Reactive and Adaptive Interphase Engineering for Regulating Interfacial Li⁺ Transport in Li₂OHCl Antiperovskite...

Lithium-rich antiperovskite solid electrolytes, exemplified by Li₂OHCl, 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 MoS₂-enabled adaptive interlayer on Li₂OHCl that stabilizes the Li/SSE interface by regulating interfacial Li⁺ transport. MoS₂ establishes a dual-regulated Li⁺ transport mechanism, in which the intrinsically Li⁺ migration barrier in the MoS₂ bulk acts as a current-limiting regulator, while the substantially lower diffusion barrier along the MoS₂ 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 MoS₂ and lithium metal form a composite interphase composed of lithiophilic Li₂S 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.