有序介孔硅/碳复合结构负极材料的制备与电化学性能研究  

Preparation and Electrochemical Performance of Ordered Mesoporous Si/C Composite for Anode Material

作　　者：王静[1] 陈志柠 郭玉忠[1] 黄瑞安[2] 王剑华[1] WANG Jing1, CHENG Zhi-Ning1, GUO Yu-Zhong1, HUANG Rui-An2, WANG Jian-Hua1(1. Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China; 2. National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, Chin)

机构地区：[1]昆明理工大学材料科学与工程学院,昆明650093 [2]昆明理工大学真空冶金国家工程实验室,昆明650093

出　　处：《无机材料学报》2018年第3期313-319,共7页Journal of Inorganic Materials

基　　金：国家自然科学基金(51464025)~~

摘　　要：以SBA-15(SiO_2)有序介孔模板为前驱体,通过镁热还原和碳包覆修饰路线,制备出二维定向组装的束捆状有序介孔覆碳纳米组织(OMP-Si/C),并细致研究了SBA-15的镁热还原过程,对OMP-Si/C复合结构进行电化学性能测试。经XRD测试分析发现:镁热还原过程中存在Mg_2Si中间相反应路径,基于此提出反应温度-时间(T-t)相转变图;DSC/TG表明,Mg相通过反应-熔化协调联动作用,在低于熔点(648℃)时熔化,且发生液/固反应。从FE-SEM观察到SBA-15柱状单元被装配成类藕根链束捆状Si有序介孔组织,并基于镁液微涡流场卷吸作用机理解释了该二维定向组装过程。所得致密纳米组织能有效抵消充放电过程中Si相的固有体积变化,从而表现出优异的循环稳定性能和倍率性能。Using SBA-15 of SiO2 template as precursor,a bundle-shaped ordered mesoporous nanoarchitecture Si/C composite（OMP-Si/C） was successfully assembled 2D-directionally by a magnesiothermic reduction reaction（MRR） route and the ensuing carbon-coating modification processing,and the MRR process of the SBA-15 was investigated in depth,the electrochemical performance of as-prepared OMP-Si/C composites was tested.Analysis based on XRD data reveals the presence of a reaction path of Mg2Si intermediate phase in MRR process,on which a T-t（reaction temperature-reaction time） phase transition diagram is proposed.DSC/TG analysis shows that Mg particles may melt below its melting point（648℃） upon reaction,and in liquid-solid reaction pattern react with SiO2 via melting-reaction teamwork.Observed from FE-SEM,SBA-15 column units are validated to assemble into a lotus-root-chain-bundle shaped nanoarchitecture of ordered mesoporous silicon,which can effectively offset the drastic volume change of Si material inherent in the charge/discharge process,and exhibit excellent cycling stability and rate capability.Based on the micro-fluid field assembling mechanism,the two-dimensional directional assembly process can be reasonably interpreted.

关 键 词：锂离子电池 Si有序介孔组织 镁热还原反应 Mg2Si中间相 微流场装配 

分 类 号：O646[理学—物理化学]