Cobalt-free perovskite Ba0.5Sr0.5Fe0.9Nb0.1O3−δ as a cathode material for intermediate temperature solid oxide fuel cells

The cobalt-free perovskite oxide, Ba0.5Sr0.5Fe0.9Nb0.1O3−δ (BSFN), was investigated as a new cathode material for intermediate-temperature solid oxide fuel cells (ITSOFCs). The electrical conductivity of BSFN reaches the maximum value of 14.1 S cm−1 at 450 °C. The average thermal expansion coefficient of BSFN is about 19.2 × 10−6 K−1 from room temperature to 1000 °C. The area specific resistance of the BSFN cathode is as low as 0.082 Ω cm2 at 700 °C. A maximum power density of 745 mW cm−2 is obtained at 700 °C for the single cell with the BSFN cathode. Our results suggest that the cobalt-free oxide BSFN is a very promising cathode material for application in ITSOFCs.