VS2 nanosheets vertically grown on graphene as high-performance cathodes for aqueous zinc-ion batteries

Abstract

Aqueous rechargeable zinc-ion batteries (ZIBs) have been considered as potential grid-scale energy storage devices owing to their low cost, high safety, and environmental friendliness. However, the cathode materials of ZIBs usually show poor cycling stability and inferior rate performance. Here, a new 2D hierarchical composite comprised of ultrathin VS2 nanosheets perpendicularly grown on graphene sheets (rGO-VS2) is prepared through a one-step solvothermal strategy. Benefiting from the unique hierarchical structure and synergistic merits between the VS2 and graphene nanosheets, the rGO-VS2 composite exhibits excellent performance as new cathode materials for ZIBs. Specifically, it not only can deliver a high capacity of 238 mAh g−1 at 0.1 A g−1, but also maintains a capacity of 190 mAh g−1 at a quite high rate of 5 A g−1 with a capacity retention over 93% after 1000 cycles. This work highlights the great promise of rational designing high-performance rechargeable aqueous ZIBs.