Dynamic diels-alder reaction crosslinked metal-organic framework/poly (ionic liquid) composite solid electrolyte for lithium-metal batteries

High-energy-density lithium-metal batteries have garnered significant interest as an emerging class of energy storage devices. However, the intrinsic high reactivity of lithium metal introduces critical safety challenges for electrolytes (dendrite penetration and thermal runaway), severely hindering their development. This paper presents the preparation of a dynamic Diels-Alder-crosslinked metal-organic framework/poly (ionic liquid) composite electrolyte (DA-PIL/MOF) using ultraviolet (UV) curing, based on the design of furan-functionalized zirconium 1,4-dicarboxybenzene MOF (Fu-UiO-66) and maleimide-functional vinylimidazole ionic liquids (MA-IL-VI). The imidazolium cations along the PIL chains facilitate the dissociation of lithium salts. Furthermore, the incorporation of Fu-UiO-66 as a crosslinker with polymer chains establishes effective Li + pathways, thereby boosting ion transport and transference number (the ionic conductivity: 3.6 mS cm −1 at 30 °C; Li + transference number: 0.51). The incorporation of MOF into the composite electrolyte imparts flame retardancy, enhancing its thermal safety. The compact cross-linked structure ensures close contact between the electrolyte and electrodes. Additionally, the dynamic DA reaction endows the electrolyte with thermal self-healing, contributing to extended durability. Consequently, lithium iron phosphate-based cells utilizing the composite electrolyte exhibit remarkable electrochemical performance.