Effective calcium co-doping in Sm0.8Ca0.2Ba1-xCaxCo2O5+δ cathode materials for intermediate-temperature solid oxide fuel cells

High performance and durability of electrode materials are key requirements for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Herein, a novel doubles perovskite oxides Sm0.8Ca0.2Ba1-xCaxCo2O5+delta (x=0.1 and 0.2; SCBCC) were prepared by A site calcium co-doping strategy. x=0.1 sample shows stabilized an orthorhombic structure with the space group Pmmm. Compared with parent SmBaCo2O5+delta, substitution of Ca for Sm and Ba effectively reduces the thermal expansion coefficient (TEC) (20.2 x 10-6 K-1 to 13.2 x 10-6 K-1). x=0.1 sample exhibits excellent chemical compatibility with CeO2-based electrolytes up to 1000 degrees C, the conductivity values reach 340-400 S cm-1 at 600-800 degrees C. The sample with x = 0.1 showed the best catalytic activity and carbon dioxide resistance. The area specific resistance and maximum power density of the x= 0.1 cathode are 0.022 omega cm2 and 885 mW cm-2 at 800 degrees C. x = 0.1 double perovskite has good chemical compatibility and electrochemical properties while greatly reducing TEC, making this double perovskite a promising material for IT-SOFCs.

Automated summary

Double perovskite oxides, prepared by A-site calcium co-doping strategy, exhibit good chemical compatibility and electrochemical properties while greatly reducing thermal expansion coefficient, making them promising materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs).