Metal Organic Framework (MOF-808) Incorporated Composite Polymer Electrolyte for Stable All-Solid-State Lithium Batteries

All-solid-state lithium-ion batteries (ASSBs) are emerging as promising candidates for power applications in electric vehicles and various energy storage systems, garnering significant research interest. However, enhancing the Li+ conductivity and stability of polymer electrolyte has been a persistent challenge in the field. This work demonstrates a novel approach to fabricating a composite polymer electrolyte (CPE) with uniformly dispersed porous MOF-808 particles in a poly(ethylene oxide) (PEO) matrix mixed with LiTFSI salt. The resulted CPE exhibits a 20-fold increase in ion conductivity (9.7 × 10–4 S cm–1 at 60 °C) and an expanded electrochemical window up to 4.8 V. The assembled ASSBs with LiFePO4 cathodes and Li metal anodes under 50 MPa pressure show good specific capacity (140.3 mAh g–1) and excellent cycling stability (93.5% capacity retention). This CPE has also demonstrated excellent compatibility with the high-voltage cathode material NCM811, exhibiting superior electrochemical stability. Results of this work highlight the use of MOF materials in CPE, advancing the development of next-generation solid-state batteries.