Enhanced reversible capacity of Li4Ti5O12-coated TiO2 nanocomposites as lithium-ion battery anodes

• A designed nanocomposite with Li4Ti5O12-coated layer around TiO2 core is prepared.
• The as-prepared dual-phase sample shows high specific capacity.
• The extra reversible capacity is due to the capacity contribution of TiO2 core.

A Li4Ti5O12-coated TiO2 nanocomposite with micron-size spherical morphology has been synthesized as an anode for lithium-ion batteries (LIBs). By employing TiO2/polyaniline microspheres and lithium hydroxide as precursors, the as-prepared Li4Ti5O12-coated TiO2 nanocomposite demonstrates excellent cycle performance with similar stability as pure Li4Ti5O12. Cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS) show that the enhanced reversible capacity is mainly attributed to the TiO2 phase, rather than by the TiO2/Li4Ti5O12 interface. At the current density of 1500 mA g− 1, the discharge capacity of the nanocomposite remains at 135.7 mAh g− 1 after 100 consecutive cycles, and shows even better electrochemical rate performance than a pure Li4Ti5O12 sample.