Performance of La2–xSrxCo0.5Ni0.5O4±δ as an Oxygen Electrode for Solid Oxide Reversible Cells

La2 – xSrxCo0.5Ni0.5O4 ± δ (LSCN) is presented as a novel electrode for both solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs). LSCN/10Sc1CeSZ (scandia and ceria stabilised zirconia)/LSCN symmetrical cells were fabricated and characterised by AC impedance spectroscopy under different oxygen partial pressures at temperatures of up to 900 °C. At 850 °C polarisation resistances of 5.15 and 5.74 Ω cm2 were found applying air and oxygen, respectively. Electrolysis and fuel cell j–V experiments were also performed at temperatures between 700 and 850 °C using a LSCN/10Sc1CeSZ/Ni‐YSZ. Electrochemical results showed that the cell performs equally in both SOFC and SOEC modes. Detailed results in terms of performance are presented and discussed. LSCN is presented as a good candidate for both SOFC and SOEC. The similar performance obtained for j–V (current density–voltage) curves in electrolysis and fuel cell operation mode is thought to be related to the flexible oxygen non‐stoichiometry of the LSCN (K2NiF4‐type structure).