Exceptionally durable CoFe-exsolved Sr0.95Nb0.1Co0.7Fe0.2O3-delta catalyst for rechargeable Zn-air batteries

Abstract

The lack of bifunctional features of perovskite oxide toward the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) significantly limits its use as a cathode catalyst for rechargeable Zn-air batteries (ZABs). Thus far, numerous techniques to disperse additional catalysts on a perovskite host have been suggested to overcome this problem; however, cost-effectiveness and catalyst lifespan remain unsatisfactory. Herein, we present cobalt-based-nanoparticle-decorated Sr0.95Nb0.1Co0.7Fe0.2O3-delta (S0.95NCF) by a simple ex-solution method and use it as a novel air-electrode catalyst. We successfully implemented the socketed nanoparticles with various compositions at different reduction temperatures, achieving notably enhanced activity towards OER and ORR. More importantly, the newly designed catalyst exhibits record-high charge/discharge durability over 500 h (or 1500 consequent cycles) when used as the ZABs cathode. Our findings provide essential guidelines for designing heterostructured electrocatalysts for future energy devices, in which multifunctionality is desirable.