Functional flexible/wearable supercapacitors

Wearable electronic textiles that store capacitive energy are a next frontier in personalized electronics. However, the lack of industrially weavable and knittable conductive yarns in conjunction with high capacitance, limits the wide-scale application of such textiles. Here pristine soft conductive yarns are continuously produced by a scalable method with the use of twist-bundle-drawing technique, and are mechanically robust enough to be knitted to a cloth by a commercial cloth knitting machine. Subsequently, we demonstrate a combination of textile industry available conductive yarn and conducting polymers can form a great basement for wearable energy storage devices. For example, a combination of metal oxide and conductive polymer can great enhanced tolerance of stretch-induced performance degradation of stretchable supercapacitors. In case of self-healable PU sheel applied, a yarn supercapacitor can be self-healable. In addition, we demonstrate a new electrolyte comprising polyacrylic acid dual cross-linked by hydrogen bonding and vinyl hybrid silica nanoparticles (VSNPs-PAA) that addresses all the superior functions and provide an ultimate solution to the intrinsic self-healability and high stretchability of a supercapacitor. Supercapacitors with VSNPs-PAA as the electrolyte are self-healed, achieving an excellent healing efficiency of ~100% even after 20 cycles of breaking/healing. By a designed facile electrode fabrication procedure, they are stretched up to 600% strain with performance enhanced. Our research represents a solid progress in portable and wearable multifunctional devices with extreme self-healability and stretchability.