Abstract:

Solid electrolyte interface (SEI) is a passivation layer on the surface of the electrode that is formed at the solid/liquid interface between the electrolyte and the electrode after electrochemical reactions. It typically forms during the formation stage of the battery and is characterized by its ability to conduct ions and insulate electrons. High-quality SEI film is crucial for improving the cycling life and safety of lithium-ion batteries (LIBs). The morphology and structure of the SEI film could be varied in different electrolyte systems, and they have different degrees of impact on the performance of LIBs. Therefore, it is crucial to have a thorough analysis of the structure-property relationship between the morphology and structure of the SEI film and battery performance. This article provides an overview of the factors influencing the structure and properties of SEI film, main in-situ/ex-situ characterization methods, especially a novel electrochemical impedance characterization technique, and the impact of SEI film structure on lithium ion transport, lithium deposition, and interface desolvation. This article summarizes the relationship between SEI film structure and LIBs performance, aiming to provide insights for enhancing the performance of LIBs through the targeted control of SEI film structure.

Key words: film, solid electrolyte interface (SEI), electrolyte, lithium-ion battery, electrochemistry

摘要：

固态电解质界面膜（SEI）是电解液与电极在固/液相界面上发生电化学反应后，覆盖在电极表面的钝化层，其通常形成于电池的化成阶段，具有传导离子、隔绝电子的特征。优良的SEI膜对于提高锂离子电池（LIBs）的循环寿命、安全性等具有重要意义。不同电解液体系形成的SEI膜形貌和结构各不相同，对LIBs性能具有不同程度的影响。因此，深入分析SEI膜形貌和结构与电池性能之间的构效关系很重要。本文首先综述了影响SEI膜结构和性质的因素；然后阐述了原位/非原位表征SEI膜形貌和结构的主要方法，并介绍了一种新型的电化学阻抗表征技术；最后总结了SEI膜结构对LIBs离子传输、锂沉积和界面脱溶剂化等方面的影响。通过总结SEI膜的结构与LIBs性能之间的关系，以期靶向调控SEI膜结构提升锂离子电池性能。

关键词: 膜, 固态电解质界面（SEI）, 电解质, 锂离子电池, 电化学