【摘要】 以工业水玻璃为硅源,采用溶胶-凝胶法制备了Si O2气凝胶;以Sn Cl2为Sn源,采用水热合成法制备了Si O2气凝胶/Sn复合负极材料。采用X射线衍射(XRD)、扫描电子显微镜(SEM)对材料的结构和形貌进行了表征,采用恒电流充放电测试了材料的电化学性能。结果表明Si O2气凝胶/Sn复合材料为三维多孔网络结构,金属Sn颗粒均匀地钉扎在Si O2气凝胶表面,该结构不仅可以改善颗粒的团聚性能,还可以大大缓解在充放电过程中的体积膨胀。电化学性能测试结果表明,在100 m A/g的电流密度下,复合材料首次可逆比容量可达472.93 m Ah/g,首次充放电效率86.19%。30次循环后可逆比容量仍可维持在417.70 m Ah/g,容量保持率76.13%,充放电效率接近100%,具有较好的电化学性能。更多还原

【Abstract】 Si O2 aerogels were prepared by sol-gel method with industrial water glass as silica source. Then the Si O2aerogels/Sn composite was synthesized by hydrothermal method using Sn Cl2 as raw material. The structure and morphology of the composite were characterized by XRD and SEM. The electrochemical properties of the Si O2aerogels/Sn composite which used as anode materials for lithium ion batteries were studied by constant current charge-discharge test. The results show that the Si O2aerogels/Sn composite is porous three-dimensional network nanostructure, and the Sn is coated on the surface of Si O2 aerogels. Not only the aggregation performance of particles could be improved, but also volume expansion in the process of charge and discharge could be greatly alleviated. The electrochemical performance shows initial reversible capacity of 472.93 m Ah/g at 100 m A/g, and the first charge-discharge efficiency reached 86.19%, the reversible capacity maintained 417.70 m Ah/g after 30 th cycle and its coulombic efficiency reached 100%, and the capacity retention is 76.13%. The Si O2 aerogels /Sn composites show a better electrochenmical performance.更多还原