Room‐Temperature Single Li + Ion Conducting Organic Solid‐State Electrolyte with 10 −4 S cm −1 Conductivity for Lithium‐Metal Batteries

Abstract Covalent organic frameworks (COFs) are promising solid‐state electrolytes (SSEs) for lithium (Li)‐metal batteries due to their tunable structures, ordered nanochannels, and suppressed segmental motion, which support Li⁺ ion transport at ambient temperatures. However, pellet‐type COF‐based SSEs have exhibited low ionic conductivity, attributed to suboptimal ion transport pathways, limited crystallinity, and extensive grain boundary formation. Here, a 20 µm‐thick disulfonate‐functionalized COF (COF ds ) film is presented that achieves an ionic conductivity of 1.0 × 10 ‒4 S cm ‒1 at 25 °C. The integration of immobile disulfonate anions and carbonyl groups enables inter‐subchannel Li⁺ hopping with minimal spatial separation. Molecular dynamics (MD) simulations under applied fields confirm that the molecular design facilitates optimized Li⁺ conduction pathways. Solution‐phase synthes…