Characterization of electrochemical systems using potential step voltammetry. Part I: Modeling by means of equivalent circuits

Abstract

Potential step voltammetry is used to characterize the resistive and capacitive properties of electrochemical systems. Within those systems, electrochemical processes are modeled by means of equivalent circuits (ECs). In this study, we established and experimentally validated algebraic expressions describing the electrical response of those ECs. We then analyzed the features that allow significant differentiation between the ECs. Finally, we have proposed a method to graphically visualize and analyze the electrical response of the circuit to a potential step sequence. The application of this method to real electrochemical systems will allow us to not only identify the electrochemical processes taking place in an experiment but to also assess parameters such as the double layer capacitance, the solution resistance, and the polarization resistance of the redox process. © 2019 Elsevier Ltd