Electrochemical impedance and complex capacitance to interpret electrochemical capacitor

The electrochemical impedance Z and complex capacitance C for typical equivalent circuits were summarized systematically in order to support the frequency domain analysis of electric double layer capacitance (EDLC). In the present paper, the impedance and the complex capacitance were calculated in the case that the electrochemical response of porous electrode was presented by a transmission line model (TLM). The loci of Z and C on the complex were divided into the lumped constant and distributed constant ranges in low and high frequency ranges, respectively. The complex capacitance plot was superior to obtain the capacitance of porous electrode than the impedance plot.