High‐Performance Solid‐State Ionic Conductive Elastomers via Hard‐Phase Enrichment Strategy: Synergistic Enhancement of Mechanical Properties and Ionic Conductivity with Sustainable LiTFSI Recycling

Abstract Solid‐state ionic conductive elastomers (SICEs) have significantly addressed the issues of evaporation and leakage associated with gel‐type ionic conductors. However, the ionic conductivity and mechanical robustness of SICEs are typically mutually exclusive. In this study, a hard‐phase enrichment strategy is proposed for the preparation of SICEs. Specifically, multiple crosslinking sites are introduced into polyurethane elastomers, allowed the material to retain a certain degree of microphase separation after the incorporation of Lithium bis(trifluoromethanesulphonyl)imide (LiTFSI). Maintenance of microphase separation allows SICEs to have mechanical property up to 3.5 MPa, while the high LiTFSI concentration resulted in idea ionic conductivity of 4.9 × 10 ⁻⁴ S cm ⁻¹ . Furthermore, SICEs exhibit excellent resilience, high strain sensitivity and environmental stability. The multi‐modal pressure sensor based on SICE demonstrated not only high sensitivity but also broad applicability in automotive attitude sensing. To address the high cost and environmental concerns associated with LiTFSI, a simple and efficient LiTFSI recycling strategy is employed to recycle LiTFSI from SICEs, and achieved a recycling rate of 53.35%. This work will offer a straightforward and practical strategy for designing advanced SICEs and provide new insights for the development and sustainable production of cutting‐edge multifunctional ionic devices.