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

• Published in: Electrochimica acta Vol. 258; pp. 433 - 441
• Main Authors: Charoen-amornkitt, Patcharawat, Suzuki, Takahiro, Tsushima, Shohji
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 20.12.2017; Elsevier BV
• Subjects: Computer simulation; CPE; Cyclic voltammetry; Electrical double layer; Electron transfer; Equivalent circuits; Experiments; Kinetics; Mass transfer; Mass transport; Mathematical models; Modeling; Non-faradaic current; Parameter estimation; Parameters; Phase (cyclic); Species diffusion; Voltammetry; Cyclic voltammetry; CPE; Non-faradaic current; Modeling; Electrical double layer
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2017.11.079

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. •Effects of CPE and ohmic resistance are encompassed in the proposed model.•The model conveniently helps separating the faradaic and non-faradaic currents.•The faradaic and non-faradaic currents are coupled through the ohmic drop effects.•CPE and ohmic resistance significantly affect cyclic voltammetry responses.