Graphene Modified Vanadium Oxide Composite Materials Used in Aqueous Na-Ion Batteries

Divanadium pentoxide as an electrode material in the aqueous-based battery has been widely explored because of its higher theoretical capacity and potential crystal structure. Here, in this work, we present vanadium pentoxide modified with graphene (V2O5@G) as an anode material in an aqueous rechargeable sodium-ion battery (ARSB) prepared via a facile one-step hydrothermal method followed by annealing. The complete ARSB was assembled by employing Na0.44MnO2 as the cathode material, which was synthesized via the sol–gel method. The assembled ARSBs were subjected to cyclic voltammetry, charge–discharge, and rate performance; it has been suggested that incorporation of graphene has a positive effect on the overall battery performance observed through charge–discharge (38.2 mAh g–1), cyclic capacity retention (200 cycles at 1A g–1 with a retention rate of 53%), and rate performance in contrast with pristine vanadium pentoxide. Further investigation suggested V2O5@G had larger sodium storage capacity, improved rate capability, increased Na+ diffusivity, and reduced electrochemical reaction resistance.