Stretchable and self-healable polyelectrolytes for flexible and sustainable supercapacitor

With the continuous development of flexible electronic devices, the corresponding demands for electrochemical storage devices with flexibility and self-healing properties have been raised. However, the current supercapacitors still have great limitations in mechanical and self-healing performance. Herein, flexible and self-healing poly (2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA)/polyvinylimidazole (PVI)/LiCl polyelectrolyte is easily fabricated by a one-step copolymerization . The combined effect of electrostatic interaction and hydrogen bonding significantly enhances the mechanical and self-repairing ability of polyelectrolytes, showing excellent stretchability of 1137%, fracture stress of 154.57 kPa, and high healing efficiency of 91% at room temperature for 24 h. Besides, flexible electrode is prepared by adsorbing poly 3,4-ethylenedioxythiophene/polystyrene sulfonate on a polyurethane sponge. After assembly with a polyelectrolyte, the as-prepared supercapacitor proves excellent electrochemical performance. The area capacitance is 106 mF cm −2 at 50 mV s −1 and excellent cycle stability (97% capacity retention rate after 2000 cycles). In addition, the completely cut off supercapacitor can be successfully restored to 90% of the original capacitance, and still maintain a capacitance retention rate of up to 98% after 1000 cycles. This work provides a possible solution for designing low-cost intelligent and durable electrochemical storage device for smart clothing or electronic skin.