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. [ABSTRACT FROM AUTHOR]