La-doped ruddlesden-popper structured PNO oxides as oxygen electrode for solid oxide fuel cells

Sluggish catalytic activity and long-term stability of oxygen electrode materials are the main challenges in the commercialization of solid oxide fuel cells (SOFCs). Herein, a Ruddlesden-Popper-structured Pr 2-x La x NiO 4+δ (PLxN) by A-site lanthanum doping are investigated to enhance catalytic activity and stability of oxygen electrodes. Interestingly, the PL 0.1 N electrode exhibits low polarization resistance of 0.090 Ω cm 2 at 800 °C, with 18.18% reduction compared to PNO. Furthermore, the Pr 1.9 La 0.1 NiO 4+δ in anode-supported single cells exhibit peak power density of 1.468 W cm −2 at 800 °C and good operational stability over 100 h. Thereinto, La-doping induces lattice expansion and charge redistribution, which enriches surface active sites and accelerates oxygen reduction reaction kinetics. Overall, trace La-doping serving as an A-site defect engineering provides an efficient design strategy for high performance SOFC cathodes.