Revealing the Mechanisms of SOFC Electrodes Using a Combination of AC and DC Methods

Abstract

A complicating feature of SOFC electrodes is the appearance of two or more arcs in the impedance spectra. This means that there are at least as many "rate limiting processes" as the number of arcs. The processes may be of physical or chemical nature. This is illustrated by examples where both physical and chemical processes are exhibiting their characters using the well known Ni-YSZ-cennet anode and the composite LSM-YSZ cathode, The practical procedures used at Riso with the aim of revealing the electrode mechanisms are reported and discussed.