Effect of heat treatment on the morphology and electrochemical performance of TiO2 nanotubes as anode materials for lithium-ion batteries

Lepidocrocite TiO2 nanotubes prepared by hydrothermal process were annealed at 300 °C and 500 °C for 1 h in air. The morphologies, structures and electrochemical performances of these TiO2 nanomaterials were investigated by transmission electron microscope, X-ray diffraction and a variety of electrochemical testing techniques. The results showed that the TiO2 nanotubes gradually collapsed during heating period, and were finally transformed into anatase TiO2 nanorods. The electrochemical measurements revealed that all the TiO2 electrodes exhibit a good cycling performance when were used as the anode materials for lithium-ion batteries. Compared with the original TiO2 nanotubes, the 500 °C annealed TiO2 nanomaterial electrode provided a higher first coulombic efficiency and higher lithium-ion transfer rate, implying a promising anode candidate for lithium-ion batteries.