High-Performance Solid Composite Electrolyte with Bifunctional Metal–Organic Frameworks as Active Fillers for All-Solid-State Lithium Batteries

In this work, a solid composite electrolyte (SCE) was prepared by incorporating a lithiated bifunctional metal–organic framework (UiO-66-SO3Li-NH2-0.85) into a PVDF-HFP/LiTFSI polymer matrix. Specifically, the lithiated sulfonate groups provide uniformly distributed lithium-ion conduction sites, while the amino groups achieve good interfacial bonding in the composite. Consequently, the optimized SCE delivers a high ionic conductivity of 5.01 × 10–4 S cm–1 (60 °C), its lithium-ion transference number is measured to be 0.65, and it possesses a wide electrochemical stability window (4.9 V). Furthermore, the assembled all-solid-state Li∥SCE∥LFP full cells also demonstrates a reversible capacity of 147.45 mAh g–1 after 120 cycles at 0.2C (60 °C) and a capacity of 113 mAh g–1 at 1C after 60 cycles (25 °C). This bifunctional MOF strategy has made it the subject of intense research for high-performance all-solid-state lithium batteries.