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

• VO 2 (B)/RGO composites were prepared via a facile hydrothermal rout. • VO 2 (B)/RGO exhibited a capacity of 456 mAh g−1 at 100 mA g−1. • The contribution of capacitive process leads to a remarkable rate ability. 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, VO 2 (B)/reduce graphene oxide (RGO) composite is designed and synthesized via a facile simple hydrothermal reaction. VO 2 (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. VO 2 (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 VO 2 (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 VO 2 (B)/RGO composite is a suitable cathode for zinc ion batteries. [ABSTRACT FROM AUTHOR]