Building a lithiumâsulfur (LiâS) battery with lean electrolytes is essential to far exceed the energy density of today's Liâion. However, earlier electrolyte depletion triggered by Liâmetal anodes (LMAs) causes sluggish LiâS redox kinetics and poor S utilization, resulting in a short cycle lifespan. To retard the electrolyte loss effectively, sustainable protection of LMAs is necessary against the dynamic interfacial evolution between LMA and protective layers (PLs). This study elucidates two critical parameters in securing the interfacial adaptivity of PLs upon local Li pitting: surface free energy (SFE) and Young's modulus through solidâmechanic simulations and experiments using three different PL models. To alleviate the PL delamination at the early stage, a dualâlayer structured, adaptive protective layer (APL) is introduced to adapt the Li pittingâdriven structural evolution of the PL|LMA interfaces. The APL consists of a highâ SFE polymer as an inner layer, reducing the interfacial energy in contact with LMA surface, and a highly stretchable polymer for outer shield, serving as a physical barrier for the electrolyte and Li polysulfides. APLâcoated LMA demonstrates stable cycling of LiâS cells, achieving a twofold extension of cycleâlife compared to unprotected LMA, even superior to other singleâlayer PLs.