Inhibiting Interfacial Failure in Garnet‐Based Solid‐State Batteries with High‐Capacity Anodes: Mechanism and Strategies

Abstract Garnet‐based solid‐state electrolytes (SSEs) with exceptional reductive stability and superior ionic conductivity have emerged as promising candidates for next‐generation solid‐state batteries (SSBs). However, critical interface challenges still persist in practical implementations. This review systematically examines interfacial failure mechanisms in garnet SSE systems with high‐capacity anodes (Si, metallic Li) through combined mechanical‐electrochemical perspectives. For Si‐based anodes, a microstructure‐property‐performance relationship is established by analyzing strain mismatch‐induced degradation, correlating ionic transport barriers with lithiation kinetics under varying internal microstructures, particle sizes, and external pressures. Multiscale stress‐relief strategies spanning atomic‐level interface engineering to macroscopic pressure optimization are proposed. Regarding Li metal interfaces, breakthrough understandings of grain boundary (GB) charge distribution effects on Li filament propagation are highlighted, along with innovative solutions for kinetic inhibition. Particular emphasis is placed on dry battery electrode (DBE) fabrication techniques as scalable approaches for achieving intimate interfacial contact in industrial‐scale SSB production. By integrating fundamental mechanical‐electrochemical insights with practical engineering considerations, this work quantitatively decouple the strain‐lithiation interplay at Si/garnet interfaces, the regulation law of GB charge distribution on lithium dendrites and the industrial potential of combining DBE with fluidized bed technology for the first time, charting a viable path toward industrial SSBs with >400 Wh kg −1 energy density.