无序介孔硅复合纳米结构的制备与慢活化行为

发布时间：2018-05-18 00:01

本文选题：白炭黑 + 镁热还原法　；参考：《高等学校化学学报》2017年05期

【摘要】：通过对SiO_2纳米粒子进行镁热还原及后处理,制备了多级无序Si介孔复合纳米结构MP-Si@SiO_x@C,此结构展现出容量非衰减缓升的电化学慢活化行为,可抵消循环容量常规衰减趋势,赋予负极优良的循环稳定性.通过X射线衍射(XRD)、透射电子显微镜(TEM)、场发射扫描电子显微镜(SEM)、N_2吸附-脱附测试和孔径分布模拟分析发现,Si介孔组织包含微-窄介孔(1~5 nm)、中介孔(5~20 nm)以及大介孔-宏孔(20~100 nm)三级孔道,分别源于原初级粒子内部孔道、粒子团聚堆垛与粒内酸蚀、团聚体再堆垛;此合成装配方法有效提升了Si材料的堆积密度,电池电极能获得较高的体积比容量和储能密度.
[Abstract]:By magnesium thermal reduction and post-treatment of SiO_2 nanoparticles, a multistage disorder Si mesoporous composite nanostructure, MP-SiSiSiOxStup, has been prepared. The structure exhibits a slow electrochemical activation behavior of non-decreasing capacity, which can counteract the trend of conventional cyclic capacity decay. Give negative excellent cyclic stability. X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (SEM), absorption desorption test and pore size distribution simulation analysis show that the mesoporous structure of Si contains micro- narrow mesoporous (1 ~ 5 ~ 5 nm), intermedium pore (~ 5 ~ 20 nm) and mesoporous structure. Macro hole 20 ~ 100 nm) three-stage channel, The composite assembly method can effectively increase the packing density of Si materials, and the battery electrode can obtain higher volume specific capacity and energy storage density because of the original primary particle inner pore channel, particle agglomeration stacking and intra-particle acid corrosion, and agglomerate restacking.
【作者单位】：昆明理工大学材料科学与工程学院;昆明理工大学真空冶金国家工程实验室;
【基金】：国家自然科学基金(批准号:51464025)资助~~
【分类号】：O613.72;TB383.1

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