Combination of electrochemical impedance spectroscopy and cyclic voltammetry to investigate oxygen ion transport in YSZ electrolyte of SOFC

Abstract

Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) can be used to study the mechanisms and kinetics of electrochemical reactions at solid-solid interfaces. A thin gold film-yttria stabilized zirconia (Au/YSZ) interface was used as a model experimental system with a three-electrode configuration. Oxidation and reduction of the sample surface under chemically well-defined experimental conditions were induced. The oxygen ion transport behavior on the Au/YSZ electrolyte interface was analyzed in order to gain a better understanding of the oxygen reduction mechanism and to improve the electrolyte performance. This work focuses primarily on the charge transfer coefficient of oxygen ion transport on the Au/YSZ electrolyte interface as interpreted in terms of kinetic parameters obtained from impedance spectra and cyclic voltammograms as functions of operating temperature. The charge transfer coefficients obtained suggest that the polarization curve is distributed to a two-electron transfer process. © The Electrochemical Society.