锂离子电池负极材料Li4Ti5O12的合成及性能研究

本文通过乙酸锂与二氧化钛反应，采用一步高温固相法在不同反应温度（750 °C/800 °C/850 °C）和反应气氛（氮气/空气）下合成Li₄Ti₅O₁₂材料. 通过热重分析、X射线衍射、扫描电子显微镜、循环伏安曲线和充放电曲线分析了Li₄Ti₅O₁₂的晶体结构，观察其微观形貌，并测试其电化学性能. 结果表明，800 °C氮气烧结得到的Li₄Ti₅O₁₂（L-800N）材料粒径较小，该材料在1.0C倍率下的首周期放电比容量达到170.7 mAh·g^-1，100周期循环后的容量保持率高达94.6%，即使是10C高倍率其首周期放电容量依然有143.0 mAh·g^-1，表现出了良好的倍率和循环寿命性能.

Syntheses and Electrochemical Performances of Li4Ti5O12 Anode Materials for Lithium Ion Battery

Series of spinel lithium titanate (Li₄Ti₅O₁₂) materials were synthesized by one-step solid-state reaction using lithium acetate and TiO₂ as raw materials under different temperatures (750/800/850 °C) and atmospheres (N₂/air). The as-prepared Li₄Ti₅O₁₂ materials were investigated by thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, cyclic voltammotry and charge-discharge test to analyze their crystal structures, microstructures and electrochemical performances. The results show that the Li₄Ti₅O₁₂（L-800N）material obtained at 800 °C under nitrogen atmosphere exhibited better electrochemical performance and smaller particle size. The initial discharge specific capacity of the optimized Li₄Ti₅O₁₂ reached 170.7 mAh·g^-1 at 1.0C with the capacity retention of 94.6% after 100 cycles. Even at the current density of 10C, the initial discharge specific capacity of 143.0 mAh·g^-1 could be achieved, which demonstrated good high-rate and cycling performances.