Cesium doping strategy boosts perovskite type bifunctional oxygen electrocatalyst toward efficient and durable rechargeable zinc-air batteries

Cesium doping in SrCo_0.9Nb_0.1O_3-δ material induces the lattice expansion, the increased oxygen vacancies concentration and high-value cations. Amongst, Sr_0.9Cs_0.1Co_0.9Nb_0.1O_3-δ (SCCN) catalyst displays outstanding electrocatalytic activities with a large half-wave potential of 0.695 V, a small overpotential of 460 mV, and excellent catalytic stability. The zinc-air battery assembled with SCCN cathode presented high specific capacity of 740 mAh g⁻¹ and maximum output power density of 156 mW cm⁻² as well as good charge–discharge cycle stability. Density functional theory (DFT) calculation demonstrates that Cs doping could greatly reduce the formation energy of oxygen vacancies and the adsorption energy of H₂O and O₂ molecules simultaneously, which accelerates the oxygen reaction processes in the alkaline environment. Our findings indicate that A-site Cs doping could efficiently regulate the electrocatalytic activities of perovskite catalysts, and effectively construct non-noble electrocatalysts with boosted electrocatalytic activity for other energy conversion and storage devices.