Research progress on the interfaces of solid-state lithium metal batteries

Solid-state lithium metal batteries (SSLMBs) with the advantages of brilliant safety, superior energy density, and improved thermal stability are regarded as one of the most promising energy storage devices. However, intrinsic defects of the solid-solid rigid interface, such as insufficient wettability and compatibility manifesting as poor interfacial contact, side reactions, space charge layer (SCL) effect, etc., lead to a rapid degradation in interfacial stability. This yields unsatisfactory electrochemical performance of SSLMBs. In this review, the origin of inferior stability and kinetics on solid-solid interfaces are first clarified. Second, recent achievements in stabilizing the interfacial stability using an interfacial buffer layer, composite electrode, liquid phase therapy, etc. are summarized from the physical and chemical/electrochemical aspects. In particular, issues related to electrode-electrolyte interfaces such as lithium dendrites, SCL effect, deficient physical contact, and parasitic reactions are emphasized. Finally, remaining challenges such as the degradation mechanism, advanced characterization techniques, and commercialization, as well as future development directions, are prospected. This review will provide certain new insights for formulating target-oriented studies on high-performance SSLMBs.

Automated summary

Solid-state lithium metal batteries (SSLMBs) are considered promising energy storage devices due to their superior safety, energy density, and thermal stability. However, inherent defects in the solid-solid interface lead to poor electrochemical performance. Recent research has focused on stabilizing the interface through methods such as interfacial buffer layers and composite electrodes. Remaining challenges include degradation mechanisms, advanced characterization techniques, and commercialization efforts.