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

Abstract

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.