Spatially Selective Lithium Plating and Stripping in Lithium Metal Anodes

A mechanistic understanding of lithium (Li) plating and stripping is essential for the practical deployment of Li metal batteries (LMBs), yet most in situ studies rely on limited fields of view or spatial averaging, obscuring local heterogeneity. Here, in situ electrochemical AFM (EC-AFM) is used to track the same region over three plating/stripping cycles in the native electrolyte, resolving few-micrometer-scale heterogeneity. Spatially aligned measurements of slope, height change (Δh), and local porosity reveal clear correlations: domains with small |Δh| colocalize with high-slope, porous regions. These observations establish a site-selective voiding mechanism in which stripping at porous, high-slope domains generates subsurface voids and “dead” Li that are only partially refilled during subsequent plating, whereas dense, low-slope domains undergo larger |Δh|. This correlative framework demonstrates that the initial plating morphology critically governs the spatial heterogeneity of void formation during stripping, providing a mechanistic basis for the rational design of Li metal anodes.