Rationally Designed Self-Healing Hydrogel Electrolyte toward a Smart and Sustainable Supercapacitor.

Excellent self-healability and renewability are crucial for the development of wearable/flexible energy-storage devices aiming for advanced personalized electronics. However, realizing low-temperature self-healing and harmless regeneration remains a big challenge for existing wearable/flexible energy-storage devices, which is fundamentally limited by conventional polymeric electrolytes that are intrinsically neither cryo-healable nor renewable. Here, we rationally design a multifunctional polymer electrolyte on the basis of the copolymer of vinylimidazole and hydroxypropyl acrylate, which exhibits all features solving the above-mentioned limitations. A supercapacitor comprising the electrolyte autonomously restores its electrochemical behaviors at temperatures ranging from 25 to -15 °C after multiple mechanical breakings. Interestingly, it is even able to regenerate for 5 cycles through a simple wetting process in the case of malfunction, while maintaining its capacitive properties and excellent self-healability. Our investigation provides a novel insight into designing smart and sustainable energy-storage devices that might be applied to intelligent apparel, electronic skin or flexible robot, and so on.