Si/C复合电极的制备及电化学性能研究  

Preparation and Electrochemical Performance Study of the Si/C Composite Electrode

作　　者：于凤斌[1] 左朋建[1] 马玉林[1] 郭俊[1] 程新群[1] 杜春雨[1] 尹鸽平[1] 

机构地区：[1]哈尔滨工业大学化工学院应用化学系,黑龙江哈尔滨150001

出　　处：《高校化学工程学报》2014年第1期123-129,共7页Journal of Chemical Engineering of Chinese Universities

基　　金：国家863计划项目(2012AA110203);国家自然科学基金(50902038)

摘　　要：由于Si/C复合材料具有较高的理论比容量和较好的循环稳定性而成为一种极具潜力的锂离子二次电池负极材料。但当Si/C复合材料电极较厚时,其在锂的嵌入脱出时的体积变化很明显,会直接导致材料的粉化,导电结构解体,进而导致容量迅速衰减。同时还会造成电极活性物质利用率降低,首次容量较低等问题。而商品化的电极一般较厚,因此对Si/C电极厚度的研究变得十分重要。本研究中首先制备了Si/C复合材料,考察了不同电极厚度Si/C复合材料电极性能的变化规律,并通过调节黏结剂CMC与SBR配比、热处理和改换纳米管为导电剂等方法对厚电极性能进行改性。结果表明,当CMC:SBR=8:2时,厚电极性能最佳。同时,热处理和以纳米管为导电剂均可以改善厚电极的性能。Si/C composite material is investigated intensively as a promising anode material for rechargeable lithium-ion batteries with very high specific capacity and good cycle stability. However, when the Si/C composite electrode is very thick, it exhibits large volume change during lithium insertion and extraction, which causes pulverization and breakdown of the electrical conductive network, and results in rapid capacity decay. Moreover, the utilization ratio of the electrode material and initial specific capacity are reduced. Generally, the commercial electrodes are thicker than those used in laboratory. Therefore, the research of the effects of Si/C electrode thickness on the electrode performarce change becomes very important. In this paper the Si/C composite material was prepared firstly, and the changes of the Si/C composite electrode performance related to the electrode thickness were also discussed. The performance improvement of the thick electrode caused by changing the proportion of CMC to SBR, the heat treatment and using carbon nanotube as conductive agent was conducted. The results show that：the performance of the electrode is the best as the proportion of CMC to SBR equals to 8：2, and heat treatment and using carbon nanotube as conductive agent can improve the performance of the thick Si/C composite electrode.

关 键 词：锂离子电池 SI C复合材料 负极材料 黏结剂 热处理 碳纳米管 

分 类 号：TM912.9[电气工程—电力电子与电力传动]