EIS analysis was carried out to gain insights about the charge transport kinetics and contribution from different resistances (Figure ). The solution resistance (RS), charge transfer resistance (RCT), and Warburg resistance (RW) were calculated from the Nyquist plots (Figure ). The initiation of semicircle in the high-frequency region corresponds to the solution resistance of the electrodes. The solution resistance increases from 0.58 Ω for GP-AC to 1.21 Ω for GS-AC and follows the sequence GP-AC < BPL-AC < GR-AC ≃ S-AC < GS-AC, the values are given in Table . The width of semicircle region in the Nyquist plots correspond to charge-transfer resistance of the electrodes. BPL-AC shows the lowest RCT of 0.29 Ω while GS-AC shows the highest RCT of 37.4 Ω, indicating the presence of charge transfer processes at the electrode surface. The charge transfer reactions can occur due to the presence of redox-active surface functionalities on activated carbons. The overall sequence of RCT is as follows: BPL-AC < GP-AC < Y-AC < S-AC < GR-AC < GS-AC. The charge transfer resistance is followed by Warburg or diffusion resistance (Rw) in the intermediate to low frequency regions of the Nyquist plots. The smaller RW indicates efficient diffusion of electrolyte ions deep inside the electrode pores. This is seen for GP-AC (0.61 Ω), Y-AC (0.97 Ω), S-AC (1.15 Ω), and BPL-AC (1.41 Ω) in the Nyquist plots. GR-AC and GS-AC exhibit higher resistance of 6.78 Ω and 36.4 Ω, respectively, indicating sluggish kinetics of pore utilization in the intermediate to low frequency regions. The appearance of quasi-vertical lines at lowest frequencies correspond to capacitive type behavior of the electrodes. The capacitance values at lowest frequencies (0.001 Hz) were calculated from the imaginary component of the Nyquist plot using equation 1 and are reported in Table . The relation between frequency and specific capacitance in Figure (b) provides further kinetic insights into the charge storage behavior of the electrodes. At high frequencies (10 5 Hz to 10 1 Hz), the electrolyte ions can only utilize the outer surface of the electrode and don't have enough time to access the pores, leading to very small and nearly constant capacitance in the high frequency region.