Construction of PEO composite electrolyte based a hybrid from metal organic framework and sepiolite (ZIF-8@SEP) for lithium-ion batteries

Abstract

Polyethylene oxide (PEO) exhibits excellent segmental flexibility and solubility for lithium salts, but its high crystallinity at room temperature results in relatively low ionic conductivity. To enhance its performance, this study incorporates highly adsorbent fibrous sepiolite (SEP) and zeolite imidazolate framework (ZIF-8) with high specific surface area and tunable pore structure. These are combined into a ZIF-8@SEP filler, aiming to synergistically reduce PEO crystallinity and establish rapid ion transport pathways. A series of PEO-based composite electrolyte films were prepared via the casting method and assembled into button cells for testing. The results demonstrate a significant improvement in ionic conductivity, reaching up to 6 × 10 ⁻⁵  S cm ⁻¹ at 60 °C. This study provides new insights for developing safe and efficient composite solid-state electrolytes.