Atomic species derived CoOx clusters on nitrogen doped mesoporous carbon as advanced bifunctional electro-catalysts for Zn-air battery

The development of earth-abundant and cost-effective electro-catalysts at the air cathodes for both oxygen reduction and evolution reactions (ORR and OER) with sluggish kinetics are central to the overall performance of rechargeable metal-air batteries, remaining an issue that is gaining increasing interest in recent years. Herein, we report a nitrogen-doped mesoporous carbon supported clustered CoOx composite catalyst (CoOx/NMC) synthesized from the anchored atomically dispersed CoOOH species by an efficient two-step nucleation method. Due to the synergistic and size effects, CoOx/NMC exhibits an enhanced bifunctional electrocatalytic performance in alkaline media than the state of the art commercial Pt/C catalyst for ORR and the OER catalyst (Ir/C). More importantly, the advanced CoOx/NMC catalyst enables recharge Zn-air batteries (ZABs) to achieve long-term cycling performance over 400 h by galvanostatic charge-discharge at current density of 10 mA cm(-2) with high efficiency, suggesting a very promising alternative to the conventional Pt/C and Ir/C catalysts for an air cathode.