Hello Fatemeh Soleimani

The charge-discharge (CD) behaviors can be described in two ways - current density and potential window aspects.

1. using low current density causes such kind of behavior as shown in blue curve (potential window 0.5 V). the curves shows saturation charging towards 0.5 V for a long time which is not desirable for supercapacitor application. Means such low current density cant able to charge upto 0.5 V. So, you can increase current density to fast charge-discharge behavior which is the primary condition for supercapacitor electrode.

2. Now you can reduce the potential window below 0.5 V (maybe 0.4 V). As you can see that at low potential window the CD behavior shows excellent charge-discharge plot with low iR drop.

First analyse the symmetric CV to get optimum potential window, the CD in between the same window. I can see your electrode shows clear pseudocapacitive behavior through non-linear CD curves.

Is it for your electrode or device? device generally shows such large iR drop for increased internal resistance.

you can check my publications as you can find similar type of CD behaviors with interpretation. I've attached a few here.

Article V2O5 encapsulated MWCNTs in 2D surface architecture: Complet...

Article Free-standing flexible MWCNTs bucky paper: Extremely stable ...

Article Large scale flexible solid state symmetric supercapacitor th...

Thank you dear Bidhan Pandit

Is it possible to measure charge/discharge behaviour of a supercapacitor through chronopotentiometry technique? Usually people use galvanostatic charge discharge or cyclic charge discharge technique. Please comment.

Kindly tell me the Formula for calculating discharge capacity from Chronopotentiometry.

I am working on Supercapacitor material. It shows -0.7 to 0.9 volts in CV, during GCD 0.9 to -0.1 volts. why difference in potentials of CV and CP?