Advances in electrolyte–anode interface engineering of solid-state lithium metal batteries

Solid-state lithium metal batteries are considered to be the next generation of energy storage systems due to the high energy density brought by the use of metal lithium anode and the safety features brought by the use of solid electrolytes (SEs). Unfortunately, besides the safety features, using SEs brings issues of interfacial contact of lithium anode and electrolytes. Recently, to realize the application of solid-state lithium metal batteries, significant achievements have been made in the interface engineering of solid-state batteries, and various new strategies have been proposed. In this review, from the interface failure perspective of solid-state lithium metal batteries, we summarize failure mechanisms in terms of poor physical contact, weak chemical/electrochemical stability, continuing contact degradation, and uncontrollable lithium deposition. We then focused on the latest strategies for solving interface issues, including advancing in improving the physical solid–solid contact, increasing the electrochemical/chemical stability, restraining continuing contact degradation, and controlling homogeneous lithium deposition. The ultimate and paramount future developing directions of solid-state lithium metal battery interface engineering are proposed.