Theory of Potentiostatic and Galvanostatic Charging of the Double Layer in Porous Electrodes

Abstract

A theory of potentiostatic and galvanostatic transients which occur during charging of the double layer in porous electrodes is developed. Solutions are presented for transients due to charging processes in the interior of idealized, one‐dimensional porous and tubular electrodes of finite length. In addition, the effect of IR drop which occurs in solution between the tip of the reference electrode capillary and the front surface of the porous electrode is calculated. The effect of the external surface of the electrode on the charging transients is also assessed. Solutions for charging transients are presented for the case of potentiostatic and galvanostatic single pulse methods, for measurements made with square waves of current or voltage, and for triangular current or voltage sweeps. The effect of the conductivity of the metallic phase on the observable transients is considered. Graphical solutions of the theoretical equations are presented.