Li metal anodes hold great promise for next-generation all-solid-state batteries (ASSBs) due to their high energy density. However, their practical implementation is severely limited by dendrite formation and interfacial instability, leading to rapid capacity degradation and short-circuiting. In this study, we introduce a Li2ZnSb (LZS) interlayer designed to suppress dendrite growth, enhance Li-ion transport, and improve Li reversibility. Electrochemical evaluations reveal that the LZS interlayer effectively stabilizes the Li metal–solid electrolyte interface, enabling highly reversible Li plating/stripping with superior cycling retention. To demonstrate the scalability of LZS, we developed a transfer printing method, successfully fabricating sheet-type LZS-Li anodes for integration into pouch-type ASSBs. The resulting pouch cells exhibit high areal capacity, excellent rate capability, and long-term cycling stability under low external pressure. These findings highlight LZS as a transformative interface engineering strategy, bridging the gap toward the practical realization of high-energy-density and long-lasting ASSBs.