The paper is devoted to the study of the behavior of capacitor type electrochemical system in the К+-containing aqueous electrolytes. Nanoporous carbon material (NCM) was used as the electrode material, obtained by carbonization of plant raw materials with the following chemical activation. Optimization of pore size distribution was carried out by chemical-thermal method using potassium hydroxide as activator. It is shown that obtained materials have high values of capacitance which is realized by charge storage on the electrical double layer and by pseudocapacitive ion storage on the surface of the material. It is established that based on NCM, electrochemical capacitors are stable in all range of current density and material capacity essentially depends on appropriate choice of electrolyte.

The paper is devoted to study the ultrasonic impact on the biomass of natural raw materials, which were used for the creation a nanoporous carbon material (NCM), which was used as electrode material for electrochemical capacitors (EC). The dry shells of apricot seeds were a feedstock, which were modified by the chemical treatment in the phosphoric acid and part of them were impacted by ultrasonic waves for 25 minutes. The NCM, which were obtained by carbonization at 550°C, were modified by chemical treatment in the nitric acid. Thus, the different of modification NCM was obtained to compare their capacitance characteristics for EC. From experimental data we can do a conclusion, that ultrasonic modification and chemical treatment in nitric acidare improvecapacitance characteristics of NCM for EC.

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In this work using sol-gel auto-combustion synthesis was synthesised single-phase magnesium-substituted lithium ferrite at different pH reaction medium. The synthesized materials were investigated by X-ray and Mossbauer methods. It was shown that the pH of the reaction medium plays a crucial role in the formation of the microstructure and properties of synthesized systems.

The ultrafine particles of magnesium-substituted lithium ferrites of the general formula were synthesized by a low-temperature gel-citrate auto-combustion method. The structural characteristics of the samples were obtained on the basis of X-ray diffraction (XRD) and SEM (emission electron spectroscopy) analyzes. XRD studies have confirmed the formation of a single-phase spinel structure with crystallite sizes around 15 - 30 nm. The M-H loop was recorded using an F-64 ferrometer for all formulations at room temperature and 50 Hz and the hysteresis parameters obtained. The hysteresis loop of the obtained samples showed a clear saturation at the applied field ± 60 E and by its very nature the loop is very symmetrical. Dielectric parameters such as dielectric steel, resistivity (s) and conductivity of samples () were investigated as a function of frequency in the range of 0.01 Hz to 100 kHz and in the temperature range 293 - 493 K using an impedance spectrometer. The dielectric constant of the samples revealed a normal frequency dependence of the dielectric, indicating that the dispersion is due to the polarization of the boundaries of the Maxwell-Wagner type grains and the jump of the electron between ions.