Flexible Supercapacitor Electrodes Based on Nitrogen-Doped Carbon Derived from Polyimide/Graphene

Nitrogen-doped carbon is a major class of high-performance electrode materials for the electrochemical supercapacitor. Herein, nitrogen-doped carbon was obtained by pyrolysis to graphene-grafted polyimide precursors on carbon cloth through in situ polymerization. The morphology, structure, and electrochemical properties of flexible electrodes were investigated in detail. Scanning electron microscopy (SEM) confirmed the preparation of nitrogen-doped carbon on carbon cloth. X-ray photoelectron spectroscopy (XPS) characterization showed the doping of the N heteroatom. Flexible electrodes obtained with the optimized mass graphene delivered high specific capacitance of 669 F g⁻¹ at 0.5 A g⁻¹ and good cycle stability, with retention of 122.3% capacitance after 6000 cycles in a three-electrode system. These typical flexible electrodes show great potential in wearable energy storage devices.