Ultrahigh peak power density of rechargeable Zn–air batteries using quadruple perovskite as air-cathode electrocatalysts

Abstract

Developing highly active, low-cost and stable bifunctional electrocatalysts is vital for the commercialization of rechargeable Zn–air batteries (ZABs). Among the various materials used as catalysts for ZABs, perovskite oxides have gained significant attention due to their structural and compositional flexibility. Herein, we report a quadruple perovskite oxide LaCu₃FeTiRu₂O₁₂ as a highly efficient OER and ORR active bifunctional electrocatalyst for rechargeable ZABs. The quadruple perovskite demonstrated excellent activity with a bifunctional index (BI) of 0.80 V, comparable to the state-of-the-art OER–ORR electrocatalyst RuO₂-Pt/C (BI = 0.75 V). The outstanding bifunctional activity of the compound is believed to stem from its unique crystal structure that provides energetically favorable Fe/Ti/Ru–Cu bridging active sites for electrocatalysis. The ZAB fabricated using LaCu₃FeTiRu₂O₁₂ as an air-cathode electrocatalyst shows long cyclic stability with an unprecedented peak power density of 617 mW cm⁻², which is three-fold higher than that of the benchmark RuO₂-Pt/C.