Effect of starting materials on electrochemical performance of sol-gel-synthesized Li4Ti5O12 anode materials for lithium-ion batteries

In this study, the effect of the sol-gel starting materials with different particle sizes on the sol-gel-synthesized spinel Li4Ti5O12 (LTO) was systematically investigated. The physical and electrochemical properties of the synthesized materials were characterized by X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller-specific surface area analyses, galvanostatic charge/discharge tests, cyclic voltammetry, and electrochemical impedance spectroscopy. It was found that the initial particle size of sol-gel starting material played a crucial role on the properties of as-prepared LTOs. The LTO synthesized with the relatively finer particle size of starting materials possessed relatively smaller particle size and larger specific surface area and therefore resulted in the superior electrochemical properties. The initial discharge capacity of the as-prepared LTO exhibited 168.2, 150.6, and 142.7 mAh g(-1) at current densities of 1, 5, and 10 C, respectively, and up to 95, 95, and 90 % of the corresponding initial discharge capacity was retained after 50 cycles.