Perovskite-Based Anode Materials for Solid Oxide Fuel Cells

The present chapter is devoted to comparison of oxide-based anode materials developed during the last 10-15 years, with a particular focus on relationships between their functional characteristics, such as phase and structural stability, electronic and ionic conductivity, thermal and chemical expansion, and the electrochemical activity of the corresponding anodes. In most studies, the strategy of selection of the anode material composition is unclear while no obvious correlations can be revealed between the anode activity and other properties of the material. The situation is complicated by the presence of catalytically active phases in the anode layers, such as CeO2-based compounds or metallic phases (Pt, Ag, Ni, etc). The latter are frequently introduced as current collecting coatings for optimizing the interface contact between the anode and interconnect; however, their influence on the catalytic activity cannot a priori be considered to be negligible. For this reason, the electrochemical characteristics of different anode materials studied by the same research group and, consequently, prepared and modified by the same route, frequently appear to be similar. The purpose of this review is to critically discuss the results where the origins of the observed anode performance are arguable, and to emphasize the studies where a reliable analysis of the performance-determining factors has been done.

Keywords: Alternative Anode, Chemical Compatibility, Chemical Expansion, Current Collector, Electrochemical Activity, Fuel Cell, Perovskite, Polarization Resistance, Surface Modification, Thermal Expansion.