Nanocrystalline TiO 2 (anatase) for Li-ion batteries

Abstract

Nanocrystalline TiO 2 (anatase) was synthesized successfully by the direct conversion of TiO 2-sol at 85 °C. The as-prepared TiO 2 at 85 °C were calcined at different temperatures and time in order to optimize the system with best electrochemical performance. The particle sizes of the synthesized materials were found to be in the range of 15–20 nm as revealed by the HR-TEM studies. Commercial TiO 2 anatase (micron size) was also studied for its Li-insertion and deinsertion properties in order to compare with the nanocrystalline TiO 2. The full cell studies were performed with LiCoO 2 cathode with the best performing nano-TiO 2 as anode. The specific capacity of the nanocrystalline TiO 2 synthesized at 500 °C/2 h in a half-cell configuration was 169 mAh g −1 while for the cell with LiCoO 2 cathode, it was 95 mAh g −1 in the 2 V region. The specific reversible capacity and the cycling performance of the synthesized nano-TiO 2 anode in full cell configuration across LiCoO 2 cathode are superior to that reported in the literature. Cyclic voltammetry measurements showed a larger peak separation for the micro-TiO 2 than the nano-TiO 2, clearly indicating the influence of nano-particle size on the electrochemical performance.