摘要
硅作为高能量密度锂离子电池的新一代负极材料,其商业化应用的关键技术路径之一是与碳材料复合构建核壳结构的硅碳材料。如何实现硅晶粒形态的精确控制是当前硅碳材料产业化量产过程中的难题之一。采用化学气相沉积法将纳米/亚纳米尺寸硅均匀沉积在多孔碳基体中制备气相沉积硅碳复合材料,通过调控最终碳层封装温度实现了硅结晶度的可控调节。结果表明,拉曼光谱技术较X射线衍射方法在硅结晶度表征方面具有更高的灵敏度与准确率优势;碳层封装温度影响硅碳中硅的结晶度水平,硅结晶度升高会对材料的整体电化学性能有负面影响。碳层封装温度在550℃时制备的硅碳表现出1599 mAh·g^(-1)的首圈放电容量和91.62%的首次库仑效率,升高到800℃时降低到了709 mAh·g^(-1)和80.97%。研究结果为气相沉积硅碳材料量产过程实现硅结晶度的准确控制提供了可靠方法,可实现高性能低结晶度硅碳负极量产过程中的高精度一致性管控。
Silicon,as a new generation anode material for high-energy-density lithium-ion batteries,is a key technological path for its commercial application by combining it with carbon materials to construct core-shell silicon-carbon materials.Achieving precise control over the morphology of silicon grains is one of the challenges in the current industrial-scale mass production of silicon-carbon materials.Silicon was uniformly deposited into a porous carbon matrix via chemical vapor deposition(CVD),followed by modulating the crystallinity of silicon through controlled carbon encapsulation temperatures.Systematic characterization revealed that Raman spectroscopy exhibits superior sensitivity and accuracy over X-ray diffraction in quantifying silicon crystallinity.The carbon encapsulation temperature was found to exert a significant influence on the crystallinity of silicon,with elevated crystallinity levels markedly degrading the overall electrochemical performance.Specifically,elevation of carbon encapsulation temperature from 550℃to 800℃induced a 55.7%capacity loss(1599→709 mAh·g^(-1))and 10.65%efficiency decay(91.62%→80.97%)in initial cycling,quantitatively demonstrating the crystallinitydependent degradation mechanism in silicon-carbon anodes.These findings confirm that Raman spectroscopy serves as a precise diagnostic tool for optimizing CVD process parameters,enabling high-precision consistency control in the mass production of high-performance,low-crystallinity silicon-carbon anodes.
作者
袁新烨
邢显博
刘登华
丁伟涛
范博瑞
钟华
韩凯
YUAN Xinye;XING Xianbo;LIU Denghua;DING Weitao;FAN Borui;ZHONG Hua;HAN Kai(College of Chemistry and Chemical Engineering,Central South University,Changsha 410000,Hunan,China;Powder Metallurgy Research Institute,Central South University,Changsha 410000,Hunan,China;Shenghua New Materials Technology Co.,Ltd.,(Meishan),Meishan 620000,Sichuan,China)
出处
《化工学报》
北大核心
2025年第12期6708-6717,共10页
CIESC Journal
基金
湖南省杰出青年科学基金项目(2023JJ10062)
中南大学研究生自主探索创新项目(2025ZZTS0232)。
关键词
电化学
复合材料
粉体
硅负极
气相沉积硅碳
拉曼光谱
锂离子电池
electrochemistry
composite materials
powders
silicon anode
CVD silicon-carbon
Raman spectroscopy
lithium-ion batteries
