Cobalt-Free Perovskite Oxide La0.6Sr0.4Fe0.8Ni0.2O3-δ as Active and Robust Oxygen Electrode for Reversible Solid Oxide Cells

Reversible solid oxide cells have received increasing attention due to high efficiency. Cobalt-free perovskite electrode has compatible thermal expansion coefficient matching with the electrolyte and the reversible operation to inhibit the segregation of Sr. Herein a novel cobalt-free La0.6Sr0.4Fe0.8Ni0.2O3-delta perovskite is developed and investigated as oxygen electrode for reversible solid oxide cells. The electrochemical performance of La0.6Sr0.4Fe0.8Ni0.2O3-delta oxygen electrode in fuel cell mode and electrolysis mode is investigated in detail. The maximum power density of 961 mW cm(-2) and polarization resistance of 0.142 52 cm(2) at 800 degrees C can be achieved in fuel cell mode. While the cell is operated in electrolysis mode, the current density ranges from 0.53 A cm(-2) at 750 degrees C to 1.09 A cm(-2) at 850 degrees C with 50 vol % absolute humidity at 1.3 V, and the hydrogen generation rate can reach up to 1348.5 mL (cm(2) h)(-1) with 90 vol % absolute humidity at 800 degrees C. The reversible solid oxide cells show excellent reversibility and stability during 144 h medium-term reversible operation. The results indicate that La0.6Sr0.4Fe0.8Ni0.2O3-delta has a bright prospect as the oxygen electrode material for reversible solid oxide cells.