VO2(B) nanobelts and reduced graphene oxides composites as cathode materials for low-cost rechargeable aqueous zinc ion batteries

Low-cost and high-safety aqueous zinc ion batteries show their potential application for a large-scale energy storage system due to the high capacity and stable Zinc metal anode. Herein, VO2(B)/reduce graphene oxide (RGO) composite is designed and synthesized via a facile simple hydrothermal reaction. VO2(B) nanobelts uniformly deposited on RGO nanoflakes, which provide an electronic transport pathway and prevent the collapse of the structure during the zinc ion (de)intercalation process. VO2(B)/RGO composite exhibits a remarkable capacity of 456 mAh g−1 at 100 mA g−1, an impressive rate capability of 292 mAh g−1 at 5 A g−1 and capable cycling stability. The existence of capacitive contribution leads to fast zinc ions storage behavior. Moreover, the VO2(B)/RGO composite also offers a maximum energy density of 317 Wh kg−1 at a power density of 70 W kg−1 (based on the mass of the positive electrode). It suggests that VO2(B)/RGO composite is a suitable cathode for zinc ion batteries.