Ce, Co co-doped LaMnO3 perovskite activating oxygen reduction reaction in Zn-air and Mg-air batteries

Abstract

Within the domain of metal-air battery systems, developing the non - precious metal catalysts featuring extraordinary catalytic activity in oxygen reduction reaction (ORR) is crucial to the air-cathode. This work unveils a sol-gel engineered synthesis of La_0.9Ce_0.1Co_0.1Mn_0.9O₃ perovskite via the co-doping strategy, with targeted exploration of its electrochemical behavior and underlying mechanism in Zn-air and Mg-air battery systems. The perovskite La_0.9Ce_0.1Co_0.1Mn_0.9O₃ has a wealth of catalytically active ORR sites and a mesoporous architecture. The diffusion-limited current density of La_0.9Ce_0.1Co_0.1Mn_0.9O₃ successfully achieves a 1.2-fold enhancement relative to commercial Pt/C with a low H₂O₂ yield of <0.27 %, underscoring its superior mass transport kinetics. The maximum power densities of La_0.9Ce_0.1Co_0.1Mn_0.9O₃-based primary/secondary zinc - air batteries are 130 and 83 mW cm⁻², respectively, which are on a par with those of Pt/C - based Zinc - air batteries. Whereas, the open - circuit voltage and maximum power density of the primary magnesium - air battery fabricated with 10 wt% KCl as the electrolyte are 1.85 V and 52 mW cm⁻², respectively, which exhibit superiority over Pt/C catalysts. In combination with DFT analyses, the La_0.9Ce_0.1Co_0.1Mn_0.9O₃ perovskite emerges as a prospective ORR catalyst for metal-air battery realization.