Enhancing the high-rate performance of Li4Ti5O12 anode material for lithium-ion battery by a wet ball milling assisted solid-state reaction and ultra-high speed nano-pulverization

• A modified solid-state reaction method with in situ coating process is investigated.
• The ultra-high speed nano-pulverization pretreatment process was introduced.
• The obtained Li4Ti5O12 electrode material showed high surface area and dispersion.
• The treated Li4Ti5O12 showed excellent electrochemical performance.

Li4Ti5O12 was successfully synthesized by a modified solid-state reaction method with an in situ coating process. The powders were characterized by X-ray diffraction, BET surface area and scanning electron microscopy. Sub-micron Li4Ti5O12 oxides, with a high phase purity and accurate stoichiometry, were obtained after calcination at 800 °C for 7 h. The pure Li4Ti5O12 electrode material showed a much higher surface area and specific capacity than the one without the ultra-high speed nano-pulverization pretreatment process. Excellent reversible high-rate capability was achieved as 137 mAh g−1 at 10C, 107 mAh g−1 at 20C, 76 mAh g−1 at 40C. The result of the cycling performance showed high capacity retention of about 100% for all charge/discharge rates after 10 cycles. Electrochemical impedance spectra tests demonstrated that the lithium-ion diffusivity in Li4Ti5O12 was improved significantly after the pretreatment, which indicated that the ultra-high speed nano-pulverization treated Li4Ti5O12 with high dispersion and smooth particle surface would be a promising high-rate anode material for lithium-ion battery.