Self-Healable Polyelectrolytes with Mechanical Enhancement for Flexible and Durable Supercapacitors

The practical application of advanced personalized electronics is inseparable from flexible, durable, and even self-healable energy storage devices. However, the mechanical and self-healing performance of supercapacitors is still limited at present. Herein, highly transparent, stretchable, and self-healable poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA)/poly(vinyl alcohol) (PVA)/LiCl polyelectrolytes were facilely prepared by one-step radical polymerization. The cooperation of PAMPSA and PVA significantly increased the mechanical and self-healing capacity of the polyelectrolyte, which exhibited superior stretchability of 938 %, stress of 112.68 kPa, good electrical performance (ionic conductivity up to 20.6 mS cm −1 ), and high healing efficiency of 92.68 % after 24 h. After assembly with polypyrrole-coated single-walled carbon nanotubes, the resulting as-prepared supercapacitor had excellent electrochemical properties with high areal capacitance of 297 mF cm −2 at 0.5 mA cm −2 and good rate capability (218 mF cm −2 at 5 mA cm −2 ). Besides, after cutting in two the supercapacitor recovered 99.2 % of its original specific capacitance after healing for 24 h at room temperature. The results also showed negligible change in the interior contact resistance of the supercapacitor after ten cutting/healing cycles. The present work provides a possible solution for the development of smart and durable energy storage devices with low cost for next-generation intelligent electronics. Graphical Back together again : A PAMPSA/PVA/LiCl polyelectrolyte with excellent mechanical strength, high ionic conductivity, and superior self-healing property was synthesized by one-step radical polymerization. Assembly with polypyrrole-coated single-walled carbon nanotubes gave a self-healable supercapacitor that recovered 99.2 % of its original specific capacitance after cutting in two and healing for 24 h at room temperature (see figure). PAMPSA: poly(2-acrylamido-2-methyl-1-propanesulfonic acid), PVA: poly(vinyl alcohol).