Carbon-Quantum-Dots-Anchored Poly(aniline-co-indole) Composite Electrodes for High-Performance Supercapacitor Applications

Supercapacitors have attracted extensive consideration due to their high power density and long cyclability. However, safety and flexibility have become tasks encountered by supercapacitors with the further increase in their demand. Herein, we report a carbon-quantum-dots-anchored poly(aniline-co-indole) (PAPI@CQDs) composite thin film fabricated by the hybrid electrospray deposition method. It was found that the PAPI@CQDs composite film showed outstanding electrochemical performance with the highest specific capacity (Cs) of 185.1 C/g at 2 A/g with an excellent cyclability of 79.4% at 20 A/g after 10000 consecutive charge–discharge cycles. Finally, the proposed electrode can be used to fabricate a hybrid solid-state supercapacitor (PAPI@CQDs//rGO, where rGO = reduced graphene oxide). The fabricated PAPI@CQDs//rGO asymmetric supercapacitor (ASC) device showed the highest specific capacity of 84.2 C/g at 1 A/g with an ultrahigh energy and a power density of 26.22 Wh/kg and 1125 W/kg, respectively. The solid-state PAPI@CQDs//rGO ASC device sustains outstanding cyclability, with a retention of 72.3% after 5000 cycles at 20 A/g. This study offers an effective tactic to attain conducting polymer-based composite electrodes for supercapacitors and extend their application in the field of flexible electronics.