纳米絮状Li_4Ti_5O_(12)的水热法合成及性能的研究

Hydrothermal synthesis and electrochemical performance of flocculent-like Li_4Ti_5O_(12)

为解决高温烧结制备的锂离子电池负极材料Li4Ti5O12易团聚、形貌差的问题,采用水热低温烧结法,以钛酸丁酯、氢氧化锂分别为钛源和锂源,异丙醇为溶剂,制备纯相Li4Ti5O12。用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和比表面测试仪对样品进行表征,采用恒流充放电法对钛酸锂进行电化学性能评价。结果表明,在400℃低温煅烧后可得到单一纯相尖晶石型Li4Ti5O12,所制备样品为具有大比表面积的纳米絮状粉体,表现出良好的电化学性能,在常温条件下,以0.1C倍率进行充放电,首次放电容量达到155.7mA·h/g,经50次循环后容量仍保持约143mA·h/g,容量保持率达到91.8%。

Pure lithium titanate Li4Ti5O12was synthesized by a facile hydrothermal method using TBT and LiOH·H2O as raw materials.The as-prepared samples were characterized by X-ray diffraction （XRD）,scanning electron microscopy （SEM）and BET analysis.The electrochemical performance of the sample was tested by using galvanostatic charge-discharge method.The results show that pure single-phase spinel Li4 Ti5 O12 can be obtained at a low calcination temperature of 400 ℃. The particles are nanoflocculent-like with greater specific surface area.The flocculent-like Li4 Ti5 O12 has excellent electro-chemical performance with initial discharge capacity of 155.7 mA·h/g at 0.1C rate.After cycled for 50 times at 0.1C,the capacity is remained about 143 mA·h/g.The capacity retention ratio can be up to 91.8%.