Li4 Ti5 O12/TiO2纳米复合材料制备及其锂离子电池性能研究

摘要

Nanocomposites containing Li4 Ti5 O12 nanosheets and TiO2 nanoparticles were synthesized by a low temperature hydrothermal method using butyl Titanate and LiOH·H2O as the precursors, and PEG200 as the structure directing agent. The as-synthesized products were characterized using X-ray diffraction ( XRD ) , scanning electron microscopy ( SEM ) . By controlling the ratio of Li and Ti, pure sheet-like Li4 Ti5 O12 and Li4 Ti5 O12/TiO2 composite nanomaterials could be prepared respectively. The Li ion battery performance of synthesized nanomaterials was measured. The results indicated that the obtained Li4 Ti5 O12-TiO2 nanocomposites had good Li ion battery performance. The initial discharge-charge capacities of Li4 Ti5 O12-TiO2 nanocomposites at 0. 2 C were 172 mAh · g-1 and 170 mAh · g-1 , respectively, in the window of 1. 0 ~2. 5 V at room temperture, the charge-discharge efficiency can reach 98. 8%.%以钛酸丁酯、氢氧化锂为原料,在聚乙二醇( PEG200)体系下通过水热法合成了Li4 Ti5 O12纳米片/TiO2纳米颗粒复合材料,采用XRD、 SEM等对材料的结构,形貌等进行了表征。通过控制Li/Ti 的摩尔比可以较好地控制TiO2的含量,分别得到纯的Li4 Ti5 O12纳米片或Li4 Ti5 O12纳米片/TiO2纳米颗粒复合材料。测试了制得材料的锂离子电池性能,结果表明, Li4 Ti5 O12-TiO2复合纳米材料具有优良的充放电容量和倍率性能。首次放电可达到172 mAh·g-1,充电可达到170 mAh·g-1,效率高达98.8%。