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Insights into the SiO2 Stress Effect on the Electrochemical Performance of Si anode
Small ( IF 13.0 ) Pub Date : 2023-12-17 , DOI: 10.1002/smll.202310240 Yanbin Wei 1 , Zhexi Xiao 1 , Yudai Huang 2 , Yukang Zhu 1 , Zhenxing Zhu 1 , Qi Zhang 3 , Dianzeng Jia 2 , Shijun Zhang 3 , Fei Wei 1, 4
Small ( IF 13.0 ) Pub Date : 2023-12-17 , DOI: 10.1002/smll.202310240 Yanbin Wei 1 , Zhexi Xiao 1 , Yudai Huang 2 , Yukang Zhu 1 , Zhenxing Zhu 1 , Qi Zhang 3 , Dianzeng Jia 2 , Shijun Zhang 3 , Fei Wei 1, 4
Affiliation
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Silicon (Si) is regarded as the most potential anode material for next-generation lithium-ion batteries (LIBs). However, huge volume expansion hinders its commercial application. Here, a yolk-shell structural nitrogen-doped carbon coated Si@SiO2 is prepared by SiO2 template and HF etching method. The as-prepared composite exhibits superior cycling stability with a high reversible capacity of 577 mA h g−1 at 1 A g−1 after 1000 cycles. The stress effect of SiO2 on stabilizing the electrochemical performance of Si anode is systematically investigated for the first time. In situ thickness measurement reveals that the volume expansion thickness of Si@SiO2 upon charge–discharge is obviously smaller than Si, demonstrating the electrode expansion can be effectively inhibited to improve the cyclability. The density functional theory (DFT) calculation further demonstrates the moderate young's modulus and enhanced hardness after SiO2 coating contribute significantly to the mechanical reinforcement of overall Si@SiO2@void@NC composite. Various post-cycling electrode analyses also address the positive effects of inner stress from the Si core on effectively relieving the damage to electrode structure, facilitating the formation of a more stable inorganic-rich solid electrolyte interphase (SEI) layer. This study provides new insights for mechanical stability and excellent electrochemical performance of Si-based anode materials.
中文翻译：
深入探讨 SiO2 应力对硅阳极电化学性能的影响
硅（Si）被认为是下一代锂离子电池（LIB）最有潜力的负极材料。然而，巨大的体积扩张阻碍了其商业应用。本文通过SiO 2模板和HF刻蚀方法制备了蛋黄壳结构的氮掺杂碳包覆Si@SiO 2 。所制备的复合材料表现出优异的循环稳定性，1000次循环后在1 A g -1下具有577 mA hg -1的高可逆容量。首次系统研究了SiO 2对稳定Si阳极电化学性能的应力影响。原位厚度测量表明，Si@SiO 2充放电时的体积膨胀厚度明显小于Si，表明可以有效抑制电极膨胀，提高循环性能。密度泛函理论（DFT）计算进一步表明，SiO 2涂层后适度的杨氏模量和增强的硬度对整体Si@SiO 2 @void@NC复合材料的机械增强有显着贡献。各种循环后电极分析还强调了硅核内应力对有效缓解电极结构损伤的积极影响，促进形成更稳定的富含无机物的固体电解质中间相（SEI）层。这项研究为硅基负极材料的机械稳定性和优异的电化学性能提供了新的见解。
更新日期：2023-12-17
中文翻译：
深入探讨 SiO2 应力对硅阳极电化学性能的影响
硅（Si）被认为是下一代锂离子电池（LIB）最有潜力的负极材料。然而，巨大的体积扩张阻碍了其商业应用。本文通过SiO 2模板和HF刻蚀方法制备了蛋黄壳结构的氮掺杂碳包覆Si@SiO 2 。所制备的复合材料表现出优异的循环稳定性，1000次循环后在1 A g -1下具有577 mA hg -1的高可逆容量。首次系统研究了SiO 2对稳定Si阳极电化学性能的应力影响。原位厚度测量表明，Si@SiO 2充放电时的体积膨胀厚度明显小于Si，表明可以有效抑制电极膨胀，提高循环性能。密度泛函理论（DFT）计算进一步表明，SiO 2涂层后适度的杨氏模量和增强的硬度对整体Si@SiO 2 @void@NC复合材料的机械增强有显着贡献。各种循环后电极分析还强调了硅核内应力对有效缓解电极结构损伤的积极影响，促进形成更稳定的富含无机物的固体电解质中间相（SEI）层。这项研究为硅基负极材料的机械稳定性和优异的电化学性能提供了新的见解。
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