One‐step synthesis of nitrogen‐doped graphene powders and application of them as high‐performance symmetrical coin cell supercapacitors in different aqueous electrolyte

Summary In this study, symmetric supercapacitors in the form of coin cells were produced by using N‐doped graphene powders as electrode components. Nitrogen‐doped graphene powders were prepared by Yucel's Method with cyclic voltammetry at different potential ranges for selective modification of the powders with functional groups. Electrochemical, spectroscopic, and microscopic characterizations of N‐doped graphene powders were carried out. The formation of graphene layers was supported by scanning electron microscopy and Raman analysis. Functional groups formed on the surfaces of N‐doped graphene powders were determined by X‐ray photoelectron spectroscopy. Specific capacitances of symmetric supercapacitors prepared with N‐doped graphene powders were determined by cyclic charge‐discharge tests. The highest specific capacitance, energy and power values were determined as 235.3 F.g−1, 158.2 Wh.kg−1 and 1760 W.kg−1, respectively. Nitrogen‐doped graphene powders were prepared by Yucel's Method with cyclic voltammetry at different potential ranges for selective modification of the powders with functional groups. The powders were used for production of the electrode materials of symmetric supercapacitors. The highest specific capacitance, energy and power values were determined as 235.3 F.g−1, 158.2 Wh.kg−1 and 1760 W.kg−1, respectively.