Self-assembled VS2 microflowers buffering volume change during charging and discharging towards high-performance zinc ion batteries

Abstract

VS2 has attracted increasing attention as a cathode material for aqueous zinc ion batteries because of its proper large layer spacing, weak interlayer interactions, multiple valence states of V, and excellent electrical conductivity, but its large volume change during charging and discharging leads to poor cycling stability. Herein, we report a one-step hydrothermal synthesis of VS2 microflowers with proper lamellar spacing, which provides a stable framework for the insertion/deinsertion of zinc ions and enhances the cycling stability, delivering an initial charge capacity of 128.3 mAh g−1 at 3 A g−1 and maintains a charge capacity of 100.1 mAh g−1 after 900 cycles. In addition, the optimized VS2 cathode shows specific capacities of 215.7 and 150.5 mAh g−1 at the current densities of 0.1 and 2 A g−1, respectively, demonstrating that the microflower structure with a high specific surface area and a short diffusion distance also significantly enhances the rate performance.