Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
Department of Chemical and Biomolecular Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA.
Science. 2022 Jan 7;375(6576):66-70. doi: 10.1126/science.abi8703. Epub 2022 Jan 6.
Although liquid-solid interfaces are foundational in broad areas of science, characterizing this delicate interface remains inherently difficult because of shortcomings in existing tools to access liquid and solid phases simultaneously at the nanoscale. This leads to substantial gaps in our understanding of the structure and chemistry of key interfaces in battery systems. We adopt and modify a thin film vitrification method to preserve the sensitive yet critical interfaces in batteries at native liquid electrolyte environments to enable cryo–electron microscopy and spectroscopy. We report substantial swelling of the solid-electrolyte interphase (SEI) on lithium metal anode in various electrolytes. The swelling behavior is dependent on electrolyte chemistry and is highly correlated to battery performance. Higher degrees of SEI swelling tend to exhibit poor electrochemical cycling.
尽管固液界面在广泛的科学领域中具有基础性，但由于现有工具在纳米尺度上同时获取液相和固相的能力存在缺陷，因此对这种微妙界面的描述仍然具有固有的难度。这导致我们对电池系统中关键界面的结构和化学的理解存在很大差距。我们采用并改进了一种薄膜玻璃化方法，以在原生液态电解质环境中保存电池中敏感但至关重要的界面，从而实现低温电子显微镜和光谱学。我们报告了在各种电解质中，锂金属阳极的固体电解质界面（SEI）发生了大量的膨胀。这种膨胀行为取决于电解质化学性质，并且与电池性能高度相关。SEI 膨胀程度越高，电化学循环性能越差。
