Fe_(2)O_(3)改性Si/SiO_(2)复合材料的制备及其电化学性能  

Preparation and electrochemical properties of Fe_(2)O_(3)modified Si/SiO_(2)composites

作　　者：马子洋 王帅[1] 曹虎 吴沁宇 马扬洲 宋广生 MA Ziyang;WANG Shuai;CAO Hu;WU Qinyu;MA Yangzhou;SONG Guangsheng(School of Materials Science and Engineering,Anhui University of Technology,Maanshan 243000,Anhui,China)

机构地区：[1]安徽工业大学材料科学与工程学院,安徽马鞍山243000

出　　处：《精细化工》2024年第11期2440-2447,2521,共9页Fine Chemicals

基　　金：国家自然科学基金项目(52207246);国家级外国专家引进计划项目(G20190219004);安徽省教育委员会自然科学研究项目(KJ2020A0263,YJS20210336);先进金属材料绿色制造与表面技术重点实验室项目(GFST2022ZR02,GFST2021KF01)。

摘　　要：以无水乙醇为砂磨剂,将微米Si粉与纳米非晶型SiO_(2)(Nano-SiO_(2))通过砂磨法制备了Si/SiO_(2)复合材料(SNSO),然后加入纳米Fe_(2)O_(3),通过机械球磨方式制备了Fe_(2)O_(3)改性Si/SiO_(2)复合材料(SNSO@Fe_(2)O_(3))。采用XRD、XPS、SEM、TEM对SNSO@Fe_(2)O_(3)进行了表征,通过恒流充放电、循环伏安法、电化学阻抗测试了其电化学性能。结果表明,SNSO@Fe_(2)O_(3)呈规则的球形核壳结构,外壳为非晶层,Fe_(2)O_(3)质量分数8%的SNSO@Fe_(2)O_(3)(SNSO@8%Fe_(2)O_(3))粒径约2μm;SNSO@8%Fe_(2)O_(3)展现出优异的循环性能,首次放电比容量为2150 mA·h/g,首次库仑效率为81.95%;在电流密度110 mA/g下,经100次循环后放电比容量仍稳定在986 mA·h/g,较SNSO提升了43.3%。SNSO@8%Fe_(2)O_(3)稳定的循环性能归因于球磨过程中FeSi相的生成及非晶SiO_(x)和Fe_(2)O_(3)原位反应在Si表面形成了厚度约30 nm的非晶层外壳结构,有效缓解了Si的体积膨胀。Fe_(2)O_(3)modified Si/SiO_(2)composites(SNSO@Fe_(2)O_(3))were synthesized by introduction of nano Fe_(2)O_(3)via mechanical ball milling into Si/SiO_(2)composites(SNSO),which were prepared by sanding of micron Si powder with nano amorphous SiO_(2)(Nano-SiO_(2))using anhydrous ethanol as sanding agent,characterized by XRD,XPS,SEM,TEM,and evaluated for their electrochemical properties through constant current charge and discharge,cyclic voltammetry,and electrochemical impedance.The results showed that SNSO@Fe_(2)O_(3)exhibited a regular spherical core-shell structure with an amorphous layer on the outer shell,and a particle size of~2μm when the Fe_(2)O_(3)mass fraction was 8%(SNSO@8%Fe_(2)O_(3)).SNSO@8%Fe_(2)O_(3)displayed excellent cycling performance,with an initial discharge capacity of 2150 mA·h/g,and initial coulombic efficiency of 81.95%;At a current density of 110 mA/g,the SNSO@8%Fe_(2)O_(3)still maintained a stable discharge specific capacity of 986 mA·h/g after 100 cycles,43.3%higher than SNSO.The stable cycling performance of SNSO@8%Fe_(2)O_(3)was attributed to the FeSi phase generated during ball milling and the amorphous layer shell structure of about 30 nm on the Si surface formed during the in-situ reaction of amorphous SiO_(x)and Fe_(2)O_(3),which effectively alleviated the volume expansion of Si.

关 键 词：锂离子电池 硅基复合材料 材料改性 核壳结构 低成本 功能材料 

分 类 号：TQ630[化学工程—精细化工]