Electrochemical performance of polyacrylamide hydrogel based nitrogen-doped porous carbon for supercapacitor

Abstract

Nitrogen-doped porous carbon materials for supercapacitor was successfully fabricated from precursor of polyacrylamide gel through freeze drying, carbonization and KOH activation process. The precursor of polyacrylamide gel was prepared using acrylamide and N,N-methylene diacrylamide as monomers and cross-linking agents, respectively. The nitrogen-doped porous carbon was tested by field emission scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscopy, Raman spectrum, X-ray electron spectrum and specific surface analysis, respectively. Further, the electrochemical performance of nitrogen-doped porous carbon was tested by using a three-electrode system, which exhibited large specific capacitance of 302.1 F/g at 1 A/g, good rate property (71.8%, 217 F/g at 20 A/g) and cycle property (96% after 8000 cycles). Symmetrical supercapacitor was also assembled with an extended operating voltage window of 1.8 V in 1 M Na2SO4 electrolyte. More significantly, the nitrogen-doped porous carbon maintains an energy density of 23.27 Wh/kg in the case of a power density of 450 W/kg.