A cobalt-free electrode material La0.5Sr0.5Fe0.8Cu0.2O3 − δ for symmetrical solid oxide fuel cells

• Cobalt-free oxide La0.5Sr0.5Fe0.8Cu0.2O3 − δ (LSFC) is tested as electrodes of SSOFCs.
• A reversible structure transition occurs for LSFC in air/humidified H2.
• The thermal compatibility of electrodes with electrolyte is examined by TEC and SEM.
• The SSOFCs show promising performances with H2 fuel and syngas fuel, respectively.
• The cell with H2 fuel displays a reasonable stability at 800 °C, 0.7 V for 100 h.

Cobalt-free perovskite oxide La0.5Sr0.5Fe0.8Cu0.2O3 − δ (LSFC) was applied as both anode and cathode for symmetrical solid oxide fuel cells (SSOFCs). The LSFC shows a reversible transition between a cubic perovskite phase in air and a mixture of SrFeLaO4, a K2NiF4-type layered perovskite oxide, metallic Cu and LaFeO3 in reducing atmosphere at elevated temperature. The average thermal expansion coefficient of LSFC in air is 17.7 × 10− 6 K− 1 at 25 °C to 900 °C. By adopting LSFC as initial electrodes to fabricate electrolyte supported SSOFCs, the cells generate maximum power output of 1054, 795 and 577 mW cm− 2 with humidified H2 fuel (~ 3% H2O) and 895, 721 and 482 mW cm− 2 with humidified syngas fuel (H2:CO = 1:1) at 900, 850 and 800 °C, respectively. Moreover, the cell with humidified H2 fuel demonstrates a reasonable stability at 800 °C under 0.7 V for 100 h.