The role of oxygen ion diffusion in the electrode reactions of β″ alumina

Abstract

A model has been proposed to explain the current-time curves obtained by applying fixed voltages to polycrystalline β alumina at elevated temperatures using gold contacts. It is proposed in the model that the oxygen electrode reaction can occur at the gold “blocking” contacts. The observed current-time curves can be explained in terms of the diffusion and migration of oxygen ions to the gold anode and sodium ion transport within the bulk of the β alumina. The model provides a new method for determining the oxygen ion diffusion coefficient within the polycrystalline β alumina.