Efficient preparation of high-toughness ionic conductors using in situ microphase-separation

Abstract

Ionic conductors are important materials for sensing devices owing to their excellent stretchability, conductivity, and transparency. However, it is extremely challenging to simultaneously achieve high tensile strength, fracture strain, and toughness in a dry ion conductor. In view of this, an acrylic acid (AA) and poly(ethylene glycol) dimethacrylate (PEGMA) based dry ion conductor (ISPSIC) with ultra-high mechanical performance is developed by an efficient one-pot method. By utilizing PEGMA to construct microphase-separated regions within the polymer network of the traditional poly(AA–ChCl) type supramolecular deep eutectic polymer, the ISPSIC can enhance the tensile strength of the dry ion conductor by 252.74% with only 0.43% PEGMA content, with no loss of tensile strain. Benefiting from the advantages of the in situ microphase-separation structure, this dry ion conductor exhibits remarkably high tensile strength (77.77 MPa), tensile strain (505.43%), toughness (232.70 MJ m⁻³), transparency (>90%), and electrical conductivity (6.7 × 10⁻⁵ S m⁻¹). Notably, the relative resistance variations of the ISPSIC are greater than 800% and can be electrohealed up to 98.5% within 0.03 s. This work provides a reliable method for further tuning the microstructure and high performance of ionic conductors during polymerization.