Mn/Fe Co-doped LaCoO3−δ perovskite oxides as efficient cathode for high-performance Zn-air batteries

Perovskite oxides are promising bifunctional electrocatalysts for oxygen reduction reaction and oxygen evolution reaction (ORR/OER). Here, a cooperative Mn–Fe–Co B-site modulation strategy is implemented in LaCoO3−δ, combined with a low-temperature combustion synthesis that stabilizes a highly defective oxygen sublattice while preserving single-phase crystallinity. A series of LaCoO3−δ–based perovskites (LMCO, LMFCO244, LMFCO334 and LMFCO) were prepared, among which LMFCO calcined at 700 °C (LMFCO-700) delivered the highest activity. When applied in a zinc–air battery, LMFCO-700 delivers an open-circuit voltage of 1.48 V, a peak power density of 179 mW cm−2, and remarkable rechargeability over 540 h (1620 cycles) with a high specific capacity of 793 mA gZn−1. Mechanism analysis indicates that the Mn–Fe co-doping promotes a favourable redistribution of B-site valence states by increasing the proportion of Mn4+ and Co2+ species and stabilizing oxygen vacancies. This coupled Mn4+–Co2+ redox modulation enhances oxygen-intermediate adsorption and accelerates ORR/OER kinetics. The low-temperature synthesis further increases the surface area (11.23 m2g−1), exposing more accessible active sites. The synergistic electronic, structural and defect modulation achieved here provides a rational pathway for designing high-performance perovskite electrocatalysts for metal–air batteries and related energy-conversion systems.