铁负载酸活化蒙脱石制备硅/硅化铁纳米复合材料及其储锂性能  

Iron Silicide/Silicon Nanomaterials Derived from Iron/Acid-Montmorillonite for High Performance Lithium-Ion Battery Anode

作　　者：杜静 李向军[4] 谢捷洋 韦寿淑 熊涛 何诗雅 陈情泽[1,2,3] 朱润良 DU Jing;LI Xiangjun;XIE Jieyang;WEI Shoushu;XIONG Tao;HE Shiya;CHEN Qingze;ZHU Runliang(CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials,Guangzhou Institute of Geochemistry,Chinese Academy of Science,Guangzhou 510640,China;CAS Center for Excellence in Deep Earth Science,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China;Huizhou Dingyuan New Energy Technology Company Limited,Huizhou 516227,Guangdong,China)

机构地区：[1]中国科学院广州地球化学研究所中国科学院矿物学与成矿学重点实验室/广东省矿物物理与材料研究开发重点实验室,广州510640 [2]中国科学院深地科学卓越创新中心,广州510640 [3]中国科学院大学,北京100049 [4]惠州市鼎元新能源科技有限公司,广东惠州516227

出　　处：《硅酸盐学报》2024年第10期3252-3262,共11页Journal of The Chinese Ceramic Society

基　　金：广东省重点领域研发计划项目(2020B0101370003);广东省自然科学基金杰出青年基金项目(2023B1515020006);中国科学院青年创新促进会项目(2020347);广东省科技计划项目(2023B1212060048);惠州市重点领域科技攻关“揭榜挂帅”项目。

摘　　要：纳米硅的储锂容量高,被认为是最有应用前景的新一代锂电负极材料。然而纳米硅的体积膨胀效应和低电导性不利于其实际应用。将天然蒙脱石酸活化和铁负载改性,再经过镁热还原反应,得到了原位复合的硅/硅化铁纳米复合材料。硅化铁具有良好的导电性和机械稳定性,可显著提升硅负极的循环稳定性和倍率性能。在1 A/g的电流密度下循环500圈后,硅/硅化铁纳米复合材料的比容量高达781 m A·h/g,容量保持率为77%。该方法为制备高性能硅基负极材料提供了新思路。Introduction Silicon is considered as one of the most promising lithium anode materials due to its high lithium storage capacity.However,the volume expansion effect and semiconductor properties of silicon hinder its practical application.Two effective strategies exist for mitigating this issue,i.e.,reducing the size of silicon to nanoscale;and introducing non-active matrices to improve stability and conductivity.In recent decades,the incorporation of iron silicide(FeSi_(2))with silicon(Si)has attracted much attention due to its high conductivity,mechanical hardness and environmental friendliness.Unfortunately,the Si/FeSi_(2) nanocomposites are mainly prepared by high-energy ball milling,which has some drawbacks such as low purity,large particle size,and uncontrollable morphology,making it difficult to achieve the commercial application.Porous silica derived from clay minerals is extensively investigated for the preparation of silicon nanoparticles by magnesiothermic reduction.In addition,porous silica has a large specific surface area,which facilitates the effective dispersion and loading of iron oxides.The reduction of iron oxide and silica dioxide to Fe and Si can be achieved by magnesium.In this paper,a natural montmorillonite(Mnt)with a high content of silica(65%,in mass)was utilized as a raw material.Silicon/iron silicide(Si/FeSi_(2))nanocomposites were synthesized via modification of Mnt(including acid etching and iron loading)and molten salt-assisted magnesiothermic reduction.Methods A porous silica(SiO_(2))was prepared via leaching Mnt at a high concentration of HCl.Subsequently,a iron oxide was loaded on SiO_(2) via precipitation in different Fe/Si mass ratios(i.e.,0,10%,and 20%).Modified SiO_(2)(Fe-SiO_(2))was mixed with Mg and NaCl in a mass ratio of 1.00:0.85:3.00.Afterwards,the mixture was heated in an inert atmosphere at 650℃for 5 h in a heating rate of 5℃/min.After cooling naturally,the product was washed with 1 mol/L HCl and 1%(in mass)HF in sequence to remove the by-product.Finally,it was rin

关 键 词：蒙脱石 镁热还原 硅化铁 硅纳米材料 锂离子电池负极 

分 类 号：TB332[一般工业技术—材料科学与工程]