溶胶-凝胶法制备Li_(4/3)Ti_(5/3)O_4/Ag复合材料及其表征  

Sol-gel Synthesis of Li_(4/3)Ti_(5/3)O_4/Ag Composite and Its Performance as Anode for Lithium Ion Battery

作　　者：吴显明[1,2] 肖卓炳[3] 麻明友[1] 陈上[1,2] 

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 [3]吉首大学林产化工工程湖南省重点实验室,湖南张家界427000

出　　处：《精细化工》2010年第8期751-754,759,共5页Fine Chemicals

基　　金：湖南省教育厅自然科学基金资助项目(07B060);湖南省科技厅资助项目(2009FJ3045)~~

摘　　要：采用溶胶-凝胶法制备Li4/3Ti5/3O4/Ag复合材料,通过X射线衍射、扫描电子显微镜、恒电流充放电及交流阻抗等技术检测和分析合成产物的物相、形貌及电化学性质。研究表明,在Li4/3Ti5/3O4中添加Ag后Li4/3Ti5/3O4的Ti—O键没受影响,Li4/3Ti5/3O4/Ag及Li4/3Ti5/3O4的晶格常数非常接近,Ag没有进入Li4/3Ti5/3O4晶格,只是均匀地分散在Li4/3Ti5/3O4颗粒中。与Li4/3Ti5/3O4相比,Li4/3Ti5/3O4/Ag复合材料具有更高的比容量,更高的库仑效率以及更低的极化。添加Ag后对Li4/3Ti5/3O4锂离子扩散系数影响不大。电化学循环过程中,Li4/3Ti5/3O4/Ag的容量损失小于Li4/3Ti5/3O4,且随着充放电倍率的增加两者容量损失差距变大。Ag的添加大大地改善了Li4/3Ti5/3O4的循环性能,尤其是大电流循环性能。The powders of Li4/3Ti5/3O4/Ag composite were prepared by the sol-gel technique.Phase identification,surface morphology and electrochemical properties were investigated with X-ray diffraction,scanning electron microscopy,galvanostatic charge-discharge experiments,and electrochemical impedance spectroscopy.Results show that the Ti-O bond is not affected by the adddition of Ag.Li4/3Ti5/3O4/Ag and Li4/3Ti5/3O4 have very similar crystal lattice parameters.Ag does not enter the Li4/3Ti5/3O4crystal and disperses homogeneously in Li4/3Ti5/3O4 particles.Compared with Li4/3Ti5/3O4,Li4/3Ti5/3O4/Ag composite has higher specific capacity,higher columbic efficiency and lower polarization.The addition of Ag has little effect on the lithium ion diffusion of Li4/3Ti5/3O4.The capacity loss of Li4/3Ti5/3O4/Ag is smaller than that of Li4/3Ti5/3O4 during the cycling.The addition of Ag greatly improves the cycleability of Li4/3Ti5/3O4 powders,especially at the higher charge-discharge rate.

关 键 词：煅烧 锂离子 阻抗 电化学 功能材料 

分 类 号：TQ050.43[化学工程] TM912.9[电气工程—电力电子与电力传动]