溶胶-凝胶法制备球形Li_4Ti_5O_(12)及其电化学性能研究

为提高Li4Ti5O12材料的振实密度,以十六烷基三甲基溴化铵(CTAB)为结构导向剂,通过溶胶-凝胶法合成了球形Li4Ti5O12材料。利用TGA/DSC、XRD、SEM、CV和恒流充放电仪对材料的结构、形貌和电化学性能进行测试。结果表明,在800℃热处理12 h所得样品为单一的尖晶石晶体结构,结晶度较高,颗粒基本呈规则球形、流动性较好,粒径分布均匀,并表现出较好的电化学性能,振实密度达1.86 g/m L。在室温下以0.1 C充放电时,其首次放电比容量为173.19 m Ah/g,50次充放电循环后其放电比容量保持率为97.4%。

Synthesis of Spherical Li4Ti5O12 Materials by a Sol-gel Method and Their Electrochemical Properties

To increase the tap density of Li4Ti5O12, spherical Li4Ti5O12 was synthesized by a sol-gel method using hexadecyl trimethyl ammonium bromide (CTAB) as structure directing agents. The structure, morphology and electrochemical performance of the sample were tested by TGA/DSC, XRD, SEM, CV and galvanostatic charge/discharge device. It is found that when heated at 800 oC for 12 h, the sample has a pure spinel crystal structure, high degree of crystallinity, spherical particle, good fluidity, uniform particle size distribution and good electrochemical performance with a tap density of 1.86 g/mL. At 0.1 C discharging rate, the first discharge specific capacity is 173.19 mAh/g, and after 50 cycles, its specific discharge capacity retention rate is 97.4%