Analytical expressions for electrochemical supercapacitor with potential dependent capacitance

Distinctly from ordinary capacitors which have a fixed capacitance, the capacitance of electrochemical supercapacitors is dependent on the applied potential. This feature introduces an additional complication to the analytical solution representing the supercapacitor circuit. Here a simplified equivalent circuit of electric double layer capacitors or electrochemical supercapacitors is proposed so that expressions evaluating the potentialdependent capacitance are derived considering short periods of charging and discharging process as in cyclic voltammetry carried out in a few minutes. Comparisons between such theoretical development and experimental cyclic voltammetry data - presenting a very good agreement - are presented and discussed.

Automated summary

The capacitance of electrochemical supercapacitors depends on the applied potential, requiring a simplified equivalent circuit for deriving related expressions. The theoretical development shows very good agreement with experimental cyclic voltammetry data.