Porous Ultrathin W-Doped VO2 Nanosheets Enable Boosted Zn2+ (De)Intercalation Kinetics in VO2 for High-Performance Aqueous Zn-Ion Batteries

Aqueous rechargeable zinc-ion batteries (ZIBs) are identified as promising candidates in energy storage devices because of their high safety, "green" property, natural abundance, and low cost, whereas, the design of an ideal cathode material with a large specific capacity, superior rate performance, and long-life cycle is still a great challenge for ZIBs. Herein, a facile hydrothermal self-assembly strategy is developed to construct tungsten-doped vanadium dioxide (W-VO2) nanosheets as the cathode materials of ZIBs. Porous ultrathin nanosheet structure, enlarged lattice distance, and W–O bond formation endow the Zn2+ ion rapid diffusion and enhance structural stability during the electrochemical operation. As a result, the W-VO2 cathode exhibits an initial capacity of 346 mA h g–1 at 100 mA g–1, an impressive rate capability of 221 mA h g–1 at 10 A g–1, and an appreciable 76.4% capacity retention after 1000 cycles at 4 A g–1. This work provides an efficient, green, and feasible approach for the design of high-performance cathode materials toward clean aqueous ZIBs.