Abstract
Carbon cloth (CC), a promising current collector with low weight and excellent robust mechanical property, has attracted increasing attention as the anode for supercapacitors recently. In this study, we show a novel two-prong strategy to remarkably enhance its capacitance via electrochemical activation and polypyrrole (PPy) deposition. The facile activation process created more active sites and induced oxygen-containing groups while the PPy layer provided extra capacitance contribution. Such strategy significantly boosted the capacitive property: The obtained PPy/ACC exhibited a high specific capacitance of ∼3.184 F cm−2 which is about 2.75 times the original CC within the potential window of −1.0–0 V in 1 M KOH electrolyte. A symmetric supercapacitor with the PPy/ACC as both the cathode and anode showed a high stable working voltage up to 1.8 V and a maximum energy density of 3.62 mWh cm−3 at 1.4 V. Moreover, an asymmetric supercapacitor employing it and Ni–Bi–S/Ni delivered an even higher energy density of 5.81 mWh cm−3.
•The capacitance of CC is significantly enhanced via a simple electrochemical process.•PPy layer contributes extra capacitance without sacrificing the capacitance of the CC.•SSCs based on PPy/ACC show high working voltage in 1 M KOH electrolyte.