Synthesis and electrochemical performance of high-rate dual-phase Li4Ti5O12–TiO2 nanocrystallines for Li-ion batteries

Dual-phase Li4Ti5O12–TiO2 nanocrystallines are prepared by a hydrothermal process and subsequent heat treatment. The as-prepared Li4Ti5O12–TiO2 nanocrystallines measure around 15–25 nm in size and have abundant phase interfaces. Electrochemical measurements demonstrate that dual-phase Li4Ti5O12–TiO2 exhibit good electrochemical performance over individual single-phase Li4Ti5O12, especially at high current rates. Initial discharge capacities of dual-phase Li4Ti5O12–TiO2 nanocrystallines are 241 and 202 mAh g−1 at discharge rates of 0.2 and 5 C, respectively. Even after 50 cycles at 20 C, the capacity still remains 140 mAh g−1, which is four times greater than that of single-phase Li4Ti5O12 (29 mAh g−1). The high electrochemical performance indicates that dual-phase Li4Ti5O12–TiO2 nanocrystallines are highly promising anode materials for lithium ion battery applications.