Atomic layer deposition of TiO2 on negative electrode for lithium ion batteries

Atomic layer deposition (ALD) technology consisting of periodically repeated series of self-limited surface reactions is a CVD technique for the well-controlled deposition of inorganic layers with thickness in the nanometer scale which has been widely used in the semiconductor industry. In this study, a novel process to fabricate TiO2 nano-layer with high uniformity by ALD on the graphite negative electrode of lithium battery is reported. We found that under accurate thickness control, a TiO2 plated graphite electrode shows better performance in cycle life, compared with the pristine graphite. Electrochemical impedance spectroscopy (EIS) results showed that after 60 cycles, the cell resistance of the TiO2 plated electrode decreased, while that of normal graphite electrode increased significantly. The enhanced performance of the electrode may be attributed to the TiO2 plating, which suppressed the increase of resistance during the prolonged cycle. (C) 2012 Elsevier B.V. All rights reserved.