多孔硅/硅钛合金的制备及在锂离子电池负极上的应用  

Preparation and electrochemical properties of Si/Si-Ti alloy nanoparticle composites as anode materials for lithium-ion batteries

作　　者：于志辉[1] 寇艳娜 汪夏燕[1] 夏定国[2] 宿婷婷[1] 

机构地区：[1]北京工业大学环境与能源工程学院,北京100124 [2]北京大学工学院,北京100871

出　　处：《功能材料》2016年第1期1017-1022,共6页Journal of Functional Materials

基　　金：国家高技术研究发展计划(863计划)资助项目(2012AA052201);北京市教委科研计划面上资助项目(KM201210005008);新世纪优秀人才支持计划资助项目(NCET-12-0603);北京市教育委员会科技发展计划重点资助项目(KZ201310005001)

摘　　要：以钛掺杂介孔二氧化硅SBA-15为前驱体,用镁热还原法制备多孔硅/硅钛合金复合材料。采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和红外光谱(FT-IR)等方法对复合材料进行表征;利用恒电流充放电对复合材料作为锂离子电池负极材料的电化学性能进行分析。结果表明,多孔结构为体积膨胀提供了缓冲空间,硅钛合金的存在起到支撑骨架的作用,同时一定程度上改善了负极材料的导电性,多孔硅/硅钛合金复合材料具有较好的循环稳定性,0.1C循环50圈后可逆容量为801mAh/g,倍率性能也较单质硅材料大大提高,1C倍率下放电容量为618.9mAh/g。A series of porous Si/Si-Ti alloy were prepared by magnesium reduction process with Ti-containing silica molecular sieves(Ti-SiO_2)as the precursor.The morphologies and structures of Si/Si-Ti alloy were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and Fourier transform infrared spectroscopy(FT-IR).The electrochemical properties of the composites as anode materials for lithium-ion batteries were evaluated by Galvanostatical text.The results show that the effect of volumetric expansion wasrelieved because porous structure provides sufficient buffer space.In addition,the existence of Si-Ti alloy improved the conductivity of the composite materials.The sample achieved remarkable electrochemical performance with a capacity of 801mAh/g at 420mA/g after 50 cycles.

关 键 词：多孔硅/硅钛合金 负极材料锂离子电池 循环稳定性 倍率性能 

分 类 号：O646[理学—物理化学]