Dynamic electro-chemo-mechanical analysis during cyclic voltammetry

Abstract

We report and validate a method for measuring the strain-response, ς, of the electrode potential of electrically conductive solids in a fluid electrolyte. Simultaneously with cyclic voltammetry, the electrode is subjected to cyclic elastic strain at frequencies of up to 100 Hz. We explore three independent strategies for separating the cyclic variation of potential or current from the voltammogram proper, and find that the results of all three are in quantitative agreement. By means of an example we explore dominantly capacitive processes at a gold electrode in H₂SO₄ and HClO₄. The response parameter ς is not sensitive to the nature of the electrolyte. Yet, its value varies by more than a factor of two in the potential interval investigated. The potential of largest magnitude of ς agrees closely with the potential of zero charge.