摘要:
使用简单的水解反应和低温热处理过程所制备的Li4Ti5O12/C复合材料具有良好的倍率性能。在水解过程中引入表面活性剂溴化十六烷基三甲铵 (CTAB), 能够明显地改善锂离子电池负极材料Li4Ti5O12/C的倍率性能。在0.5, 1, 2, 5, 10C的倍率条件下, 电极材料的比容量分别达到162, 154, 121, 80, 60 m Ah/g。明显高于使用物理混合方法所制备的Li4Ti5O12/C复合材料。同时使用CTAB所制备的Li4Ti5O12/C复合材料, 在高倍率条件下, 还显示出了非常良好的循环稳定性, 因为其拥有快速的Li+迁移速率 (8.97×10-13cm2/s), 较小的传荷电阻 (Rct) 35.2Ω和较小的体积电阻 (Rs) 6.8Ω。该方法具有实际的应用价值。
Abstract:
The Li4Ti5O12/C (LTO/C) composite with excellent rate performances was synthesized via a facile hydrolysis reaction followed by a low temperature heat treatment. In the hydrolysis process,the introduction of cetyltrimethylammonium bromide (CTAB) as a surfactant can significantly improve the rate performances of Li4Ti5O12/C composite as anode material for lithium ion battery (LIB). The specific capacities of the obtained composite at charge and discharge rates of 0.5,1,2,5 and 10 C were respectively 162,154,121,80 and 60 m Ah/g,which was apparently larger than those of the Li4Ti5O12/C by physical mixing processes. The Li4Ti5O12/C prepared with CTAB also showed excellent cycling stability at high rate,attributed to its larger diffusion coefficient of lithium ion (8.97 × 10-13cm2/s),smaller charge-transfer resistance Rct (35.2 Ω) and volume resistance Rs (6.8 Ω) than those of the composite by physical mixing. Therefore,this study has important theory significance and practical application value.