La0.6Sr0.4Fe0.8Cu0.2O3−δ perovskite oxide as cathode for IT-SOFC

A La0.6Sr0.4Fe0.8Cu0.2O3−δ (LSFCu) perovskite was investigated as a cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFC). The LSFCu material exhibited chemical compatibility with the Sm0.2Ce0.8O1.9 (SDC) electrolyte up to a temperature of 1100 °C. The electrical conductivity of the sintered sample was measured as a function of temperature from 100 to 800 °C. The highest conductivity of about 238 S cm−1 was observed for LSFCu. The average thermal-expansion coefficient (TEC) of LSFCu was 14.6 × 10−6 K−1, close to that of typical CeO2 electrolyte material. The investigation of electrical properties indicated that the LSFCu cathode had lower interfacial polarization resistance of 0.070 Ω cm2 at 800 °C and 0.138 Ω cm2 at 750 °C in air. An electrolyte-supported single cell with 300 μm thick SDC electrolyte and LSFCu as cathode shows peak power densities of 530 mW cm−2 at 800 °C.