Reactive and Adaptive Interphase Engineering for Regulating Interfacial Li+ Transport in Li2OHCl Antiperovskite Solid‐State Batteries

Why It Matters

Stabilizing the Li|SSE interface eliminates dendrite‑driven failures, a critical hurdle for commercial solid‑state batteries, and could accelerate their entry into electric‑vehicle and grid markets.

Key Takeaways

• MoS2 interlayer creates Li2S‑Mo composite interphase.
• Bulk MoS2 limits current, surface enables fast Li+ spread.
• Symmetric cells cycle >1000 h without short‑circuit.
• Full cells show markedly improved cycling stability.
• Strategy offers design principle for antiperovskite SSEs.

Pulse Analysis

The race toward all‑solid‑state lithium‑metal batteries has placed lithium‑rich antiperovskite electrolytes such as Li2OHCl in the spotlight. Their high ionic conductivity and wide electrochemical window promise energy densities far beyond conventional liquid‑electrolyte cells. Yet, direct contact with lithium metal triggers interfacial instability: uneven Li⁺ flux, mechanical stress, and dendrite penetration that quickly short‑circuit the cell. Overcoming this barrier is essential for translating laboratory performance into commercial products, and researchers have turned to interface engineering as a viable remedy.

In the latest study, a molybdenum disulfide (MoS2) nanosheet is introduced as an adaptive interlayer between Li2OHCl and lithium metal. The bulk of MoS2 presents a relatively high Li⁺ migration barrier, acting as a current‑limiting regulator that prevents localized ion crowding. Simultaneously, the atomically smooth basal plane offers a low‑energy pathway for lateral Li⁺ diffusion, rapidly redistributing ions across the interface. During cycling, MoS2 reacts with lithium to generate a mixed Li2S‑Mo interphase, which lowers nucleation overpotential and provides electronic conductivity, further stabilizing deposition.

The engineered cells demonstrate remarkable durability: symmetric Li|Li2OHCl|Li cells sustain over 1,000 hours of continuous cycling, and full solid‑state batteries exhibit a pronounced extension of cycle life compared with untreated interfaces. By decoupling current density from ion transport speed, the MoS2 strategy suppresses dendrite initiation without sacrificing rate capability. This approach establishes interfacial ion‑transport regulation as a design principle for antiperovskite solid‑state batteries, offering a scalable path toward safer, higher‑energy storage solutions that could accelerate the adoption of electric vehicles and grid‑scale storage.