高温固相法合成尖晶石型Li4Ti5O12及其性能研究

摘要

以Li2CO3和TiO2为原料,以乙醇为分散剂,采用高温固相方法合成Li4Ti5O12锂离子电池负极材料,利用XRD、SEM和电化学测试等方法对合成材料的结构、形貌以及电化学性能进行了表征.系统考察了热处理温度对Li4Ti5O12负极材料结构及电化学性能的影响,同时也研究了锂的投料量对Li4Ti5O12电化学性能的影响.在1.0～2.2 V(vs.Li/Li+)范围内,以0.1 mA/cm2的电流密度对最佳工艺条件下合成的Li4Ti5O12负极材料进行了恒电流充放电测试.其首次放电比容量为167 mAh/g,经过30周充放电循环后放电比容量几乎没有衰减,表现出较大的初始放电比容量和良好的循环性能.%Li4Ti5O12 anode material for lithium-ion batteries was synthetized from solid-state method using Li2CO3 and TiO2 as the starting materials and ethanol as dispersing agent. The synthesized material was characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and galvanostatic charge/discharge cycling. The effects of thermal treatment and lithium content on their structure and electrochemical behavior have also been investigated. The synthesized Li4 Ti5 O12 at optimum condition exhibits a good electrochemical property with initial discharge specific capacity of 167 mAh/g in the voltage range 1. 0～2.2 V (versus Li/Li+ ) at a constant current density of 0. 1 mA/cm2 , and the discharge capacity is almost no change after 30 cycles.