Strategy to Elucidate the Reaction Mechanism of Electrodes for Realistic Solid Oxide Electrochemical Cells Using a Dense Bulk Material

Abstract

Tremendous research has focused on dense thin films to elucidate the reaction mechanism of perovskite-based electrodes in solid oxide electrochemical cells (SOCs). However, thin film studies may not reflect the mechanisms of commercialized electrodes fabricated with bulk materials. Herein, an unprecedented strategy for elucidating the electrode reaction is introduced via a La0.6Sr0.4Co0.2Fe0.8O3-delta dense bulk electrode fabricated by tape casting/lamination. By adjusting the electrolyte composition, the dense bulk electrode was successfully formed onto the electrolyte by co-sintering. The electrochemical properties of the bulk electrode were generally similar to those of the thin films. However, the degradation rate was significantly lower, possibly due to a difference in cation diffusivity, making the bulk electrode suitable for studying the reaction mechanism. Additionally, the bias effect needed for studying electrodes under operating conditions can be easily investigated without lithography. Our experiments provide a new platform for identifying the reaction mechanism of bulk SOC electrodes.