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

V 2 O 5 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 V 2 O 5 nanomaterials are characterized by X-ray diffraction (XRD), Brunauer−Emmett−Teller (BET) N 2 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 ([C 3 mpyr][NTf 2 ] containing 1 M LiNTf 2 ) in rechargeable lithium metal batteries by combining V 2 O 5 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 V 2 O 5 during charge and discharge. The rechargeable lithium battery presented here using V 2 O 5 nanoribbons as cathode materials and RTIL as electrolyte could be the next generation lithium battery with high capacity, safety, and long cycle life.