制备方法对尖晶石Li_4Ti_5O_(12)负极材料性质的影响  

Effect of Preparation Method on the Performance of Li_4 Ti_5 O_12

作　　者：吴显明[1,2] 陈上[1,2] 麦发任[1] 赵俊海[1] 何海亮[1] 

机构地区：[1]吉首大学化学化工学院,湖南吉首416000 [2]湘西自治州矿产与新材料技术创新服务中心,湖南吉首416000

出　　处：《精细化工》2014年第1期21-24,共4页Fine Chemicals

基　　金：国家自然科学基金(21263004)~~

摘　　要：采用高温固相法、热聚合法和改良溶胶-凝胶法制备锂离子电池负极材料Li4Ti5O12。通过X射线衍射、扫描电镜、恒电流充放电及电化学阻抗表征了合成产物的结构、形貌及电化学性能。结果表明,溶胶-凝胶法合成的粉末为纯相Li4Ti5O12,而高温固相法和聚合法合成的Li4Ti5O12则存在TiO2杂相。高温固相法合成的Li4Ti5O12粉末晶粒最大,溶胶-凝胶法合成的粉末晶粒最小,分布最为均匀,晶粒尺寸约为80 nm。高温固相法、热聚合法和溶胶-凝胶法制备的Li4Ti5O12粉末首次放电容量分别为161.6、165.9 mA·h/g和171.5 mA·h/g,循环25次后的容量保持率分别为84.7%、87.7%和94.3%,溶胶-凝胶法合成的Li4Ti5O12粉末电化学性能最好。Spinel Li4Ti5O12 powders were prepared by solid state reaction, thermal polymerization method and sol-gel. The phase identification, surface morphology, and electrochemical properties of the powders were investigated by X-ray diffraction, scanning electron microscopy, galvanostatic charge- discharge experiments and electrochemical impedance spectroscopy. The results show that the powders prepared by sol-gel are pure Li4Ti5O12. The powders prepared by solid state reaction and thermal polymerization method are impure with TiO2 phase. The grain size of the powders prepared by sol-gel is about 80 nm, which is much smaller than the powders prepared by solid state reaction and thermal polymerization method. The capacities of the Li4Ti5O12 powders prepared by solid state reaction,thermal polymerization method and sol-gel are 161.6 mA· h/g, 165. 9 mA·h/g and 171.5 mA·h/g, respectively. Their capacity retention after being cycled 25 times for the powders prepared by solid state reaction and thermal polymerization method is 84.7% and 87.7%, which is smaller than that of 94. 3% for the powders prepared by sol-gel. The electrochemical properties. Li4Ti5O12 powders prepared by sol-gel shows the best

关 键 词：锂离子电池 LI4TI5O12 高温固相法 溶胶-凝胶法 热聚合法 功能材料 

分 类 号：TM912.9[电气工程—电力电子与电力传动]