纳米Si/C复合微球材料制备及电化学性能表征

摘要

通过高温热解法合成不同纳米硅含量的Si/C复合微球材料并对其形貌及电化学性能进行了探究.采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、恒电流充放电和循环伏安测试等技术对样品进行表征分析.电化学测试结果表明:当样品中的硅含量为8％(质量分数)时,制备的纳米Si/C复合微球负极材料在100 mA/g的电流密度下,首次可逆充电比容量为532.0 mAh/g,循环100次后,比容量可稳定在321.8 mAh/g.该结果归因于无定形碳良好的导电性及较高的比表面积.%Novel Si/C microsphere composites with different nano silicon contents were prepared by high-temperature pyrolysis.The obtained samples were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),transmission electron microscope (TEM),constant current charging and discharging and cyclic voltammetry test.The results show that when the addition content of nano silicon is 8％,the first discharge capacity of Si/C composite microsphere anode material is 991 mAh/g at 100 mA/g;and after 100 cycles it remains a capacity of 321.8 mAh/g.The good perfromance was attributed to the high electric conductivity and relatively large surface areas of amorphous carbon.