Surface Modification of Graphite Anode Material By Coating WO_3-X for Fast Chargeable Lithium Ion Battery

Abstract

Fast charging capability of lithium ion battery (LIB) is one of the most important requirements for popularization of electric vehicle (EV). However, currently used graphite anode materials cannot fully meet the requirements on the fast charge capability for EV applications. In this work, with an aiming to improve the electrochemical kinetics of graphite anode upon charging process, the surface modified graphite with tungsten oxide (WO 3-x ) was investigated as an anode material for LIB. The resulting anode material shows the improved electrochemical performance at high rates without severe capacity fading. At a rate of 1800 mA g -1 (5 C-rate), 5 wt% WO 3-x coated graphite anode material exhibited 94 % of capacity obtained at a rate of 72 mA g -1 (0.2 C-rate). These results showed that surface modification by coating WO 3-x on graphite anode material would be an effective way to advance the fast charging ability of graphite anode materials for LIB for EV. In this presentation, microstructure and electrochemical properties of WO 3-x coated graphite material will be discussed in more detail.