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 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. The spindle-like TiO₂ electrode shows a flat plateau at ~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. ©2012 The Electrochemical Society