The influence of the TiO₂ particle size on the properties of Li₄Ti₅O₁₂ anode material for lithium-ion battery

The spinel Li₄Ti₅O₁₂ anode materials were prepared using high-energy ball milling assisted solid-state reaction method. In order to obtain the electrode materials with the best electrochemical performance, the influence of different TiO₂ particle sizes for Li₄Ti₅O₁₂ synthesis was systematically studied. The physical and electrochemical properties of the obtained samples were characterized by X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller surface area analysis, A.C. impedance, galvanostatic charge-discharge and cyclic voltammetry tests. The results showed that the initial particle size of TiO₂ played an important role on the properties of Li₄Ti₅O₁₂. It could affect the final grain size, the specific surface area, the electrochemical properties and the Li-ion diffusion coefficient of Li₄Ti₅O₁₂. Electrochemical testing results showed that the Li₄Ti ₅O₁₂ prepared by TiO₂ with particle size of 25 nm exhibited the best electrochemical properties. The discharge capacity reached 164.7 mAh/g at 0.5 C. When the current rate was increased to 10 C, the first discharge capacity was only dropped to 70.6 mAh/g, and the capacity retention was 94.5% at the 50th cycle.