In this paper we show the discrepancies between the current frequency- and time-domain analyses (i.e. galvanostatic charge/discharge and cyclic voltammetry) being used for characterizing electric double-layer capacitors, and propose new formulae based on Rs-CPE model. See table below.

Constant-current time-voltage (a) and (d), time-energy (b) and (e), and power-energy (c) and (f) profiles of PS and NEC EDLCs respectively. The solid lines represent the experimental data, whereas the dash-dot lines and the dashed lines represent the fitted data using the RsC model and the Rs–CPE(Q, α) model, respectively.