Self-healing and recyclable polyurethane-based solid-state polymer electrolyte via Diels-Alder dynamic network

• Published in: Journal of molecular structure 2025-02, Vol.1321, p.139793, Article 139793
• Main Authors: Du, Xiaoyu, Tong, Yongfen, Wang, Ting, Zhang, Aiqin, Xu, Qiuhua
• Format: Article
• Language: English
• Subjects: Diels-Alder reaction; Hydrogen bond; Polyurethane; Self-healing; Solid-state polymer electrolyte
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2024.139793

•A series of polyurethane-based solid polymer electrolytes were prepared via D-A reaction.•PUBXSPE exhibits high thermal stability, good shape memory and superior recyclability.•The hydrogen bond and dynamic covalent bond endow PUBXSPE with excellent self-healing ability.•The Li|PUB1SPE|LiFePO4 pouch cells can light the blue diode under a harsh conditions. Compared with liquid electrolytes, solid-state polymer electrolytes (SPEs) with better thermal, mechanical stability and processablilty are urgently required for the development of next-generation flexible energy storage devices. Herein, a series of polyurethane-based solid polymer electrolytes (PUBXSPE) with cross-linking structure were prepared by Diels-Alder reaction. The hydrogen bonding between the urea groups and dynamic Diels-Alder reaction endows the solid polymer electrolyte with excellent self-healing ability without external stimuli at room temperature. The PUBXSPE also displays good liquid affinity and superior recyclable properties, which provide a practical idea for the design of multifunctional polymer electrolytes. Although the cross-linking solid polymer electrolytes films display unsatisfied ionic conductivity about 10−6 S cm−1 at 60°C, the ionic conductivity value of the self-healing and recycled PUB1SPE were close to their pristine one. The wide working voltage window of PUBXSPE (>5.0 V) indicate that they can meet the requirements of most cathode materials. Moreover, the Li|PUB1SPE|LiFePO4 maintained a good coulombic efficiency (> 98.0 %) throughout all the cycle at 60°C, and the flexible cells can successfully light the blue diode under harsh conditions. This work provides new insights and concepts to design flexible, reliable, and safe polymer electrolytes for electronic devices at high-temperature. [Display omitted]