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The electrochemical properties of C/MnO₂ composite materials in 1 M sodium sulfate solution were investigated using the methods of cyclic voltammetry, galvanostatic charge-discharge and impedance spectroscopy. It was shown that the capacitive characteristics of the electrodes depend on the nature and the method of obtaining manganese oxide nanoparticles. It was established that the material containing manganese oxide obtained using isoamyl alcohol as a reducing agent has high electrochemical characteristics.

The results of the study of electrochemical dispersion of flake graphite in sulfuric acid were presented. It was shown that the highest dispersion efficiency was achieved while using large fractions of graphite with a particle size being more than 200 microns. The formation of the multilayer graphene oxide structures with the thickness of 0.1–1.0 microns and lateral dimensions up to 100 microns during anodic oxidation of graphite was established. The graphene structures were identified by the x-ray phase analysis and IR-Fourier spectroscopy.

The energy characteristics of prototypes of supercapacitors with carbon fabric electrodes Busofit T-040 were studied depending on the concentration of aqueous solutions of sulfate, sodium iodide and their mixtures without and in the presence of a corrosion inhibitor of the nickel collector – benzotriazole. It was found that the specific capacity of devices based on sodium iodide is almost two times higher than in the case using sulfate media. Close values of specific capacitance were obtained in devices based on mixed electrolytes.

The cyclic voltammetry was used to study the behavior of a symmetric supercapacitor with activated carbon cloth electrodes and a solution of an ionic liquid (C₈H₁₅N₂PF₆) in freon-22 as an electrolyte in the temperature range from  − 140 to  + 130°C. The measurements were carried out in a special autoclave. At temperatures above 90°C, the supercapacitor exhibits purely capacitive behavior, whereas at the temperature lowering, the influence of resistance strongly increases.

The electrochemical characteristics of the electrode material based on activated “NORIT B Test EUR” carbon in 1 M sodium sulfate solution were evaluated by cyclic voltammetry, galvanostatic charge-discharge curves, and impedance spectroscopy. It is established that this material has low resistance, and the specific capacity of the electrode was 45 F/g.

DOI: 10.18500/1608-4039-2015-15-4-160-166

Behavior of electrodes based on activated carbon P2 (Ener G2) wih additions of plain carbon black, as well as carbon black doped with silver nanoparticles have been studied. Depending on potential range and polarization direction the electrodes were found to reveal a capacitance close to double-layer or pseudocapacitance.

This work is dedicated to phosphoric acid esters working as solvents for lithium-ion and supercapacitor (SC) electrolyte. The electrical conductivity of electrolytes based on phosphoric acid esters, lithium salts, commonly used in lithium-ion batteries (LIB), and salts used in SC technology was measured. The thermodynamic stability of new electrolytes in comparison with other solvents used in chemical power sources technology was also estimated. It was shown that the thermodynamic stability of phosphoric acid ester increases in a homologous series.

This article show results of research work which focused on a new electrodes for symmetrical supercapacitor which made from electrochemically reduced graphene oxide films.

The recovery process illustrated by experimental recordings С-V curves. Was identified the dependence of the reduced graphene oxide specific capacity from rate of charge/discharge, for symmetric and unipolar working voltage range. Was identified supercapacitor power density when it was tested in cyclic charge-discharge duty of the potentiostat with different speeds.

A various features of the electrochemical behavior of number superfine carbon materials in electrolyte based on an ionic liquid 1-methyl-3-butilimidazolium tetrafluorineborate (1Me3BuImBF4) were determined by voltammetry and impedance methods. A comparative analysis of the effect of the type and nature of the electrolyte material on the main electrochemical characteristics of carbon electrodes which may be used in supercapacitors was done.

In this paper we investigate carbon materials prepared from different organic raw materials of vegetable nature by the method of pyrolysis. Properties of obtained carbon substances are established by the methods of impedance spectroscopy, voltamperometry, and chronoamperometry. Starting from the data of electron paramagnetic resonance, impedance spectroscopy and an analysis of the Regon diagrams it is concluded that the obtained carbon materials contain carbon nanostructures in the form of bungles of multiwall nanotubes. On the basis of the obtained vegetable-based carbon materials laboratory patterns of supercapacitors with an aqueous alkaline electrolyte were fabricated and investigated.