Interfacial Characterization in Solid-State Lithium Metal Batteries: Advances in Temporal, Spatial, and Energy Resolution

Abstract

All-solid-state lithium metal batteries (ASSLMBs) are widely regarded as promising candidates for next-generation energy storage systems due to their high energy density and intrinsic safety. However, the full realization of their performance potential is significantly hindered by critical challenges at the solid–solid interfaces between electrodes and solid-state electrolytes (SSEs). The interfaces are typically buried within the cell architecture, exhibit substantial chemical heterogeneity, and undergo dynamic evolution across a wide range of spatial and temporal scales, posing formidable obstacles to conventional characterization techniques. In this Perspective, we systematically examine the inherent difficulties in probing solid-state battery interfaces and highlight recent advances in temporal-, spatial-, and energy-resolved characterization methods. Looking forward, the integration of multidimensional analytical platforms with cell configurations tailored for realistic operating conditions will be critical for unravelling interfacial mechanisms, advancing interface engineering, and accelerating the development of high energy-density solid-state batteries.