Observing Two-Dimensional Spontaneous Reaction between a Silicon Electrode and a LiPF6-Based Electrolyte In Situ and in Real Time
Observing Two-Dimensional Spontaneous Reaction between a Silicon Electrode and a LiPF6-Based Electrolyte In Situ and in Real Time
复制标题
原位实时观察硅电极和 LiPF6 基电解质之间的二维自发反应
DOI：
10.1021/acs.jpclett.2c00516
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Ye Shuji
中科院分区：
文献类型：
--
作者：
Wang Zhuo;Tan Junjun;Yang Zhe;Luo Yi;Ye Shuji
电极和电解质之间的二维自发反应对于固体电解质界面相（SEI）的形成非常重要，但由于研究这种反应需要具有足够结构和时间分辨率的表面/界面敏感技术，因此很难进行研究。在这项研究中，我们应用飞秒宽带和频产生振动光谱（SFG-VS）实时研究了硅电极与基于lipf6的碳酸二乙酯电解质溶液之间的相互作用。我们发现在硅表面存在两种碳酸二乙酯，并且它们的C = O拉伸方向相反。观察了硅电极和lipf6电解质溶液之间的内在自发化学反应。这些反应产生氢化硅，并引起硅电极的腐蚀。在硅表面涂覆聚乙烯醇层可以有效地延缓和减弱这些反应。这项工作表明，SFG-VS可以为阐明SEI形成的分子机制提供一个独特而强大的最新工具。
Two-dimensional spontaneous reactions between an electrode and an electrolyte are very important for the formation of a solid electrolyte interphase (SEI) but difficult to study because studying such reactions requires surface/interface sensitive techniques with sufficiently structural and temporal resolutions. In this study, we have applied femtosecond broadband sum-frequency generation vibrational spectroscopy (SFG-VS) to investigate the interaction between a silicon electrode and a LiPF6-based diethyl carbonate electrolyte solutionin situand in real time. We found that two kinds of diethyl carbonate species are present on the silicon surface and their C═O stretching aligns in opposite directions. Intrinsically spontaneous chemical reactions between silicon electrodes and a LiPF6electrolyte solution are observed. The reactions generate silicon hydride and cause corrosion of the silicon electrodes. Coating of the silicon surface with a poly(vinyl alcohol) layer can effectively retard and attenuate these reactions. This work demonstrates that SFG-VS can provide a unique and powerful state-of-the-art tool for elucidating the molecular mechanisms of SEI formation.