以竹叶为碳源制备Li4Ti5O12/C复合材料

Preparation of Li4Ti5O12/C composites using bamboo leaves as carbon source

摘要:

以钛酸四丁酯、醋酸锂、柠檬酸和竹炭为原料，采用两步煅烧和溶胶-凝胶法制备锂离子电池Li4Ti5O12/C负极材料。采用XRD、SEM表征材料的微观结构和形貌。采用恒流充放电、交流阻抗和循环伏安法研究材料的电化学性能。结果显示，Li4Ti5O12/C具有良好的结晶度，颗粒表面光滑，分散均匀，粒径为200~300 nm。10 C倍率下，Li4Ti5O12/C的首次放电比容量为180.4 mA•h/g，循环300圈后为167.5 mA•h/g，容量保持率为92.8%，远高于Li4Ti5O12的46.9%。在20 C大倍率下，Li4Ti5O12/C和Li4Ti5O12的容量保持率分别为68.9%和41.3%

Abstract:

Li4Ti5O12/C anode material for lithium-ion batteries were prepared by two-step calcination and sol-gel method using tetrabutyl titanate, lithium acetate, citric acid and bamboo charcoal as starting materials. The microstructure and morphology of the materials were characterized by XRD and SEM. The electrochemical properties of the materials were studied by constant current charge discharge, AC impedance and cyclic voltammetry . The electrochemical properties of the materials were investigated by constant current charge-discharge test, AC impedance and cyclic voltammetry. The results show that the Li4Ti5O12/C has good crystallinity, smooth particle surface and uniform dispersion, and the particle size is 200~300 nm. The first discharge specific capacity of Li4Ti5O12/C is 180.4 mA•h/g at 10 C, and 167.5 mA•h/g after 300 cycles. The capacity retention is 92.8%, which is much higher than 46.9% of Li4Ti5O12. At a high rate of 20 C, the capacity retention of Li4Ti5O12/C and Li4Ti5O12 were 68.9% and 41.3%, respectively.