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The energetic properties of the new composite electrode materials suitable for electrochemical capacitors were investigated. Composite electrodes were made using Norit A activated carbon and synthesized sparingly soluble copper salts such as copper iodide(I) and hexacyanoferrates (II), etc. (III). The composition of the salts was confirmed by elemental analysis and the particle size was determined by the Scherrer equation using the data of X­-ray phase analysis.

It is experimentally established that the use of Ni-Zn batteries as positive oxide-Ni electrodes of metal-cell electrodes on porous polymer bases leads to a significant decrease in their capacity. Reduce zincate poisoning of positive electrodes of this type is possible with the introduction of cobalt hydroxide into the active substance. Various methods of introducing an activating additive into the active mass of the electrode have been studied.

DOI: https://doi.org/10.18500/1608-4039-2017-17-1-9-18

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.

For nickel-cadmium batteries of stationary application, a global empiric correlation C(i) describing the dependency of released capacitance by the batteries at different discharge currents was suggested, which is true for batteries of any capacitance and any mode of discharge (H, M, L). The global correlation C(i) can be described by generalized Peukert's equation, Korovin-Skundin's equation, probability integral, and porous electrode equation with accuracy sufficient for practical application. This correlation is most easily described by the generalized Peukert's equation C=Cm/(1+(i/IC/2)3.6).

In the current paper electrospun nanofiber mats were derived from polyacrylonitrile (PAN). The temperature influence on the volumetric and surface composition of the resulting pyropolymers was studied by means of elemental analysis and X-ray photoelectron spectroscopy. Rotating disc electrode (RDE) and rotating ring disc electrode (RRDE) methods were used to determine the catalytic properties of PAN pyropolymers, derived at carbonization temperature interval of 600–1200°C, as well as composite PAN/support catalysts, carbonized at 900°C, in the oxygen reduction reaction in H₂SO₄ и KOH solutions. The methods of cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic polarization were utilized to characterize the charge capacitive properties. An equivalent scheme modeling the electrochemical response of PAN pyropolymer in H₂SO₄ solution was proposed. An assumption was made of interrelation between the PAN-T catalytic activity and the occurrence of condensed parquet aromatic structure comprising of nitrogen-carbon bonds. Evidence was given that Fe atoms play the key role in the synthesis of active non-precious catalysts with high selectivity towards the 4-electron O₂ reduction. The possibility of the catalysts synthesis for 2-electron ORR without the use of metal precursors was evidently shown. Prominent correlation of capacitive and catalytic properties for these materials was observed in H₂SO₄ solution. The optimal PAN pyropolymers synthesis temperature was determined to be in the range of 750–950°C. The mats of PAN-T were shown to be feasible as the negative electrodes of supercapacitors.