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.

► Atomic layer deposition is an effective process to fabricate TiO2 nano-layer.
► The high uniformity TiO2-deposited electrode is applied in lithium ion battery.
► TiO2 deposited electrode enhances the electrochemical performance of Li-ion cells.
► Electrode with TiO2 shows smaller resistance than controlled one after cell cycling.
► The resistance suppression results in a good cycle stability of the Li-ion cell.