Preparation and electrochemical performance of cobalt-free cathode material Ba0.5Sr0.5Fe0.9Nb0.1O3−δ for intermediate-temperature solid oxide fuel cells

Abstract

Perovskite oxide Ba0.5Sr0.5Fe0.9Nb0.1O3−δ(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−δ(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 °C for 10 h in air. The BSFN cathode exhibited excellent chemical stability on the SDC and LSGM electrolytes at temperatures below 950 °C. The area specific resistance of the BSFN cathode on the SDC and LSGM electrolytes were 0.024 and 0.021 Ω·cm2 at 800 °C, respectively. The maximum power densities of the single cell with BSFN cathode in 300 μm-thick SDC and LSGM electrolytes achieved 414 and 516 mW/cm2 at 800 °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.