Self-assembled V2O5 nanosheets/reduced graphene oxide hierarchical nanocomposite as a high-performance cathode material for lithium ion batteries

Abstract

A simple solvothermal method was used to prepare self-assembled V₂O₅ nanosheets/reduced graphene oxide (RGO) hierarchical nanocomposite. In this nanocomposite, the V₂O₅ nanosheets assembling on the RGO constitute a 3-D hierarchical nanostructure with high specific surface area and good electronic/ionic conducting path. When used as the cathode materials, the V₂O₅ nanosheets/RGO nanocomposites exhibit highly reversible capacity and good rate capability relative to the bulk material. The V₂O₅ nanosheets/RGO nanocomposite anode was able to charge/discharge at high current densities of 3000 mA g⁻¹ (10 C), 6000 mA g⁻¹ (20 C) and 15 A g⁻¹ (50 C), with discharge capacities of approximately 138, 112 and 76 mA h g⁻¹, respectively. Meanwhile, a discharge capacity of 102 mA h g⁻¹ can be delivered after 160 cycles at 2 C, showing a good cycling stability. The improved performance could be attributed to the enhanced electron transport and Li⁺ diffusion that results from the hierarchical nanostructure of V₂O₅ nanosheets/RGO nanocomposites.