Comparison of Electrical Conductivities in Complex Perovskites and Layered Perovskite for Cathode Materials of Intermediate Temperature-operating Solid Oxide Fuel Cell

Electrical conductivities of complex perovskites, layered perovskite and Sr doped layered perovskite oxides were measured and analyzed for cathode materials of Intermediate Temperature-operating Solid Oxide Fuel Cells (IT-SOFCs).The electrical conductivities of Sm 1-x Sr x CoO 3-δ (x = 0.3 and 0.7) exhibit a metal-insulator transition (MIT) behavior as a function of temperature.However, Sm 0.5 Sr 0.5 CoO 3-δ (SSC55) shows metallic conductivity characteristics and the maximum electrical conductivity value compared to the values of Pr 0.5 Sr 0.5 CoO 3-δ (PSC55) and Nd 0.5 Sr 0.5 CoO 3-δ (NSC55).The electrical conductivity of SmBaCo 2 O 5+δ (SBCO) exhibits a MIT at about 250 o C. The maximum conductivity is 570 S/cm at 200 o C and its value is higher than 170 S/cm over the whole temperature range tested.SmBa 0.5 Sr 0.5 Co 2 O 5+δ (SBSCO), 0.5 mol% Sr and Ba substituted at the layered perovskite shows a typically metallic conductivity that is very similar to the behavior of the SSC55 cathode, and the maximum and minimum electrical conductivity in the SBSCO are 1280 S/cm at 50