Fabrication and Characterization of Nano-Crystalline TiO2 Thin Film Electrodes for Lithium Ion Batteries

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 O-2 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. The spindle-like TiO2 electrode shows a flat plateau at similar to 1.7 V, and exhibits a reversible capacity of around 330 mAhg(-1) as cycled between 3.0 to 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 high capacity electrodes for lithium ion thin film batteries. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.055203jes] All rights reserved.