A Solvent-Free Covalent Organic Framework Single-Ion Conductor Based on Ion-Dipole Interaction for All-Solid-State...

Single-ion conductors based on covalent organic frameworks (COFs) have garnered attention as a potential alternative to currently prevalent inorganic ion conductors owing to their structural uniqueness and chemical versatility. However, the sluggish Li⁺ conduction has hindered their practical applications. Here, we present a class of solvent-free COF single-ion conductors (Li-COF@P) based on weak ion-dipole interaction as opposed to traditional strong ion-ion interaction. The ion (Li⁺ from the COF)-dipole (oxygen from poly(ethylene glycol) diacrylate embedded in the COF pores) interaction in the Li-COF@P promotes ion dissociation and Li⁺ migration via directional ionic channels. Driven by this single-ion transport behavior, the Li-COF@P enables reversible Li plating/stripping on Li-metal electrodes and stable cycling performance (88.3% after 2000 cycles) in organic batteries (Li metal anode||5,5'-dimethyl-2,2'-bis-p-benzoquinone (Me₂BBQ) cathode) under ambient operating conditions, highlighting the electrochemical viability of the Li-COF@P for all-solid-state organic batteries.