Nanocrystalline TiO2 (anatase) for Li-ion batteries

Nanocrystalline TiO2 (anatase) was synthesized successfully by the direct conversion of TiO2-sol at 85 degrees C. The as-prepared TiO2 at 85 degrees 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 TiO2 anatase (Micron size) was also studied for its Li-insertion and deinsertion properties in order to compare with the nanocrystalline TiO2. The full cell studies were performed with LiCoO2 cathode with the best performing nano-TiO2 as anode. The specific capacity of the nanocrystalline TiO2 synthesized at 500 degrees C/2 h in a half-cell configuration was 169 mAh g(-1) while for the cell with LiCoO2 cathode, it was 95 mAh g(-1) in the 2 V region. The specific reversible capacity and the cycling performance of the synthesized nano-TiO2 anode in full cell configuration across LiCoO2 cathode are superior to that reported in the literature. Cyclic voltammetry measurements showed a larger peak separation for the micro-TiO2 than the nano-TiO2, clearly indicating the influence of nano-particle size on the electrochemical performance. (c) 2006 Elsevier B.V. All rights reserved.