Flexible Solid Electrolytes\nfrom Two-Dimensional Metal\nCarbide, Polymer, and Ionic Covalent Organic Frameworks

As the demand for mobile electronic devices continues\nto grow,\nthe development of all-solid-state lithium metal batteries has emerged\nas a promising solution to reduce the safety risks associated with\nconventional lithium-ion batteries. Herein, we introduce an approach\nto preparing a composite solid-state electrolyte by integrating two-dimensional\n(2D) MXenes with cationic covalent organic frameworks (cCOFs). These\nframeworks are based on ethidium bromide (EB-cCOF) and porphyrin (POR-cCOF),\nand are incorporated into the poly(ethylene oxide) (PEO)-based solid\nelectrolytes. The synthesized MXenes and cCOFs serve as multifunctional\nadditives, reducing the PEO crystallinity and enhancing segmental\nmotion. We observed a synergistic effect when COFs and MXene were\nused in preparing electrolytes, highlighted in the observed increase\nin the ionic conductivity at room temperature. Additionally, the electrolyte\nexhibits improved thermal stability up to ≈380 °C and\nretains ≈9% more residual mass at 1000 °C. These results\nhighlight the potential of hybrid solid electrolytes as promising\ncandidates for advancing high-performance solid-state batteries.