Cathodic properties of La1.2Sr0.8NiO4+δ perovskite doped with Cu/Fe in the Ruddlesden–Popper phase

This work investigates cathode materials based on the traditional La 1.2 Sr 0.8 NiO 4+δ (LSNO) structure of Ruddlesden–Popper perovskites. Cu and Fe elements were introduced via B-site substitution to synthesize a series of La 1.2 Sr 0.8 Ni 0.5 Cu x Fe0.5-xO 4-δ (x = 0.4, 0.3, and 0.2) compounds. X-ray diffraction was employed to determine the phase composition of the materials, and conductivity measurements confirmed the enhancement of electronic conductivity due to Cu doping. Electrochemical impedance spectroscopy analysis identified LSNCuF41 as the optimal composition, its peak power density was 0.556 W·cm ‐2 at 650 °C, and its polarization resistance was 0.251 Ω·cm 2 . These values are significantly superior to those of LSNCuF32 and LSNCuF23, demonstrating the effectiveness of co-doping in enhancing LSNO-based cathode materials’ electrochemical performance.