锂离子电池电极材料Li_(4)Ti_(5)O_(12)@TiO_(2)的制备及性能  

Li_(4)Ti_(5)O_(12)@TiO_(2)composite preparations as electrode materials for lithium ion battery and research into its characteristics

作　　者：华丽[1] 曾建华[1] 樊锋凯 朱玉涵 翁方青 HUALi;ZENG Jian-hua;FAN Feng-kai;ZHU Yu-han;WENG Fang-qing(Hubei Key Laboratory of Purification and Application of Anticancer Active Substances,School of Chemistry and Life Science,Hubei University of Education,Wuhan 430205,China)

机构地区：[1]湖北第二师范学院化学与生命科学学院,湖北省抗癌活性物质提纯与应用重点实验室,武汉430205

出　　处：《兰州大学学报（自然科学版）》2023年第2期271-278,共8页Journal of Lanzhou University(Natural Sciences)

基　　金：湖北省自然科学基金项目(2021CFB251);国家自然科学基金青年项目(22004029);湖北第二师范学院校级教学研究项目(X2020001);国家级大学生创新创业训练计划项目(202114099004)。

摘　　要：用水热法制备Li_(4)Ti_(5)O_(12)@TiO_(2)复合材料与同样方法制备的尖晶石型Li_(4)Ti_(5)O_(12)进行对比.对2种材料采用扫描电子显微镜、X射线衍射仪、光电子能谱仪(XPS)进行表征;N_(2)吸附-脱附曲线进行比表面积分析;恒电流充放电测试和电化学交流阻抗(EIS)技术进行电化学性能分析.结果表明,Li_(4)Ti_(5)O_(12),和Li_(4)Ti_(5)O_(12)均呈颗粒状,粒径分别约为50和70nm.XPS分析显示Li_(4)Ti_(5)O_(12)@TiO_(2)中的Ti为+4价态.电化学测试结果显示Li_(4)Ti_(5)O_(12),复合了锐钛型TiO_(2)后其充放电比容量较纯Li_(4)Ti_(5)O_(12)高,主要原因是嵌入到尖晶石型Li_(4)Ti_(5)O_(12)晶格中的Li_(4)Ti_(5)O_(12)分析显示Li_(4)Ti_(5)O_(12)复合TiO_(2)后降低了欧姆接触电阻和电化学反应中的电荷转移电阻,提高了电极表面与电解液间的固-液界面双电层电容,有利于Li的嵌入和脱出,增大其可逆比容量.两种材料中Li的扩散系数分别为3.36×10^(-10)和2.03×10^(-12 )cm^(2)/s.比表面积分析显示复合TiO_(2)后的Li_(4)Ti_(5)O_(12)具有较大的比表面积(73.65m/g),纯Li_(4)Ti_(5)O_(12)的比表面积为56.23m/g.Li_(4)Ti_(5)O_(12),复合TiO_(2)后作为锂电池的阳极材料更有利于Li扩散,为Li的脱嵌提供较好的通道,其比容量也得到提高。Li_(4)Ti_(5)O_(12)@TiO_(2)composites were synthesized via the hydrothermal method.For a comparison,the spinel Li,Ti,Or was prepared with the same method.Scanning electron microscope X-ray diffraction instrument and X-ray photoelectron spectroscopy technology(XPS)were employed to characterize the products.N_(2)adsorption-desorption isotherm curves were aimed at detecting the specific surface area,and the electrochemical properties were detected by the constant current charge-discharge test and electrochemical impedance spectrum technology(EIS).The results showed that the two products of Li_(4)Ti_(5)O_(12)@TiO_(2),composites were nanoparticles with sizes of about 50 and 70 nm,respectively.XPS analysis showed that element Li_(4)Ti_(5)O_(12)@TiO_(2)composites was+4 valence.Electrochemical test showed that the charge and discharge specific capacity of Li_(4)Ti_(5)O_(12)composites as electrodes in lithium ion battery were higher than that of Li_(4)Ti_(5)O_(12)the main reason being that anatase TiO_(2)was embedded in the spinel Li_(4)Ti_(5)O_(12)lattice and the contribution of TiO_(2)with a large capacity.EIS analysis showed that after compositing TiO2,the ohmic contact resistance and charge transfer resistance of Li_(4)Ti_(5)O_(12) material as electrode were decreased in the electrochemical reaction and the electric double layer capacitors of solid-liquid interface between the electrode surface and the electrolyte were also improved,which was beneficial to lithium ion embedding and emergence,and the reversible specific capacity of Li_(4)Ti_(5)O_(12) was increased.The lithium ion diffusion coefficient of Li_(4)Ti_(5)O_(12)@TiO_(2) composite electrodes was calculated to be 3.36×10^(-1)and 2.03×10^(-12) cm/s,respectively.The specific surface area analysis revealed that Li_(4)Ti_(5)O_(12)@TiO_(2),composites had a larger specific surface area of 73.65 m^(2)/g,while this was 56.23 m/g for pure Li_(4)Ti_(5)O_(12).After compositing TiO_(2),Li_(4)Ti_(5)O_(12) material as electrode was more conducive to lithium ion diffusion,w

关 键 词：Li_(4)Ti_(5)O_(12) TiO_(2) 复合物 锂离子电池 

分 类 号：O646[理学—物理化学]