3-D Tunnel TiO2 Crystal Phase as a Fast Charging Lithium Battery Anode from Stochastic Surface Walking-Based Material Screening

Abstract

To search for both high-rate capacity and high stability Li-ion battery anodes, here we design a new strategy of high-throughput material screening based on novel global potential energy surface exploration techniques. This permits us to quantify the structural evolution thermodynamics for 11 candidate materials after lithiation. When reaching the high capacity (∼300 mA h/g) in lithiation, all bulk materials studied are shown to experience solid-to-solid phase transition with appreciable volume expansion. Among 11 candidates, we screen out a new three-dimensional (3-D) tunnel TiO2 (TiO2-S) phase to be a high-performance anode material. This TiO2-S phase has a spinel-like structure, achieving only 5.5% volume expansion at 335.5 mA h/g capacity (Li + TiO2 → LiTiO2) and also possessing a fast charging kinetics as seen from the low Li diffusion barrier in a wide range of Li concentrations. Because all common stable forms of materials are not good anode materials at high-rate condition, our results indicate th...