W Doped V₂O₅ Nanosheets as Cathode Material for High-Performance Aqueous Zinc Ion Battery

Aqueous zinc-ion batteries (ZIBs) are considered to be prospective candidates in energy storage devices because of their excellent safety, crustal abundance, low cost and environmental benignity. Whereas, the design of a satisfied cathode material with a large specific capacity, superior rate performance and long-cycle life is still a significant challenge for ZIBs. Herein, a new strategy is proposed to use W doped V₂O₅ as cathode material for aqueous ZIBs. The W doping can effectively enlarge the lattice spacing and ion migration efficiency of V₂O₅, and the formation of W—O bond can obviously alleviate the capacity decay problem caused by structural damage and low intrinsic conductivity in the cycling process. As a result, the V₂O₅-W cathode exhibits an excellent capacity of 195.0 mA·h/g after 100 cycles at 0.1 A/g, and an impressive rate capability of 243.0 mA·h/g at the high current density of 1 A/g after 1000 cycles. This work provides a simple, efficient and feasible strategy for designing high-performance cathode materials in ZIBs.