Liquid phase therapy to solid electrolyte–electrode interface in solid-state Li metal batteries: A review

Solid-state lithium (Li) metal batteries, employing solid electrolytes, with high energy density and enhanced safety are promising choices for next-generation electrochemical energy storage devices. However, the large interfacial resistances seriously hinder their commercialization. To construct a conformal interface with acceptable resistances, introducing small amounts of additional liquid electrolytes is one of the most convenient and effective solutions. This review summarizes the fundamental understandings on the interfacial behaviors between liquid electrolytes, electrodes and solid-state electrolytes. Afterwards, emerging strategies are discussed, involving interfacial wetting, in situ polymerization and interfacial reactions. Finally, current limitations and perspectives are presented for liquid phase therapy regarding the interfacial science and engineering.