Design of COF Crosslinker Within Polymeric Ionogels for Simultaneous Enhancement of Toughness and Ionic Conductivity

Developing soft ionic conductors that combine high toughness and high ionic conductivity remains a formidable challenge, as these properties are typically mutually exclusive. Here, we report a synergistic strategy using in situ synthesized sulfonated covalent organic frameworks (COFs) as multifunctional crosslinkers within a poly(vinylidene fluoride-co-hexafluoropropylene) ionogel. COFs, at an ultralow content of 0.005 wt.%, could concurrently serve as dynamic physical and topological crosslinks within the polymer network. This unique design results in a remarkable simultaneous enhancement of mechanical properties and ionic conductivity (e.g., fracture stress from 4 to 10 MPa, elongation at break rised from 1006% to 2460%, and conductivity improved from 0.037 to 0.168 S m − 1 . Unlike conventional crosslinkers, which often impede ion transport, the intrinsic ionic nanochannels of the COFs enable efficient ion conduction. The resulting ionogel demonstrated exceptional performance as a durable and sensitive pressure sensor for both wearable and underwater applications, overcoming a key limitation in soft electronics.