Artificial SEI Films for Lithium Metal Anodes via Multiphase Interfacial Engineering

Despite the advantageous high specific capacity of lithium metal anodes, challenges such as dendritic growth and the inherent instability of the native solid electrolyte interphase (SEI) film readily give rise to dead lithium formation, increased interfacial impedance, and diminished Coulombic efficiency. Consequently, the construction of a stable artificial SEI film is of paramount importance. Interfacial engineering strategies enable the fabrication of artificial SEI films that concurrently possess chemical stability, electronic insulation, mechanical robustness, and rapid and uniform lithium-ion conduction capabilities. This review summarizes the research progress on surface modification of lithium metal anodes via pre-treatment methodologies, categorizes these approaches according to the physical state of the pre-treatment agents (solid, liquid, and gas phases), and concurrently discusses critical design principles. This comprehensive review provides a systematic theoretical framework and rational design guidelines for the construction of artificial SEI films, which hold significant implications for advancing the practical development of lithium metal batteries, particularly solid-state battery systems.