Triple-Conducting Oxide as a Cathode for Solid Oxide Fuel Cells: Review

Solid oxide fuel cells (SOFCs) are at a technological level close to commercialization, which could be enabled by new material research. Especially, not only an electrolyte, but also a cathode material becomes very important to further increase electrochemical performance, due to the effort to lower operating temperature of SOFCs to intermediate range (400-600℃) to take advantage of high and low temperature operation. Unfortunately, this trend inevitably results in demand for new cathode materials with high oxygen reduction reaction activity, as well as high mechanical durability. Recently, ceramic materials which conduct oxygen ion, proton, and electron, thereby called ‘triple conducting oxide’ are being highlighted, due to their excellent material properties, to be used for cathodes of SOFCs. This paper reviews the three representative triple-conducting oxides, which were already used and tested in SOFC operating conditions.