Transport-interface coupling regulates calendar aging in lithium metal batteries

Lithium metal batteries (LMBs) are promising next-generation energy storage systems, yet their practical deployment is severely hindered by rapid capacity loss during long-term storage, known as calendar aging. This degradation is commonly attributed to the chemical instability of the solid electrolyte interphase (SEI), while the role of electrolyte transport remains largely overlooked. Here, using a model Cl − /NO 3 − -containing electrolyte system with systematically varied glyme chain length (G2-G4), we demonstrate that both SEI chemistry and electrolyte transport properties synergistically influence interfacial stability under static conditions. Shorter glyme chains promote the formation of an SEI enriched in Li 2 O and LiF, whereas longer chains yield a less protective SEI. Meanwhile, increasing solvent chain length progressively deteriorates ionic transport and interfacial kinetics. These combined effects lead to heterogeneous lithium (Li) deposition and porous interfacial structures in electrolytes with longer glyme chains. Under static storage, the less protective SEI together with transport-limited interfacial heterogeneity synergistically accelerates micro-galvanic corrosion, Li loss, and calendar capacity decay, while the SEI with higher Li 2 O/LiF content and favorable transport properties effectively suppresses corrosion. By quantitatively correlating electrolyte transport properties, SEI composition, deposition morphology, corrosion kinetics, and full-cell performance, this work establishes that both the chemical nature of the SEI and the transport capability of the electrolyte are critical design parameters for achieving stable cycling and extended calendar life in LMBs.