prepared via Hummer's method, and the composite of NCNS with carbon black (NCNS-CB) electrodes studied under the same experimental conditions. The specific capacitances of N-Gr, CB and NCNS-CB electrodes were found to be 136 F g -1 , 184 F g -1 , and 358 F g -1 , respectively at 0.5 A g -1 . The NCNS-CB electrode exhibited the maximum specific capacitance value among all other fabricated electrodes. Further, solid-state supercapacitor electrode was fabricated using poly(hydroxyethyl methacrylate-co-trimethylolpropane allyl ether) gel polymer electrolyte, and the corresponding active material was kept at 4 mg cm -2 to study its supercapacitive performance. The geometric area normalized capacitance measured for the solid-state supercapacitor electrode were found to be 300 mF cm -2 , at the current density of 0.25 mA cm -2 . The NCNS-CB composite electrode with the thickness of 0.099 mm of active material showed the volummetric capacitance of 303 F cm -3 , and the energy density calculated per unit volume of the fabricated device was 0.27 mW h cm -3 , and the power density of the device was found as 1.35 mW cm -3 .