Preparation and Electrochemical Performance of Cobalt-free Cathode Material Ba0.5Sr0.5Fe0.9Nb0.1O3-δ for Intermediate-temperature Solid Oxide Fuel Cells

Perovskite oxide Ba0.5Sr0.5Fe0.9Nb0.1O3-delta(BSFN) as a cobalt-free cathode for intermediate-temperature solid oxide fuel cells(IT-SOFCs) on the Ce0.8Sm0.2O1.9(SDC) and La0.9Sr0.1Ga0.8Mg0.2O3-delta(LSGM) electrolytes was prepared and investigated. The single phase BSFN oxide with a cubic perovskite structure and relatively high electrical conductivities was obtained after sintering at 1250 degrees C for 10 h in air. The BSFN cathode exhibited excellent chemical stability on the SDC and LSGM electrolytes at temperatures below 950 degrees C. The area specific resistance of the BSFN cathode on the SDC and LSGM electrolytes were 0.024 and 0.021 Omega.cm(2) at 800 degrees C, respectively. The maximum power densities of the single cell with BSFN cathode in 300 mu m-thick SDC and LSGM electrolytes achieved 414 and 516 mW/cm(2) at 800 degrees C, respectively. These results show that the BSFN material is a promising cobalt-free cathode candidate to be used in IT-SOFCs. A combination of the BSFN cathode and LSGM electrolyte is preferred owing to its excellent electrochemical performance.