Dendrite-tolerant fast-kinetics design for all-solid-state lithium-metal batteries via site-specific customized sulfide electrolytes

초록

Sulfide-based all-solid-state lithium-metal batteries (ASSLMBs) offer enhanced safety compared to conventional liquid electrolyte systems. However, fast and stable cycling remains challenging due to dendrite growth and the formation of resistive by-products at multi-layer interfaces. Here, we propose a site-specific electrolyte customization strategy to enable high-rate stable operation through sequential modifications of the composite cathode, separator layer, and Li-metal interface. Oxygen-substituted argyrodite (Li6PS4OCl) synthesized via high-energy ball milling serves as the catholyte for Ni-rich cathodes, exhibiting superior oxidative and interfacial stability compared to conventional Li6PS5Cl, as confirmed by impedance spectroscopy and X-ray photoelectron spectroscopy. A comparative analysis reveals that Cl-rich Li5.4PS4.4Cl1.6 becomes critical for the separator at rates above 1C, where ionic conductivity limits the cell performance. A mixed solid electrolyte interlayer combining Li5.4PS4.4Cl1.6 and Li6PS4OCl at the Li-metal anode provides high ionic conductivity while promoting the formation of a robust Li3PO4-based interphase, establishing a dendrite-tolerant interface confirmed by microstructural characterizations. The optimized ASSLMB demonstrates stable cycling over 500 cycles at 1C under controlled conditions (20 MPa, 45 °C) without short-circuiting, while also sustaining over 100 cycles at room temperature. The design principles presented in this research provide valuable insights into critical factors for developing high-performance ASSLMBs with increased energy density and long cycle life. © 2026 Elsevier B.V.

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