TiO2/Si composites synthesized by sol-gel method and their improved electrode performance as Li-ion battery anodes

Composites of rutile-type TiO2 and Si were synthesized by a facile sol-gel method for a high-performance anode of Li-ion battery. We have investigated anode performance of binder-free thick-film electrodes prepared by a gas-deposition method using the TiO2/Si composites obtained. The composite electrode exhibited a remarkably improved cyclability and a good high-rate performance: a discharge capacity at the 900th cycle was 710 mA h g–1, and a specific capacity per Si weight was as large as 1870 mA h g(Si)–1 even at a high current rate of 4.8C. It is suggested that a fast Li-ion diffusion in TiO2 provides smooth insertion/extraction of Li-ion into/from the composite electrodes. The results offer a utility of rutile TiO2 as a Li-ion conductor in Si-based electrodes for the next-generation Li-ion battery.