摘要
以钛酸丁酯和乙酸锂为原料、三乙醇胺为结构导向剂,通过水热法合成前驱物,然后采用固相烧结制备Li4Ti5O12,探讨不同的钛锂比和煅烧温度对Li4Ti5O12结构和电化学性能的影响,并通过XRD、SEM、恒电流充放电和循环伏安测试对其进行表征。结果表明:当钛和锂的摩尔比为1:0.82、煅烧温度为800℃时,制备得到平均粒径为200nm的纯相尖晶石型Li4Ti5O12,并具有良好的电化学性能;在0.1C倍率下,其首次放电比容量高达到181.7mA·h/g,经过50次循环后放电比容量仍有151.5mA·h/g,从第5次到第50次循环,平均每个循环放电比容量衰减量仅为6μA·h/g;当电流倍率增大到2.0C时,其首次放电比容量仍然保持135mA·h/g,从第5次到第50次循环,平均每个循环放电比容量衰减量为0.48mA·h/g。
Li4Ti5O12 was prepared by a hydrothermal method followed by solid state calcination using lithium acetate and tetrabutyl titanate as raw materials,triethanolamine as a structure-directing agent. The effects of different mole ratios of titanium to lithium and calcination temperature on the structure and electrochemical performance of Li4Ti5O12 were investigated by XRD,SEM,constant current charge-discharge and cyclic voltammetry. The results show that,when the mole ratio of titanium to lithium is 1：0.82 and the calcination temperature is 800 ℃,the obtained pure phase spinel Li4Ti5O12 with average particle size of 200 nm has better electrochemical performance. The initial discharge specific capacity of the sample is as high as 181.7 mA·h/g at the current density of 0.1C,and the capacity remains 151.5 mA·h/g after 50 cycles with the capacity fading rate of only 6 μA·h/g per cycle during 5-50th cycles. The sample still remains initial discharge capacity of 135 mA·h/g at 2.0C and the capacity fading rate is 0.48 mA·h/g per cycle during the 5-50th cycles.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2010年第12期2366-2371,共6页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(20871101)
国家科技部科技计划资助项目(2009GJD20021)
湖南省科技厅重点资助项目(2009WK2007)
湖南省自然科学市州联合基金重点资助项目(09JJ8001)
