Enhancement of Solid-State Lithium-Ion Batteries Using Zeolitic Imidazolate Framework-67 in Polyethylene Oxide-Based Composite Polymer Electrolytes for Improved Ionic Conductivity and Stability

Polyethylene oxide (PEO)-based polymers are commonly used in solid-state lithium-ion batteries, though their high crystallinity at room temperature reduces ionic conductivity. In this research, zeolitic imidazolate framework-67 (ZIF-67), with its regular dodecahedral structure, large surface area, and numerous nanoscopic pores, is synthesized and uniformly dispersed into a PEO matrix to create a novel composite polymer electrolyte (CPE). ZIF-67 effectively reduces PEO crystallinity and enhances the mechanical properties of the electrolyte by disrupting the order structure of the PEO polymer chains. The resulting CPE achieves an ion conductivity of 6.50 × 10 −4 S cm −1 , and demonstrated high interfacial compatibility and stability with optimized ZIF-67 content. Furthermore, the LiCoO 2 /CPE/Li battery exhibits good cycle stability at 0.1 C, with discharge capacities of 130.81, 125.31, and 112.25 mAh/g at 0.1, 0.2, and 0.5 C. Therefore, ZIF-67 presents a promising strategy for enhancing battery performance and developing high-performance lithium-ion batteries.