Composites with a pitch-based carbon (PC) matrix and a mixture of nanoparticle silicon and natural flake graphite (NG) as filler (Si-NG/PC) was prepared by high energy mechanical milling of mixtures of nano-Si, NG and high softening point pitch, followed by pyrolysis at 1000t for 2h to convert the pitch into carbon. The influence of the preparation conditions on the electrochemical properties of the composites for use as the anode of a lithium ion battery was investigated. This included milling time, rotation speed and the precursor formulations. XRD and SEM were used to examine the composition and structure of the composites. Results indicated that the optimum milling time is 21 h at a rotation speed of 300r/min, and the optimum proportions of nano-Si and pitch carbon in the composites were less than 35 wt. % and around 30 wt. % , respectively. Under the optimized conditions, the Si-NG/PC composite presented a high specific capacity and a good cycling stability when tested for 50 cycles.%以纳米硅(Si)、天然石墨(NG)和高软化点沥青为前驱体,通过球磨和裂解制备了具有壳核结构的硅/天然石墨/沥青炭( Si-NG/PC)复合材料.考察了球磨时间、球磨速率和物料比等因素对制备材料的组成、结构及其作为锂离子电池阳极电化学性能的影响.结果表明:最佳球磨速率为300 r/min,最适宜的球磨时间为21h.所制Si-NG/PC复合材料的循环性能随PC含量的增加而提高,但其比容量却随PC含量的增加迅速降低,PC的最佳质量分数为30％.同时,Si-NG/PC复合材料的比容量随Si含量的增加而增大,为获得好的循环性能,纳米Si质量分数应低于35％.在优化条件下制备的Si-NG/PC复合材料在50个循环中表现出高的比容量和优异的循环性能.
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