Enhanced reversible capacity of Li_4Ti_5O _(12)-coated TiO_2 nanocomposites as lithium-ion battery anodes

摘要

A Li_4Ti_5O_(12)-coated TiO_2 nanocomposite with micron-size spherical morphology has been synthesized as an anode for lithium-ion batteries (LIBs). By employing TiO_2/polyaniline microspheres and lithium hydroxide as precursors, the as-prepared Li _4Ti_5O_(12)-coated TiO_2 nanocomposite demonstrates excellent cycle performance with similar stability as pure Li _4Ti_5O_(12). Cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS) show that the enhanced reversible capacity is mainly attributed to the TiO_2 phase, rather than by the TiO_2/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 Li _4Ti_5O_(12) sample.