Triple Enhancement Effect of Fluoro and Phenol Dual‐Hybrid MOF in High‐Voltage Solid‐State Lithium Metal Batteries

ABSTRACT Solid‐state lithium metal batteries (SS‐LMBs) are restrained currently by their ionic conductivity, interface stability, and lithium dendrite penetration. Here, a high‐voltage SS‐LMB is enabled by a tailored functional composite electrolyte, which achieves a synergistic enhancement effect of “free radical scavenging–ion transport regulating–interface stabilizing.” This electrolyte obtained by embedding fluoro (F) and phenol (Ar─OH) dual‐hybrid ZIF‐8 into a PVDF‐HFP matrix exhibits a high room temperature ionic conductivity of 6.7 × 10 −4 S cm −1 (E a = 0.19 eV) and an electrochemical stability window above 5 V. The Ar─OH groups can effectively scavenge superoxide radicals (O 2 − ·) to suppress side reactions in NCM811‐based batteries. Active sites from triazole‐Zn coordination can specifically adsorb TFSI − (adsorption energy −2.45 eV) to enhance the Li + transference number (0.68). The F groups can preferentially decompose to form an inorganic F/N‐enriched solid electrolyte interface (SEI) layer with 65.8% LiF and 68.5% Li 3 N content. The assembled NCM811‐based SS‐LMB achieved an initial capacity of 177 mAh g −1 under 4.6 V high voltage, with a capacity retention of 76% after 300 cycles (1C). These results jointly reveal that this synergistic effect Fluoro and Phenol Dual‐hybrid MOF, High‐Voltage, Solid Electrolyte, Triple Enhancement Effect of functional groups is a promising strategy for the development of high‐performance batteries.