(La 0.65 Sr 0.3 ) 0.95 FeO 3- δ perovskite with high oxygen vacancy as efficient bifunctional electrocatalysts for Zn-air batteries.

Developing low-cost, highly efficient electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is desirable for rechargeable metal-air batteries. Herein, a series of perovskite structured (La 0.65 Sr 0.3 ) 0.95 FeO 3- δ catalysts with A-site deficiency were synthesized through a scalable solid state synthesis method at different calcination temperatures. The electrocatalytic activities of these catalysts were investigated by thin-film RDE technique. The catalyst calcined at 1000 °C exhibits an outstanding bi-functional activity towards the ORR and OER in alkaline electrolyte, and it also exhibits an outstanding performance in primary and rechargeable Zn-air batteries, which is comparable with the commercial noble metals Pt/C and RuO 2 .