Li4Ti5O12材料的固相法制备及其煅烧温度

以Li₂CO₃，TiO₂为原料，无水乙醇为分散剂，采用高温固相法，通过两步煅烧方式制备出不同煅烧温度下的Li₄Ti₅O₁₂粉末材料.采用X射线衍射（XRD）、扫描电镜（SEM）表征材料的结构和形貌，采用恒电流充放电、交流阻抗和循环伏安等方法测试材料电化学性能.结果表明：在800 ℃下煅烧6 h后可得到晶型完整的纯相Li₄Ti₅O₁₂，其颗粒均匀分布在200~400 nm.Li₄Ti₅O₁₂在0.5C倍率下首次可逆比容量为157.67 mA·h/g，库伦效率为96.1%，经过100次循环充放电后容量保持率为98.63%；在5C倍率下首次可逆比容量为107.0 mA·h/g，经过1 000次循环充放电后容量保持率为84.1%.

Preparation of Li4Ti5O12 by Solid-State Method and Exploration of Calcination Temperature

Li₄Ti₅O₁₂ powders were prepared by solid-state reaction and two-step calcination method with Li₂CO₃ and TiO₂ as starting materials and anhydrous ethanol as dispersant.The microstructure and morphology of the materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The electrochemical properties of the materials were tested by constant current charge-discharge,AC impedance and cyclic voltammetry.The results show that the pure phase Li₄Ti₅O₁₂ with complete crystal structure could be synthesized after calcination at 800 ℃ for 6h,and uniform dispersion with particle size of 200~400 nm.The first reversible specific capacity of the Li₄Ti₅O₁₂ sample was 157.67 mA·h/g at the rate of 0.5 C,and the coulombic efficiency was 96.1%,the capacity retention was 94.3% after 100 cycles.The first reversible specific capacity was 107.0 mA·h/g at the rate of 0.5C,the coulombic efficiency was 96.1% and capacity retention was 84.1% after 1 000 cycles.