Lanthanum nickelate as an efficient oxygen electrode for solid oxide electrolysis cell

Abstract The present study focuses on an alternative structured oxygen electrode for solid oxide electrolysis cells (SOECs). La 2 NiO 4+δ nickelate, LNO, was selected with respect to its mixed electronic and ionic conductivity and its good chemical stability. Complete single cells were built using screen printing of LNO and LaNi 0.6 Fe 0.4 O 3 (LNF) layers on a standard hydrogen electrode supported half cell consisting of a porous NiO‐YSZ layer, a dense 8YSZ electrolyte layer, and a thin interlayer of gadolinia doped ceria (GDC). The LNO cells' polarization curves under various anodic flows of H 2 O/H 2 (90/10) show excellent performances compared to the commercial LSCF (La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3‐x ) based cells. The steam conversion ratio increases from around 40% to 80% when the gas flow decreases from 36 to 12 N ml min –1 cm –2 . With a degradation rate of 1.5% 1000 h –1 after 500 h operating time ( i = –0.5 A cm –2 ) at 800°C, using a medium H 2 O/H 2 (90/10) gas flow of 24 N ml min –1 cm –2 , LNO oxygen electrode shows higher durability than the state of the art LSCF oxygen electrode. Energy efficiency analysis confirms the dependency of the total efficiency with the current density and gas flow allowing us to suggest optimized conditions for reaching targets of commercial H 2 production.