Lithium Insertion and Transport in the TiO2-B Anode Material: A Computational Study

TiO2-B is a highly promising anode material for rechargeable lithium batteries. Computational studies based on density functional theory (DFT) have been carried out on this material focusing on key issues relating to lithium insertion sites and lithium diffusion paths. Our simulation model shows good reproduction of the observed crystal structure of TiO2-B. Electronic structure calculations suggest that the lowest energy lithium site is a slightly off-center position in the b-axis channel for low lithium concentration (x < 0.125 for LixTiO2-B). Our calculated cell voltages are compatible with values from electrochemical measurements. Low Li migration energies are found for pathways along the b-axis channel and the [001] c-axis direction, suggesting significant Li ion mobility in this anode material.