Investigation of effects of carbon coating on the electrochemical performance of Li4Ti5O12/C nanocomposites

Carbon-coated Li4Ti5O12 (LTO/C) particles were synthesized via a simple solid-state reaction using a hydrothermally prepared TiO2/C precursor. The effects of the sintering temperature and carbon content on the electrochemical properties of the as-prepared materials were systematically investigated. Among the temperature examined, the sample treated at 800 °C showed the best performance due to the combination of relatively high crystallinity, small particle size, and high electrical conductivity. In addition, the ionic transport mechanism in the carbon coating layer was studied by in situ Raman analysis. It is proposed that the defects and vacancies in the carbon are responsible for the efficient Li ion transportation. The results indicate that the enhanced electrode properties can be achieved by optimizing the content of the coated carbon due to the balance between the electric conduction and the ionic transport.