PROSPECTS OF USING GRAPHENE-LIKE NANOSTRUCTURES IN SUPERCAPACITORS.

The present paper describes the prospects of using various graphene-like nanostructures as supercapacitor electrode materials. The studies were conducted in two stages. At the first stage, comparative potentiometric tests were performed with pristine (nonmodified) and polyaniline-modified graphene-based nanomaterials and activated carbon (as reference electrode material) in the inorganic electrolyte - 30 % H₂SO₄. The specific capacitance of the pristine nanostructure was 1.5-1.9 times higher than that of the other materials. At the second stage, the effect of the morphology of samples of this nonmodified material (activated under different conditions: time 2 and 3.5 h, and temperature 700, 750 and 800 °C) on the electrical characteristics of the supercapacitor was investigated in the aqueous and organic electrolytes using cyclic voltammetry and impedancemetry. In the organic electrolyte - 1 M tetraethylammonium tetrafluoroborate in acetonitrile, strong distortions of the cyclic current-voltage parameters were revealed when increasing the potential scan rate, which may be related to transport restrictions imposed on large organic ions. At the same time, in the aqueous electrolyte, the increase in the scan rate did not lead to any distortions, thereby implying effective ion transfer. However, additional testing of the electrode complex impedance confirmed the operational efficiency of the nanomaterials for intensive charge/discharge cycles in the organic electrolyte. Thus, establishing the possibility of adaptation of the morphological structure of the graphene-based nanomaterials for various electrolyte types to ensure the successful selection of an electrolyte for a corresponding graphene-based electrode was the most important result of these studies. [ABSTRACT FROM AUTHOR]