It is widely acceptable method. You can find several supercapacitor studies using CHI instrument,I guess CHI760 is more advanced than CHI660. for example please go through the attachment.

K.P. Thanks a lot. But CHI 660 is a potentiostat/galvanostat, not a potentiostat. But our one is a potentiostat only.

CHI 660 is a potentiostat but CHI 760D is a potentistat/galvanostst. CHI 760D has both potentiostatic and galvanostatic characterization facilities. 

Thanks Santimoy.CHI 760D that we are using is a potentiostat only .

CHI700 version is an bipotentiostat ,You can use it for capacitor studies . please go through the below papers ,where they used CHI760D for capacitor applications

http://www.sciencedirect.com/science/article/pii/S0378775313008719

http://www.nature.com/srep/2012/121214/srep00981/full/srep00981.html

• K.P thanks a lot. Actually we are using very low concentrated solution so the ir drop is very high. In these papers they have used very high concentrated electrolyte. Our curve is not starting from 0V at 0 time and the ir drop is also high at low current. Can we get rid off this problem by using the potentiostat or we need to buy galvanostat.

How are you getting your data? I plotted it and it looks like you're using constant current charging-discharging to me (3 amps and 20 amps). If that's the case, then your data is fine.

If you want the curve to start from 0 V you can hold the cell at 0 V in a potentiostatic experiment before starting the charge-discharge measurement. Or you can just cut off the first charge-discharge cycle and shift the x-axis. This should not change the data in any way. 

I guess IR drop mainly depend on active material conductivity. the electrode already have a charge of 0.3V so when you start your charge-discharge ,it start from 0.3V .so you better start the chronopotentiometry  from cathodic .So it will discharge first and you will get complete charge-discharge cyle. if you like to get high capacitive performance you should start with atleast 0.5M -1M electrolyte. see the snapshot for the parameter information

Dear K.P. and Dicarmine thanks a lot. By making it cathodic I got the data starting from zero. That problem is solved.

But I am not getting symmetrical curve as people are publishing.I am attaching one paper where they published symmetrical curves and one of my recent data to show the difference . In my case the discharge time is very less compared to charging time. and it is too fast to reach the loest potential (0 volt) as well as highest potential (0.6v) in 2nd, 3rd and later cycles.

I am using 2 electrode set up (taking same Pt wire as reference and counter) and active material coated Pt foil as working). 3M KOH is the electrolyte. PLease see my recent data (attached word as well as text) and please help me to get symmetrical curve.

I am using 5.04x10-5 gm active material. So I if 2A current I am applying I am multiplying 2A with the amount of material and that value I am putting in parameters as cathodic and anodic current. Is that correct?

Normally two electrode setup ,both of the electrode will be your  active materials coated current collector, ,just coat your material on two pt-foil.

Start from 3 electrode setup.then see the difference in the curves.lower discharge time basically due to your materials behavior.

From your doc,

its 4.5 cycles,one complete charge-discharge is one cycle. Normally Keep the mass of the material to be more than 1 mg-2mg. so that your output will be more reliable.

Keep the Cathodic and anodic time  10sec  is enough.

IF you want A/g; Divide current your applying /weight of the active material 

K.P. thank you. I will try in three electrode set up. One more thing I want to know should I must have to put one separator in between two electrodes(both the elctrodes are active material coated Pt foil) for two electrode set up?

if space between the two electrode have well separated space . then no need of separator.if you press the two electrode together ,you separator must be present between the two electrodes.

Immerse your two electrode in electrolyte  and keep some space between two electrode.if you like to make some coin type or paper model supercapacitor, then you should place the separator between the electrode.

Your using Pt foil as Current collector,  electrolyte wont affect the CC.so immerse the electrode in electrolyte without  touching each other then do CV tests.

Thanks a lot K.P. I have done in this way only and found fine results. Thank you again. If you have any reference where it is done in this way(2 same elctrodes without separator) or it is written that this can be done please send me.

We are loading 50 micro gram sample in Pt foil and all the results are reproducing. Is these results are acceptable or not with this low loading.Please tell me. Because in the papers the ratio of binder and active material is written only, not the exact amount loaded.

Please find the attachment. examples for two electrode 

Loading depends on sample density.

Of course some of the papers were accepted with micrgram scale loading. if the 1*1cm2 Pt foil means you cannot attain uniform coating on Pt foil When you use such low loading..

After coating the materials, press the electrode under pressure of 2-5MPa. It may improve the binding on CC

Dear K.P. thank you. I am really grateful to you. In that paper they have done without separator. Now I can do chronopotentiometry in potentiostat.

please I have CHI potentiostate but the first working electrode have problem and donot work and secod working electode work

do i can measure by using the secod working electrode ?

what do you exactly mean by 1st working and 2nd working electrode.Are you using rotating disk electrode

the device have 5 wires (counter ,reference .first working electrode and second working electrode  and sensitive electrode)

1. Electrode connection (Video connector)

Pin Function

1 Working electrode (Green)

2 Sensing electrode (Black)*

3 N/C

4 Reference electrode (White)

5 Counter electrode (Red)

6 Analog Ground

what the function N/C and 2 Sensing electrode (Black)?

Dear Majid,

I think your discharge is occuring too fast. You can increase the data intervel that will help to give you the discharge points. I have done using CHi 760d only. Free to ask me for further help.

You are always welcome.