ABO_3-δ perovskite-type oxides are known for their compositional flexibility, possible formation of various orderings in the cationic and anionic sublattices, and a broad range of resulting physicochemical properties. Those properties can be tuned for a particular application, including usage in reversible Solid Oxide Cells (SOCs), as well as for the oxygen storage in pressure swing-type processes.
This work summarizes general guidelines for designing effectively-working perovskite-type oxygen electrodes in SOCs, as well as presents possibility of obtaining oxygen storage materials (OSMs) with the high capacity and low operation temperature. In particular, the A-site layered RE(Ba,Sr)Co_2-yMn_yO_5+δ (RE: selected rare-earth cations; 0 ≤ y ≤ 2) oxides are discussed in more details, as it can be shown that the properly selected Mn substitution results in the high electrocatalytic activity toward the oxygen reduction reaction (ORR), while different Mn content is preferred for the oxygen storage processes [1, 2]. Less commonly studied substitution with Cu is also shown as the effective way of altering physicochemical characteristics, and allows designing electrocatalytically-active RE(Ba,Sr)Co_2-yCu_yO_5+δ series [3]. Furthermore, Co-free La_1-x(Ba,Sr)_xCuO_3-δcompositions can be also designed and obtained, showing promising performance when used as the SOC oxygen electrodes [4, 5]. Notably, the recently emerging high entropy approach provides unique new opportunities, as the resulting multicomponent perovskites may exhibit properties crossing the commonly observed rule of mixtures [6].