Nanostructured polypyrrole nanowires/nitrogen-functionalized graphene composites for supercapacitor electrode

The well-defined polypyrrole (PPy) nanowires are successfully grown on the nitrogen-functionalized graphene (NFG) nanosheets by electrochemical polymerization method (PPy/NFG). The synthesized PPy/NFG composites as supercapacitor electrodes present specific capacitance of 1058 and 910 F g-1 at 0.5 and 10 A g-1, far higher than pristine PPy (309 and 160 F g-1) and NFG (265 and 186 F g-1) electrodes, respectively. Particularly, symmetric supercapacitor device assembled with two PPy10/NFG electrodes delivered 601 F g-1 and 480 F g-1 specific capacitance at 0.5 A g-1 and 20 A g-1, good cycling stability (retaining over 85 % capacitance after 10,000 cycles), large energy density (83.5 Wh kg-1 at 0.5 A g-1). These results indicated the PPy/NFG composites have promising application in supercapacitors.