Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China.
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
Small. 2023 Jun;19(25):e2208239. doi: 10.1002/smll.202208239. Epub 2023 Mar 17.
Solid electrolyte interphase (SEI) plays an important role in regulating the interfacial ion transfer and safety of Lithium-ion batteries (LIBs). It is unstable and readily decomposed releasing much heat and gases and thus triggering thermal runaway. Herein, in situ heating X-ray photoelectron spectroscopy is applied to uncover the inherent thermal decomposition process of the SEI. The evolution of the composition, nanostructure, and the released gases are further probed by cryogenic transmission electron microscopy, and gas chromatography. The results show that the organic components of SEI are readily decomposed even at room temperature, releasing some flammable gases (e.g., H , CO, C H , etc.). The residual SEI after heat treatment is rich in inorganic components (e.g., Li O, LiF, and Li CO ), provides a nanostructure model for a beneficial SEI with enhanced stability. This work deepens the understanding of SEI intrinsic thermal stability, reveals its underlying relationship with the thermal runaway of LIBs, and enlightens to enhance the safety of LIBs by achieving inorganics-rich SEI.
固体电解质界面相（SEI）在调节锂离子电池（LIBs）的界面离子传输和安全性方面起着重要作用。它不稳定，容易分解释放大量热量和气体，从而引发热失控。在此，我们应用原位加热 X 射线光电子能谱揭示 SEI 的固有热分解过程。通过低温透射电子显微镜和气相色谱进一步研究了组成、纳米结构和释放气体的演变。结果表明，SEI 的有机成分即使在室温下也容易分解，释放出一些易燃气体（例如 H2、CO、C2H4 等）。热处理后的残余 SEI 富含无机成分（例如 Li2O、LiF 和 Li2CO3），为具有增强稳定性的有益 SEI 提供了纳米结构模型。这项工作加深了对 SEI 固有热稳定性的理解，揭示了其与 LIBs 热失控的内在关系，并为通过实现富含无机物的 SEI 来提高 LIBs 的安全性提供了启示。
