S/TiO2纳米复合材料在锂硫电池中的应用  

Application of S/TiO_2 Nanocomposite in the Lithium-Sulphur Battery

作　　者：胡昌晨 魏良明[1] 李晓琳[1] 鲁得泂 

机构地区：[1]上海交通大学电子信息与电气工程学院薄膜和微细技术教育部重点实验室,上海200240

出　　处：《微纳电子技术》2015年第1期20-24,36,共6页Micronanoelectronic Technology

基　　金：国家自然科学基金资助项目(51272155);U-M/SJTU联合研究项目

摘　　要：为了克服锂硫电池中硫在循环过程中的不稳定性,通过一种乳液破乳-析出的方法得到了水溶液中均匀分散的硫纳米粒子,再通过水解法制备了球形的硫/二氧化钛（S/TiO2）核-壳结构纳米复合材料。X射线衍射（XRD）、热重分析（TGA）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）表征结果表明,硫纳米粒子粒径小于200 nm,二氧化钛均匀包覆在硫纳米粒子表面,硫/二氧化钛纳米复合材料粒径为200-400 nm,硫的质量分数为72.4%。电化学测试结果表明在500 mA·g^-1电流密度下,硫/二氧化钛纳米复合材料首次循环比容量为791 mA·h·g^-1,50次循环后比容量达623 mA·h·g^-1,库仑效率保持在99.2%。锂硫电池的电化学性能得到了显著提高。To resolve the sulphur instability of the lithium-sulphur battery in the cyclic process,the sulphur nanoparticle evenly dispersed in the aqueous solution was obtained by the emulsion demulsification-precipitation method,then spherical S/TiO2core-shell structure nanocomposite was synthesized by hydrolysis method.The characterization results of X-Ray diffraction（XRD）,thermo gravimetric analysis（TGA）,scanning electron microscope（SEM）and transmission electron microscope（TEM）show that the size of the as-synthesis sulphur nanoparticle is less than200 nm,the TiO2 is uniformly coated on the surface of the sulphur nanoparticle,the particle size of the S/TiO2 nanocomposite is 200-400 nm.The mass percentage of sulphur in the S/TiO2 nanocomposite is 72.4%.The electrochemical test results show that an initial recycling specific capacity is 791 mA·h·g^-1 at the current density of 500 mA·g^-1,and after 50 cycles,the specific capacity reaches 623 mA·h·g^-1 and the Coulombic efficiency maintains 99.2%.The electrochemical performance of the lithium-sulphur battery is improved significantly.

关 键 词：纳米复合材料 硫 二氧化钛 锂电池 电化学性能 

分 类 号：TM911[电气工程—电力电子与电力传动]