Hello Amrita De Adhikari

From inner and outer charge contributions, you can easily calculate the EDLC and pseudocapacitance contributions. The origin of the electrochemical activities is controlled by inner and outer charge contributions. The outer charge (qout) is straightway related to direct contact area of electrode and electrolyte normally referred as outer electrochemical surface. But, the inner charge (qin) refers to the electrochemical contributions coming from pores, voids, grain boundaries, cracks, dislocations (both edge and screw dislocations), crevices and other inner materials parameters. The qout has been calculated from extrapolation obtained from ‘q’ versus ‘v−1/2’ curve assuming ‘v’ goes to infinite, where 'v' is scan rate. But the total charge (qtotal =qin +qout) has been calculated from extrapolation obtained from ‘q−1’ versus ‘v1/2’ plot assuming ‘v’ goes to zero. So, you can compare the dominance of qout (EDLC) and qin (pseudocapacitance) in charge storage mechanism.

You can check my publications. I'm attaching some of them here.

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

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

You may refer to the bellow paper (Fig. 5), there is another way to calculate EDLC and pseudocapacitance contribution

Article Co3O4/SiO2 nanocomposites for supercapacitor application

I believe Gomaa A. M. Ali's method only works if you see non-triangular profiles from the Galvanostatic charge-discharge experiments. This is not always seen for pseudocapacitive materials and many people say this type of profile is not supercapacitor-like but instead battery-like.

If you follow Fig. 4 in the following paper, you should get the information you need with only scan rate and current (AKA charge/capacitance):

Article Porosity-Engineered Carbons for Supercapacitive Energy Stora...

You are correct that fixed potential usually refers to one potential input, and in terms of CV, this is scan rate.

You have to plot the power plot at different fixed potential to find the b value closer to 0.5. You will get detailed information in the attached publication

Dear Jet-Sing M. Lee

The method -you provided (Trasatti method)- is known method. But if you read the question, Amrita De Adhikari is asking for OTHER method (other than Trasatti method?). So if we suggest Trasatti method, it will not be an answer.

Thanks