arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2308.04701cond-mat.mtrl-sci
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同位素标记固体电解质界面中Li+传输动力学的直接原位检测

Direct and in situ examination of Li+ transport kinetics in isotope labelled solid electrolyte interphase

Xiaofei Yu, Stefany Angarita-Gomez, Yaobin Xu, Peiyuan Gao, Jun-Gang Wang, Xin Zhang, Hao Jia, Wu Xu, Xiaolin Li, Yingge Du, Zhijie Xu, Janet S. Ho, Kang Xu, Pe… 展开作者

Xiaofei Yu, Stefany Angarita-Gomez, Yaobin Xu, Peiyuan Gao, Jun-Gang Wang, Xin Zhang, Hao Jia, Wu Xu, Xiaolin Li, Yingge Du, Zhijie Xu, Janet S. Ho, Kang Xu, Perla B. Balbuena, Chongmin Wang, Zihua Zhu

AI总结:

本文通过原位液相二次离子质谱结合低温电镜和分子动力学模拟,首次直接揭示SEI中Li+传输遵循连续位移机制,并定量测定其自扩散系数,为电池界面设计提供依据。

摘要:

本文利用独特的原位液相二次离子质谱技术,对同位素标记的固体电解质界面(SEI)进行研究,并辅以低温透射电子显微镜和约束从头算分子动力学模拟,首次回答了Li+在SEI中的传输机制问题,并定量确定了其中的Li+迁移率。我们明确揭示,Li+在SEI中的传输遵循连续位移机制,而非“直接跳跃”机制。我们进一步揭示,与SEI结构随厚度变化的空间依赖性一致,表观Li+自扩散系数从6.7×10⁻¹⁹ m²/s变化至1.0×10⁻²⁰ m²/s,从而为SEI层相对于底层电极的离子传输行为以及电池运行的速率限制步骤提供了定量标定。这项关于SEI中Li+动力学的直接研究填补了关于先进电池中最重要组分的长达十年的知识空白的一部分,并为未来电池化学中界面化学的调控提供了更精确的指导。

英文摘要:

Here, using unique in-situ liquid secondary ion mass spectroscopy on isotope-labelled solid-electrolyte-interphase (SEI), assisted by cryogenic transmission electron microscopy and constrained ab initio molecular dynamics simulation, for the first time we answer the question regarding Li+ transport mechanism across SEI, and quantitatively determine the Li+-mobility therein. We unequivocally unveil that Li+ transport in SEI follows a mechanism of successive displacement, rather than "direct-hopping". We further reveal, in accordance with spatial-dependence of SEI structure across the thickness, the apparent Li+ self-diffusivity varies from 6.7*10-19 m2/s to 1.0*10-20 m2/s, setting a quantitative gauging of ionic transport behavior of SEI layer against the underlining electrode as well as the rate limiting step of battery operation. This direct study on Li+ kinetics in SEI fills part of the decade-long knowledge gap about the most important component in advanced batteries and provides more precise guidelines to the tailoring of interphasial chemistries for future battery chemistries.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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