Ion conducting elastomer designed from thiourea-based dynamic covalent bonds with reprocessing capability

Developing ion conducting elastomer (ICE) that possesses reprocessing capability is highly desirable to avoid resource wastage and environmental crises. However, elastomers with covalent cross-linking are difficult to reprocess due to their thermosets properties. To address this challenge, a thiourea-based dynamic covalent network was employed to design the ICE. An analysis of the interaction between the lithium salt and the polymer chain resulted in the selection of LiTFSI. Furthermore, the finding from the analysis confirmed that not only the formation but also the behavior of the dynamic covalent network was affected by the interactions between the polymer chain and lithium salts. The resulting dynamic covalent elastomer can be repeatedly reprocessed through various methods (hot-press and solution processes) and exhibits proper dimensional stability and ionic conductivity (∼4.6 × 10−4 S/cm at 25 °C).