Preparation of Li₄Ti₅O₁₂ submicrospheres and their application as anode materials of rechargeable lithium-ion batteries

Abstract

We report on the preparation of spinel Li₄Ti₅O₁₂ submicrospheres and their application as anode materials of rechargeable lithium-ion batteries. The spinel Li₄Ti₅O₁₂ submicrospheres are synthesized with three steps of the hydrolysis of TiCl₄ to form rutile TiO₂, the hydrothermal treatment of rutile TiO₂ with LiOH to prepare an intermediate phase of LiTi₂O_4+δ , and the calcinations of LiTi₂O_4+δ to obtain spinel Li₄Ti₅O₁₂. The as-prepared products are investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The diameters of Li₄Ti₅O₁₂ submicrospheres with novel hierarchical microstructures are about 200–300 nm with the assembly of 20–30 nm nanoparticles. The electrochemical properties of Li₄Ti₅O₁₂ submicrospheres are measured by galvanostatical discharge/charge test and cyclic voltammetry (CV). The as-prepared Li₄Ti₅O₁₂ display excellent discharge/charge rate and cycling capability. A high discharge capacity of 174.3 mAh/g is obtained in the first discharge at 1 C rate. Meanwhile, there is only tiny capacity fading with nearly 100% columbic efficiency in the sequential 5–50 cycles. Moreover, lithium-ion diffusion coefficient in Li₄Ti₅O₁₂ is calculated to be 1.03 × 10⁻⁷ cm²/s. The present results indicate that the as-prepared Li₄Ti₅O₁₂ submicrospheres are promising anode candidates of rechargeable Li-ion batteries for high-power applications.