Facile Synthesis of Na_0.33V₂O₅ Nanosheet-Graphene Hybrids as Ultrahigh Performance Cathode Materials for Lithium Ion Batteries

Na_0.33V₂O₅ nanosheet-graphene hybrids were successfully fabricated for the first time via a two-step route involving a novel hydrothermal method and a freeze-drying technique. Uniform Na_0.33V₂O₅ nanosheets with a thickness of about 30 nm are well-dispersed between graphene layers. The special sandwich-like nanostructures endow the hybrids with high discharge capacity, good cycling stability, and superior rate performance as cathodes for lithium storage. Desirable discharge capacities of 313, 232, 159, and 108 mA·h·g^–1 can be delivered at 0.3, 3, 6, and 9 A·g^–1, respectively. Moreover, the Na_0.33V₂O₅-graphene hybrids can maintain a high discharge capacity of 199 mA·h·g^–1 after 400 cycles even at an extremely high current density of 4.5 A·g^–1, with an average fading rate of 0.03% per cycle