A Li4Ti5O12/TiO2@CNT Core/Shell Structure for Rechargeable Li Batteries

Li4Ti5O12 is an important type of anode material for rechargeable Li battery due to its excellent cycling and thermal reliability, but the poor conductivity represents a significant challenge in the scalable application. Here we design a ternary Li4Ti5O12/TiO2@CNT core/shell structure to well mitigate the conductivity issue. The hybrid core/shell structure is fabricated by a facile hydrothermal reaction followed by heat treatment at 600 degrees C. It is comprised of Li4Ti5O12/TiO2 nanocrystals several nanometers in dimension tightly anchored on CNT network. The CNT network provides a fast and robust conductive way for electron transport, while the minor rutile-TiO2 phase improves the kinetics of Li4Ti5O12 toward fast lithium insertion/extraction. The electrochemical results indicate that the core/shell structure displays a high electrochemical activity in terms of reversible capacity and rate capability. The hybrid structure also shows excellent long-term cycling stability when operated at a high rate of 5 C.