Super‐Toughness Self‐Healing Bimetallic MOF‐based Composite Solid Electrolyte with Nanoconfined Ion Channels and Dynamic Crosslinking for High‐Performance Solid‐State Lithium Metal Batteries

ABSTRACT Solid‐state lithium metal batteries are considered ideal candidates for next‐generation energy storage systems due to high energy density and safety. However, NCM811||Li battery systems face severe issues in practical application, such as interface failure between the cathode and anode, lithium dendrite growth, and the insufficient stability of conventional electrolytes. Here, we proposed a synergistic modification strategy combined with nanoconfined polymerization and interface dynamic crosslinking to fabricate self‐healing bimetallic MOF‐based composite solid electrolyte with enhanced ionic conduction and interface stability. The as‐prepared electrolyte exhibits high room‐temperature ionic conductivity (12.63×10 −4 S cm − 1 ), extended electrochemical voltage windows (5.14 V), excellent elongation at break (270%), high puncture resistance (5.28 N), superior thermal stability (200 °C), and outstanding cycling stability (94.77% retention over 150 cycles at 0.1 C), which exceeds previously reported electrolytes. Even under high mass loadings of 9.24 mg cm − 2 and 20.38 mg cm − 2 for the cathode, the capacity retention rates can still reach 90.88% and 86.35% after 150 and 100 cycles, respectively, demonstrating practical potential under high‐loading conditions. This strategy reconstructs the Li + transport, interface stability, and recyclability of composite solid electrolytes at the molecular level, paving the way for the development of next‐generation high‐performance solid‐state batteries.