中文摘要：

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。

英文摘要：

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.