Theory of Faradaic Distortion

The passage of a pure a.c. across an electrode gives rise to a cell potential containing sinusoidal components of frequencies which are multiples of the fundamental. The first harmonic is predominant and expressions are here derived for its amplitude and phase angle. The magnitude of the effect is similar to that of faradaic rectification, but its measurement may offer advantages over the latter in the determination of the kinetic parameters of some electrode reactions. The effect of the double layer is considered, and an apparatus is described which enables faradaic admittance, rectification, and distortion to be measured simultaneously.