Multiscale Interfacial Engineering Strategies for Inorganic All-Solid-State Lithium Batteries

Abstract

All-solid-state lithium batteries (ASSLBs) offer exceptional energy density and safety, yet interfacial instability at both cathode and anode remains a major challenge. This review pioneers a unified, multiscale framework that systematically dissects interfacial failure mechanisms across mainstream inorganic solid-state electrolytes (SSEs)-including oxides, sulfides, and halides-under multiphysics coupling. Unlike previous studies focusing on isolated materials or single strategies, we provide a critical, side-by-side comparison of leading interface engineering routes-electrode engineering, interlayer construction, electrolyte regulation, and integrated dual-interface design-emphasizing their respective merits, limitations, and application boundaries. Special attention is given to the functional synergy and engineering feasibility of different approaches, offering actionable insights for robust interface design. Finally, future perspectives highlight multiphysics characterization, machine-learning-assisted interface material screening, and scalable process integration. This review offers a comprehensive, comparative, and practical guide to interface innovation in high-performance ASSLBs.Accordingly, this review focuses on three representative classes of SSEs-oxides, sulfides, and halides-and systematically analyzes the key interfacial challenges related to physical contact, electrochemical stability, and the formation and evolution of lithium dendrites. It further summarizes the current mainstream interfacial engineering strategies and their applicability boundaries, aiming to provide theoretical insight and practical guidance for the interface design and application of high-performance ASSLBs.