High energy density flexible Zn-ion hybrid supercapacitors with conductive cotton fabric constructed by rGO/CNT/PPy nanocomposite.

Fiber-shaped energy-storage devices for high energy and power density are crucial to power wearable electronics. In this work, reduced graphene oxide/carbon nanotubes/polypyrrole (GCP-op) cotton fabric with the optimal performance is prepared via a facile and cost-effective dipping-drying together with chemical polymerization approach. The structural characterizations confirm that the GCP-op cotton fabric has been successfully attached with numerous nanoparticles and carbon nanotubes, which can serve as a channel for electronical transfer. And GCP-op cotton fabric electrode displays admirable areal specific capacitance with 8397 mF cm-2 at 1 mA cm-2. By combining GCP-op cathode with zinc anode, a GCP-op//PAM/ZnCl2//Zn flexible Zn-ion hybrid supercapacitor (FZHSC) is produced with 2 M polyacrylamide/ZnCl2 (PAM/ZnCl2) hydrogel as the gel electrolyte. The FZHSC has superior cycle stability of 88.2 %, outstanding energy density of up to 158 μWh cm-2 and power density at 0.5 mW cm-2. The remarkable performance proves that PPy-based material can provide more options for design and fabricate high energy flexible Zn-ion hybrid supercapacitors.