Nano-Crystalline TiO2 as Intercalation Electrodes for Li Batteries

Abstract

Nano-crystalline TiO2 thin films have been fabricated by direct-current sputter deposition. The crystalline TiO2 films are deposited without thermal annealing. The crystal structures, morphologies and electrochemical performances of the fabricated TiO2 electrodes toward lithium have been systematically investigated. By controlling the total deposition pressures and O2 partial pressures, anatase-phase TiO2 electrodes with granular grains and spindle-like grains can be fabricated. The TiO2 electrode exhibits with granular morphology shows short discharge plateau and lower capacity, whereas the spindle-like TiO2 electrode shows a long flat plateau at ~1.7 V with a reversible capacity around 400 mAhg-1 (3.0-0.0 V v.s. Li/Li+ at 0.2 C). The results have demonstrated that the nano-structured spindle-like TiO2 can be used as safe and high capacity electrodes for lithium ion thin film batteries.