Long-term stability of solid oxide cell air electrodes influenced by gaseous contaminants

Solid oxide cells, i.e. solid oxide fuel cells (SOFCs) and solid oxide electrolyzer cells (SOECs), are efficient energy converters for a future energy system. Poisoning of air electrodes of solid oxide cells by gaseous contaminants is a serious issue limiting the long-term stability of their electrochemical performance, and is thus a challenge for successful commercialization. This review provides an overview of poisoning of perovskite and Ruddlesden-Popper-type air electrodes by gaseous Cr- and Si-species as well as SO 2 , including recent results. It discusses fundamental aspects of Sr-segregation and reactions with gaseous contaminants, emphasizing the importance of size mismatch and basicity of the constituents of the ceramic oxide electrode. Studies on Cr-, Si- and SO 2 -poisoning of air electrodes are presented together with mitigation and recovery measures. • Sr-segregation and reaction with gaseous contaminants. • Poisoning of air electrodes of solid oxide cells by Cr- and Si-containing species as well as SO 2. • Mitigation of air electrode poisoning and recovery measures.