Brush-like Co/CoSe nanoheterostructures embedded in N-doped carbon for rechargeable Zn-air batteries.

Rational design and preparation of high-performance bifunctional oxygen electrocatalysts with effective sites and excellent mass/electron transfer structures are in demand for Zn-air batteries to overcome the sluggish oxygen reduction/evolution kinetics. Herein, a scalable and facile strategy is proposed to obtain brush-like Co/CoSe nanoheterostructures embedded in N-doped carbon catalysts with optimized active sites and hierarchical nanostructures. Systematic investigation indicates that nanoheterogeneous interfaces with appropriate composition deliver significantly improved electrochemical activity. As a result, a zinc-air battery assembled with the obtained Co/CoSe nanoheterostructures embedded in the N-doped carbon (CoSe/Co@NC-1) catalyst exhibits outstanding electrochemical performance with a peak power density of 215 mW cm and excellent stability for 475 hours (2850 cycles). These results indicate that this strategy is an effective method for fabricating multicomponent and hierarchically nanostructured materials with enhanced catalytic efficiency for advanced energy devices.