A pretreated-carbon cloth/polypyrrole/rGO electrode material with enhanced hydrophilicity and low impedance for flexible quasi-solid supercapacitors

The hydrophilicity of carbon cloth was improved through pretreatment using an oxidation process resulting in activated carbon cloth with microscopically pronounced grooved cracks. This activated carbon cloth served as a highly hydrophilic substrate suitable for electrode material loading while also possessing attractive electrochemical properties. Polypyrrole/reduced graphene oxide (PPy/rGO) composites were subsequently polymerized and chemically reduced in situ on the pretreated carbon cloth (HCC), introducing nitrogen atoms of different valences into the composite. Contact angle and electrochemical tests demonstrate that the prepared electrode material displayed enhanced hydrophilicity and low impedance. Based on HCC/PPy/rGO, the symmetrical flexible quasi-solid supercapacitor exhibited a high energy density of 0.60 mWh cm −3 at a power density of 6.25 mW cm −3 , as well as a great power density of 62.5 mW cm −3 at 0.34 mWh cm −3 and good flexibility. Moreover, three fabricated supercapacitor devices connected in series illuminated a white LED for about 4 min, demonstrating the potential use of pretreated-carbon cloth/polypyrrole/rGO materials for flexible wearable devices.