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.