关键词: 膜, 固态电解质界面（SEI）, 电解质, 锂离子电池, 电化学

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