Heterointerface Built Up by Ultrathin Amorphous MoO3 Conformal Coating Enables V5O12·6H2O with Superior Properties for Aqueous Zinc Batteries

Layered V 5 O 12 ·6H 2 O is a promising candidate for aqueous zinc batteries (AZBs) but with moderate electrochemical performances. Herein, the charge storage properties of V 5 O 12 ·6H 2 O are markedly improved by building up the heterointerface on its surface using amorphous molybdenum trioxide as the heteromaterial. The amorphous molybdenum trioxide functioning as the proton reservoir enables the proton-involved electrochemical reactions and induces the formation of a built-in electric field along the [001] orientation at the heterointerface constructed by the (001) plane of V 5 O 12 ·6H 2 O, which could provide new diffusion pathways and extra sites for ion storage. As a result, V 5 O 12 ·6H 2 O with significantly improved kinetics realizes an ultrahigh capacity of 510 mAh g –1, better rate capability, and prolonged lifespan. This work provides general guidance for designing advanced cathode materials for AZBs with respect to heterostructure.