High Capacity, Safety, and Enhanced Cyclability of Lithium Metal Battery Using a V2O5 Nanomaterial Cathode and Room Temperature Ionic Liquid Electrolyte

V2O5 nanomaterials including nanoribbons, nanowires, and microflakes have been synthesized by an ultrasonic assisted hydrothermal method and combined with a post-annealing process. The as-annealed V2O5 nanomaterials are characterized by X-ray diffraction (XRD), Brunauer−Emmett−Teller (BET) N2 adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM). A room temperature ionic liquid (RTIL) has been used as an electrolyte ([C3mpyr][NTf2] containing 1 M LiNTf2) in rechargeable lithium metal batteries by combining V2O5 nanomaterials as cathode materials. The electrochemical tests including constant current charge−discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) show near theoretical specific capacity, improved cyclability, good high-rate capability, and enhanced kinetics. The thermogravimetric analysis (TGA) results show that the RTIL can prevent the dissolution of V2O5 during charge and discharge. The rechargeable lithium battery presented here using V2O5 nanoribbons as cathode materials and RTIL as electrolyte could be the next generation lithium battery with high capacity, safety, and long cycle life.