In this work, the perovskite LaMnO3 material has been prepared based on the sol-gel process of synthesis with the participation of combustion. According to the X-ray phase analysis, it was determined that the obtained material consists of LaMnO3 one phase (space group Pm-3m). Nevertheless, it has been determined that the average size of the coherent scattering region of the obtained material is about 24 nm. Moreover, the average particle size is 40-60 nm in case the approximation that the particles are spherical shape. Thus, it has been determined that the specific surface area of the material is 42.1 m2/g. The electrochemical investigations have been performed using nanosized LaMnO3 powder as a cathode material for electrochemical capacitors. The LaMnO3 material under research showed a specific capacity of 40 F/g at a discharge of up to 1V.

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In this work, the morphology of carbon material (CM) has been researched by the nitrogen adsorption/ desorption method. Furthermore, it was determined that the specific surface area is about 1200-1300 m 2 /g. NiWO4 was synthesized by co-precipitation method, and its structure was investigated by XRD. Additionally, the electrochemical properties of CM and NiWO4 were studied by the methods of chronoamperometry and voltammetry, and the use of these materials as electrodes of hybrid supercapacitors (HSC) -anode and cathode, respectively, was tested. A hybrid electrochemical system of the CM/KOH/NiWO4 type was formed. The use of this system makes it possible to increase the operating voltage range of HSC based on aqueous electrolytes from 0-1 V to 0.6-1.6 V, and, consequently, to increase the energy characteristics of a unit cell by more than 2 times. It is shown that at operating currents of 1 mA, the specific capacity of the HSC is 57.1 F/g, while the specific energy density and power are 7.09 Wh/kg and 1.39 W/kg, respectively.