Reactive and Adaptive Interphase Engineering for Regulating Interfacial Li(+) Transport in Li(2)OHCl Antiperovskite Solid-State Batteries.

Lithium-rich antiperovskite solid electrolytes, exemplified by LiOHCl, are promising for all-solid-state lithium metal batteries. However, their practical implementation is severely constrained by interfacial instability with lithium metal, where nonuniform Li flux and mechanical degradation induce dendrite growth. Herein, we introduce a MoS-enabled adaptive interlayer on LiOHCl that stabilizes the Li/SSE interface by regulating interfacial Li transport. MoS establishes a dual-regulated Li transport mechanism, in which the intrinsically Li migration barrier in the MoS bulk acts as a current-limiting regulator, while the substantially lower diffusion barrier along the MoS surface enables rapid lateral Li redistribution. This synergistic "current-limiting and fast-transfer" effect effectively homogenizes interfacial Li flux and suppresses localized ion accumulation that initiates lithium dendrites. Meanwhile, electrochemical reactions between MoS and lithium metal form a composite interphase composed of lithiophilic LiS and conductive Mo, which collectively lower the lithium nucleation overpotential, accelerate interfacial charge transfer, and stabilize the deposition front. Consequently, lithium-metal symmetric cells exhibit stable cycling for over 1000 h with prolonged short-circuit time, and all-solid-state lithium-metal full cells demonstrate markedly improved cycling stability. This work establishes interfacial ion-transport regulation as a design principle for stabilizing lithium-metal anodes and provides a strategy for interface engineering in antiperovskite solid-state batteries.