You can use glassy carbon as your current collect as long as you stay in the stable range of potential given by your electrolyte.

Not familiar with the type of potenciostat you mention sorry.

v.

I agree with vanesa,.

Thank you Vanesa and Shridhar. I have done charging-discharging in 1M NaoH at 1mA/cm2. But the voltages are only in the range of -1 to -1.2V, not over desired voltages. I want to go from 0-3V range. If I change to higher currents, I am damaging the GC electrode. Could you guys answer me how can I go to desired voltages without damaging the electrode?

Dear Kolla Praveen,.

Use three probe set up, if graphene works for the mentioned potential window. -1 to 1.2 V is big enough. About current 1mA/cm2, try for various current densities. But keep the potentail window -1 to 1.2V. I think you will get te desired results. Dont go for high voltages, obviously it will spoil the sample.

with regards

shridhar

Dear Kolla, when using aqueous media (e.g. NaOH solution) the potential is limited by the breakdown of water, this means 1.23 V theoretical value. In certain situations you can increase such value , but getting to 3 V basically means you are decomposing your electrolyte and degrading your glassy carbon electrode.

If cycling at 3 V is a requirement, you can use organic or ionic liquid media

regards

As we known, the supercapacitor need two electrodes with similar capactance, other wise the charge has no enough site to save. In your case, the GC has very low capatance because of its small specific surface which is the most important factor for your evulation. So i think it is not a good alternative with GC as auxiliary electrode, other than a common graphite powder electrode.

Try to use "my" electrochemical cell like (+)C-KOH.2H2O-Sn or TiFe

I have never used the pine instruments bi-potentiostat, but I am sure you must have an option for Constant Current Potentiometry where you can set your current and voltage limits.However, this will allow you to only charge your supercap.To get the full charge/discharge profile you can use the Cyclic Potentiometry option and enter your parameters to obtain multiple scans

First could you describe the exeprimental setup? You plan to use or use the GC electrode as working or counter and what is the reference (if any).Or do you use two electrode setup without any reference (reference cable connected to the counter electrode) ?? If galvanostatic mode is used the current is the controlled paramter and the potential value is a dependence of the reactions in the cell. Thus you cannot expect to get the potential range as desired. If you use the potential limit (for working electrode in the three electrode setup) or cell voltage limit in the two elelctrode one it can happen that the set current value is to high the machine switches off. In addition to that aqueous electrolyte what was mentioned above is not stable in the three 3V potenetial window. Production of gaseous hydrogen (on the negative electrode) and oxygen (onth epositive one) should start at about 1,5V of the cell potential (if no kinetic limitations which is the case of the carbon electrode in water- overpotential of the gas evolution are present - one of the best examples of the phenomenon existence is the extreme overpotential of the hydrogen evolution on mercury allowing for sodium and potassium cation reduction in water. Generally the voltage of the aqueous supercap is limited to about 1V beciouse of that reason. If you use a high surface area material e.g. carbon powder/black, nanotubes, carbon onions, or graphene as a working electrode (or one of the two in the non-symmetric two electrode setup the nature of the current is notdue to the Faradaic reaction but due to charging discharging of the double layer capacitance being proportional to the surface of the structured electrode. This not the case for GC(id used as the counter/second el;ectrode) which if polished is applied in various mesurements due to the low specific adsorpton and lower than other solid elecrodes values of the double layer capacitance (per surface unit). Thus the faradiac process is needed to depolarize the glassy carobn electrode. Whis leasd to the GC degradation.