High‐Strength and High‐Stretchability All‐Solid‐State Double‐Network Ion‐conductive Elastomers Based on Supramolecular Deep Eutectic Polymer

Abstract The double‐network (DN) structure has been proven to be an effective approach to enhancing the strength and stretchability of stretchable ionic conductors. However, the conventional strategy of using a rigid first network to encapsulate a loose second network often suffers from insufficient strength and poor stability in practical applications due to the presence of solvents in the system or significant compatibility differences between the two networks. Therefore, developing double‐network ion‐conductive elastomers with minimal compatibility differences and strong environmental stability is critical to addressing these challenges in flexible electronics. This study leverages highly customizable all‐solid‐state supramolecular deep eutectic polymers to design Poly ( N ‐(2‐Hydroxyethyl) acrylamide‐Choline chloride) (HEAA‐ChCl) as the rigid first network and Poly(Acrylic acid‐Choline chloride) (AA‐ChCl) as the flexible second network, both exhibiting similar compatibility. This compatibility ensures uniform embedding of the two networks, enabling efficient and uniform energy dissipation under external forces. The resulting all‐solid‐state double‐network ion‐conductive elastomer achieves a strength of 13.8 MPa, a tensile strain of 2780%, and toughness as high as 161 MJ m − 3 . Such a design strategy, with its exceptional mechanical properties, provides robust support for advancing ion‐conductive elastomers in high‐strength intelligent manufacturing.