Enhanced electrochemical performance of carbon quantum dots-polyaniline hybrid

Abstract

Abstract Carbon quantum dots-polyaniline (CQDs-PANI) hybrid was developed as supercapacitor electorde material by incorporating CQDs into PANI. PANI nanowires were grown vertically on carbon fiber substrate to form an interconnected network structure. Meanwhile, CQDs were uniformly distributed in the interior and on the surface of well-established net-like PANI nanowires. High specific capacitance of 738.3 F g−1 at 1.0 A g−1 was obtained for CQDs-PANI compared to that of 432.5 F g−1 for pure PANI. The capacitance retention after 1000 cycles of CQDs-PANI and PANI is 78.0% and 68.0% at 5.0 A g−1, respectively. The high capacitance and reasonable cycle stability were ascribed to the incorporation of CQDs into PANI, which improved the conductivity and alleviated the volume change of the CQDs-PANI electrode during the charge/discharge process. In addition, a flexible solid-state CQDs-PANI supercapacitor was constructed using carbon paper as current collector and polyvinyl alcohol gel electrolyte, exhibiting the stable capacitive performance at planar and bending state. The specific capacitance, energy and power density were determined to be 169.2 mF cm−2, 33.8 μWh cm−2 and 0.3 mW cm−2 at a potential window of 1.2 V and a current density of 1.0 mA cm−2. CQDs-PANI presented the promising application in flexible energy-related device.