V2 O3 /MnS Arrays as Bifunctional Air Electrode for Long-Lasting and Flexible Rechargeable Zn-Air Batteries.

ABSTRACT

Exploring highly efficient, stable, and cost-effective bifunctional electrocatalysts is crucial for the wide commercialization of rechargeable Zn-air batteries. Herein, a vanadium-oxide-based hybrid air electrode comprising a heterostructure of V2 O3 and MnS (V2 O3 /MnS) is reported. The V2 O3 /MnS catalyst shows a decent catalytic activity that is comparable to Pt/C toward the oxygen reduction reaction and acceptable toward oxygen evolution. The extraordinary stability as well as the low cost set the V2 O3 /MnS among the best bifunctional oxygen electrocatalysts. In a demonstration of an assembled liquid-state Zn-air battery using V2 O3 /MnS as cathode, high power density (118 mW cm-2 ), specific capacity (808 mAh gZn -1 ), and energy density (970 Wh kgZn -1 ), as well as the outstanding rechargeability and durability for 4000 cycles (>1333 h, i.e., >55 days) are enabled. The V2 O3 /MnS is also integrated into an all-solid-state Zn-air battery to demonstrate its great potential as a flexible power source for next-generation electronics. Density functional theory calculations further elucidate the origin of the intrinsic activity and stability of the V2 O3 /MnS heterostructure.