate calculations 3 4 3 1 Description Fig 162 Graphic description of the Corrosimetry application 183 Techniques and Applications Manual 1 RestfortAe 0 hp mn poon Limit IdEwe d
152. echnique allows the user to control a tempera ture and change it during the experiment A direct link to the External Device window is done by clicking on External RDE The user can choose to apply different rotation speeds successively for different durations and perform a certain experiment at this rotation speed To do so several Sequences each one with the desired rotation speed and duration must be created Then the desired techniques need to be linked after the RDEC technique Finally the series of techniques must be ended with a Loop technique The sequences in the RDEC technique will be incremented only at each time the Loop technique is reached See below for additional info 86 Techniques and Applications Manual Set rotating speed to 2000 0 rom on External ADE and wait with previous control Tor tg 0 h o mr 5 0000 E _ Record every dE 0 00 rei 0 000 momo e E Range AAN l w M Fone Caution This technique i mainly used combined with a loop technique In this Case sequences are not executed successively At each loop only One sequence jf executed the number of the executed sequence is incremented Fig 78 Rotating Disk Electrode Control Set rotating speed to rpm one can set a temperature or the rotating electrodes speed if configured External devices windows The recordings are optional Record every dE mV dl pA A and dt S chooses one or several optional recor
153. ection 3 1 page 107 for more details on loop conditions e Process A process function is associated with chronopotentiometry technique The variables that can be processed are the same as for the CV technique For more details about CP process see the previous CV part 2 Techniques and Applications Manual Note In this technique the first and last data points of each current steps are not recorded automatically 2 1 9 SV Staircase Voltammetry Staircase Voltammetry SV is one of the most widely used techniques for acquiring qualitative information about electrochemical reactions SV similarly to cyclic voltammetry provides in formation on redox processes heterogeneous electron transfer reactions and adsorption pro cesses It offers a rapid location of redox potential of the electroactive species SV consists in linearly scanning the potential of a working electrode using a triangular potential waveform with a potential step amplitude and duration defined by the user During the potential sweep the potentiostat measures the current resulting from the electrochemical reactions con secutive to the applied potential The cyclic voltammogram is displayed as a current response vs the applied potential Unlike the CV technique the potential steps are not minimized by the software but adjusted exactly to the user s convenience Begin Set Initial Potential to Ee Potential Sweep to S Reverse Potential Sweep to SE Repe
154. ed the experiment must go to the next sequence 174 1 Start discharge on R EA for at most IM Limit Ewel lt Epa ADI gt AQ H lt gt ANB Record ever dE dq dt E Range Range Bandwidth 2 Rest for tp Limit Ke dl lt dep dt Record even dep or dtp Techniques and Applications Manual 21 000 Ohm a 2 hia moon 3 500 y 1 354 954 0 550 10 0 md 1 000 mAh v 120 000 0 S 100 m ho h mr jooooo e ho oh 200 m 120 000 0 8 fig Ger ni Ae atin FP 4 3 lf Ewel EL pass V goto 1 Fig 156 CLD detailed diagram Record every dE mV dq A h fA h kC pC and dt s defines the recording conditions These values can be entered simultaneously the first condi tion that is reached determines the recording A zero value disables the recording for each criterion Range and Bandwidth sets the current range and bandwidth for this experiment 3 3 3 CPW Constant Power The Constant Power application is designed to study the discharge of an energy device at constant power The constant power control is made by checking the current to maintain the E constant The current increases when Ewe decreases 175 Techniques and Applications Manual Set P Ell at for at most tW 10 hijo ma Oon nia Ol gt keep Wl Iw 200 000 Limits Ewe gt EN A0 gt ADM lt gt AX Record ever dE dq dt
155. ed value vs Ref the reference electrode potential or relatively to the previous potential E or Eoc Limit I lt pA A defines a current limit for the reverse scan If I lt l then the scan is stopped before the Ex potential is reached A zero value disables the test At the end the working electrode is disconnected 3 4 6 DP Depassivation Potential The Depassivation Potential technique is the concatenation of the MPSP without the I test and MPP techniques see figure below First the MPSP technique is used to depassivate the electrode metal while applying the appropriate potential The MPSP technique can be consid ered as a pre conditioning step where the electrode surface is cleaned Secondly the MPP technique is used to study pitting corrosion Begin End Fig 168 General diagram of the Depassivation Potential application 190 Techniques and Applications Manual ali Fo e CC all Dam q T 3 4 D dE ZO 100 uv 600 0 ms JEM 100 ul Fig 169 Detailed diagram of the Depassivation Potential application e Rest potential or open circuit sequence See EVT technique above 191 Techniques and Applications Manual e Potentiostatic period Set Ewe Es V vs Ref Eoc Ectrl Emeas for ts h mn S sets the potential vs Ref the reference electrode potential or with respect to the final rest po tential value Eoc or pr
156. edox poten tials of the electroactive species The CV technique consists in scanning the potential of a stationary working electrode using a triangular potential waveform During the potential sweep the potentiostat measures the cur Techniques and Applications Manual rent resulting from electrochemical reactions occurring at the electrode interface and consec utive to the applied potential The cyclic voltammogram is a current response plotted as a function of the applied potential Traditionally this technique is performed using an analog ramp Due to the digital nature of the potentiostat the actual applied ramp consists in a series of small potential steps that approxi mate the targeted linear ramp see the control potential resolution part in the EC Lab Software User s Manual Begin set Initial Potential to Ej Potential sweep to Ey 4 Reverse Potential sweep to Ejs Repeat m timers Reverse Potential sweep to Ei End Fig 3 General diagram for Cyclic Voltammetry The Cyclic Voltammetry technique has been briefly detailed in the EC Lab Software User s Manual This technique corresponds to normal cyclic voltammetry using a digital potential Staircase e it runs defined potential increments at regular time intervals The software adjusts the potential steps composing the increment to be as small as possible The technique is composed of Fig 2 Fig 3 and Fig 4 e astarting potential setting bl
157. eiogini 2 te forty Lp pass tp 0 0000 Record ER wll ever dt OI og amp E Range JEY 25W b enue Fae Range Auto Bandwidth D medum e Go back to sequence Net 10 EGS ante Hace for pe 0 Dmelsl TAV as aan Fig 65 Special Modular Potentio potentiostatic detailed diagram e Potentiostatic Mode 1 Set Ewe to Es V vs Ref Eoc Ectrl Emeas sets the potential to a fixed value vs Ref or versusto the previous open circuit potential Eoc or to the previous controlled Ectri or measured Emeas potential in linked experiments or linked sequences for ts h MN S defines the potential step duration if not stopped on limits Limit AQ to AQm fA h A h pC kC and to Imax D A and to Imn pA A sets limits for the potential step If one limit is reached AO gt AQm gt Imax or lt Imin before the end of the step duration ts then the program goes to the next sequence A zero value disables the AQy limit and type p to enter pass to disable Imax and Imin limits Note the AQ value tested here versus AQw is the current sequence Ns integral charge And Analog In 1 Analog In2 lt gt Lp V for tp S sets limits of the sequence considering the value recorded with the analog input If the value reached Lp during t then the sequence is stopped and the next sequence is applied 74 Techniques and Applications Manual
158. en the current is equal to 0 A the theoretical power Pr which is defined by the following relationship Pr Isc X Eoc the maximum power the fill factor FF which is the ratio of Puax and Pr the efficiency can also be calculated 3 3 2 CLD Constant Load Discharge The Constant Load Discharge application has been designed to discharge a device at a con stant resistance The potentiostat is seen as a constant resistor by the energy device The constant resistance control is made by controlling the current necessary to maintain the ratio E I constant Start discharge on R E l wWOhm MOhm for at most tm h mn S sets the cell resistance to R E I for tw duration Limit Ewe lt Em V AQ gt AQu A h fA h kC pC lt gt Axm sets the limit of the working electrode potential Ewe and the charge from the beginning of the sequence AQ Ax for the whole step The maximum charge can be entered into mA h AQm or aS a normalized charge related to intercalation electrodes Axm Once a limit is reached the experiment proceeds to the next step Rest even if the programmed time tw is not terminated These limits can be bypassed by entering 0 values into the controls Note when the AQwy Axm limit is reached the E test is skipped This is due to the fact that the AQw limit is considered as the maximal charge that can be applied to the energy device during the discharge Once reach
159. ence Ns 9999 at any sequence which then will be the last one executed even if the next sequence has its settings 3 1 17 GPI Galvano Profile Importation This technique consists in applying various current values on a battery during a defined time This technique corresponds to battery cycling under galvanostatic mode This technique can be used in charge and in discharge mode depending on the sign of the current This tech nique is specially designed to fit with the urban driving patterns designed to test EV batteries The particularity of this technique is the large number of sequences available and the fact that the experimental settings can be defined by importing a text file Note that experimental limits are not present in the setting it is highly recommended to use safety limits located in the Ad vanced Settings tab to avoid overcharge or overdischarge of the batteries The text file im portation columns are time s differential or absolute and current 160 Techniques and Applications Manual etltols 1929 ma sl 0 hg mp 01000 3 Record Ewe ever dE s 00 ul and atleast every dtg Di oo Range 1A Bandwidth E medumi eee eee GESCHT Gobackto seq Ns 10 AEGIS aa fea for ne 10 times d ne asf wage Ne d D 1 2 3 4 5 6 F 8 3 0D Fig 146 GPI detailed diagram e Pulsed galvano Charge Set tol pA A for ts h mn S define the current pulse value and duration
160. ents Electrode surface area 0 001 or e Characteristic mass 0 001 g e Mass of active material 0 D mg a 0 000 Molecular weight of active material at x 0 oo g mol Atomic weight of intercalated wm oo gral Acquisition started at xo ooo Number of e transtered per intercalated tone i for Anel theoretical capacity AU 76 802 m ih Daten capacity C 0 000 AA M Reference electrode unspecified M Offset potential vs Normal Hydrogen Electrode 0 000 4 Record Ecem F1 Ewe E ce gd E i WE PAM Cos Analog IN 17 Analog IN AN ee cE Record extemal devices on Analog INH Pe Files Fig 119 Cell characteristics window for battery applications This window has been designed for battery electrode materials acting as intercalation elec trode which is the case of several primary and secondary batteries It allows you to e Enter the physical characteristics corresponding to the active material of the working elec trode This makes on line monitoring of the redox processes possible in terms of normal ized units molar amounts of intercalation You can also enter the capacity of the cell and use this capacity as a parameter or a limit in your experiment e Select the recording of the counter electrode potential e Select the recording of external signals pH T P using auxiliary inputs 1 2 Additional info on this window can be found in the User s Manual 139 Techniques and Ap
161. eq Mgt 10 JORG ate Hee Me for Mg f time s E AVAE Gd ad Fig 108 GCPL3 detailed diagram 119 Techniques and Applications Manual Limits Ewe Ece gt lt Em V Ewe gt lt Ew V Ece gt lt Ere V Go to the next block if one of these conditions is reached The tests depend on the ls sign If ls gt 0 and Ewe Ece gt Em Or Ewe gt Eww or Ece lt Etc then go to the next block OCV if Is lt 0 and Ewe Ece lt Emor Ewe lt Eww or Ece gt Etc then go to the next block OCV Note the Ece test is reversed because the Ece potential has the opposite sign of Ewe Record Ewe Ece every dE mV and at least every dt records one point each time Ewe Ece variation gt dE and time dt These recording conditions can be set separately or together The first condition that is reached decides the recording A zero value cancels the recording condition e Potentiostatic period Set Ewe Ere to Es V for ts h mn S after the galvanostatic period it is possible to maintain Ewe Ere Ewe Ref1 Ref2 ata certain potential during a certain amount of time Limit I lt Im pA A or dI dt lt dl dt A s JuA mn limits the absolute value of the current during the potentiostatic period at a value lower than Im or when the variation of the current is lower than given value dl dt Record every dq A h fA h kC pC or dt S records one point
162. ero for AQm For the galvanostatic mode AQvy is not accessible and is calculated from I and ts AQm Is ts Record every dE mV dtp s and dQ fA h A h pC kKC defines the recording conditions A zero value cancels the corresponding recording criterion These values can be entered simultaneously If so the first condition that is reached determines the recording For the galvanostatic mode dQ is not accessible and is calculated from and dtp dQp ls dtp E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment IRange Bandwidth sets the current range and bandwidth values for the entire experiment 19 Techniques and Applications Manual O cv IO Mode C Galvanostatic 1 Go Galvanodynamic 2 Scant with dd dt 200 000 000000 mAs with 2000 per 0002 from dj 40 000 Je tolp 100 000 roc oe oe Limits Ey 0 500 V JAG gt AW 0 000 Record ever de f1 dtp 0 500 0 3 dap 0 000 m h w E Range 10 10 WS Rea Range Bandwidth Go back to sequence Ns 10 SSS ate Heya for mng 0 time s jovi aa o Acal Fig 70 Modular Galvano Galvanodynamic detailed diagram Go back to Ns for nc time s each one of the OCV potentiostatic and potentiodynamic per
163. es per potential level duration defines the number of points recorded per potential steps that will be recorded every At nr seconds Note that lt l gt average current between 2 recorded points is stored into the data files for this technique So if one sets n 1 there will be only one point per potential step with the average current of the step However it is recommended to record several points per step 211 Techniques and Applications Manual because the associated process described below is able to skip the first points where the current may be perturbed by the potential step establishment E Range enables the user to select the potential range and adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range and Bandwidth sets the Range and Bandwidth for the whole experiment Note that the bandwidth does not perform any action on the measures but acts on the instrument s control loop to establish the potential e Open Circuit Voltage The open circuit voltage is the standard block so report to the OCV technique chapter for more information e Reverse potential step s Apply a second set of potential step s with reverse sign on AE If checked then it will perform the potential steps again then with AE e Repeat Repeat n time s repeats the whole sequence ne time s Note that the number of repeat
164. et vs reference electrode po tential or according to the previous open circuit potential Eoc reference potential Eet or initial potential Ej Notice that only the last point of this period is recorded at the time 0 e Pulse waveform Scan Ewe from E to Ey V vs Ref Eoc Ei defines the vertex potential as Ey either vs reference electrode potential or vs Eoc or Ei with pulses height Pu mV pulses width Pw ms step height S4 mV step time S7 MS 55 Techniques and Applications Manual The pulse train is made of pulses of pulse height PH amplitude and pulse width Pw duration These steps are superimposed on a staircase of step height amplitude S and step time Sr duration As mentioned above only one point is recorded at the end of the potential pulse and one point before making two points during the Gr period The example above Fig 41 is given for a positive scan To perform a negative scan set E inferior to Ei and Sx to a negative value Set Ewe ta Ej 0 200 V w Eoc forty hin mm foooo0 ScanEwe from Ej to Ey 0500 vs Eoo e Wi with pulses height PH 25 m So e d pulses width Py 000 ms 2 y lt Sa a stepheight SH B0 m step time ST 500 0 me a t 7 r average over the last 20 4 of each step Add away Sone VOM denon Fig 45 DPV waveform E Ranges 2 24 Za gen Fae Range 10 ma vi Bandwidth 7
165. evious controlled potential E aal or previous measured value Emeas for ts duration Record lt l gt every dt S I every dls pA Aor dt S Two different recording conditions on a current are available with the potentiostatic mode ei ther recording an averaged current lt l gt on given time duration or recording an instantaneous current with a time variation and or an instantaneous current variation dl and or charge var iation dQ Range Bandwidth The current range depends on the Ip value and is automatically fixed The choice of the current range depends on the threshold pitting current value lp and is automatically fixed The band width is selected by the user The choice of the bandwidth is made by the user see the EC Lab Software User s Manual Upon detection of the pitting limit in current or if the time for the application of the potential has been reached the working electrode is disconnected In the case of a multi pitting exper iment the applied potential after the open circuit period will be the average potential of the working electrodes These electrodes will be disconnected one by one as and when they reach their pitting current e Rest potential or open circuit sequence See the first step for more details about the open circuit period e Potential sweep with threshold pitting detection sequence Scan Ewe with dE dt mV mn Sets the scan rate dE dt in mV mn The softwa
166. evious open circuit potential Eoc controlled potential Eei O measured potential Emeas Notice that only the last point of this period is recorded at the time O e Pulse waveform Scan Ewe from E to Ey V vs Ref Eoc Ei defines the vertex potential as Ey either vs reference electrode potential or vs Eoc or Ei with pulses height Pu mV pulses width Pw ms step time S7 MS The pulse train is made of pulses with pulse height Pu amplitude that is added to the pulse height of the previous pulse and pulse width Pw duration After each pulse the potential always 60 Techniques and Applications Manual returns to the initial potential The scan increment is defined by a pseudo staircase composed of steps with amplitude Py and duration Sr As mentioned above only one point is recorded at the end of the potential forward pulse and one point at the end of the potential reverse pulse making two points during the Gr period The settings above Fig 50 are given for a positive scan To perform a negative scan set Ev inferior to Ei and Sx to a negative value SetEweto Ej 0 500 loys Fei fartis D bY ma pooo Scan Ewe from Ej to Ey 0 500 vs Ref F with pulses height PH Aoo mv pulses width Pyy 250 mes step time ST 1000 ms average over the last i oo ofeach step Ate aware aca ais JE a oes Aenea D dp ET E Ranges 2u 2u M m Arn Aye Range 10 m Bandwidth 7 sl
167. example a scan from fi 100 KHz to fr 1 kHz with Na 5 points per decade in logarithm spacing will perform measures at the following frequencies in KHz 100 63 1 39 8 25 1 15 8 10 6 31 3 98 2 51 1 58 1 and a scan from fi 100 kHz to ft 1 kHz with N 11 total number of points in linear spacing will make measures at these following frequencies Hz 100 90 80 70 60 50 40 30 20 10 1 Clicking on the Show frequencies gt gt button to display the list of the scanned frequencies Note it is not possible to select Na points per decade in linear spacing sinus amplitude Va mV sets the sinus amplitude to Va Equivalence with Vous Is also given Note the following relationships between Va Mon and Vrms Va Vpp2 and Vrms Vpp 2 V2 Wait for pw period before each frequency measurement offers the possibility to add a delay before the measurement at each frequency This delay is defined as a part of the period Of course for low frequencies the delay may be long average N mesure s per frequency repeats Na measure s and average the values for each frequency o Drift correction corrects the drift of the system It needs to be used when the system has not reached its steady state regime This feature is more specifically dedicated to low frequencies at which the impedance measurement can be pretty lengthy and for which the effect of the drift can be seen Note 1 If this option is selected the si
168. f the frequency applied between Va min and Va max Wait for Pw period before each frequency offers the possibility to add a delay before the measurement at each frequency This delay is defined as a part of the period At low frequencies the delay may be long Average Na measure s per frequency repeats Na measure s and average values for each frequency Drift correction corrects the drift of the system It needs to be used when the sytem has not reached its styeady state regime This feature is more specifically dedicated to low frequencies at which the impedance measurement can be pretty lengthy and for which the effect of the drift can be seen Note 1 If this option is selected the sinus frequencies are evaluated over 2 periods instead of 1 increasing the acquisition time by a factor of 2 2 Inthe bottom right corner of the block the approximate experiment duration is indicated as information for the user During the run several parameters remain accessible for modification such as the min and max frequencies and the number of points per decade For more information about the drift correction please refer to the Application Note 17 E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth enables the user to select the current range and
169. fixed value for ts time The current value can be defined in absolute or versus a previous controlled current or measured current With Range and Bandwidth sets the current range and the bandwidth for this experiment Record every dE mV dtp s and dQ fA h A h pC kKC defines the recording conditions A zero value cancels the corresponding recording criterion These values can be entered simultaneously then this is the first condition that is reached that determines the recording For the galvanostatic mode dQ is not accessible and is calculated from Is and dtp dQp ls dtp 81 Techniques and Applications Manual Limit Ewe to EL V and AO to AQm fA h A h pC kC defines the potential and sequence charge limits The E limit is depending on the charge sign the limit ts Ewe gt E if ls gt 0 Ewe lt Ex else To cancel the limits type p for pass into the E edition box and zero for AQu For the galvanostatic mode AQy is not accessible and is calculated from ls and ts AQm Is ts And Analog In 1 Analog In2 lt gt Lg V for ty S sets limits of the sequence considering the value recorded with the analog input If the value reached Lp during t then the sequence is stopped and the next sequence is applied vu 8 OLY 0 Mode o Galvanostatic 1 Galvanodynamic 2 Setlto l 50000 pA sl w lt None gt for te 0 hin m poog Limits Ewe v
170. for at most ty h mn S Sets the rate C N or CxN at wich the battery will be charged I gt 0 or discharged LO The estimated capacity of battery must be entered in the cell characteristics see 3 1 10 2 Set C 3 mean that the battery will be charged discharged in 3 h Set CAN wthN fig andl 39 se 1 260 mA forty ho hijo mn ooo00 Limit Ewe gt Enq 4 2 V and Ewe lt EW 26 V Record even dE q i oo rei o dty 0 0000 S cl Hold E pqq once reached Limit Ils CAN e with My 20 130 m Record even dt E Range Range Bandwidth Result Capacity 0 000 m4 h use Capacity value for the rest of the experiment Fig 100 BCD detailed diagram Limit Ewe gt Emi V Ewe lt Em2 V sets the limits of the working electrode potential under charge and discharge regime see warn ing 1 in Description of a galvanostatic sequence Record Ewe every dE mV or dt S allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dE or and every dt time interval Hold Em for tm h MN S once Emi is reached it is held for a given time tm 108 Techniques and Applications Manual Limit I lt Im pA A offers the possibility to stop the potentiostatic period when the limit current Im is reached Record every dt
171. for the description of the second third and fourth part of this technique e In order to plot the apparent resistance variation versus logarithmic time the user must process the raw file after the experiment See the data processing section in the EC Lab Software User s Manual Selecting Keep only values with geometric progression of time allows the user to keep data recorded with geometric time spacing in a processed file Once selected it calculates the ohmic drop or apparent resistance Ri at different times recorded with geometric time spac ing Then the name of the compacted processed file is filename channel ch mpp in the case where Riis the only processed variable Process Data Input Files Z Mest 03 GCPL5_12 mpr Technique Galvanostatic Cycling with Potential Limitation 5 Processed File Z Stest_O3_GCPL5_12_ceqQsnA mpp Load Add Remove Clear Variables To select from the input file To be added W mode dQ maA h W ox red 0 Oal mA h W error E control changes cycle number W Ns changes Wf RE 0Ohm Mf counter inc times control mA Ewen m do m h Analog IN 1 4 F All All Process J Keep only values with geometric progression of time Allow Reprocessing Cycles definition auto M Export As Text Count half cycles Process Display Close Fig 111 GCPL 5 Process window 125 Techniques and Applications Manual Other processed val
172. ge steps zl E Range SEAN Zant Z n Auto v Bandwidth 7 we Range Go back to sequence Ng ANN ATE facta for mg P time s fate aaa oa dE Zo 100 py 5 0 ma IEN 500 py Fig 62 Modular Potentio potentiodynamic detailed diagram The three modes of the Modular Potentio technique can be linked as sequences in the table in any order the user requires Each of the parameters can be modified in its box But param eters like Range or Bandwidth must keep the same value for all the sequences Note that the first sequence has the number N 0 The table view can be accessed with the following path View gt Settings With Flowcharts Era WA D a 0 00 1 0000 0 0 O 00 0 0000 0 0 O 00 0 0000 0 0 0 5000 0 0000 0 0000 0 0000 0 0000 0 0000 Moner Moner Moner Norner shlanga DS Fig 63 Modular Potentio table O 00 0 0000 0 000 O 00 30 0000 0 000 O 00 0 0000 20 000 Note in this technique the first and last data points of each potential steps are not recorded automatically 72 Techniques and Applications Manual 2 4 2 SMP Special Modular Potentio As the Modular Potentio technique the SMP allows performing OCV potentiostatic and po tentiodynamic periods It is possible to chain these periods in any orders and to perform loops that give a lot of flexibility An additional limit condition on Analog In1 or Ana
173. hat for the VMP3 based instruments the compensation made in the linked techniques is software compensation The consequences are that there is not limit on the value of Ru and Auto Range can be used in the linked techniques for which the compensation is made A draw back is that it can only be used with relatively low potential scan rates 92 Techniques and Applications Manual For the SP300 based instrument the compensation could be made by software as well as by hardware For more information please refer to the Application Notes 27 28 29 2 6 1 MIR Manual IR compensation If the user already knows the value of Ru it can be entered in the box and the compensation percentage can be defined This value can be used for IR compensation in linked techniques For the SP300 based instruments hardware ohmic drop compensation can be performed Set Ru 7000 compensate at E Re 0 850 km o compensation mode Software Ve Sotware Fig 88 MIR diagram Note The hardware compensation is not available with the WE to Ground and CE to Ground connections 2 6 2 ZIR IR determination with EIS The ZIR technique offers the possibility to determine the solution resistance Ru for one high frequency value The user can select the percentage of compensation It is highly recom mended not to exceed 85 of the Ru measured value to avoid oscillations of the instrument To compensate the solution resistance the user has to put thi
174. he open circuit potential of the battery 136 Techniques and Applications Manual ScanEwe with dEs 5 000 rn perdt f2 hn mm pog amp ta Eg 4 200 V vg Ref w Curtail step duration if I lt If 10 000 mA ze Limit OUT Au 1 054 315 lt gt AXM 0 550 LU Record ever dQ 500 or do i 20 0000 E Range Range Bandwidth 2 Rest fortR E fo mn nooo Limit IdE werdt lt dEpfd o1 rv A Record even dep i 00 mi o dp 20 0000 3 BEE E EN aay en ie 4 3 Test Ewevs EL pas Vvs Ref cl goto 1 4 Gobacktoseg Ne RR anok tavivninae for pe E timels ETAY seg SA Fig 118 Detailed diagram of a PCGA sweep to E V vs Ref Eoc Ei sets the final potential vs reference electrode potential or versus the previous open circuit potential or previous the initial potential Curtail step duration if I lt l pA A sets a minimum value for the current As soon as the measured current value is lower than kr the next potential step is performed This is the galvanostatic acceleration Record AQ every dQ A h fA h kC pC and at least every d s S in the constant potential mode the system acts as a coulometer and a recording is performed every time the charge increment decrement since the previous recording is gt dQ a
175. he potential resolution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Reverse scan O Reverse scan with same scan rate towards final limit E2 V vs Ref Eoc Ei defines the reverse scan up to the final potential E2 This potential can be defined in absolute Or versus previous Eoc or Ei e Rest Executes a rest potential period similar to the initial one At the end the working electrode is disconnected 3 4 4 2 Process and fits related to GC Like the LP the GC application can be used for Rp and Icorr determination using the Rp Fit see the EC Lab Software User s Manual for more details It can also be used to determine the corrosion rate with the Tafel Fit see the EC Lab Software User s Manual for more details 3 4 5 CPP Cyclic Potentiodynamic Polarization The Cyclic Potentiodynamic Polarization is often used to evaluate pitting susceptibility It is the most common electrochemical test for localized corrosion resistance The potential is swept over a single cycle or slightly less than one cycle The size of the hysteresis is examined along with the difference between the values of the starting open circuit corrosion potential and the return passivation potential The existence of hysteresis is usually indicative of pitting while the size of the loop is often related to the amount of pitting This application
176. he potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth sets the current range and bandwidth values for the entire experiment Note It is highly recommended to avoid using the automatic current range with pulsed tech niques The resolution of each range is different and dynamic current range changes may lead to spikes on the plot DPA recorded and calculated variables The variables below are stored into the DPA raw files MPR state byte time s control V Ewe V lt l gt mA Q Qo mA h 67 Techniques and Applications Manual And the next variables are calculated from lt I gt or from the potential to save space on disk forward mA lt l gt values at the end of the pulses lp reverse mA lt l gt values before the pulses lbp delta UA difference between lt I gt values before and at the end of the pulse Ip lbp E step V step potential value resulting from the potential sweep and used to plot the current 2 4 Technique Builder Insert Techniques a lc Electrochemical Techniques i op oy Yoltamperometic Techniques ken Impedance Spectroscopy de Pulsed Techniques bruoue Builder Modular Potentia MP Special Modular Potentio SMP Modular Galvano MG Special Modular Galvano SMG ve L Trigger In TI J Temperature Control TC 2 d Rotating Disk E
177. he relevant maintenance documentation must do adjustments maintenance or repair EQUIPMENT MODIFICATION To avoid introducing safety hazards never install non standard parts in the equipment or make any unauthorized modification To maintain safety always return the equipment to Bio Logic SAS for service and repair GUARANTEE Guarantee and liability claims in the event of injury or material damage are excluded when they are the result of one of the following Improper use of the device Improper installation operation or maintenance of the device Operating the device when the safety and protective devices are defective and or inoperable Non observance of the instructions in the manual with regard to transport storage installation Unauthorized structural alterations to the device Unauthorized modifications to the system settings Inadequate monitoring of device components subject to wear Improperly executed and unauthorized repairs Unauthorized opening of the device or its components Catastrophic events due to the effect of foreign bodies IN CASE OF PROBLEM Information on your hardware and software configuration is necessary to analyze and finally solve the problem you encounter If you have any questions or if any problem occurs that is not mentioned in this document please contact your local retailer The highly qualified staff will be glad to help you Please keep information on the following at hand
178. ial and applied to the working electrode The Square wave is characterized by a pulse height PH and a pulse width Pw The pulse width can be expressed in terms of the square wave frequency f 1 2Pw The scan rate v is PH 2Pw The current is sampled twice during each square wave cycle once at the end of the forward pulse and once at the end of the reverse pulse The difference between the two measurements is plotted versus the base staircase potential The resulting peak shaped volt ammogram is symmetrical around the half wave potential and the peak current is proportional to the concentration Excellent sensitivity accrues from the fact that the net current is larger than either the forward or the reverse components since the net current is the difference be tween the forward and the reverse currents Description e Initial potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas forti h mn s sets Ewe to the initial potential Ei This potential value can be set vs reference electrode po tential or according to the previous open circuit potential Eoc or controlled potential Ect or measured potential Emeas Notice that only the last point of this period is recorded at the time 0 e Pulse waveform Scan Ewe from E to Ey V vs Ref Eoc Ei defines the vertex potential as Ey either vs reference electrode potential or vs Eoc or Ei with pulses height Pu mV pulses width Pw ms step height S mV 58
179. ications Manual d i Inn ne me oi I Ir m 4 4 Fig 32 PEISW detailed diagram e Wait period Until IZI gt lt Zim defines the duration of the wait as a function of a IZI value Ziim MO KQ O mQO pO sets the value of Z Or for tw h mn S or as a function of the time o record data offers the user the possibility to record the data before reaching the limit condition E Range enables the user to select the potential range for adjusting the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth sets the current range and bandwidth values for the whole experiment 2 2 6 Visualization of impedance data files 2 2 6 1 Standard visualization modes EC Lab software provides a full range of variables and visualization modes defined by default When an impedance data file is displayed click on Selector to show all the variables and visualization modes available with impedance data files 48 Variables Representation a 1 Ye egHe F O O Ewi 0 0O IA O O O Ref Ohm A d Im 2 Ohm F ihm O0 TI Phazel deg time s Ovo Oo Oo cycle number Range Re 0Ohm 1 0 C Im Ohm O Same selection for all files Frequencies _ Hide Additional Variables Fig 33 Impedance data file selector
180. idth 2 Rest for tp Limits KE werd lt dEpfdt IEwel lt Em LA Record every dep or dtp Techniques and Applications Manual 130 000 m s lt None gt ho hi mn Ooo 4 500 oo md 100 mv 60 0000 1 hin mrjooooo 0 000 m m0 ei v 120 0000 2 D an r 0 000 Analogln1 gt Koy sl Lg forty pass N ooo s 10W 10W AONAR F h hg mh i000 Bo mvh 00 m fotp Analog In 1 p sl LR forth Pp oss Y 10 0 mv 60 0000 3 Pe Oar AG Aa o Ca 3 Uwe EL pass V then go to 1 4 Go back to seq Net 0 RGIS aa feces for pe 0 time s r eat Hand Fig 115 Detailed diagram of one SGCPL sequence Techniques and Applications Manual e First step galvanostatic period that can be followed by a potentiostatic period Galvanostatic period Set to Is pA A vs lt None gt Ictri Imeas for at most ti h mn S sets the current value in absolute versus the previous controlled current previous sequence or versus the previous measured current and the maximum duration of the imposed current period The sign of the current value is for a discharge and for a charge when the positive electrode of the cell is connected to the Working electrode cable red Limit IdEy dtl lt dE dt mV h with Range and Bandwidth gives to the user the possibility to shorten the period when the decay of the potential is lower
181. in the opposite way as for the NPV technique Scan rate speed of the potential sweep defined with the smallest possible step amplitude Square Wave Voltammetry SWV technique used in analytical electrochemistry to discrim inate faradic from capacitive current This technique is made of successive positive and nega tive pulses according to the averaged potential sweep Stepwise Potential Fast Chronoamperometry SPFC Simple general electrochemistry technique used to loop quickly on two potential steps Triggers option that allows the instrument to set a trigger out TTL signal at experiment start stop or to wait for an external trigger in to start or stop the run Zero Resistance Ammeter ZRA technique used to perform measurements to examine the effects of coupling dissimilar metals or to perform electrochemical noise measurements A potential of O V is applied between the working and the counter electrode 232 Techniques and Applications Manual Zero Voltage Current ZVC technique similar to ZRA except that the control is done between the working and the reference electrode 233 Techniques and Applications Manual Index Alternating Current Voltammetry ACHT 32 ADDal Cnt MCSISIAN CCR ocala nec ced antares oatsuuroneeiedenteuunc niu iede neurone ntuuoneiientat ies 115 125 le B Fee goa DE 50 BOCE ral Wa cest ote apiece tit duet dd eta etete cease reds Ghiat eed theca seeteaeatcetes hatte dads thee 49 Cell Characteristi
182. increasing frequency Calibration operation that must be done for each channel in order to reduce the difference between a controlled value for example Ect and the corresponding measured value for ex ample Ewe Channels each one of the boards corresponding to an independent Potentiostat galvanostat ChronoAmperometry chronocoulometry CA controlled potential technique that consists in increasing step by step the potential of the working electrode from an open circuit potential to another potential E where electrochemical reactions occur The resulting curve is a current time response Chronocoulometry is an alternative mode for recording the charged passed as a function of time with current integration ChronoPotentiometry CP controlled current technique where the potential is the variable determined as a function of time during a current step Compact mathematical function allowing the user to compress data points from the raw data file Compact functions are available with GCPL and PCGA techniques All points of each po tential step are replaced by their average taken at the end of the potential step The number of points of the compacted data file decreases a lot according to the raw file Constant Load Discharge CLD technique especially designed for battery testing This tech nique is used to discharge a battery at a constant resistance The potentiostat is seen as a constant resistor by the battery Constant Power CPW
183. iods is represented by a single line in the grid parameters If nc is set to 0 the sequence lines are executed one after another Then an OCV potentiodynamic and OCV sequence for example will be programmed by 3 lines in the parameters table Setting Nn gt 0 will loop to a previous line Ns lt Ns for ne times 2 4 3 4 Sequences with the Modular galvano technique The three modes of the Modular Galvano technique can be chained as sequences in the table in any order that the user requires Each of the parameters can be modified in its box However parameters like Range or Bandwidth must keep the same value for all the sequences Note that the first sequence has the number Ns 0 To switch from one sequence to another click on the desired row in the table The table view can be accessed with the following path View gt Settings With Flowcharts Management of the various steps can be done thanks to sequence or table Fig 71 80 Techniques and Applications Manual O 00 7 0000 0 0 0 5000 0 000 Mone 0 00 0 001 0 00 0 0000 UU 0 0000 OU UU Mone 0 01 0 001 0 00 0 0000 UU 0 0000 0 000 Moner 0 00 0 001 Mone hlano WM i Fig 71 Modular Galvano table Note In this technique the first and last data points of each current steps are not automatically recorded 2 4 4 SMG Special Modular Galvano The Special Modular Galvano technique is very close to the Modular Galvano technique This technique allows the u
184. ion In the first case the settings can be loaded from the initial folder and in the second case they appear in the applications forlder in the techniques menu and can be reloaded when necessary Linked experiments can be created using the Technique Builder in the technique window All the techniques of this section have been previously described see section 2 4 page 68 The WAIT and LOOP options have been designed especially for linked experiments Building linked ex periments is very easy with the right click menu When the user right clicks on the parameter settings window the following menu appears iz New Ctrl N d Load Settings Ctrl L Import Settings From Text fe Load Data File Ctrl O VI Load Report KI Save Settings As Liz Save As Custom Application Import From Text Export as Text Ctrl T Accept Ctrl M JS Cancel Modify P Run Ctrl R Pause Next Technique Print Ctrl P Exit et Fig 199 Mouse right click with the insert and remove options The second frame is especially dedicated to linked experiments The Insert New Technique function opens the technique selection window and offers the ability to insert a new technique into the experiment The user can select where to add the new technique into the settings according to the activated selected technique arrow on the left of the technique name in the parameter settings window at the bottom left corner frame of the techniqu
185. ion diagram The detailed diagram is made of three blocks see Fig 31 e single or multi sine mode e initial current e waiting period before EIS frequency scan with recording conditions and current scan with number of current steps definition e Current scan with number of current steps Scan I from li D A vs lt None gt Ictri Imeas to D I A vs lt None gt li With N current steps sets the initial current to a fixed value lt none gt or relatively to the previous controlled current letn measured current luess sets the final current to a fixed value lt none gt or relatively to the previous current User defines the number of steps between li and Ir e Waiting period before EIS For each current step Wait fort h mn S O Record every dE mV and dt S before the EIS measurement the sample can rest for a duration ts The current can be recorded and no impedance measurement is done e Impedance scan Scan frequencies from fi MHz uHz to f MHz Jus defines the initial fi and final d frequencies of the scan To have results more rapidly it is better to scan from the highest frequencies to the slowest ones but it is possible to reverse the frequencies scan order with Ng points per decade N points from fito fi in Logarithm spacing Linear spacing defines the frequencies distribution between the scan bounds fi and f It i
186. ion of the lowest temperature on the test surface at which stable propagating pitting occurs under specified test conditions indicated by a rapid increase beyond a set limit of the measured anodic current density of the specimen Before running any CPT experiment one must first calibrate the temperature controls Select Thermostat Device Type Device Name in the list in the External Device windows as is shown in Fig 170 Either the standard supplied Ministat or an external thermostat can be selected If external thermostats are used the user needs to define the control calibration values temperatures range corresponding to specific thermostat in use Quite often as with the Ministat and Eu rotherm controllers the temperature range can also be changed in the thermostat itself Once this is done the T C box allows manual setting and activation of the temperature of the cell Note if the temperature is activated for a channel all the experiments will record the temper ature This will be then possible to run the OCV and see the effects of manual changes of the temperature This menu can be used in the same way to control rotating electrode speed instead of temper ature In this case select Device Type RDE Then the Temperature Rotating speed config uration window will allow the user to set manually the rotating speed The Wait technique can be used to control the rotating speed in an experiment Device
187. iques and Applications Manual gives the user the ability to shorten the open circuit period when the decay of the potential is lower than a given value Record Ewe every dEr mV or d r S allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dEr or and at least every dtr time interval Note the conditional test if tz 0 which bypasses the open circuit period e Third step test on the final open circuit potential If Ewe gt lt EL V The test is performed with the conditional value gt if the open circuit period just before the test occurs after a charge I gt 0 and with the conditional value lt after a discharge I lt 0 If the condition is not fulfilled the above 3 steps will be repeated until the working electrode potential reaches the final open circuit condition Ewe E after a charge or Ewe lt Ex after a discharge Note the user is allowed to bypass this test by entering p pass instead of a voltage value e Fourth step conditional test which proposes to go to the next sequence or to loop on a previous sequence Ns Ns lt Ns If Nc is set to 0 then the technique executes the next sequence If the user wants to loop to a previous sequence line the 2 last columns of the table needs to be filled Go back to Ns and n cycles The end of the technique is obtained by setting Ns and n
188. is technique can be loaded only when another technique has been previously loaded Goto technique Me i for n i timels Fig 81 Loop technique The techniques loaded before the Loop and after the technique Ne option are repeated n times Note that it is possible to apply a 50 ms OCV period between two techniques with linked tech niques reduced to 0 6 ms if the previous technique is an OCV The user just has to activate Turn to OCV between techniques in the Advanced Settings window Note Turn to OCV between techniques option forces the system to go to OCV but no OCV measurement is performed If after this forced OCV period a technique uses the OCV value as reference the value used will be the last value measured during the previous techniques 2 4 11 Pause Pause ing De da rt A0 eae ae Ga dea aah ene Ane Allen ae ay AC Een ee d eae Z G tzen Fig 82 Pause technique Once this technique is reached the experiment turns into Pause mode The user must click on the resume button to continue the experiment The instrument is in the OCV mode 2 4 12 EXTAPP External application ieren Wait until the application closes Fig 83 External application technique 89 Techniques and Applications Manual This technique is included in an experiment with linked techniques It allows one to execute an independent program from EC Lab software This can be used to start an external device con t
189. is set to a fixed value or relatively to the previous controlled current len that is the current of the previous sequence current step block or to the previous measured current Lues This option is not available on the first sequence Ns 0 To select the current step type check the option box fort h MN S sets the current step duration 169 Techniques and Applications Manual Limits Ewe gt lt Em mV and AQ lt AQw fA h A h pC KC curtails the step duration if the potential or charge limit is reached If the limit is reached the loop condition go to Ns for ne times if set is not used and the program continues to the next sequence Nz 1 The AQ value is the integral charge for the current sequence This value is not reset if there is a loop on the same sequence Ns Ns O values disable the tests Record Ewe or lt Ewe gt every dE mV and at least every dt S defines the recording conditions during the potential step 0 values disable the recording con dition and the corresponding box turns blue These values can be entered simultaneously and this is the first condition that is reached that determines the recording E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab software user s manual for more details on the potential resolution ad justment I Range Bandwidth enables the u
190. isables the recording for each condition For the averaged current the user defines the time for the calculation of the average In this case the data points are recorded in the channel board memory every 200 us for all instruments set dQ 0 for Chronoamperometry experiments and dl 0 for Chronocoulometry experiments E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Loop Go back to Ns for nc time s allows the experiment to go back to a previous sequence Ns lt Ns for ne times For example on N 3 if one enters go back to Ns 2 for n 1 time the sequence N 2 Ns 3 will be executed twice Nc 0 disables the loop and the execution continues to the next sequence Ns Ns 1 If there is no next sequence the execution stops 23 Techniques and Applications Manual In the current technique it is possible to loop to the first sequence Ns 0 and the current sequence Ns Ns This is different from battery experiments GCPL and PCGA Report to the battery techniques section 3 1 page 107 for more details on loop conditions Example Setting Ei En on the first sequence Ns 0 and
191. it is applied to extract the semi conductor parameters t Fig 27 SPEIS description diagram The potential of the working electrode follows the equation Ewe E V sin 2 x f t The detailed diagram is made of three blocks e single or multi sine mode e initial potential e waiting period before EIS frequency scan with recording conditions and potential sweep with definition of the number of potential steps 40 Mode scan Ewe from Er to Ef with A For each potential step Wait fork Record every dl or dt to Ff Na ocan frequencies from Fy or with ONT d sinus amplitude W walt For Pyy average Ha Logarithmic spacing Linear spacing Techniques and Applications Manual Co Single Sine Multiple Sine mn Vows Ref w 10000 Vows Re e 20 potential steps E h o mp f000 Dn mi v 0 100 S mmm us v 000 ks ei 6 points Der decade A4 points fron Fy to FF 25 0 m Mors 17 68 my 0 1 T pernod before each frequency 1 measurefs per frequency drift correction E Range Range Bandwidth Ovo Za een GG au zl 715 scan dE 0 050 4 Fig 28 SPEIS detailed diagram e Potential scan with number of potential steps Scan Ewe from E V vs Ref Eoc Ectrl Emeas to E V vs previous
192. ition reached that determines the recording A zero value disables the recording for each criterion For the averaged current the user defines the time for the average calculation In that case the data points are recorded in the channel board memory every 200 us for VMP3 based instruments and for VMP300 based instruments Leave dl alone for Chronoamperometry experiments and dQ for Chronocoulometry experi ments 167 Techniques and Applications Manual RestiootR o hi mn foo Limit IdEwedtl lt dER dt Dn mi Record ever dER on mV o dR O00000 Apply Ej 2 000 V w Ret vi fortj fO ho mn pooo Limits Imax pass m Imin pass EN vi AO AQw 0 000 muh gt mh sl Record p every dl 9000 uA dQ 0 000 mah si dt A0000 E Range DV BM m enhance A ei Range Auto d Bandwidth 5 medium medium Go back to sequence Ne 10 RGIS erer Heche forme p imela AAVA weer Fig 151 Constant Voltage detailed diagram E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab software user s manual for more details on the potential resolution ad justment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Loop Go back to Ns for nc time s allows the experiment to loop to a previous line Ns
193. l lt dERg dt jg vi Record exen dERoa O NM o dtRo 10000 3 2 Scan Ewewith dE dt 0167 mis from E 0025 Wo vs Eoc to EL bo NM vs Eoc Record ER over the last 25 of the step duration average E voltage steps Ap fit parameters dE 25 0 DM Ba 120 0 Dm Be 11200 pm ERange 2 2 i Gren Fe ye Range Auto Bandwidth F medium e 3 HestfortR k4 hig mn fdn Limit IdEwe dtl lt dER dt 90 meh Record evem dER 9 mi o dp 60 0000 3 dE dt 100 py 598 8 ms JEM 500 ul Fig 163 Detailed diagram of the Corrosimetry application e Rest potential or open circuit sequence Equivalent to the EVT technique described above e Potential scan Scan Ewe with dE dt mV s defines the potential scan The software selects the smallest potential step according to the control potential resolution defined at the top of the Parameter settings window see the cor responding section in the EC Lab Software User s Manual for more details 184 Techniques and Applications Manual From Ei V vs Ref Eoc Ectrl Emeas to E V vs Ref Eoc Ei from a potential Ei defined vs Ref the reference electrode potential or versus a previous open circuit potential Eoc or previous controlled potential Ecin or previous measured potential Emeas to Ep value defined in absolute or versus Eoc or Ei Record lt l gt over the last of the step duration
194. l E Ewe Disk two vertex potentials E1 and EZ E4 a final potential Ef SC 2 scan rate definition E recording conditions repeat option instrument parameters configuration RCA block e potential step e recording conditions e instrument parameters configuration Fig 94 CV_RCA description 98 Techniques and Applications Manual Turn to OCY between techniques dl Disk Channel 1 CY SetEwe to Ej 0 000 V wa Eoc s acan Ewe with dE dt 20 000 DM ss to vertex potential Eq i O00 V w Dei wt Reverse scan to vertex E gt L O00 Wows Pef w Repeat np 0 tire Measure l gt over the last 50 of the step duration Record l gt averaged over N 10 voltage steps E Range 25V 25V w J ene Aah Range Auto Endscanto Eg 0 000 V w Eoc w dE dt 100 pv Zb me dEN 1 0 ml 4000 ponts per cycle Ring Channel 6 ACA Ann Ei oo vs Pe E Range 254 25 wal m recta AE Goad Range Auto wi Bandwidth 7 v Fig 95 CV_RCA detailed setup e CV block e Starting potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas sets the starting potential vs reference electrode potential or vs the open circuit potential Eoc or the previous controlled potential Ecti or measured potential Emeas e First potential sweep with measurement and data rec
195. l or current is applied to the working electrode The cell is disconnected and only the potential measurement is available Pause button of the EC Lab main window that pauses the progress of the technique and the measurement recording During Pause the cell is disconnected OCV period The Pause button turns to Resume when clicked Polarization Resistance PR technique similar to CV that is adapted to corrosion This tech nique allows the determination of polarization resistance Rp and corrosion current Icorr Potentiodynamic Cycling with Galvanostatic Acceleration PCGA Battery technique de signed for battery cycling under stepwise potentiodynamic mode The user can reduce the potential step duration if the charge or discharge is lower than a given value Potentiostatic Electrochemical Impedance Spectroscopy PEIS technique that performs impedance measurements in potentiostatic mode by applying a sinus around a potential E that can be set to fixed value or relatively to the cell equilibrium potential Technique linker tool of EC Lab software used to link techniques in order to build a com plete experiment with or without open circuit period between techniques Reverse Normal Pulse Voltammetry RNPV technique used in analytical electrochemistry to discriminate faradic from capacitive current This technique is made of increasing pulses with time that always come back to the beginning potential The current is sampled
196. l steps The diagram is made of five blocks e Initial Open Circuit e Applied E period e Applied E2 period e Open Circuit e Repeat They are detailed below End Fig 194 SPFC general diagram 214 Techniques and Applications Manual 5 Go to 2 ne o tirne Fig 195 SPFC detailed diagram e Initial Open Circuit This is the standard OCV block without the dEp dt test Therefore report to the OCV section for more details e Applied E period Apply E V fort S sets the potential to E4 for t duration Record lt l gt every dt S records points every dt time E Range enables the user to select the potential range for adjusting the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range and Bandwidth sets the Range and Bandwidth for the entire experiment 215 Techniques and Applications Manual e Applied E2 period Apply E2 V for t2 S applies a second potential step E2 in the same way than the first step with different parameters Record lt l gt every dt S records points every dtz time e Open Circuit refer to the OCV technique for more details e Repeat Go to ne time s repeats the E E2 and OCV blocks ns times A value of n 0 cancels the loop 3 5 3 How to add a homemade experiment to the custom applications EC Lab
197. l value Ei defined vs Ref the reference electrode potential vs Eoc the open circuit potential vs Ectrl the previous controlled potential or vs Emeas the previous measured potential to a final value Ef defined vs Ref the reference elec trode potential vs Eoc the open circuit potential or vs EL at a scan rate defined above 3 1 11 2 7 Cl Current Interrupt Control Type CI s Current Interrupt Limits Ich Number din b Fig 130 Current Interrupt control See 2 6 3 for more information about the application of this technique 3 1 11 2 8 Other types e Rest see 2 1 1 e Loop see 2 4 10 e PEIS it is a simplified version of the PEIS technique described in 0 146 Techniques and Applications Manual Type Peis v Fotentio Electrochemical Impedance Spectroscopy o The DC level remains the same as the last measured value in the previous sequence Ampl 0000 mv v From 0000 kHz we To mme fh Nq E Doirttzl per decade in logarithmic spacing Ns 1 average measurels per Frequency drift correction Fig 131 PEIS control e GEIS it is a simplified version of the GEIS technique described in 2 2 2 Type y Galvano Electrochemical Impedance Spectroscopy CS The DC level remains the same as the last measured value in the previous sequence Amp io0 000 m wl From 10000 kHz k To Wm fh e Has E point s per
198. ld E gt fo t 10 hijo ma nmn Record ever dto Di ono 3 Measure l gt over the last 50 Of the step duration Record JS averaged over H H T voltage steps Repeat ng fr tire Record the first and ever my i cycle s ERange 2 5 25 Ed Lol ean Ad din Range Auto k Bandwidth F medium v End scanta Er 0 000 V ws Eoc we Hold Er fote 0 bh 0 mp 00000 r Record every dti D1000 s dE dt 100 u 1 0 ms dEM 1 0 ry 4000 points per cycle Fig 10 Cyclic Voltammetry Advanced detailed diagram Hold E fort h mn s and Record every dt S offers the ability to hold the first vertex potential for a given time and to record data points during this holding period e Reverse scan Reverse scan to vertex potential E2 V vs Ref Eoc Ei runs the reverse sweep towards a 2 limit potential The vertex potential value can be set vs reference electrode potential or according to the previous open circuit potential Eoc or accord ing to the potential of the previous experiment E Hold E for tz h mn s and Record every dt s offers the ability to hold the second vertex potential for a given time and to record data points during this holding period 18 Techniques and Applications Manual e Data recording conditions Measure lt l gt over the last of the step duration selects the end part of
199. le Scan rate mV s number of points These values are given as an indication and are calculated in the PC The scan rate is directly given by Go 0 00157 and the number of points is roughly 2 Ey Ei Sy for the forward scan E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth sets the current range and bandwidth values for the whole experiment e Reverse scan definition O Reverse scan towards E V vs Ref Eoc Ei Checks the Reverse scan box to perform a scan towards Er vs Ref or versus Eoc or Ei 59 Techniques and Applications Manual Note It is highly recommended to avoid using the automatic current range with pulsed tech niques The resolution of each range is different and dynamic current range changes may lead to spikes on the plot SWV recorded and calculated variables The variables below are stored into the SWV raw files mpr State byte time s control V Eye V lt l gt mA Q Qo mA h And the next variables are calculated from lt I gt or the potential to save space on disk forward mA lt l gt values at the end of the pulses Ip reverse mA lt l gt values before the pulses lbp delta UA difference between lt I gt values before and at the end of the pulse
200. le Amplitude Sinusoidal microPolarization c ccccceeeeeee 207 3 4 13 CASP Constant Amplitude Sinusoidal mcrobolazaton 208 3 5 E Een eelere 210 E nbc Olan ZallOM IME SISLAN CO EE 210 3 5 2 SPFC Stepwise Potential Fast Chronoamperometry cccecceeeeeeeeeeeeees 214 3 5 3 How to add a homemade experiment to the custom application 216 3 6 leier E ele ee 217 Techniques and Applications Manual A EI RE En CC 219 4 1 Re delen due EE 219 4 2 Example of linked experiment cccceccceecceeeceeeeceuceceeeceuseseeeeseeesueeseeesseeens 220 4 3 PAD DIG el BEE 222 5 Summary of the available techniques in EC Lab sssssseeeeeeeeeeeeeeeeeeeeees 224 6 List of abbreviations used in EC Lab Softwar e sssssssssssssssssssssssssseeeees 227 Fi GOS SAN E E E ssa etuatiatvcctausce E E E 229 DEET e TC E 234 Techniques and Applications Manual Introduction EC Lab software has been designed and built to control all our potentiostats single or multi channels SP 50 SP 150 SP 200 SP 240 and SP 300 MPG2xx series VMP2 Z VMP3 VSP VSP 300 VMP300 HCP 803 HCP 1005 CLB 500 and CLB 2000 Each channel board of our multichannel instruments is an independent potentiostat galvanostat that can be con trolled by EC Lab software Each channel can be set run paused or stopped independently of each other using identical or different techniques Any settings of any channel c
201. least every dtr s allows the user to record the working electrode potential wnenever the change in the potential is gt dEr or every dtr time interval Data recording with dEr resolution reduces the number of experimental points without loosing any interesting changes in potential When there is no potential change only points according to the dtr value are recorded but if there is a sharp peak in potential the rate of the potential recording is governed by the potential recording resolution RestfortR 0 hit mn mon Limit dE edd lt dEgfdt on m h Record even dp on mW o dtg 05000 Scan Ewe with dE dt i O ggg rrr from Ej 0 000 V YG Eoc to Ep om V ys Fei vi Limit IN Ip 50 000 pA alter th th 0 500 0 e from scan beginning Record vi every dl 6 000 wa vi ois 1 0000 E Ranges 2u 2u a rena JE ad I Range 100 p Bandwidth dE dt 100 uv 600 0 ms Fig 175 Detailed diagram of the Potentiodynamic Pitting technique e Second step potential sweep with threshold pitting detection sequence Scan Ewe with dE dt mV mn sets the scan rate dE dt in mV mn The software adjusts the potential step amplitude and its duration From Ei V vs Ref Eoc Ectrl Emeas to E V vs Ref Eoc Ei from a potential Ei defined vs Ref the reference electrode potential or versus a previous open circuit potential Eoc previous controlled potential Ecti
202. lectrode Control ADEC External Device Control EDC External Application EXTAPP fi Send E Mail EMAIL gt Manual Control gt fe Ohmic Drop Determination gt Bipotentiostat Ale Electrochemical Applications b 4S Batteries Testing Insert Technique Load from default Custom Applications Before WV Advanced setting V External devices bn _ __ After V Cell characteristics Rename Add Remove Stack Cancel Fig 58 Technique builder selection window This section is dedicated to experiment building With the techniques and tools described in this section the user has the ability to easily create their own applications with linked techniques and eventually to save the created experiment in the custom applications The Modular Gal vano and Modular Potentio techniques have been designed to cover all the electrochemical fields and experiments thanks to a modular approach Linked with Triggers Wait periods external device control methods Loops External application and Email application these techniques become powerful enough to build complex settings 68 Techniques and Applications Manual 2 4 1 MP Modular Potentio The Modular Potentio technique performs OCV potentiostatic and potentiodynamic periods It is possible to chain these periods in any order and performs loops that provide great flexibility This technique is very useful because it allows coupling potential sweep detections with pre con
203. line in the parameter value table associated with the technique accessible using the following path View gt Settings With Flowcharts The user can set the variable values directly in the table or can set them in the diagram After a first specific sequence or sweep Ns 0 which enables the user to perform an open circuit period while recording only the potential no controlled value can be set in this first se quence sweep the technique executes the successive Ns sequences sweeps of the table lines It is possible to run partial cycling before changing cycling conditions To do so the user must loop a previous sequence sweep Ns Ns lt Ns and repeat the loop ne times note that the number of such cycles will be ne 1 Moving on to the next sequence sweep or line is ob tained by setting ne to O An usual technique consists in a first sequence sweep Ns 0 of open circuit potential then a second sequence sweep Ns 1 of charge then a third sequence sweep Ns 2 of dis charge and finally a loop on the second sequence sweep Ns 1 for a given time To move on directly from a controlled current potential period mode to the next sequence without an open circuit period the user must set the open circuit period to O t 0 The end of the technique is obtained when Ns and ns take 0 values in the last sequence sweep It is also possible to force the end of the technique by setting Ns to 9999 at any se quence sweep 3
204. log In2 is added which makes it special fol 1 2 o OLY IO Mode Hotenbostoaic 1 Potentiodvramic 2 Rest fotp 0 h H mp 00000 2 Limits E edd dEnp dt 00 mu A IEwel lt Ep pass my for tp th 0 0000 or until Analog In 1 vi E LA forth Lp pass Y Record ever dep If DM or dtp 0 500 0 S Go back to sequence Net 10 NNN eege Aaa for pe 0 time s Avie asf seer Fig 64 Special Modular Potentio Potentiostatic detailed diagram Mode selection selects the experiment Mode OCV 0 Potentiostatic 1 or Potentiodynamic 2 to select the corresponding mode e Open Circuit Voltage Mode 0 See SOCV Loop Go back to N for ne time s each one of the OCV potentiostatic and potentiodynamic periods is represented by a single sequence If n is set to 0 the sequence lines are executed one after one Then an OCV potentiodynamic and OCV sequence for example will be programmed by 3 lines into the pa rameters table Setting nc gt 0 will loop to a previous line Ns lt Ns for ne times Report to the battery techniques section 3 1 page 107 for more details on loops conditions It is possible to loop to Ns 0 but Ns must be lt Ns current sequence line number 73 Techniques and Applications Manual Oc 0 Mode o Potentiostatic 1 Potentiodynamic 2 SetEwetoEs Dm Yvs pet forts D hn mp f30 0000 Limits Imax pass m u a AOI gt AM 0 000 mah sl fan
205. lowing window is displayed to select frequencies to plot 52 Frequencies 215 437 kHz 146 781 kHz 100 000 kHz 68 125 kHz 46 406 kHz 31 622 kHz 21 547 kHz 14 677 kHz 3 996 kHz 6 616 kHz 4 642 kHz 3 160 kHz 2 153 kHz 1 467 kHz 1 002 kHz 681 090 Hz 464 309 Hz 315 505 Hz 215 344 Hz 146 358 Hz 100 296 Hz All frequencies Techniques and Applications Manual 68 163 Hz 46 503 Hz 31 672 Hz 21 552 Hz 14 655 Hz 10 016 Hz 6 829 Hz 4 650 Hz 3 168 Hz 2 146 Hz 1 465 Hz 1 000 Hz Cancel Fig 41 Z vs time display used to select frequencies Choose the desired frequencies and click Ok The graphic representation will automatically display one trace for each chosen frequency In the graphic display Z f t is displayed for the four different frequencies selected before Z Ohm 146 358 Hz 315 505 Hz emm RAR e eg gg A op e 681 090 Hz 6 816 kHz ey 50 Fig 42 Graphic display for four different frequencies times 100 150 53 Techniques and Applications Manual 2 2 7 Multisine option The main advantage of using a multisine excitation signal is that it is faster than single frequen cies excitation Significant amounts of time can be saved especially if the measurement re quires low frequencies and measurement drifts can be avoided if the system changes quickly with time With single frequencies excitation the system is excited by one frequency at a time resulting i
206. ment Refer to the GCPL application section for more information on the other blocks The process option is the same as for the GCPL application 122 Techniques and Applications Manual 3 1 6 GCPL5 Galvanostatic Cycling with Potential Limitation 5 A parameter commonly used by industrial battery manufacturers is the Apparent Re sistance of the cell This parameter written Ri i stands for internal is considered by manufacturers to be an internal characteristic of their cell The Ri value is determined by the ratio Em Eo Im lo with Em and Im the data points on the current steps corresponding to a time tm At2 and m 1 2 3 Eo and lo are the values corresponding to the last point of the OCV period Such a geometric progression of time ensures a good distribution of points versus time Ri determination is now available in EC Lab software using a GCPL application Refer to the process data section in EC Lab Software User s Manual to the GCPL application sec tion 3 1 2 page 109 or to the Application Note 38 for more details 1 Set wl tols for at most t4 Lint Ewe gt Ep Record upto tmay 100000 mA v vs lt None gt ze 10 ho m OOO s 4 200 20000 amp with geometric progression of time and then even dE 4 or dii Hold EM for tpg Limit Ie Im or dl dt lt dl dt Record ever dq or do Limit G gt ADM gt AX hw E Range Range Bandwidth
207. mined and plotted versus sinus amplitude A parametric identification is done on the curve to determine the corrosion current and corrosion coefficients This technique is only available on channel board with EIS ability This technique is essentially an intermediate that may be less destructive to a sample than Tafel polarization but probes a more expanded voltage window than the Polarization Re sistance technique As a result it is a balance of accuracy and sample damage that lies be tween the two techniques Ewe Va max Va mp Time T Fig 185 Variable Amplitude Sinusoidal microPolarization technique Apply a sinusoidal potential modulation af foi He e from Yamin 100 m Yme 7 07 ml to Ya max 1000 m Vrms 70 71 m with N 10 sinus amplitudes wait for De 0 00 period before each frequency average WN 1 measures per frequency drift correction Show Amplitudes gt gt ERange 24 24 ial rena TE Range Auto Bandwidth 5 step 10 0 mid duration Tmn40s Fig 186 Detailed diagram of the Variable Amplitude Sinusoidal microPolarization technique 207 Techniques and Applications Manual Apply a sinusoidal potential modulation at f MHz kHz Hz mHz uHz sets the frequency of the modulation applied to the cell From Va min mV to Va max mV sets the range of the sinus The equivalent value in mVawms Is indicated With N sinus amplitude sets the number o
208. mined by the ratio between the measured voltage and the measured current The Cl technique enables the user to determine the resistance when the current step is applied Rising Edge E2 E1 l2 l1 and or interrupted Falling Edge E4 Es l4 Is Then an averaged cor recting Ru value is calculated Averaged values can be determined on several cycles The user can select the percentage of compensation It is highly recommended not to exceed 85 of the Ru measured value in order to avoid oscillations of the instrument E3 E we E gt E E 4 la Is la U t Fig 90 Current Interrupt principle 95 Techniques and Applications Manual Set l pooo for k 0 050 0 3 Record ever dE i D m dt 0002 E Range 40W 10Y sell Range Bandwidth Tum to OC for tR 0 050 T with the same recordings Repeat and UCY blocs np 10 timels compensation mode Calculate Ru at ERT Results Hu He Fig 91 Current Interrupt detailed diagram Set l pA Afort s sets the current to a fixed value Record every dE mV and dt s chooses one or several optional recording conditions E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment Range Bandwidth sets the current range and bandwidth values for
209. mit allows the user to stand at the potential Ew until the end of the sequence or until the current reaches a low limit value Im The limit In could be disabled by entering pass type p in the control Limits I lt Im pA A dI dt lt dl dt A s uA mn II gt Is when holding Ew return to Is on limit if the current I is over ls in constant potential mode the system returns to constant current mode in order to protect the cell Record every dq A h fA h kC pC dl pA A and dt defines the recording conditions during the potential period These values can be entered sim ultaneously The first condition that is reached determines the recording A zero value disables the recording for each criterion Limit the whole time to ts h mn S defines the total sequence duration if not stopped on limits and AQ to AQm A h fA h KC pC lt gt AX fixes the maximum charge change from the beginning of this sequence during the sequence This charge is equivalent to a Axum quantity which corresponds to a normalized charge related to intercalation electrodes E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution ad justment I Range Bandwidth sets the current range and bandwidth for this experi
210. mits Ewe Ece gt lt Em V Ewe gt lt Etw V Ece gt lt Erc V Go to the next block if one of these conditions is reached The tests depend on the ls sign if ls gt 0 and Ewe Ece gt Emor Ewe gt Ew Or Ece lt Etc then go to the next block OCV If ls lt 0 and Ewe Ece lt Emor Ewe lt Ew or Ece gt Erc then go to the next block OCV Note the Ece test is reversed because the Ece potential has the opposite sign of Ewe 117 Techniques and Applications Manual Limit AQ to AQy Ah A A KC pC lt gt AXm sets the maximum charge change from the beginning of this sequence This charge is equiv alent to a AXm quantity which corresponds to a normalized charge related to intercalation electrodes Record Ewe Ece every dE mV and at least every dt records one point each time Ewe Ece variation gt dE and time dt These recording conditions can be set separately or together The first condition that is reached decides the recording A zero value cancels the recording condition Range and Bandwidth sets the current range and bandwidth for this experiment e Open Circuit Voltage The open circuit voltage is the standard block so report to the OCV or GCPL techniques sec tions for more information e Potential test If Ewe Ece gt lt EL V The third step is the test on the open circuit final potential This test is skipped if there is no OCH period tr
211. more details 173 Techniques and Applications Manual From E V vs Ref Eoc Ectrl Emeas to E V vs Ref Eoc Ei from a potential E defined vs Ref the reference electrode potential or vs a previous open circuit potential Eoc previous controlled potential al or previous measured potential Emeas to Ep value or versus Eoc or Ei Record lt I gt over the last of the step duration averaged N voltage steps I every dlp pA nA LA mA A or dtp S Two different recording conditions on the current are available with the potentiodynamic mode either recording an averaged current lt I gt on each potential step or recording an instantaneous current with a time variation and or an instantaneous current variation dl and or charge var iation dQ E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution ad justment I Range and Bandwidth sets the current range and bandwidth for this experiment Range is automatically set accord ing to h and le values 3 3 1 2 Process Associated with the l V characterization an analysis is available for this section offering the determination of the following parameters Short Circuit Current Usel which corresponds to the maximum current when E 0 V the Open Circuit Voltage Eoc which is the potential wh
212. mul taneously to the change of minimum and Default Cancel maximum potentials resolution 50 pi Range enables the user to select the current range For controlled voltage techniques three kinds of current range are availables on EC Lab software Auto Auto Limited and fixed current ranges Range Bandwidth 100 m 7 End canto Ef i 100 p 10 p The automatic current range is selected when the user has no idea about the amplitude of the measured current A fixed current range is selected when the amplitude of the measured cur rent is known Auto limited current range is selected when the measured current varies in wide values ganges between numerous current ranges In this last case the user has to set the maximum current range and the minimum current range and also the Inintial current range in the Edit range Limits window 11 Techniques and Applications Manual Edit I Range Limits Set the limits of the current range I range max 10 mA L I range min 100 pA wll Start I range determination with I range init 100 uA 1A 100 mA 610 ma L mo 100 pA E i pA In galvano mode only the fixed current range are availables in EC Lab software Bandwidth enables the user to select the bandwidth damping factor of the potentiostat regulation e Final potential End scan to E V vs Ref Eoc Ei gives the possibility to end the potential sweep o
213. n a very long experiment The total time taken for the complete analysis is the sum of the individual measurement times In multisine measurement the system is excited by all the frequencies at the same time using a Schroeder multisine The multisine signal is defined as the sum of sinusoids at different frequencies having the same programmable amplitudes A resulting in a time signal and different phases with the following equation 1 N k 1 k n u t A gt cos 2Trf t where the phase 27 ce 1 H k k k 1 H N The EIS multisine measurement developed in EC Lab software is defined in order to minimize the crest factor defined by Cr u a m where Un aj 2 eff The crest factor values are between 2 and 3 u t Um Um Fig 43 Scheme of multisine signal To avoid a large excitation at the sine origin that could damage the electrochemical cell all the sine waves are out of phase Indeed in multisine measurement a multiplicative factor can be applied on the signal amplitude which can reach Um or Um values Generally it is better not to exceed 50 mV of sinus amplitude lf the excitation amplitude which is the sum of the maximum amplitude of all the applied frequencies is too large the system response can begin to be non linear This is why the sine amplitude values need to be minimized However since a lot of frequencies are stimulated at the same time there is less
214. n beginning orl change delta i T z With tdelta 10000 integration duration Record every di os 05000 E Range 2 2 Za ten Fada Range 100 pA v Bandwidth 5 medium v Go back to sequence Net 10 RGIS ATE OARA forme O time js AAV vase neuf Fig 179 Detailed diagram of the Potentiostatic Pitting application e First step standard open circuit sequence Previously described with conditional duration and choice of recording resolution 202 Techniques and Applications Manual e Second step potentiostatic period with pitting limit for the current Apply Ei V vs Ref Eoc Ectrl Emeas for ti h mN S sets the potential vs Ref the reference electrode potential or with respect to the final rest po tential value Eoc or previous controlled potential Ect or previous measured value Emeas for ti duration Limit I gt Ip pA A after t S or change lt delta with taena S integration duration Two different limits are available Limit I gt lp sets the threshold pitting current Ip to detect Setting of a blanking time tp eliminates a possible large peak of current when just applying the initial potential step in case of large AU value change lt delta stop the measurement if the current variation is lower than a percent of it delta The variation of the current is evalu
215. nd E wel A E max 4200 VM AQ Es dl AQM DD mah v Record every dE i 0 0 DM o dt 00100 one l4 l2 alternation over na 130 one sequence over De E Range 10 104 ell e HEEN Hange 100 m w Bandwidth 7 w Rest fortR N h ma o oo00 Limit Me dtl lt dEqg dt 00 ri A Record ever dE p i OU DM odtR 50000 3 d d r Aide Gea oer ae A 3 IF Ewel EL pass V goto 1 4 Goback to sequence Ne 0 PORTS oer dar eas forme 0 time s fetta rasan wear Fig 142 APGC detailed diagram with resolution dE mV and at least every dt s On l2 alternation multiple of na and sequence multiple of ns record one point each time the potential variation from previously recorded value is superior to dE and time gt dt These recording conditions can be set separately or together The first condition reached determines the recording A zero value cancels the recording condition Range Bandwidth sets the current range and the bandwidth for this experiment 157 Techniques and Applications Manual e Rest Potential Sequence The open circuit voltage is the standard block so refer to the OCV or GCPL techniques chap ters for more information e Test Ewe gt EL Tests that the battery is charged or discharged For a proper run of this test one must ensure that g
216. nd or every di time interval 137 Techniques and Applications Manual Limit AQ to AQnu A h fA A kKC pC lt gt Axm sets the maximum charge change from the beginning of this sequence during the sequence This charge is equivalent to a Axum quantity which corresponds to a normalized charge related to intercalation electrodes E Range enables the user to select the potential range for adjusting the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment Range and Bandwidth sets the current range and bandwidth for this experiment e Second step open circuit period as in the GCPL technique turn to Rest for tr h MN S or until dEwe dt lt dER dt mV h Record Ewe every dEr mV and at least every dtr reports to the OCV technique description for more details section 2 1 1 page 6 e Third step test on the open circuit final potential as in the GCPL technique too test Ewe vs EL V vs Ref Eoc Ei the test is performed according to the conditional value either gt if the open circuit sequence occurs after a charge I gt 0 or lt in the case of a discharge I lt 0 As seen previously the above 3 steps will be repeated until the working electrode potential reaches the limiting condition Ewe E after a charge or Ewe lt E after a discharge Note the user is allowed
217. next figure in Run Tec The num ber of loops executed is displayed in Tec Loop As for a single experiment run it is possible to Pause Resume and Stop the acquisition The Stop button will terminate the whole experiments acquisition Nevertheless one can stop the current experiment and continue to the next one with the Next Exp button S in the tool bar Channel 1 values Status Stopped Time 0 0000 4 Ewe 0 550 mi 0 000 A Buffer 0 Eoc 0 550 rmi U Uo 0 00 Ah Range oper Fig 202 Linked experiment current values In our example the output files will be Eesen F e iia ege ee SESCH el BET La U 0 2 UA 0 6 0 8 1 Ewe Fig 203 Linked experiment results 222 Techniques and Applications Manual Notes e The ZRA technique and the manual controls cannot be linked e The Polarization Resistance process calculation can be performed on the technique linker loops separately Linked experiments settings can be saved with Experiment Save As or on the right click menu with Save experiment and reloaded with Experiment Load settings or with the right click Load settings Linked experiments files are text files with the mps extension like the standard settings files 223 Techniques and Applications Manual 5 Summary of the available techniques inEC Lab sis INSTRUMENTS VMP2 Voltamperometric techniques OCV SOCV VMP3 VSP SP 150 HCP 803 HCP 1005 CLB 500 SP
218. nge 0y BM scil Greaney Ad ed Range 1A a Bandwidth 5 medium v 2 RestfortR D his mn pon Limit He dtl lt dERfdt oi rit Record ever dep 00 mi o dp f20 0000 dee Ger JI aly goto Ey 3 IFEwe lt EL 4200 goto 1 4 Go back to seq Ne 0 RGIS eege jaca for pe E timels d e AAR vote Fig 102 Detailed diagram of one GCPL sequence In the battery applications the current values panel displays additional information Q Qo and x Xo are respectively the total charge and the normalized charge from the begin ning of the experiment Ns is the current Sequence number in the case of a technique using several sequences It corresponds to the line number in the associated table The first sequence number is 0 Hei Dep are the current values of the 5 loop counters Reference Weppner W Huggins R A J Electrochem Soc 126 1977 1569 1578 111 Techniques and Applications Manual 3 1 2 1 Description of a galvanostatic sequence See Fig 102 e First step galvanostatic period that can be followed by a potentiostatic period 1 Galvanostatic period Set I to Is pA A vs lt None gt Ictrl Imeas for at most ti h mn S sets the current value in absolute versus the previous controlled current previous sequence or versus the previous measured current and the maximum duration of the imposed current perio
219. nique or the beginning of a particular technique Until the month day year h mn S The user can define the date of the end of the wait technique until O Record every dE mV dl pA Aand dt s choose one or several recording conditions 2 4 7 TC Temperature Control The Temperature Control TC technique allows the user to control a temperature and change it during the experiment A direct link to the External Device Control technique is done by click ing on External Thermostat The user can choose to apply different temperature successively for different durations and perform a certain experiment at this temperature To do so several Sequences each one with the desired temperature and duration must be created Then the desired techniques need to be linked after the TC technique Finally the series of techniques must be ended with a Loop technique see 2 4 10 The sequences in the TC technique will be incremented only at each time the Loop technique is reached See below for additional info 85 Techniques and Applications Manual Set temperature to 50 0 C on External Thermostat and wait with previous control for tg 0 h E mA 5 0000 z Record ever dE 0 00 DM d 0 000 dt 90000 E Range 20 104 sell Caution This technique i mainly used combined with 4 loop technique In this Case Sequences are not executed successively At each loop only one sequence is
220. nocoulometm 21 Zo OP CGMOonopoteniomely cessa a aa 25 219 OV otaca Votame y eege Eege 28 2 1 10 LASV Large Amplitude Sinusoidal Voltammetry 0 ccceeeeeeeeeeeeeeeeeeens 30 2 1 11 ACV Alternating Current Voltammetry cccccccccssecesesceteeeeseeeeteneetaneeenens 32 2 2 Electrochemical Impedance Spectroscopy ccccseccceeeeceeeseeeeseeeeseeeeeeeeneeeeaes 35 2 2 1 PEIS Potentiostatic Electrochemical Impedance Spectroscopy 0010010000n 35 Bebe Re e e 35 2 2 1 2 Additional ELE 38 2 2 2 GEIS Galvanostatic Electrochemical Impedance Spectroscopy 0 cc 39 2 2 3 SPEIS Staircase Potentio Electrochemical Impedance Spectroscopy 40 E Ge E Re le de EE 40 222 ie et e EE 43 2 2 4 SGEIS Staircase Galvano Electrochemical Impedance Spectroscopy 44 2 2 5 PEISW Potentio Electrochemical Impedance Spectroscopy Wan 47 2 2 6 Visualization of impedance data files 2 0 ecceeccceeeeeeeeeeeeeseeeeseeeeeeeeseeesaeeenaees 48 2 2 6 1 Standard visualiZation MOS cccceecccseeeeceeeeeeeeeeceeeeseeeeseueesaeeeeseeeeas 48 2 2 6 2 Counter electrode ElS data poor 50 2203 FREQUENCY VS IMG Eed 52 22 Mult SNe ee e D WE 54 2 3 Pulsed WR ln e EEN 55 2 3 1 DPV Differential Pulse Voltammetry cccccccceccssecceeceeeeeeeceeeceeeeeeeeeeeeeenees 55 2 3 2 SWV Square Wave Voltammeti y een 58 2 3 3 NPV Normal Pulse Volammetry ccccccceecceeeeeeeseeeseee
221. ns Manual First CA block e potential step Ewe Disk e potential sequences E e recording conditions Es repeat option Le e instrument parameters configuration 7 Second RCA block potential step potential sequences recording conditions instrument parameters configuration Fig 98 CA_RCA description The detailed parameter setup is displayed on the Fig 93 First CA block e Potential step Apply E V vs Ref Eoc Ectrl Emeas the potential step is defined vs reference electrode potential or according to the previous open circuit potential Eoc controlled potential Ect or measured potential Emeas for ti h mn S sets the potential step duration Limits Imax D JA Imin D JA AQ gt AQm fA h A h pC kKC curtails the step duration if the current or charge limit is reached If the limit is reached the loop condition go to Ns for nc times if set is not used and the program continues to the next sequence Ns 1 The AQ value is the integral charge for the current sequence This value is not reset if there is a loop on the same sequence Ns Ns O values disable the tests e Data recording conditions Record I every dl pA A dQp fA h A h pC kC and dtp S lt I gt every dts S Either an instantaneous current value or an averaged current value lt l gt can be recorded The recording conditions during
222. nt may be disturbed by the step establishment A value of 100 will take all the step points for the average and a value of 0 will take only the last point Note that the current average lt I gt is recorded at the end of the potential step into the data file Scan rate mV s number of points these values are given as an indication and are calculated in the PC The scan rate is directly given by Py 0 001Sr and the number of points is roughly 2 E Ei St for the forward scan E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth sets the current range and bandwidth values for the entire experiment Note It is highly recommended to avoid using the automatic current range with pulsed tech niques The resolution of each range is different and dynamic current range changes may lead to spikes on the plot RNPV recorded and calculated variables The variables below are stored into the RNPV raw files mpr State byte time s control V Ewe V lt l gt mA Q Qo mA h 63 Techniques and Applications Manual And the next variables are calculated from lt I gt or from the potential to save size on disk forward mA lt l gt values at the end of the pulses lp reverse mA lt l gt values before th
223. ntial will be applied Etri Last controlled potential versus which WE potential will be applied Emeas Last measured potential versus which WE potential will be applied ti Time duration to Hold Ei dti Recording condition during ti dE dt Potential scan rate E First vertex potential t Time duration to Hold E dt Recording condition during t1 N Number of averaged voltage steps between two data points Range Current range E2 Second vertex potential t2 Time duration to Hold E2 dt2 Recording condition during t2 Nc Number of repeated cycles Nr cycle recording frequency E Final potential tf Time duration to Hold E Oh Recording condition during tf Lin Minimum current Limit Imax Maximum current Limit Au Maximum total Charge variation dl Recording condition on a variation of current dQ Recording condition on a variation of charge Ns Previous sequence to go back to ls Current step applied ts Time duration to Hold ls letri Last controlled current versus which the cell current will be applied lmeas Last measured current versus which the cell current will be applied Em Maximum potential limit dEs Recording condition on a variation of potential dts Recording condition on a variation of time Ru Uncompensated resistance IR Compensated ohmic drop fi Initial frequency fi Final frequency Na Number of points per decade N Total number of points la Sinus current amplitude Na Number of averaged measures per frequency 2
224. ntiostatic period 1 Galvanostatic period Set I to Is pA A vs lt None gt Ictrl Imeas for at most ti h mn S sets the current value in absolute versus the previous controlled current previous sequence or versus the previous measured current and the maximum duration of the imposed current period The sign of the current value is for a discharge and for a charge when the positive electrode of the cell is connected to the working electrode cable red Set C N or CXN with N and I gt 0 or lt 0 for at most t h mn s sets the rate C N or CXN at which the battery will be charged I gt 0 or discharged I lt 0 The C value could be a noninteger value For instance if the capacity of a battery is 1800 mA h setting C N with N 3 and I gt 0 means that a current of 600 mA will be passed during 3h The total capacity of the battery will be reached in 3h Setting CxN with N 2 and I lt 0 means that a current of 3600 mA will be passed during 30 min The total capacity of the battery will be reached in half an hour There is still the possibility to set a time limit Limit Ewe lt Em V sets the limit of the working electrode potential under charge discharge see warning 1 Record Ewe every dE mV and or d S allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dE or and at least
225. nts or damage resulting from any failure to comply with these precautions GROUNDING To minimize the hazard of electrical shock it is essential that the equipment is connected to a protective ground through the AC supply cable The continuity of the ground connection should be checked periodically ATMOSPHERE The equipment shall not be operated in corrosive atmosphere If the equipment is exposed to a highly corrosive atmosphere the components and the metallic parts can be corroded and can involve malfunction of the instrument The user must also be careful that the ventilation grids are not obstructed An external cleaning can be performed with a vacuum cleaner if necessary Please consult our specialists to discuss the best location in your lab for the instrument avoid glove box hood chemical products AVOID UNSAFE EQUIPMENT The equipment may be unsafe if any of the following statements apply Equipment shows visible damage Equipment has failed to perform an intended operation Equipment has been stored in unfavourable conditions Equipment has been subjected to physical stress In case of doubt as to the serviceability of the equipment don t use it Get it properly checked by a qualified service technician LIVE CONDUCTORS When the equipment is connected to its measurement inputs or supply the opening of covers or removal of parts could expose live conductors Only qualified personnel who should refer to t
226. nual in an Experiment If the current ranges are different between the different sequences then the potentiostat must have a short open period during which the change of current range will be performed This period lasts 100 ms during which no points are recorded Ticking the box will force a Rest period at the beginning of the sequence If there is current range change between sequence 0 and 1 then the Turn to rest box must be ticked on sequence 1 If this box is not ticked on all the sequences and there is a current range change the following warning message will show up WARNING k Se i several I ranges found within technique 1 MB Ensure that each I range changes follows an OCH period else the changes will have no effect this is not tested by the software Do not show this message again Fig 123 Warning message when several current ranges are chosen If your experiment is set up properly just ignore this message Note Turn to OCV button forces the system to go to OCV but no OCV measurement is per formed If after this forced OCV period a technique uses the OCV value as reference the value used will be the last value measured during the previous techniques 3 1 11 2 Control types 3 1 11 2 1 CC Constant Current CCl Constant Current Type Apply 100 000 n we lt None gt ze Bhoimiber all h Fig 124 Constant Current control Apply pA A vs lt None gt Ictrl Im
227. nus frequencies are evaluated over 2 periods instead of 1 increasing the acquisition time by a factor of 2 2 Inthe bottom right corner of the block the approximate experiment duration is indicated as information for the user 3 7 Techniques and Applications Manual During the run several parameters remain accessible for modification such as the min and max frequencies and the number of points per decade For more information about the drift correction please refer to the Application Note 17 e Repeat Repeat for n time s allows for repeating PEIS measurements in order to represent Z evolution vs time see below E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Loop Go back to sequence Ns for nc time s allows the experiment to go back to a previous sequence Ns lt Ns for ne times For example on N 3 if one enters go back to Ns 2 for n 1 time the sequence N 2 Ns 3 will be executed twice Nc 0 disables the loop and the execution continues to the next sequence Ns Ns 1 If there is no next sequence the execution stops In the current technique it is pos
228. ny Faye Bandwidth Reverse scan towards vertes potential Es 0 000 V va Fief v 20 points per cycle Repeat n 0 tire Reverse scan towards E Erd Fig 8 Cyclic Voltammetry Linear detailed flow diagram e Starting potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas sets the starting potential vs reference electrode potential or vs the open circuit potential Eoc or the previous controlled potential Ecti or measured potential Emeas e First potential sweep with measurement and data recording conditions Scan Ewe with dE dt kV s V s mV s mV mn allows the user to set the scan rate in kV s V s mV s or mV mn As mentioned above a real analog voltage scan to vertex potential E V vs Ref Eoc Ei sets the first vertex potential value vs reference electrode potential or vs the open circuit potential Eoc or vs the potential of the previous experiment Ei 15 Techniques and Applications Manual ScanEwe with dEfdt 000 to Vertex potential E4 oon o YV ovs es Reverse scan to vertex E gt 0 000 V VE Repeatme o time s e Record even dE 0 001 mi Average dt 000000 s E Range UV DM Ke J DOURAR Fae ue Range 10p v dE dt 100 py 100 0 me 20 points per cycle Fig 9 Cyclic Voltammetry Linear detailed column diagram e Reverse scan Reverse scan to vertex potential E2 Vve Ref E
229. oc Ei runs the reverse sweep towards a 2 limit potential The vertex potential value can be set vs reference electrode potential or according to the previous open circuit potential Eoc or ac cording to the potential of the previous experiment Ei e Repeat option for cycling Repeat ns times repeats the scan from Ei to E and to E2 ne time s Note that the number of repetition does not include the first sequence if nc O then the sequence will be done once if nc 1 the sequence will be done twice if nc 2 the sequence will be done 3 times etc e Data recording conditions Record every dE mV dite defines the recording conditions during the potential scan Only one condition can be selected E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation Techniques and Applications Manual e Final potential End scan to E the measurement is finished at the starting potential Note CVL technique is not available with CE to ground or WE to ground connections 2 1 5 CVA Cyclic Voltammetry Advanced The Cyclic Voltammetry Advanced CVA is an advanced version of the standard CV technique report to
230. ock a 12 potential sweep with a final limit E4 a 2 potential sweep in the opposite direction with a final limit E2 the possibility to repeat ns times the 1 and the 2 potential sweeps a final conditional scan reverse to the previous one with its own limit Er Note that all the different sweeps have the same scan rate absolute value The detailed flow diagram in the Fig below is made of five blocks it is also possible to display the column diagram Fig 5 Techniques and Applications Manual SetE we to E 0 000 V vs ScanE we with dEvdt 20000 to vertex potential E A000 WV w Measure lt I gt over the last 50 Sot the step de Record l gt averaged over H 0 voltage steps 7 1 0 mi left Za diti Z i Reverse scan towards vertex potential E 1 000 V v 4000 points per cycle Repeat n 0 time s Reverse scan towards E 0 000 V va Up End Fig 4 Cyclic Voltammetry detailed flow diagram Techniques and Applications Manual SetEwe ta Ej 0 000 V v Scan Ewe with dEvdt 0 000 to vertex potential Ey 1 000 Vo vs Reverse scan to vertes Ep 1000 Vo vs Repeat ne O timefs Measure lt le over the last ep 2 Of the step duration Record l gt averaged over H 10 voltage steps ERange 2 5 25 ki SW Za den Add Ae Range Auto k Bandwidth Endscanto Ef 0 000 V ve dE dt 100 u 50 me IOEN 1 0 rv 400
231. of the battery will be reached in 3h Setting CxN with N 2 and I lt 0 means that a current of 3600 mA will be passed during 30 min The total capacity of the battery will be reached in half an hour There is still the possibility to set a time limit Limit Ewe gt lt Em V sets the limit of the working electrode potential under charge discharge see warning 1 lf the limit potential Em is not reached within the time t4 or if tm is set to 0 the system skips to the next step Record Ewe Up tO tmax S with geometric progression of time and then every dE mV or d S allows the user to record the working electrode potential with two successive resolutions First the potential is recorded with a geometric time resolution tn 1 a tn in order to determine the apparent resistance with a process Secondly the potential is recorded with a given potential resolution whenever the change in the working electrode potential is gt dE1 or and at least every dt time interval 2 Potentiostatic period Hold Em fort h mn s once Ew is reached it is held for a given time t Limit I lt Im A pA or dl dt lt dl dt A s uA mn offers the possibility to stop the potentiostatic period when the limit current Im is reached or when the variation of the current is lower than given value dl dt Record AQ every dQ A h fA h kC pC and at least every dt S in the constant potential mode the sy
232. oftware version the procedure to generate cycles is 1 Inthe main menu bar click on Analysis General Electrochemistry Process data The following window appears Techniques and Applications Manual Process Data Input Files C Users electrochime Desktop S amples Fundamental ElectrochemistyCY Fe bazig Technique Cyclic Voltarnimetry Processed File C Users electrochime Desktop S amples Fundamental Electrochemistry Load Add Remove Clear VY arnables To select from the input file To be added d ISS Sis cycle number 0 Qo m h O charge m h C control changes O dizcharge m h C counter inc dl dts times cycle timers control step timers E we Jl charge time s gl rnd discharge timers mode oxvred C error R I Al Process Average E steps Allow Reprocessing Cycles definition auto ha Export As Text F Count half cycles Process Display Close Fig 6 Cyclic Voltammetry process window 2 Select the variables to process 3 Click on the Process box 4 The process is finished when DONE appears 5 Click on Display to plot the processed file n has been added to the name of the processed file as an extension for the cycle number The other variables that can be processed in a CV experiment are 13 Techniques and Applications Manual Q charge the charg
233. ohmic drop in the cell can be overcome At the user s convenience the potential limitations can lead to different options e Skipping to an open circuit potential period or to the next imposed current sequence e Switching from imposed current mode to imposed potential mode by maintaining for a given time the potential of the working electrode at the limit potential once it is reached The technique is by default composed of three sequences resting period i e OCV charge and discharge 109 110 Techniques and Applications Manual Initial Rest Potential Sequence Hs 0 Galvanostatic Sequence with Potential Lirnutation Rest Potential Sequence Test Ewe vs E imit Next Sequence ea ODC 30 CD Op ow End Galvanostatic Sequence with Potential Limitation np est U Rest Potential Sequence Test Ewe vs t irit He Next Sequence or go ne times to sequence Ns End Fig 101 General diagram of the GCPL application mio a Oe om of To Wes Techniques and Applications Manual OF ce crocs for at most tg ho hip mn omm0n Limit Ewe gt EM A500 Record every dE 00 mv or di 10 0000 Hold Epq for tpg f ho mp pooo Limit I lt Im 0 000 mi ze o M i difdt 0000 me Record ever d 1 000 o dtg 120 000 0 Limit AG gt Al 0 000 m h v SCH AX 0 000 ERa
234. olts between the working electrode WE and the counter electrode CE and then measuring the current and the potentials Ewe Ece versus the reference elec trode REF In most cases the coupling current is measured between two electrodes from the same material The microstructure differences between these two electrodes result in the fact that one of them behaves anodically and the other one behaves cathodically The potential is controlled in this application between Ref1 S1 for the SP300 based instru ments and Ref3 S3 for the SP300 based instruments in the standard connection mode The first metal must be connected to Ref1 CA2 leads S1 P1 for the SP300 based instruments and the other metal must be connected to Ref8 CA1 leads S3 P2 for the SP300 based 203 Techniques and Applications Manual instruments Ref2 S2 in the SP300 based instruments is connected to the reference elec trode Figs 174 and 175 show the connections for the VPM3 and SP300 based instruments lt could be necessary to connect the ground lead if the signal is noisy WE CA2 re E RE et we Ece rel CECA Fig 180 VMP3 based instruments con Fig 181 SP300 based instruments con nection nection The currents involved are generally very low uA The quality of the measurement will be greatly enhanced if the cell is placed in a Faraday cage in order to remove environmental noise and other electrodynamics perturbations Begin Initial Open
235. olution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth sets the current range and bandwidth values for the whole experiment Note It is possible to modify on line the settings of an impedance measurement during the experiment The user can Modify Pause Resume or Stop the experiment while it s running 2 2 5 PEISW Potentio Electrochemical Impedance Spectroscopy Wait The Potentio Electrochemical Impedance Spectroscopy Wait is a technique designed to do an impedance measurement at one frequency when the value of IZI reaches a defined value or after a certain time e Impedance scan Do PEIS measurement at Ewe V vs Ref Eoc Ectrl Emeas defines at which potential the measurement will be done fi MHz kHz Hz mHz uHz defines at which frequency the measurement will be done with an amplitude Va mV sets the sinus amplitude to Va Equivalence with Vous Is also given Note the following relationships between Va Vpp and Vrms Va Vpp2 and Nous Vpp 2 V2 Wait for pw period before each frequency measurement offers the possibility to add a delay before the measurement at each frequency This delay is defined as a part of the period Of course for low frequencies the delay may be long average N mesure s per frequency repeats Na measure s and average values for each frequency 47 Techniques and Appl
236. oop and go to the next sequence Ns 1 Note Ece and Ewe Ece recording are forced into the GCPL2 data files 120 Techniques and Applications Manual 3 1 5 GCPL4 Galvanostatic Cycling with Potential Limitation 4 The GCPL4 application is similar to the GCPL application but with a global time limitation for the charge discharge period The technique is by default composed of three sequences rest ing period i e OCV charge and discharge v to Is Lint Ewe gt EM Record ever dE l o dt foo Hold EM once reached Limits I lt Im foo m o H didt 0 000 Il Ig retum to l control Record ever dq 1 000 mAh v di 10 000 p v or dt Limit the whole time to tg E hijo mn 00000 and I GI gt AQM DI m ih v lt gt AM 0 000 ERange Ou Eu sell EE Range Bandwidth 5 medium wl Restforthp f hilo mn goo Limit ldEwe dtl lt dER fdt oo miih Record every dp oo DM o dp 0000 Ra dor Aad A Adr one tt LG 3 Jf E we g EL pass Y goto 1 4 Go back o seq Mgt 0 RGIS Boks face for pe E imela JE dr ES DANAS Fig 109 GCPL4 detailed diagram e Galvanostatic period Set I to Is pA A vs lt None gt Ictrl Imeas sets the current value in absolute versus the previous controlled
237. or cycling Repeat ne times repeats the scan from Ei to E and to E2 ne time s Note that the number of repetition does not include the first sequence if nc O then the sequence will be done once if nc 1 the sequence will be done twice if nc 2 the sequence will be done 3 times etc e Data recording conditions Measure lt l gt over the last of the step duration selects the end part of the potential step from 1 to 100 for the current average lt I gt calcu lation It may be necessary to exclude the first points of the current response which may only be due to the capacitive rather than faradic behavior of the system Record lt l gt averaged over N voltage step s averages N current values on N potential steps in order to reduce the data file size and smooth the trace The potential step between two recording points Is indicated between brackets Once selected an estimation of the number of points per cycle is displayed in the diagram E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment ERange 25 25 e some potential ranges are defined by de eae fault but the user can customize the Edit Potential Range E Range in agreement to the system by Erange min Vomax 1 000 W clicking on mi Information on the resolution is given si
238. ording and limiting conditions Almost all the DC techniques in EC Lab can be recreated or customized by setting the adequate sequences Modular Galvano MG technique designed to perform a combination of OCV galvanostatic and galvanodynamic periods The user can link the MG sequences in any desired way Modular Potentio MP Technique designed to perform a combination of OCV potentiostatic and potentiodynamic periods The user is free to link the MP sequences the way in any desired way This technique can be used to couple potential sweep detections with preconditioning steps either in OCV or at a particular potential Multielectrode Potentiodynamic Pitting MPP corrosion technique designed to study pit ting corrosion on one or several electrodes together in the same electrochemical cell This 231 Techniques and Applications Manual technique corresponds to the pitting potential determination of a material using a potential sweep Multielectrode PotentioStatic Pitting MPSP corrosion technique designed to study pitting corrosion on one or several electrodes together in the electrochemical cell using a potential step Normal Pulse Voltammetry NPV technique used in analytical electrochemistry to discrimi nate faradic from capacitive current This technique is made of increasing pulses with time that always return to the beginning potential Open Circuit Voltage OCV technique that consists in a period during which no potentia
239. ording conditions Scan Ewe with dE dt mV s allows the user to set the scan rate in mV s The potential step height and its duration are optimized by the software in order to be as close as possible to an analogic scan Between 99 Techniques and Applications Manual brackets the potential step height and the duration are displayed according to the potential resolution defined by the user in the Advanced Settings window see the corresponding section in the EC Lab Software User s Manual to vertex potential E V vs Ref Eoc Ei sets the first vertex potential value vs reference electrode potential or vs the open circuit potential Eoc or vs the potential of the previous experiment Ei e Reverse scan Reverse scan to vertex potential E2 Vve Ref Eoc Ei runs the reverse sweep towards a 2 limit potential The vertex potential value can be set in absolute Ref or according to the previous open circuit potential Eoc or according to the potential of the previous experiment Ei e Repeat option for cycling Repeat n times repeats the scan Ei to E to E2 ne time s Note that the number of repetition does not include the first sequence if n 0 then the sequence will be done once if ne 1 the sequence will be done twice if nc 2 the sequence will be done 3 times etc e Data recording conditions Measure lt l gt over the last of the step duration selects the end part of the potential
240. otential End scan to E V vs Ref Eoc Ei gives the ability to end the potential sweep or to run a final sweep with a limit Er Hold E for t h mn s and Record every dt S offers the possibility to hold the final potential for a given time and record data points during this holding period Options 1 Reverse While the experiment is running clicking on this button allows the user to reverse the potential scan direction instantaneously Contrary to the Force button the vertex potential is not re placed by the current potential value E and E2 are kept 2 Force E E2 During the experiment clicking on this button allows the user to stop the potential scan set the instantaneous running potential Ewe to E or E2 according to the scan direction and to start the reverse scan Thus E or and E2 are modified and adjusted in order to reduce the potential range Clicking on this button is equivalent to clicking on the Modify button setting the running po tential as Ex or Era and validating the modified parameters with the Accept button The Force E E2 button allows the user to perform the operation in a faster way in the case where the 19 Techniques and Applications Manual potential limits have not been properly estimated and to continue the scan without damaging the cell Note it is highly recommended that the user adjusts the potential resolution from 300 uV for 20 V amplitude to 5 uV for 0 2
241. otential Eoc or the previous controlled potential Ecti or measured potential Emeas Hold E for ti h mn s and Record every dti S offers the possibility to hold the initial potential for a given time and record data points during this holding period Note This function can correspond to a preconditioning capability in an anodic stripping volt ammetry experiment e First potential sweep with measurement and data recording conditions Scan Ewe with dE dt V s mV s mV mn allows the user to set the scan rate in V s mV s or mV mn The potential step height and its duration are optimized by the software in order to be as close as possible to an analogic scan Between brackets the potential step height and the duration are displayed according to the potential resolution defined by the user in the Advanced Settings window see the corre sponding section in the EC Lab Software User s Manual to vertex potential E V vs Ref Eoc Ei sets the first vertex potential value vs reference electrode potential or vs the open circuit potential Eoc or vs the potential of the previous experiment Ei 17 Techniques and Applications Manual Get Ee to Ey 0 000 V w Hold Ej forty 0 h fo mn fooga Record ever dti 1 O00 0 amp ScanEwe with dit M00000 to vertex potential E4 koo vs Hold Eq forty 0o hu mp Recon every dt oio00 Reverse scan to vertex Ep 1 DO V vs Ret we Ho
242. over the last of each step points Selects the end part of the potential step for the current average lt I gt calculation to exclude the first points where the current may be disturbed by the step establishment A value of 100 will take all the step points for the average and a value of 0 will take only the last point Note that the current average lt I gt is recorded at the end of the potential step into the data file Scan rate mV s number of points These values are given as an indication and are calculated by the computer The scan rate is directly given by Gu 0 001S1 and the number of points is roughly 2 E Er for the forward scan E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth sets the current range and bandwidth values for the entire experiment Note It is highly recommended to avoid using the automatic current range with pulsed tech niques The resolution of each range is different and dynamic current range changes may lead to spikes on the plot 65 Techniques and Applications Manual DNPV recorded and calculated variables The variables below are stored in the DNPV raw files MPR State byte time s control V Eye V lt l gt mA Q Qo mA h And the next variables a
243. p then the sequence is stopped and the next sequence is applied E Range enables the user to select the potential range and adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment e Second step open circuit period with monitoring of the electrode potentials Rest for tr h mn s sets a maximum time tr to stay in open circuit mode or until dEwe dt lt dEr dt mV h gives to the user the possibility to shorten the open circuit period when the decay of the poten tial is lower than a given value 133 Techniques and Applications Manual Record Ewe every dEr mV and at least every dt S allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dEr or and at least every dtr time interval Note the conditional test if tz 0 which bypasses the open circuit period e Third step test on the final open circuit potential test If Ewe ziel EL V The test is performed with the conditional value gt if the open circuit period just before the test occurs after a charge I gt 0 and with the conditional value lt after a discharge I lt 0 lf the condition is not fulfilled the above 3 steps will be repeated until the working electrode potential reaches the final open circuit condition Ewe E after a charge or Ewe
244. periment corresponds to an increase of the current in absolute value when the potential decreases The user must be careful to note the final current of the first constant power step For example let us consider a 30 watts power discharge applied to a battery with a 10 A booster We suppose that the potential limits of this experiment are 4 V and 2 5 V The initial current will be 7 5 A but the final current will be 12 A overload in current It will not be possible to go to the final current 3 1 11 2 5 CS Current Scan we Current Scan 00 000 m mn ze Fig 128 Current Scan control Apply A s mA s A s A mn mA mn pA mn From pA A vs lt None gt Ictrl Imeas To pA A vs lt Nones Ii 145 Techniques and Applications Manual applies a current scan from an initial current value li defined in absolute value vs Ictrl the previous controlled current or vs Imeas the previous measured current to a final value If defined in absolute value or vs li at a scan rate defined above This technique is similar to the galvanodynamic mode available in the Modular Galvano technique see 2 4 3 3 3 1 11 2 6 VS Voltage Scan Control Type WS Voltage Scan Apply 00 000 From D om To 4 000 Limits Miimher Ai h Fig 129 Voltage Scan control Apply V s mV s mV mn From V mV vs Ref Eoc Ectrl Emeas To V mV vs Ref Eoc Ei applies a potential scan from an initial potentia
245. ph Icon and Ecor are also calculated in the processed file mpp and can be displayed in real time on the second graph 3 4 4 GC Generalized Corrosion The generalized corrosion technique is applied for general corrosion sometimes called uni form corrosion study In this type of corrosion anodic dissolution is uniformly distributed over the entire metallic surface The corrosion rate is nearly constant at all locations Microscopic anodes and cathodes are continuously changing their electrochemical behavior from anode to cathode cells for a uniform attack This technique corresponds to half a cycle or one cycle of usual cyclic voltammetry with the particularity of a digital potential sweep i e it runs by potential steps defined and periodic in amplitude and time For the VMP3 VMP2 VSP SP 150 50 the SP 300 200 240 VSP 300 and VMP300 the potential step and its duration are defined according to the potential control 185 Techniques and Applications Manual resolution see the EC Lab Software User s Manual for more details In the present version of this application the result file contains the mean value of the current measured for the whole potential step duration This mean value is the result of measurements carried out every 2 ms Begin Reverse Scan End Fig 164 General diagram of the Generalized Corrosion technique 3 4 4 1 Description aii ah wesch RK 4 CH zl a lj 4 D
246. plications Manual 3 1 10 3 PCGA Data processing 3 1 10 3 1 Compact function The Compact function is very useful in representing the incremental capacity of a battery The user has to represent dQ f Ewe in the graphic display see the application note 2 on our web site for more details Using the compact function a new variable can be created dQ which is the charge calculated for every potential step See the EC Lab Software User s Man ual 0 35 0 3 0 25 Li yyw OP CH J Ui UU 0 05 3 4 3 6 ES d 42 Ewen Fig 120 Incremental capacity dQ vs Ewe graph red dots and x the insertion rate vs Ewe plot blue lines of a Li coin cell 140 Techniques and Applications Manual 3 1 10 3 2 Intercalation coefficient determination Process Data Input Files C UserselectrochimesDesktop4PiITT 1 mpr Technique Potentiodyrarnic Cycling with Galvanostatic Acceleration Processed File C Usershelectrochime sDesktop PilT 7 1 WUvnt mpp Load Add Remove Clear Yarnables To select from the input file To be added cl dm mode Di Gol mA h osred Kull error V cycle number control changes M O charge m h Ns changes O dischargema h counter INE F Energy h A Energy chargea h e E V Energy diecharge w h pai V cycle times v dg mA step times charge times discharge times All F All Process EIER ca is Allow Reproces
247. potential step is defined vs Ref the reference electrode potential or according to the pre vious open circuit potential Eoc controlled potential Eet or measured potential Emeas fortt h mn s sets the potential step duration Limits Wl to Imax pA A and AQ lt AQw fA h A h pC kC lmin D JA curtails the step duration if the current or charge limit is reached If the limit is reached the loop condition go to Ng for nc times if set is not used and the program continues to the next sequence Nz 1 The AQ value is the integral charge for the current sequence This value is not reset if there is a loop on the same sequence Ns Ns 0 values disable the tests Record I every dl pA A dQ fA h A h pC kC and dtp S lt I gt every dt S you can record either an instantaneous current value or an averaged current value lt l gt The recording conditions during the potential step depend on the chosen current variable For the 177 Techniques and Applications Manual instantaneous current the recording values can be entered simultaneously Then it is the first condition reached that determines the recording A zero value disables the recording for each criterion For the averaged current the user defines the time for the average calculation In that case the data points are recorded in the channel board memory every 200 us for VMP3 based instruments and for V
248. potentio and galvano triggers wait and loop options The Electrochemical Applications are made of techniques more dedicated to specific fields of electrochemistry such as battery fuel cells super capacitors testing corrosion study and cus tom applications Electrochemical Techniques and Applications are obtained by associations of elementary sequences blocks and appear as flow diagrams combining these sequences The settings can also be displayed as column setup Conditional tests can be performed at various levels of any sequence on the working electrode potential or current or on the counter electrode potential or on the external parameters These conditional tests force the experiment to go to the next step loop to a previous sequence or end the sequence The aim of this manual is to describe each technique and application available in the EC Lab software The first part is an introduction The second part describes the electrochemical tech niques The third part explains the electrochemical applications The fourth chapter details how to build complex experiments as linked techniques It is assumed that the user is familiar with Microsoft Windows and knows how to use the mouse and keyboard to access the drop down menus Please note that another manual is available detailing the various graphic and analysis toolsoffered by EC Lab WHEN A USER RECEIVES A NEW UNIT FROM THE FACTORY THE SOFTWARE AND FIRMWARE ARE IN STALLED AND UPG
249. quence 0 The other action that can be taken when a limit is reached is Stop Records it is possible to set three different recording conditions on e the Time in day h mn S ms the working electrode potential Ewe in V mV the counter electrode potential Ece in V mV the potential difference Ewe Ece in V mV the current in A mA pA nA pA the charge Q in A h mA h the power P in W mW uW the Energy in kW h W h mW h pW h lf several conditions are used the one taken into account is the one that is met the most quickly For instance on Fig 115 one point will be recorded every 0 1 s unless the potential varies more than 3 V during this time in which case one point will be recorded when the poten tial variation reaches 3 V The same applies for the current if the current change of 10 pA occurs faster than 0 1 s then one point will be recorded when the current change of 10 pA is reached Ranges E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab software User s Manual for more details on the potential reso lution adjustment I Range Bandwidth sets the current range and the bandwidth for this experiment Turn automatically to Rest to change Range between sequences this button has for the sequences in Modulo Bat the same function as the Turn to OCV button for linked techniques 143 Techniques and Applications Ma
250. r to run a final sweep with a limit Ey Option Force E E2 During the experiment clicking on this button allows the user to stop the potential scan set the instantaneous running potential Ewe to E or E2 according to the scan direction and to start the reverse scan Thus E or and E2 are modified and adjusted in order to reduce the potential range Clicking on this button is equivalent to clicking on the Modify button setting the running po tential as E or E2 and validating the modified parameters with the Accept button The Force E E2 button allows the user to perform the operation in a faster way in the case where the potential limits have not been properly estimated and to continue the scan without damaging the cell Note it is highly recommended to adjust the potential resolution from 300 uV for 20 V of amplitude to 5 uV for 0 2 V of amplitude with a SP 150 VSP or VMP3 according to the experiment potential limits This will considerably reduce the noise level and increase the plot quality Graph tool Process data to Generate cycles It is not necessary to process the data file to generate the cycle numbers The software can generate the cycle numbers by itself For data recorded with older versions the user must process the file to generate the cycle numbers Note the automatic cycle number generation is only available with the CV and the CVA tech niques lf a data file with several cycles is produced with an older s
251. r tr h MN S sets a defined duration tr for the recording of the rest potential Limit dEwe dt lt dEr dt mV h stops the rest sequence when the slope of the open circuit potential with time dEp dt be comes lower than the set value value 0 invalidates the condition Record Ewe every dEr mV resolution and at least every dtr S allows the user to record the working electrode potential whenever the change in the potential is gt dEr with a minimum recording period in time dtr e Potential sweep with measurement and data recording conditions Scan Ewe with dE dt mV s allows the user to set the scan rate in mV s The potential step height and its duration are optimized by the software in order to be as close as possible to an analogic scan Between brackets the potential step height and the duration are displayed according to the potential resolution defined on the top of the window in the Advanced tool bar From E V vs Ref Eoc Ectrl Emeas sets the intial potential value vs reference electrode potential or according to the previous open circuit potential Eoc or according to the potential of the previous experiment Ei 20 Techniques and Applications Manual to E V vs Ref Eoc Ei sets the limit potential value vs reference electrode potential or according to the previous open circuit potential Eoc or according to the potential of the previous experiment Ei RestfortR
252. r ts h MN S sets the current step duration Limits Ewe gt lt Em mV and AQ lt AQrn fA h A h pC IkC curtails the step duration if the potential or charge limit is reached If the limit is reached the loop condition go to Ns for nc times if set is not used and the program continues to the next sequence Ng 1 The AQ value is the integral charge for the current sequence This value is not reset if there is a loop on the same sequence Ns Ns 0 values disable the tests Record Ewe or lt Ewe gt every dE mV and at least every dts S defines the recording conditions during the potential step 0 values disable the recording con dition and the corresponding box turns blue These values can be entered simultaneously and this is the first condition that is reached that determines the recording E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab software user s manual for more details on the potential resolution ad justment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Loop Go back to Ns for nc time s gives the ability to loop to a previous sequence Ns lt Ns for ne times Sequences of the chronopotentiometry technique can be chained using the Table frame The first sequence is Ns 0
253. ral data files several Modulo Bat techniques can be linked A general description of the diagram is given and then each control type is described separately 3 1 11 1 General Description of the Modulo Bat technique Limits 2 v New sequence wv nis Goo seqence SE Fig 122 General Modulo Bat diagram 142 Techniques and Applications Manual This technique is composed of four blocks Control The first block is related to the control mode Each control type is explicited below Limits The second block is related to the limits of the experiment The maximum number of limits is 3 They can be set on e the Time in day h mn S ms the working electrode potential Ewe in V mV the counter electrode potential Ece in V mV the potential difference Ewe Ece in V mV the current in A mA pA nA pA the charge Q in A h m h the power P in W mW pW the Energy in kW h W h mW h pW h the potential time variation dE dt in V s mV s mV mn mV h the current time variation dl dt in A s mA s A s A mn mA mn pA mn the temperature T in C the temperature time variation dT dt in C mn C h For each parameter the limit can either a lower or an upper boundary For example in Fig 124 the first limit must be understood as if the time of the experiment is longer than 1 s then move to the next sequence The second limit must be understood as if the current var lation with time is less than 100 mA s then move to se
254. rcuit potential Eoc controlled potential Ecti or measured potential Emeas for ti h mN S sets the potential step duration Limits Imax pA JA Imin PA A AQ gt AQm IAM A h pC IKC curtails the step duration if the current or charge limit is reached If the limit is reached the loop condition go to Ns for nc times if set is not used and the program continues to the next sequence Ns 1 The AQ value is the integral charge for the current sequence This value is not reset if there is a loop on the same sequence Ns Ns O values disable the tests 22 Techniques and Applications Manual forty 0 hin ma ioo000 AD gt Aw 0 000 m i every d Em pA ei da Dm an dt j1000 E Range 25 V2 5 hc LL Areca Fee Gobackto sequence Ng 0 GS Gene ace forme 0 timels Ahan aest seg Fig 13 Chronoamperometry Chronocoulometry detailed diagram and table e Data recording conditions Record every dl pA A dQp fA h A h pC kC and dtp S lt l gt every dta S Either an instantaneous current value or an averaged current value lt l gt can be recorded The recording conditions during the potential step depend on the chosen current variable For the instantaneous current the recording values can be entered simultaneously It is the first reached condition that determines the recording A zero value d
255. rd ever dt 0 5000 amp ERange 2V 2M Zaang Adar Range HOI Bandwidth 7 duration 210 000 Fig 188 Detailed diagram of the Constant Amplitude Sinusoidal microPolarization technique Apply a sinusoidal potential with frequency fs KHZ Hz mHz pHz sets the frequency of the modulation applied to the cell The maximum frequency is 500 Hz Amplitude Va mV vs Ecorr Sets the amplitude the sinus Repeat n s time s allows repeating sinusoidal period Repetition leads to optimized results It is recommend to perform 20 cycles at least Record every dt s sets the sampling rate of the measurement E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment 209 Techniques and Applications Manual I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation lt is recommended to set a constant current range to have a constant sampling rate 3 5 Custom Applications 3 5 1 PR Polarization Resistance The polarization resistance can be used in several electrochemical techniques such as corro sion monitoring or general electrochemistry This technique makes measurement of the polar ization resistance A of a material and kor through potential steps around the
256. re adjusts the potential step amplitude and its duration From Ei V vs Ref Eoc Ectrl Emeas to E V vs Ref Eoc Ei from a potential Ei defined vs Ref the reference electrode potential or versus a previous open circuit potential Eoc previous controlled potential Ecti or previous measured potential Emeas to Ep value defined in absolute or versus Eoc or Ei Limit I lt Ip pA A after tb S sets the threshold pitting current Ip to detect Setting of a blanking time tp eliminates a possible large peak of current when just applying the initial potential step in case of large AU value Record lt I gt over the last of the step duration averaged N voltage steps I every dla pA A Two different recording conditions on current are available with the potentiodynamic mode either recording an averaged current lt l gt on each potential step or recording an instantaneous current with a time variation and or an instantaneous current variation dl and or charge var iation dQ E Range enables the user to select the potential range and adjust the potential resolution to his her system See EC Lab Software User s Manual for more details on the potential resolution adjustment 192 Techniques and Applications Manual The cell is disconnected at the end of the experiment 3 4 7 CPT Critical Pitting Temperature The CPT technique is based on the AST G150 standard for the determinat
257. re calculated from lt I gt or the potential to Save space on disk forward mA lt l gt values at the end of the pulses lp reverse mA lt l gt values before the pulses lbp delta A difference between lt l gt values before and at the end of the pulse Ip lbp E step V step potential value resulting from the potential sweep and used to plot the current 2 3 6 DPA Differential Pulse Amperometry The Differential Pulse Amperometry results from the DNPV technique without increasing pulse steps The potential waveform and the current sampling are the same as for DNPV A DPA experiment is often used as a sensitive method for the quantification of electrochemical species at a defined potential Es This potential value is often determined with a DNPV ex periment using a potential sweep with the same waveform previously performed This tech nique is dedicated to the quantification of biological electroactive species SetEwe to Ej 0 400 Y vs Ref ll me fort D hp mh Oooo Apoly waveform with prepulse height PPH 50 0 mi prepulse width PP 250 ms pulses height PH foo mv pulse width Pw mun me Fig 57 DPA waveform pulse period P 000 me forty O hho mn mnnmn zs average over the last 100 Of each pulse Cte eas AAA ov een RAA E Ranges 2 2 Zeene Fant ge Range 10 p 7 Bandwidth z Fig 56 DPA detailed diagram 66 Techniques and Applications Manu
258. rent to a final value If de fined in absolute value or vs li at a scan rate defined above Limits The second block is related to the limits of the experiment The maximum number of limits is 3 They can be set on the Time in day h mn s ms the working electrode potential Ewe in V mV the counter electrode potential Ece in V mV the potential difference Ewe Ece in V mV the current in A mA pA nA pA the charge Q in A h m h the power P in W mW uW the Energy in kW h W h mW h pW h the potential time variation dE dt in V s mV s mV mn mV h the current time variation dl dt in A s mA s A s A mn mA mn pA mn the temperature T in C the temperature time variation dT dt in C mn C h Records it is possible to set three different recording conditions on the Time in day h mn s ms the working electrode potential Ewe in V mV the counter electrode potential Ece in V mV the potential difference Ewe Ece in V mV the current I in A mA PA nA pA the charge Q in A h mA h the power P in W mW uW 171 Techniques and Applications Manual e the Energy in kW h W h mW h uW h If several conditions are used the one taken into account Is the one that is met the most quickly 3 3 Photovoltaics Fuel Cells This section is especially dedicated to energy devices not requiring any charge sequence They are studied only in the discharge mode fuel being for these devices a gas or the sun
259. rnal analog signals through the auxiliary DB9 connector the user has to configure Analog In and or Analog In2 inputs Our instruments can control and record an alog signals from 10 to 10 V Most of the external devices work within a 0 5 V range The user has to define the conversion between the input voltage and the variable to plot in the activated frame It is a direct linear conversion in the range defined by the user between the min and the max value Device Type Device Name Analog OUT with 100 SE 5 W mas D 0 Yimin TC og Analog IN Cowen EW to with 0 WE E L max o y P C min Analog IN 2 Fltawer EN with 10 Wes p mas Os imn Fig 197 External devices configuration window The user must define several parameters to configure the external to record measure data via analog input 1 and 2 right column The way to proceed for the configuration is described below 1 o 3 4 5 Choose the channel to configure Each channel can be configured for a specific device Each channel can record a separate device Select the Device Type in this case Other The user must tick the box to activate the selected Analog input In the activated frame the user must define the conversion between the input voltage and the variable to plot This is a direct linear conversion in the range defined by the user between the min and the max value The user can also define the name and the unit of the
260. rode potential or according to the previous open circuit potential Eoc controlled potential Eet or measured potential Emeas Notice that only the last point of this period is recorded at the time 0 e Pulse waveform Scan Ewe from E to Ey V vs Ref Eoc Ei defines the vertex potential as Ev either vs Ref reference electrode potential in the cell or Versus Eoc or Ei with pulses height Du MV prepulse width PPw ms pulse width Pw ms step height Du mV step time St mMs 64 Techniques and Applications Manual SetEwe to Ej 0200 Vv Eoo fort D hA mm mon Scan Ewe from Ejto Ey p600 Y va Ref gt with pulses height Py 100 mV prepulse width PPyy 500 ms pulse width Pyw 00 ms step height SH S00 m step time ST 1000 me average over the last i of ofeach pulse ZG v ote aoa aye AEA ae ERange 2 2 e Greaney Aa ei Range 10 ps Bandwidth E Fig 54 DNPV detailed diagram ret i Fw Finy I St Fig 55 DNPV waveform The scan increment is defined by a pseudo staircase made of steps of amplitude Py and duration Sr As mentioned above only one point is recorded at the end of the potential forward pulse and one point at the end of the potential reverse pulse making two points during the Gr period The settings above Fig 54 are given for a positive scan To perform a negative scan set Ey inferior to Ei and Sx to a negative value average
261. rolled by another application Programe Name allows the user to select the external application Parameters This option allows the user set the commands parameters that will be sent to the external application In addition selecting Wait until the application closes it is possible to wait until this pro gram is closed Untils this time the experiment turns into Pause mode until the external appli cation is closed If this box is not ticked the experiment will continue in parallel 2 4 13 EMAIL Send an E Mail aufies S Fig 84 Pause technique This technique can be added in an experiment including linked techniques When this tech nique is reached allows one to send an email to one or several addresses A file can be en closed Max size 8 Mb 90 Techniques and Applications Manual The exact file name must be indicated Remember that the EC Lab a Parameters Settings default file structure is the following name Z technique position in the protocol technique name _C channel number mpr a In the example of Fig 79 if one can send the result of the PEIS tech P 1 GCPL nique the file name is test_02_PEIS_C04 mpr supposing that this gt PEJE experiment is running in the channel 04 3 GCPL A Loop Note the exact location of the enclosed file has to be also indicated This can be used to inform the user of the progress of the experiment Note The email settings of the sender have to
262. rrent as absolute value The sign of the current value is for a discharge and for a charge when the positive electrode of the cell is connected to the working electrode cable red Set to C N or CxN with N and I gt 0 or lt 0 fort h mn s Sets the rate C N or CxN at wich the battery will be charged I gt 0 or discharged LO The capacity of battery must be entered in the cell characteristics see 3 1 10 2 Set C 3 mean that the battery will be charged discharged in 3 h J Tum to DEY between techniques dl Kl n et for ty 10 hn mmnnmnn 3 Limit Ewe gt Eu and Ewe Ep Record every dE 4 or d E Range Range Bandwidth ho back to fo nge seq NM ee d V 2 75 5 0 mv 60 3 OV 104 Zanen GGG SG yd ia rs i AE anche Gabes Bo Dmelsl Aa nes serene Fig 133 CED detailed diagram Limit Ewe gt Emi V Ewa lt Em2 V sets the limits of the working electrode potential under charge and discharge regime See warn ing 1 in Description of a galvanostatic sequence Record Ewe every dE mV or dt S allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dE or and every dt time interval E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s
263. rtex E2 V vs Ref Eoc Ei offers the possibility to do a reverse scan and to fix the value of the vertex potential value vs reference electrode potential or according to the previous open circuit potential Eoc or previ ous potential Ei Repeat n times repeats the whole sequence ns time s Note that the number of repeat does not count the first sequence if nc 0 then the sequence will be done 1 time N 1 the sequence will be done 2 times Nc 2 the sequence will be 3 times Record I every dt s and dl nA UA mA A offers the possibility to record with two conditions on the current variation dl and or on time variation E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment I Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation Reverse scan towards E offers the possibility to do a reverse scan towards Ei 34 Techniques and Applications Manual 2 2 Electrochemical Impedance Spectroscopy The methods based on the excitation of an electrochemical cell by a sinusoidal signal were first employed as a way of measuring the rate constant of fast electron transfer reactions at short times The principle of Electrochemical Impedance Spectroscopy EIS is to
264. s EL 0 500 V WU gt AM 935 335 n h eE x Lg otg Lg pass tg 0 000 0 gd dE we l gt dEy dt pass Mis Record even dn AO mv dtp 05000 ddp 6344 n h E Range 2 2 ATEOA Ad edd Range 10m Bandwidth 5 medium Go back to sequence Ng 10 RGIS aot face forme 0 mell Aviv aas SA Fig 72 Special Modular Galvano Galvanostatic detailed diagram e Galvanodynamic Mode 2 Scan I with di dt mA s with pA A s defines the scan rate By the same way than for the Modular Potentio technique entering the di dt value will automatically calculate the dl and dt values in order to minimize the current steps dl Nevertheless one can enter dl and dt directly from li D JA vs lt None gt Ictri Imeas to I pA A vs lt None gt li 82 Techniques and Applications Manual defines the initial l and final current of the scan Recording and limits are the same than for the galvanostatic period except that dQp and AQw that can be accessible for the galvanodynamic mode I Range and Bandwidth sets the current range and the bandwidth for this experiment gt OLY 0 Mode 5 Galvanostatic 1 o Galvanodynamic 2 Scant with difdt 1 000 OO OO reds with 0 200 p A 2000s fom ty 50000 wh s lt None gt to lp Hmmm pA sl vs lt None gt Limits Ewe Ys EL 0 500 V AO gt Aw 0000 nih si Analog ln
265. s ZIR technique before other experiments in a series of linked experiments Ru value will be automatically accounted for in the following experiments of the series This technique is similar to the Potentiostatic Electrochemical Impedance Spectroscopy PEIS technique except that it is performed at a single frequency Refer to the PEIS experiment section for more details Please note that the ZIR technique is available on the SP 300 tech nology even if the board is not equipped with impedance ability This technique is not available with WE to Ground and CE to Ground connections 93 Techniques and Applications Manual SetEweto E 00000 W vs Calculate A with PEIS method at f fo0o00 sinus amplitude Ya 200 mV waitfor Dw 010 pernod before measurement average Ma 4 measure s compensate at op SZ compensation mode E Range Bandwidth Results Ru He Fig 89 ZIR diagram e Impedance scan Set Ewe to E V vs Ref Eoc Ectril Emeas sets the potential to a fixed value vs reference electrode potential or relatively to the previous OCV potential Eoc controlled potential Ecin measured potential Emeas Calculate IR with PEIS method at f MHz kHz Hz mHz ywHz defines the frequency to measure the resistance with an amplitude V mV sets the sinus amplitude to Va wait for pw period before each frequency measurement offers the possibility to add a delay before the measuremen
266. s does not count the first sequence if nc 0 then the sequence will be done 1 time nc 1 the sequence will be done 2 times nc 2 the sequence will be 3 times Process The polarization resistance files can be processed to calculate the Rp and Icor values select Analysis Corrosion Polarization Resistance to load the following window 212 Techniques and Applications Manual Polarization Resistance Process EN File R WIMP Files PA mpr Load Settings n 2 AE 20 0 mm D 10 li Apply a second set of potential stepele with reverse sign on AE electrode surface area 0 001 cre Options f Spornts AE ZAE SAE Method e 4pornts AE 2ZAE AE 24E point i to point 10 Calculate lt I gt for e all the points CHA ome Calculate R_ in p e o Outputs Linear Polarization resistance Rp anodic 9959 5 Compute Rp cathodic 9 963 1 Copy Rp averaged 9961 45 Number of digits E Leon 00135777 Close Fig 191 Polarization Resistance process Click on the Load button to select a polarization resistance file Then a summary of the parameters will be displayed into the settings frame Note that it is possible to modify the elec trode surface area value for Rp in Q cm calculus here Then according to the experiment type it is possible to select the 4 points or the 3 points methods that both correspond to specific settings el Fig 192 4 points method Fig
267. s in the RDEC tech nique then the RDEC technique starts all over again as long as the total number of Loop increments is not reached 2 4 9 EDC External Device Control The External Device Control EDC technique allows the user to control a temperature and change it during the experiment A direct link to the External Device window is done by clicking on External Device The user can choose to apply different values of the chosen parameter successively for differ ent durations and perform a certain experiment at this value To do so several sequences each one with the desired value and duration must be created Then the desired techniques need to be linked after the EDC technique Finally the series of techniques must be ended with a Loop technique see 2 4 10 The sequences in the EDC technique will be incremented only at each time the Loop technique is reached See below for additional info Set control to i ur op External Device and wait with previous control for tg 0 h o mA 5 000 Oo 3 Record every dE 0 00 rity d 0 000 dt 90000 Arena ie Caution This technique te mainly used combined with a loop technique In this case sequences are not executed successively At each loop only one Sequence i executed the number of the executed sequence it incremented Fig 80 External Device Control parameters Set control to one can configure the External Device using the link External Device
268. s possible to select the number of points per decade Na or the total number of points Ni in linear or logarithm spacing For example a scan from fi 100 kHz to fr 1 kHz with Na 5 points per decade in logarithm spacing will perform measures at the following frequencies in KHz 100 63 1 39 8 25 1 15 8 10 6 31 3 98 2 51 1 58 1 45 Techniques and Applications Manual and a scan from fi 100 kHz to ft 1 kHz with N 11 total number of points in linear spacing will make measures at the following frequencies Hz 100 90 80 70 60 50 40 30 20 10 1 Click on the Show frequencies gt gt button to display the list of scanned frequencies Note it is not possible to select Ng points per decade in linear spacing Mod Single Sine Multiple Sine H mA sel YS lt None gt ze o200 WE oner v 10 cament steps For each curent step wait for t D oh g m Record evem dE 0000 mv o dt 0100 Scan frequencies from Fy 200 000 kHz E oft 1000 kHz vi T Na 6 points 7 per decade NT 4 points from Fy to FF Show frequencies gt gt Linear spacing Logarithm spacing n o amplitude I i 0 000 walt FOr Pyy 0 1 T ae Ges each frequency average Ng i measures per frequency drift correction E Range 10 10 sell Zeen eee Range 100 m al Bandwidth 7 v
269. s technique is an OCV The user has just to activate Turn to OCV between techniques in the advanced settings window Note Turn to OCV between techniques option forces the system to go to OCV but no OCV measurement is performed If after this forced OCV period a technique uses the OCV value as reference the value used will be the last value measured during the previous techniques Click on the Run button gt to run the acquisition The program will then ask for a file name that will be used for all the linked experiments with the following rules experiment file name user file name _ experiment number _ experiment short name _ channel number mpr For example the user file name MyFileName will be used to generate the following files experiment 1 no file name for the Trigger In option experiment 2 MyFileName_2 MP_01 mpr 221 Techniques and Applications Manual experiment 3 MyFileName_3 WAIT _01 mpr experiment 4 no file name for the technique linker loop Each of these files will store the corresponding data points for all the loops Note it is possible to synchronize linked experiments on several channels 4 3 Application Once the file name has been entered the acquisition starts and the program shows the graphic display with the data files During the run the running technique can easily be identified by the arrow on the left of it Its number is displayed in the running experiment box see
270. scharge and for a charge when the positive electrode of the cell is connected to the working electrode cable red Set C N or CxN with N and I gt 0 or lt 0 for at most t h mn s sets the rate C N or CXN at which the battery will be charged I gt 0 or discharged I lt 0 The C value could be a noninteger value 116 Techniques and Applications Manual For instance if the capacity of a battery is 1800 mA h setting C N with N 3 and I gt 0 means that a current of 600 mA will be passed during 3h The total capacity of the battery will be reached in 3h Setting CxN with N 2 and I lt 0 means that a current of 3600 mA will be passed during 30 min The total capacity of the battery will be reached in half an hour There is still the possibility to set a time limit 8 8 F109 000 foratmostty ho hilo mm 0mm00 Limits Epe Ece lt EM 1 000 NM Ewe lt Elw 3400 Y Ece gt Etes 3000 VM AOI gt AQM Do lt gt AxM 0 000 Record Ewe Ece every dEy 10 0 rm o di 00000 E Range jov 10 scil Zar ftien Range 100 m we Bandwidth 2 RestiootRA ff hig mn aoo Limit E eil dEp dt on md dh Record every dp i lr DM o dtp 300000 d i bar Aa i 3 Au one te LC 3 Ir Ewe Ece gt EL bass goto 1 4 Go back to seq Net 0 ANN aie AAS for pe 0 timels JE AV aay Ge al Fig 107 GCPL2 detailed diagram Li
271. seeeteeeseeeteeeseeeseeeseeees 60 2 3 4 RNPV Reverse Normal Pulse Voltammetry ccccceececeeeeeeeeeeeeeneeeeeeeeneees 62 2 3 5 DNPV Differential Normal Pulse VoltammMetry cccccceeeseeeceeeeeeeeeeeeeeeeeeees 64 2 3 6 DPA Differential Pulse Armperomeir 66 2 4 FOGHMIGUC DUNG e EE Ee 68 2 4 1 MP ell Ee E e DEE 69 2 4 1 1 Open Circuit Voltage Mode 01 69 2 4 1 2 Potentiostatic M de 1 isisisi eea a a aiana 70 2 4 1 3 Potentiodynamic Mode 21 71 24 OM SDeCIal Modular FP OLCMUG E 73 24 3 MGO Modular Galvano snn 76 2 4 3 1 Open Circuit Voltage Mode 01 77 2 4 3 2 Galvanostatic Mode 7 78 2 4 3 3 Galvanodynamic Mode 21 79 2 4 3 4 Sequences with the Modular galvano technoue 80 2 4 4 SMG Special Modular Gaang 81 2 4 5 TI and TO Trigger In and Trigger Out 84 Techniques and Applications Manual ZAO ee 24 7 TC Temperature COME Ol E 2 4 8 RDEC Rotating Disk Electrode Control 2 4 9 EDC External Device Control PaO MOOD GE E a DN 2412 E dl teller e EE E ON EMAILS Send sani MeN REEEEEE 2 4 13 1 E Mail CGOMTIOUIT ATION E 2 5 Manual Ke la e EEN 2 5 1 PC Potential Control 252 IC Current Manual Conio EEN 2 6 Ohmic Drop Determination ccccccecccssceceeeceeeeseeeesseeseeeeseeeeseeeseueesseesaneenaees 2 6 1 MIR Manual IR compensation 26 2 ZIR IR determination With Eeer 2 6 3 Cl IR determination by Current Interupt 2 BIPOLTEMTOSTAlTECMINQUCS a
272. ser to perform combination of OCV galvanostatic and galvanodynamic periods It is possible to chain these periods in any orders and to perform loops It gives a lot of flexibility to create galvano techniques The galvanodymamic mode can be used to study stepwise electron transfer reactions and multicomponent systems An additional limit condition on Analog Ini or Analog In2 is added which makes it special e Mode selection Click on Mode OCV 0 Potentiostatic 1 or Potentiodynamic 2 to select the corresponding mode Then the detailed diagram is automatically displayed e Open Circuit Voltage Mode 0 the open circuit voltage is the standard block So report to the OCV technique section 2 1 1 page 6 for more details e Loop goto Ns for nc time s each one of the OCV potentiostatic and potentiodynamic periods is represented by a single line into the grid parameters If nc is set to 0 the sequence lines are executed one after one Then an OCV potentiodynamic and OCV sequence for example will be programmed by 3 lines into the parameters table Setting nc gt O will loop to a previous line Ns lt Ns for ne times Go to the battery protocols section 3 1 page 107 for more details on loops conditions It is possible to loop to Ns 0 but Ns must be lt Ns current Sequence line number e Galvanostatic Mode 1 Set to I pA A vs lt None gt Ictrl Imeas for ts h mn S sets the SEN to a
273. ser to select the current range and the bandwidth damping factor of the poten tiostat regulation e Loop Go back to Ns for nc time s gives the ability to loop to a previous sequence Ns lt Ns for nc times Sequences of the chronopotentiometry technique can be chained using the Table frame The first sequence is Ns 0 The number of loops starts while the loop block is reached For example on Ns 3 if one enters goto Ns 2 for nc 1 time the sequence Ns 2 Ns 3 will be executed 2 times Nc 0 disables the loop and the execution continue to the next line Ns Ns 1 If there is no next line the execution stops 3 2 4 CS Current Scan The CS technique consists of a current scan between two limits of current The voltage is measured instantaneously Different limits could be set such as voltage Ewe Ece Ecell or charge 170 Techniques and Applications Manual Control Apply fog Limits ab Records Ranges E Range DV DV wi d Resolution 100 pi Range 1 Allow to set a different I Range Fromm l previous sequence turn to rest Bandwidth Fig 153 Current Scan detailed diagram Apply A s mA s A s A mn mA mn pA mn From pA A vs lt Nones gt Ictrl Imeas To pA A vs lt Nones li applies a current scan from an initial current value li defined in absolute value vs Ictrl the previous controlled current or vs Imeas the previous measured cur
274. sible to loop to the first sequence Ns 0 and the current sequence Ns Ns This is different from battery experiments GCPL and PCGA Report to the battery techniques section 3 1 page 107 for more details on loop conditions e Sequence repetition The last part of this technique is dedicated to repeat sequences when many sequences are done It is possible to add sequence in impedance measurements This tool is convenient to save time indeed during the same experiment it is possible to work in single sine mode at high frequencies and in multisine mode at low frequencies or to change the sinus amplitude When the box Increment cycle number is ticked each sequence will be considered as a cycle This tool is useful to fit EIS data files with ZFit 2 2 1 2 Additional features e It is possible to add sequences This could be very useful to do a first part of the high frequencies experiment with single sine measurement and the second part of the experiment at low frequencies with multisine measurement This will allow the user to save time e It is possible to modify on line the settings of an impedance measurement during the experiment The user can Modify Pause Resume or Stop the experiment while running e The counter electrode potential can be recorded in EIS techniques So the EIS meas urement is done simultaneously on the working electrode and on the counter electrode To do that select Record Ece in the Cell characteristics
275. signal level at each frequency and impedance measurement results tend to be noisier These two effects have to be taken into account when choosing the frequency The number of frequencies depends on user needs and is defined in the settings of the elec trochemical impedance spectroscopy technique In EC Lab software the multisine measure ment is done simultaneously on a maximum of two decades If more than two decades of twenty sine waves are chosen the software automatically divides the frequencies by sets of twenty 54 Techniques and Applications Manual The maximum amplitude of the signal is 0 5 V or IRange 2 for potentiostatic or galvanostatic mode measurement respectively Multisine measurements are done only for frequencies smaller that 1 Hz in the remainder of the frequency range only one single sine measurement is available Note that if the frequency range defined by the user is included in the two kinds of techniques single sine and multisine the measurement will be done in continuity with first a single sine measurement and afterwards a multisine measurement In EC Lab software multisine measurements are faster than single sine ones by an order of 3 which is very interesting for fast systems Nevertheless the definition of the measurement conditions especially the value of the excitation of the electrochemical cell has to be done in agreement with the preservation of a linear response of the system Please refer
276. sing Cycles definition auto C Espot As Text Compact 1 Count half cycles Fig 121 Process window for PCGA technique The x variable is obtained by processing the PCGA raw data file but without compacting it X can be processed if the user has previously defined the cell characteristics If the user forgot it it is still possible to modify the cell characteristics after the experiment in the raw data file In the Tools menu select Modify cell characteristics Open the desired raw data file and the cell characteristics window appears Once the characteristics are changed click on Save 141 Techniques and Applications Manual 3 1 11 MB Modulo Bat Modulo Bat a modular technique designed for battery applications is a protocol including in one technique all the control modes available in a potentiostat galvanostat These control modes are CC Constant Current CV Constant Voltage CR Constant Resistance CP Constant Power CS Current Scan VS Voltage Scan Cl Current Interrupt Rest Loop PEIS Potentio Electrochemical Impedance Spectroscopy GEIS Galvano Electrochemical Impedance Spectroscopy TI Trigger In TO Trigger Out All the control modes can be sequenced to create a unique experiment For each sequence up to three limits and three recording conditions can be set Different actions can be taken when a limit is reached Only one data file is created per technique To have seve
277. ss Data Input Files C Users electrochime Desktops amples Fundamental Electrachemistry CA Fe 1 mpr Technique Chronoamperometry Chronocoulormetry Processed File C UsershelectrochimeDesktop S amples Fundamental Electrochemistry Load Add Remove Clear VY anables To select from the input file To be added mode MWY cycle number ox red Al D Doldm error 7 0 chargednmg h control changes 7 D discharge m h Ns changes Wl cycle timers counter inc Vi step times times charge time s contral MW discharge times Ewe m d mA h All A Process JI Allow Reprocessing Cycles definition auto Export As Text C Count half cycles Process Display Close Fig 15 Chronoamperometry chronocoulometry processing window 2 1 8 CP Chronopotentiometry The Chronopotentiometry is a controlled current technique The current is controlled and the potential is the variable determined as a function of time The chronopotentiometry technique is similar to the Chronoamperometry Chronocoulometry technique potential step being re placed by current steps The constant current is applied between the working and the counter electrode This technique can be used to investigate electrode kinetics but is considered less sensitive than voltammetric techniques for analytical uses Generally the curves Ewe f t contain plat eaus that correspond to the redox potential of the electroa
278. stance pulse value and duration Record Ewe every dE mV and at least every dts S limits the recordings conditions in voltage variation and or time variation Range Bandwidth sets the current range and the bandwidth for this experiment e Conditional test proposes to go to the next sequence or to loop on a previous sequence Ns Ns lt Ns 3 1 19 PWPI Power Profile Importation This technique consists in applying various power values on a battery during a defined dura tion This technique is specially designed to fit with the urban driving patterns designed to test EV batteries The particularity of this technique is the large number of sequences available and the fact that the experimental settings can be defined by importation of a text file Note that experimental limits are not present in the setting it is highly recommended to use safety limits located in the Advanced Settings tab to avoid overcharge or overdischarge of the batteries The text file importation columns are time s differential or absolute and power Watt 162 Techniques and Applications Manual Set power to P L 6 601 na for ke 0 H E mn 32000 Record Ewe ever des If ri and at least ever dts 07 m Range m Bandwidth E medium Gobackto seq Ns 10 RGIS Gent facta for ne 0 times d r aer re al Ne dl 0 1 2 3 4 5 6 7 8 93 10 gt Fig 148 PWPI detailed diagram e Pulsed power discharge
279. stem acts as a coulometer and a recording is performed every time the charge increment decrement since the previous recording is gt dQ and or every di time interval Limit AQ to AQm A h fA h kC pC lt gt AXxm sets the maximum charge change from the beginning of this sequence during the sequence This charge is equivalent to a Axum quantity which corresponds to a normalized charge related to intercalation electrodes 3 Safety limit for the cell If Ewe Een gt lt EL ae V The third step is the test on the open circuit final potential This test is skipped if there is no OCV period tr 0 The test performed takes the conditional value gt or lt whether the open circuit sequence oc curs after a charge gt 0 or a discharge lt 0 124 Techniques and Applications Manual The above 2 steps Galvanostatic and resting period will be repeated until the working elec trode potential reaches the limiting condition Ewe gt E after a charge or Ewe lt E after a dis charge Note the user can bypass this test by entering p pass instead of a voltage value E Range enables the user to select the potential range and to adjust the potential resolution with his her system See EC Lab Software User s Manual for more details on the potential resolution ad justment I Range Bandwidth sets the current range and bandwidth for this experiment e Report to the GCPL section
280. t occurs after a charge gt 0 and with the conditional value lt after a discharge I lt 0 If the condition is not fulfilled the above 3 steps will be repeated until the working electrode potential reaches the final open circuit condition Ewe E after a charge or Ewe lt Ex after a discharge Note the user is allowed to bypass this test by entering p pass instead of a voltage value e Fourth step conditional test which proposes to go to the next sequence or to loop on a previous sequence Ns Ns lt Ns If Nc is set to 0 then the technique executes the next sequence If the user wants to loop to a previous sequence line the 2 last columns of the table needs to be filled Go back to Ns and n cycles 128 Techniques and Applications Manual The end of the technique is obtained by setting Ns and ns to 0 in the last sequence or setting Go back to sequence Ns 9999 at any sequence which then will be the last one executed even if the next sequence has its settings Such a complete sequence corresponds to one line of the table This line is composed of the columns which represent the successive variables encountered when setting the diagram the current range and the loop conditions all parameters which must be set by the user see Warning 2 Note that it is always possible to force the end of a technique while it is running at any se quence sweep using the Modify button and setting Goto sequence Ns 9
281. t le then if h l2 Ewe lt Ex oxidation then the galvano pulse is performed again else the execu tion continues to the next sequence if h lt l2 Ewe lt Ex reduction then the galvano pulse is performed again else the exe cution continues to the next sequence If the OCV period is canceled tr 0 or the Emin Emax or AQw limits have been reached then the E test is not performed If the user types the p character for pass for EL then the test is skipped too e Next sequence Next sequence or Go back to sequence Ns for ne time s loops to a previous sequence Ns lt Ns Nc time s Set Nc O to cancel the loop and go to the next sequence Ns 1 Note in this technique the first and last data points of each current steps are not recorded automatically 3 1 16 PPI Potentio Profile Importation Insert Techniques Battery Capacity Determination BCD Fotential Galvanostatic Cycling with Potential Limitation GP Galyvanostatic Cycling with Potential Limitation 2 GCPL2 Galvanostatic Cycling with Potential Limitation 3 GPL Galvanostatic Cycling with Potential Limitation 4 GDL A Galyvanostatic Cycling with Potential Limitation D GCPLS Galvanostatic Cycling with Potential Limitation 7 GOPL Special Galyanostatic Cycling With Potential Limitation SGCPL Potentiodynamic Cycling with Galyanostatic Acceleration PEGA Modulo Bat MB Coulombic Efficiency Determination CED Constant
282. t Power application is designed to study the discharge or the charge of a cell at constant power The following figure presents the working electrode potential evolution vs time when the power is constant P E l limit Eve Fig 135 CPW discharge control P and measure Ewe sample vs time The constant power control is made by applying the current necessary to maintain E constant The current increases when Ewe decreases 151 Techniques and Applications Manual Set P Ell at for at most tW 10 hijo ma Oon nia Ol gt keep Wl Iw 200 000 Limits Ewe gt EN A0 gt ADM lt gt AX Record ever dE dq dt E Range ov 10 Z nn NNN at Range 1A Bandwidth 7 wi 2 RestfortR b hfs mn foon s Limit ME we dl lt dEp dt 00 ri A Record even dep If DM or dtp 16 0000 dee Ger Za adi goi Fs 3 IE E we Ej pass V goto 1 4 Go back to seq Ne 0 ANN age EM for pe 0 time s Zi oa sez Fig 136 CPW detailed diagram Set P E l uW mW W for at most tm h mn S sets the cell power to P El for tm duration With I gt 0 orl lt 0 and keep I lt lm pA A defines the charge I gt 0 or discharge I lt 0 mode and limits the current to a maximum value lu in order to preserve the cell and or the instrument Limit Ewe gt lt Eu V AQ gt AQu A h fA h
283. t at each frequency This delay is defined as a part of the period Of course for low frequencies the delay may be long average N measure s per frequency repeats Na measure s and average values Compensate at defines the level of the measured uncompensated resistance Ru that will be compensated to define IR The user can check the box to consider the compensated resistance in the following technique or not Compensation mode in the SP300 based instruments the compensation could be made by software or by hardware Note that the hardware compensation is not available with the CE to ground and WE to ground connections E Range 94 Techniques and Applications Manual enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment I Range Bandwidth sets the current range and bandwidth values for the whole experiment Results Ru Ohm Rc Ohm shows the uncompensated and compensate resistance obtained with this technique 2 6 3 Cl IR determination by Current Interrupt some set up induces ohmic drop iRu In that case ohmic drop can be significant and affect the measurement A method to estimate the resulting uncompensated resistance Ru is to perform the Current Interrupt Cl method A current step is applied and the Ru value is deter
284. t the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential res olution adjustment Range Bandwidth sets the current range and bandwidth values for the entire experiment Go back to Ns for nc time s each one of the OCV potentiostatic and potentiodynamic periods is represented by a single line in the grid parameters If nc is set to 0 the sequence lines are executed one after another Then an OCV potentiodynamic and OCV sequence for example will be programmed by 3 lines in the parameters table Setting n gt 0 will loop to a previous line Ns lt Ns for ne times 2 4 3 3 Galvanodynamic Mode 2 Scan with dl dt mA s with pA A per S defines the scan rate The same as for the Modular Potentio technique entering the dl dt value will automatically calculate the dl and dt values in order to minimize the current steps dl Nev ertheless one can enter dl and dt directly from li pA A vs lt None gt Ictrl Imeas to I pA A vs lt None gt Ii defines the initial l and final current of the scan Limits E V and AQ to AQwu fA h A h pC kC defines the potential and sequence charge limits The E1 limit is dependent on the charge sign the limit is Ewe gt Eu if ls gt 0 Ewe lt E else To cancel the limits type p for pass in the Ex edition box and z
285. tation 4 GCPL4 battery testing technique simi lar to the GCPL with a global time limitation for the charge discharge period Galvanostatic Cycling with Potential Limitation 5 GCPL5 battery testing technique simi lar to the GCPL technique with a different recording conditions of the potential at the beginning of the galvanostatic period The potential is recorded with a geometric time progression The current potential is used to calculate the apparent resistance of the cell Galvanostatic Cycling with Potential Limitation 6 GCPL6 battery testing technique simi lar to the GCPL technique except that the Limit potential during the galvanostatic period is applied the potential difference between the working and the counter electrodes 230 Techniques and Applications Manual Galvanostatic Cycling with Potential Limitation 7 GCPL7 battery testing technique simi lar to the GCPL technique except that the Limit potential is held by controlling the current needed to keep Ewe at Em value By doing so the whole experiment is performed in galvano mode Galvanostatic Electrochemical Impedance Spectroscopy GEIS technique for imped ance measurement in galvanostatic mode Generalized corrosion GC technique used to study general corrosion It consists of half a cycle or a cycle of usual cyclic voltammetry with a digital potential sweep Range current range used in the experiment It is related to the current resolution Impedance
286. technique with RRDE control is described in Fig 76 of section 2 4 6 page 85 For the LOOP option choose Goto technique 2 MP for 5 times and report to the section 2 4 10 page 89 for more details Then click on the Accept button This will send the experiment list and the experiment param eters to the instrument Note that the current experiment number is now displayed for the 4 pages Advanced Set tings Cell Characteristics Parameters Settings and Linked Experiments Note that one can accept all the experiment parameters at the end Once in modify mode one cannot change the current experiment number 220 Techniques and Applications Manual Devices 4 Tum to OC between techniques dl d amp E g Wat with previous control i MPG 210 241 forta o hn mn 10 0000 s slit WPS 237 or from technique i begin untilthe 7 month f3 day 2009 year 1 han m 55 Record ever dE 0 00 ry Experiments di opp pA sl Advanced Settings dt o0000 s Cell Characteristics i 2 MP of 3 WAIT oe A Loop Fig 201 Linked experiment parameters setting window The linked techniques are displayed on the left of the window with their number in the experi ment Click on the button corresponding to the technique you want to see to display the detailed diagram Note it is possible with the technique linker to apply 50 ms OCV period between two tech niques reduced to 0 6 ms if the previou
287. tential step from 1 to 100 for the current average lt I gt calcu lation It may be necessary to exclude the first points of the current response which may only be due to the capacitive rather than faradic behavior of the system 29 Techniques and Applications Manual Record lt l gt averaged over N voltage step s averages N current values on N potential steps in order to reduce the data file size and smooth the trace The potential step between two recording points Is indicated between brackets Once selected an estimation of the number of points per cycle is displayed in the diagram E Range enables the user to select the potential range and to adjust the potential resolution according to the experiment See EC Lab Software User s Manual for more details on the potential resolution adjustment Range Bandwidth enables the user to select the current range and the bandwidth damping factor of the poten tiostat regulation e Final potential End scan to E V vs Ref Eoc Ei gives the possibility to end the potential sweep or to run a final sweep with a limit Er Option Force EE During the experiment clicking on this button allows the user to stop the potential scan set the instantaneous running potential Ewe to E or E2 according to the scan direction and to start the reverse scan Thus E or and E2 are modified and adjusted in order to reduce the potential range Clicking on this but
288. the CV description part for more details about the technique This technique was implemented to offer the user all the extended capabilities that can be required during a po tential sweep In particular a table was added to the CVA to link potential sweeps with different scan rates A vertex delay is possible at the beginning potential at both vertex potentials and at the final potential For each of these delays the current and the potential can be recorded at the user s convenience A recording condition on cycles offers the possibility to choose which cycle to record A reverse button can be used to reverse the potential sweep when necessary without modifying the vertex potentials different from the Force button The technique is composed of e astarting potential setting block a 1 potential sweep with a vertex limit E4 a 2 potential sweep in the opposite direction with a vertex limit E2 a possibility to repeat nc times the 1 and the 2 potential sweeps a final conditional scan in the reverse direction to the previous one with its own limit Er Note that all the different sweeps have the same scan rate absolute value But it is possible to add sequences allowing using different rates for each sequence The detailed diagram the following figure is made of three blocks e Starting potential Set Ewe to Ej V vs Ref Eoc Ectrl Emeas sets the starting potential vs reference electrode potential or vs the open circuit p
289. the bandwidth damping factor of the poten tiostat regulation 3 4 13 CASP Constant Amplitude Sinusoidal microPolarization Constant Amplitude Sinusoidal microPolarization is used to determine the corrosion current and the corrosion coefficients of a tafelian system A sinusoidal voltage is applied around the corrosion potential Eor with a small amplitude Va and a constant low frequency fs This technique is associated to a dedicated fit CASP Fit that uses a direct Fourier transform to determine the amplitude of the harmonics They are then used to calculate the corrosion pa rameters This technique is faster than the standard polarization technique and there is no need to know the corrosion coefficient values This technique is available whether the channel board has EIS ability or not This technique is essentially an intermediate that may be less destructive to a sample than Tafel polarization but probes a more expanded voltage window than the Polarization Resistance technique As a result it is a balance of accuracy and sample damage that lies between the two techniques 208 Techniques and Applications Manual E we ITFI E corr Time frequency T ne cycles Fig 187 Principle of the Constant Amplitude Sinusoidal microPolarization technique and its associated analysis Set Ewe to Ecorr Apply a sinusoidal potential with frequency Fe 0 100 Hz amplitude Ya i oo mv ws E corr Repeat np 20 timels Reco
290. the first vertex potential value vs reference electrode potential or vs the open circuit potential Eoc or vs the potential of the previous experiment Ei Sete we ta Eq 0 000 Wows Eoc ScanEwe with dE mmm m perdt 0m0n 3 to vertex potential Eq 1000 Y wa Ref Reverse scan to vertes Ep 1000 Vo vs Ref gt Repeat ne 0 tirne Measure lt i gt over the last EN of the step duration Record lt i gt averaged over H i voltage steps ERange 25 25 EI Grea Ad ei Range Auto vi Bandwidth E 4 Endscanto Ef 0 000 V w Eoc e dE dt 100 000 nm del IEN 1 0 ml 4000 points per cycle Fig 19 Staircase Voltammetry detailed diagram e Reverse scan Reverse scan to vertex potential E Vve Ref Eoc Ei runs the reverse sweep towards a 2 limit potential The vertex potential value can be set vs reference electrode or according to the previous open circuit potential Eoc or according to the potential of the previous experiment Ei e Repeat option for cycling Repeat ne times repeats the scan Ei to E to E2 ne time s Note that the number of repetition does not include the first sequence if n 0 then the sequence will be done once if ne 1 the sequence will be done twice if n 2 the sequence will be done 3 times etc e Data recording conditions Measure lt l gt over the last of the step duration selects the end part of the po
291. the whole experiment Turn to OCV for tr s with the same recordings Turn to the OCV mode for a given time with the same recording conditions as the galvanostatic block Repeat and OCV blocks nc times repeats the previous two sequences to calculate an averaged resistance value Compensate at 96 Techniques and Applications Manual defines the level of the measured uncompensated resistance Ry that will be compensated to define IR The user can check the box to consider the compensated resistance in the following technique or not Compensation mode in the SP300 based instruments the compensation could be made by software or by hardware Note that the hardware compensation is not available in WE to Ground and CE to ground connections Calculate Ri at Both Rising Falling edge performs the resistance calculation for either the rising edge or the falling edge or both of them Results Ru Ohm Rc Ohm shows the uncompensated and compensate resistance obtained with this technique 2 Bipotentiostat techniques The bipotentiostat techniques were added to EC Lab software since the version 10 30 These techniques are available on multichannel potentiostat VSP VMP2 VMP3 SP 300 VSP 300 and VMP 300 This kind of experiment consists in applying two synchronized techniques on two electrodes one technique on each electrode This is the case of the Rotating Ring Disk Electrode RRDE or hydrogen perm
292. to apply successively several voltage steps to the cell s Between each voltage step an open circuit voltage period can be added e Rest period The rest period is an open circuit voltage period Refer to the OCV description for more details e Potential step with data recording conditions Apply E V vs Ref Eoc Ectrl Emeas the potential step is defined vs Ref the reference electrode potential or according to the pre vious open circuit potential Eoc controlled potential Eet or measured potential Emeas fort h mn s sets the potential step duration Limits I to Imax pA A and AQ lt AQw fA h A h pC kC Imin D JA curtails the step duration if the current or charge limit is reached If the limit is reached the loop condition go to Ns for nc times if set is not used and the program continues to the next sequence Nz 1 The AQ value is the integral charge for the current sequence This value is not reset if there is a loop on the same sequence Ns Ns 0 values disable the tests Record I every dl pA A dQ fA h A h pC kC and dtp S lt I gt every dt S you can record either an instantaneous current value or an averaged current value lt l gt The recording conditions during the potential step depend on the chosen current variable For the instantaneous current the recording values can be entered simultaneously Then it is the first cond
293. to the Application Note 19 for more information References Van Gheem E Vereecken J Schoukens J Pintelon R Guillaume P Verboven P and Pauwels L Electrochim Acta 49 2004 2919 2925 Pintelon R and Schoukens J System identification A frequency Domain approach Ed IEEE Press 2001 Van der Ouderaa E Schoukens J Renneboog J IEEE Trans Instrum Meas 37 1 1988 145 147 Schoeder M R Pintelon R Rolain Y IEEE Trans Instrum Meas IM 49 2000 275 2 3 Pulsed Techniques 2 3 1 DPV Differential Pulse Voltammetry DPV is considering as an electroanalytical method It is very useful for analytical determination for example metal ion quantification in a sample The differential measurements discriminate a faradaic current from a capacitive one In this technique the applied waveform is the sum of a pulse train and a staircase from the initial potential Ei to a limit potential Ev or to the final potential Es if the scan is reversed The current is sampled just before the pulse and near the end of the pulse The resulting current is the difference between these two currents It has a relatively flat baseline The current peak height is directly related to the concentration of the electroactive species in the electrochemical cell Description e Initial potential Set Ewe to Ej V vs Ref Eoc Ectri Emeas forti h mn s sets Ewe to the initial potential E This potential value can be s
294. ton is equivalent to clicking on the Modify button setting the running po tential as E or E2 and validating the modified parameters with the Accept button The Force E E2 button allows the user to perform the operation in a faster way in the case where the potential limits have not been properly estimated and to continue the scan without damaging the cell Note it is highly recommended to adjust the potential resolution according to the experiment potential limits This will considerably reduce the noise level and increase the plot quality Graph tool Generate cycles see the CV technique for more details 2 1 10 LASV Large Amplitude Sinusoidal Voltammetry Large Amplitude Sinusoidal Voltammeiry LASV is an electrochemical technique where the potential excitation of the working electrode is a large amplitude sinusoidal waveform Similar to the CV technique it gives qualitative and quantitative information on the redox processes In contrast to the CV the double layer capacitive current is not subject to sharp transitions at reverse potentials As the electrochemical systems are non linear the current response exhib its higher order harmonics at large sinusoidal amplitudes Valuable information can be found from data analysis in the frequency domain 30 Techniques and Applications Manual Begin Set Initial Potential to E WE Set frequency Potential range definition from E to E End f Fig 20 General diagram for Large
295. trode cable red Set C N or CXN with N and I gt 0 or lt 0 for at most t h mn s sets the rate C N or CxN at which the battery will be charged I gt 0 or discharged LO The C value could be a noninteger value 118 Techniques and Applications Manual For instance if the capacity of a battery is 1800 mA h setting C N with N 3 and I gt 0 means that a current of 600 mA will be passed during 3h The total capacity of the battery will be reached in 3h Setting CxN with N 2 and I lt 0 means that a current of 3600 mA will be passed during 30 min The total capacity of the battery will be reached in half an hour There is still the possibility to set a time limit 1 Set w tots 100 000 m se 198 lt Noner forat most ty ho hig mn mm00n Limits Ewe Ece gt ER 4 000 Ewe gt Elw 4 200 Ece E le foo Record Ewe Ece pen dEy 00 mW o dty 00000 foe Ef cet Ef doe on ip Ay Set Ewe Eyeto Eg 3 000 fortgs h hig mn ooooo0 Limit I lt IM 0 000 ms vw o MA d dt 0000 mas v Record even dq 7 000 pAah or da 30 0000 Limit AQ gt AQy 6 000 mah v gt AM 0 000 ERange DV EM scil Arena Z r Range 100 m wi Bandwidth 5 medium 2 RestiortR D hjo mn pooo s Limit HE e dl lt dEp dt op mmh Record every dip ffr ut o dp 30 0000 s itty Ger d t Ae gots L 3 Ewe Ece lt EL pas gato 1 a Goback to s
296. ues such as dQ I Q Qo X and cycle number are also available as with other GCPL applications For more detail see the GCPL application One classical application of this technique is to follow the ohmic drop Ri evolution with an aging Li ion cell after several charge discharge cycles Another application is to determine the internal resistance of the battery versus time Ewe V UL Gia Haa 5 3808 5 3808 5 3808 5 3808 5 3808 5 3808 time Fig 112 GCPL 5 processed file display for Ri determination 3 1 7 GCPL6 Galvanostatic Cycling with Potential Limitation 6 This technique is similar to the GCPL technique Contrary to the GCPL technique the potential control during the potentiostatic period value is not done between Ref1 and Ref2 Ewe but between Ref1 and Ref3 Ewe Ece This technique offers the user the possibility to follow the voltage of each electrode Hei and Ref3 vs a reference electrode in the battery This tech nique is only available with SP 50 SP 150 VSP VMP3 HCP 803 HCP 1005 CLB 500 and CLB 2000 as it requires the measurement of the potential on Refs 1 Galvanostatic period Set to Is pA A vs lt None gt Ictri Imeas for at most ti h mn S sets the current value in absolute versus the previous controlled current previous sequence or versus the previous measured current and the maximum duration of the imposed current period The sign of the current value is for a discharge and
297. ution ad justment I Range Bandwidth sets the current range and bandwidth for this experiment e Second step open circuit period with monitoring of the electrode potentials turn to Rest for tr h mn S sets a maximum time tr to stay in open circuit mode Limit dEwe dt lt dEr dt mV h gives the user the ability to shorten the open circuit period when the decay of the potential is lower than a given value Record Ewe every dEr mV and at least every dtr S allows the user to record the working electrode potential with a given potential resolution whenever the change in the working electrode potential is gt dEr or and at least every dtr time interval Note the conditional test if tr O0 which bypasses the open circuit period e Third step test on the final open circuit potential If Ewe gt lt EL V The test is performed with the conditional value gt if the open circuit period just before the test occurs after a charge I gt 0 and with the conditional value lt after a discharge I lt 0 If the condition is not fulfilled the above 3 steps will be repeated until the working electrode potential reaches the final open circuit condition Ewe gt E after a charge or Ewe lt Ex after a discharge Note the user is allowed to bypass this test by entering p pass instead of a voltage value e Fourth step conditional test which proposes to go to the next sequence
298. window Report to the multipitting statistics process for more details in the EC Lab Software User s Manual 3 4 9 MPSP Multielectrode Potentiostatic Pitting Pitting corrosion occurs when discrete areas of a material undergo rapid attack while the vast majority of the surface remains virtually unatfected The MPSP technique corresponds to studying pitting occurrence under applied constant po tential This technique is especially designed to study pitting on several electrodes in the same electrochemical cell First there is an open circuit sequence where the working electrode potential is recorded for a given time or until its time variation is lower than a defined limit Then the system applies a constant potential which can be the potential value reached at the end of the open circuit period plus a given potential offset or a defined value until the current reaches a value defined as the pitting current At the end of the technique the working elec trode is disconnected 201 Techniques and Applications Manual Begin m zZ gt o Initial Rest Potential Sequence Potential Sweep with threshold pitting detection Disconnect the working electrode End Fig 178 General diagram of the Potentiostatic Pitting application RestfortR 0 hi mm 00000 Limit HE edd lt dEnp dt on md dh Record even dp or dtp Apply E for tj Limit Ill gt Ip th 0 500 T amp from sca
299. x acts on the potential value in the given limits You can also change the potential value in the intermediate box It is applied when you hit enter The cell is turned off by using the Stop button You can always read the applied potential and the current running in the cell in the potential and current panels on the right 2 5 2 IC Current Manual Control This menu proposes the same features as the Potential Manual Control by replacing the po tential control by the current control Therefore refer to the Potential Manual Control section previously described for more details 2 6 Ohmic Drop Determination The ohmic drop is defined by the solution resistance between the working electrode and the reference electrode It is a critical parameter that can be significant when experiments are made in non aqueous media It may lead to severe distortion of the voltammetric response as the applied potential and the potential seen by the electrodes can be significantly different The best way to determine this ohmic drop named in EC Lab the uncompensated resistance Ru is to perform an impedance measurement at high frequencies before running other exper iments ZIR EC Lab also proposes to calculate the ohmic drop using the Current Interrupt method Cl After determining Ru it will be compensated on the techniques linked thereafter Only tech niques for which the potential is controlled are concerned by the ohmic drop compensation Note t

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