Highly Ionic Conductive and Transparent Self-Healing Lithium Salt Elastomers Based on Eutectic Strategy

Transparent conductive stretchable liquid-free lithium salt elastomers are well suited for the composition of flexible electronics, as they are not subject to the leakage limitation of ionic gels and the water evaporation of hydrogels. However, the quest for stretchable transparent conductive elastomers with high ionic conductivity remains daunting, as current transparent liquid-free lithium salt elastomers have problems, including their low conductivity (<10–1 S m–1) and the release of volatile organic compounds (VOCs) due to the evaporation of the organic solvents during the preparation process. Herein, a new type of transparent, stretchable, self-healing, and ultrahigh ionic conductive liquid-free lithium salt elastomers (LSEs) was produced by adjusting the ratio of two types of lithium salt-type polymerizable deep eutectic solvent (Li-PDES) monomers (lithium salt-type polymerizable deep eutectic solvent monomers) and the rapid photoinitiated copolymerization of mixed Li-PDES monomers. One of the LSEs exhibits the highest ionic conductivity (1.43 S m–1) of all liquid-free lithium salt elastomers reported to date. Owing to their excellent ionic conductivity and simple preparation process, we believe that LSEs with transparency (92.1% at 600 nm) and self-healing capability (91.02% for 48 h at 70 °C) should be more deeply investigated and applied in the field of flexible electronics and energy.