高能球磨法制备锂离子电池Si/Co/C负极材料

Synthesis of Si/Co/C Anode Materials by a High Energy Ball-milling Method

采用高能球磨法制备得到了Si/Co/C负极材料,并研究了其组成对电化学循环性能的影响.XRD结果表明,3种元素只以单质形式存在.充放电曲线结果表明,材料中Si和C为活性物质,Co为非活性物质.恒流充放电结果显示,当3者的重量比为20∶30∶50时形成的Si20Co30C50材料表现出了较好的电化学循环性能,其首周放锂容量和吸锂容量分别为877.6和1 038.7mAh/g,首周库伦效率为84.5%;循环50周后容量仍可以保持为581.2mAh/g.

A series of Si/C.Si/Co.C/Co and Si/Co/C anode materials with different weight ratios have been prepared by a high energy ball-milling method, and the optimized composi- tions are investigated. The XRD results indicate that no any compound is formed among the el- ementals Si, Co and C. The electrochemical galvanostatic charge and discharge results show that Si and C are active components and Co is inactive one. When the weight ratio of the ele- ments Si/Co/C is equals to 20 ： 30 ： 50, its initial charge/discharge capacity is 877. 6 and 1 038.7 mAh/g, respectively, corresponding to a coulombic efficiency of 84.5 %. After 50 cy- cles, the remained capacity reaches 581.2 mAh/g.