Li_4Ti_5O_(12)/TiN复合材料的制备及电化学性能

Preparation and electrochemical performance of Li_4Ti_5O_(12)/TiN composites

以尿素为氮源,采用高温热处理方法在Li4Ti5O12表面自生长一层纳米尺寸厚度的TiN导电包覆膜。利用DSC-TG、Raman、TEM、FT-IR、XRD及恒流充放电等测试手段,研究热处理工艺对材料结构、形貌及电化学性能的影响。结果表明:使用适中的尿素原料含量可以获得均匀连续、厚度适中的TiN导电膜,较高的热处理温度有利于促进TiN的生成,而较短的热处理时间可以保持材料物相的纯净和较高结晶度。在尿素含量10%(质量分数)、热处理温度800℃、热处理时间20 min的工艺条件下,所制备的复合材料的容量和倍率性能最优,0.2C和3C初始放电比容量分别达到162.4和130.2 mA.h/g。

Conductive TiN self-growing film was prepared on the surface of Li4Ti5O12 particles through heat treatment with urea as nitrogen source.The crystalline structure,morphology and electrochemical properties were studied by DSC-TG,Raman,TEM,FT-IR,XRD and charge/discharge test.The results show that using appropriate urea content uniform and continuous TiN conductive film with proper thickness can be obtained.High temperature of heat treatment can promote the growth of TiN.Short time of heat treatment can keep high purity and crystallinity of material.The best process for synthesizing Li4Ti5O12/TiN composite is urea mass fraction of 10%,heat treatment temperature of 800 ℃ and heat treatment time of 20 min.Under this condition,the initial discharge specific capacity of the material at 0.2C and 3C are 162.4 and 130.2 mA-h/g,respectively.