球磨工艺对炭气凝胶(CA)-SiO复合材料结构和电化学性能的影响  

Effects of Ball-Milling on Structure and Electrochemical Property of CA-SiO Composite

作　　者：巢亚军[1] 原鲜霞[1] 马紫峰[1] 邓晓燕[2] 于文利[1] 

机构地区：[1]上海交通大学化学工程系,上海200240 [2]青岛科技大学材料与环境科学学院,青岛266042

出　　处：《无机材料学报》2008年第5期917-922,共6页Journal of Inorganic Materials

基　　金：国家重点基础研究发展计划项目(2007CB209705);国家自然科学基金(20776085，20476055，20471037);上海市科委项目(06SN07115，065211020)

摘　　要：单纯的炭气凝胶(CA)与SiO球磨后可以制得性能优异的复合材料CA-SiO,实验研究了球磨时间和球磨转速等工艺条件对CA-SiO的结构和电化学性能的影响.结果表明,无定形态的SiO与CA球磨后,逐渐有晶粒细小的Si晶体析出,Si的晶粒随球磨时间的延长或球磨转速的提高先减小然后增大,Si的结晶度随球磨时间的延长或球磨转速的提高而增强,但过长的球磨时间或过快的球磨转速均会导致材料中的晶体Si向非晶态转变;球磨使材料中C的晶粒有所增大,但球磨时间和球磨转速对C的晶粒大小没有明显的影响;CA-SiO中Si的结晶度越高、晶粒越小,材料的嵌脱锂容量越高、充放电循环稳定性越好,非晶态Si的存在不仅不利于锂离子在CA-SiO中的嵌入和脱出,而且会导致材料的循环稳定性变差.将CA-SiO用作锂离子电池负极材料时,其最佳的制备工艺为,以400r/min的速度球磨10h.Carbon aerogel （CA）-SiO with excellent lithium insertion-extraction property could be prepared through ball-milling of carbon aerogel （CA） with SiO. Effects of ball-milling process including ball-milling time and ball-milling speed on structure and electrochemical property of CA-SiO composite were investigated. The results show that ball-milling of amorphous SiO with CA can crystallize Si with small particle size, the crystal size of Si increases with the extension of ball-milling time and the increase of ball-milling speed, and then decreases. The crystallization of Si can be improved by the extension of ball-milling time and the increase of ball-milling speed. However, ball-milling for too long time or at too high speed will result in transformation of crystal Si to amorphous. Little influence of ball-milling time and ball-milling speed is found on crystal size of C in the prepared CA-SiO, though ball-milling leads to some increase of C crystal size. CA-SiO has higher capacity and better cycling stability when the silicon within this material shows higher crystallization and smaller crystal size. In contrast, amorphous Si is disadvantageous for lithium insertion-extraction in CA-SiO which will lead to poorer cycling stability. The ball-milling speed of 400r/min and the ball-milling time of 10h are the best preparation parameters for CA-SiO used as anode material of lithium-ion battery.

关 键 词：球磨工艺 CA-SiO复合材料 负极材料 锂离子电池 

分 类 号：TB33[一般工业技术—材料科学与工程]