分别采用球磨法和高温热解法制备了Si/C复合材料，XRD、SEM、电化学阻抗谱、循环伏安法和恒流充放电测试表征该Si/C复合材料的结构、形貌和电化学性能.结果表明，相比于球磨法，高温热解HDPE制备的Si/C复合材料颗粒形貌规则，碳的包覆较为均匀，导电性较好，阻抗较小.该复合材料首次嵌锂容量为4495 mAh/g，首次库仑效率65.3% ，从第2周开始库仑电效率都保持在97% 左右，经过100次充放电循环后仍能达到438 mAh/g的可逆容量，具有较好的电化学循环稳定性.

Si/C composite for lithium ion batteries was obtained by pyrolyzing and ball-milling. The microstructure and component of the composite was characterized by SEM and XRD, the electrochemical performance was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvano static charge-discharge tests. The results illustrate that the particle of Si/C composite prepared by pyrolysis exhibits inerratic morphology, uniform carbon-coating layer, good electrical conductivity, low resistance. The first intercalated-lithium capacity of the composite material is 4495 mAh/g; the first coulomb efficiency is 65.3%. From the second week the coulomb efficiency maintains 97%, and the capacity at the 100th cycle can retain 438 mAh/g. The Si/C composite has good electrochemical cycle stability.