Ohmic resistance and constant phase element effects on cyclic voltammograms using a combined model of mass transport and equivalent circuits

Abstract

Cyclic voltammetry is a very useful tool for estimating several parameters such as electron transfer kinetics, diffusivity of active species, and effective surface area in a redox system. In cyclic voltammetry modeling, a simulated cyclic voltammogram is usually treated by neglecting the nonlinear effects of an electrical double layer and ohmic resistance. However, this approach leads to inaccurate prediction of such parameters. In this study, numerical modeling, including the combined effects of ohmic resistance, constant phase element, mass transfer, and faradaic processes, of cyclic voltammetry was carried out to show that, using this approach, nonlinear behaviors of the time-domain response of cyclic voltammetry can be encompassed. The model showed a good agreement with the experimental measurements. Furthermore, the numerical investigation of ohmic resistance and constant phase element effects on a cyclic voltammogram were performed.