On second order effects in a galvanic cell : Part I. Polarization by a sine wave modulated high frequency current

Abstract

A theoretical study is presented concerning the application of a high-frequency alternating current, amplitude modulated by a low-frequency sine wave, to a galvanic cell. Based on the correlation with the faradaic rectification technique, expressions are given for the low-frequency demodulation voltages of the faradaic process and for the double-layer capacity. Both responses, which are in-phase with the modulation signal, are combined by considering them as voltage sources, having respectively the faradaic impedance and the double-layer impedance as internal impedances. The resulting demodulation voltage appears to possess an in-phase and a quadrature component, from which information can be obtained of the high-frequency as well as the low-frequency behaviour of the cell.