Starchuk Y. Synthesis, structure, physical and electrochemical properties of NiWO4/C nanocomposite.

The result of the dissertation work is the establishment of regularities of influence of synthesis and modification of materials on their structural-morphological, physical and specific electrochemical characteristics.Object of research: the influence of the conditions of obtaining and modification of nickel tungstate, carbon materials and their composites on the specific electrochemical characteristics of electrical energy storage devices.Purpose of the research: to establish the regularities of the influence of synthesis and modification of materials on their structural-morphological, physical and specific electrochemical characteristics.Description of methodology / research methods. To achieve the goal of the tasks, complementary and mutually controlling methods were used, namely: X-ray analysis, Low-temperature adsorption porometry, Impedance spectroscopy, Raman spectroscopy, Potentiodynamic and galvanostatic methods, Methods of mathematical processing of experimental results.Special tools and equipment: DRON-3 diffractometer, Expert 3L X-ray fluorescence spectrometer, Horiba Jobin-Yvon T64000 Raman spectrometer, Autolab PGSTAT impedance spectrometer, Quantachrome Nova 2200e sorbometer.Software that was used during the processing of the obtained data or for conducting research: Match, Quantachrome NovaWin 11.0., FRA2, ZView-2, OriginPro 2018, MS Excel 2016,Theoretical and practical results: electrode materials used in electrical energy storage and generation devices were obtained. The research results show the prospects of using the obtained materials in such devices.Novelty: Proposed methods of synthesis and optimal conditions for modification of NiWO4, under which the material demonstrates the highest specific energy characteristics. A method of obtaining and multiple chemical activation of nanoporous carbon material is also proposed. It was established that multiple chemical activation increases the capacity of the carbon material by twice and reduces its specific resistance. The optimal conditions and modes of laser, thermal and thermochemical modification of the obtained materials in terms of their electrochemical properties were established. Nanocomposites NiWO4/C were formed and the influence of the percentage contribution of porous carbon material on their electrochemical properties was determined. The quantitative ratio between the contributions of Electric Double Layer and Faradaic capacitance in hybrid supercapacitors was also established.Effectiveness of implementation: the obtained materials have the prospect of used in devices for generation and storage of electrical energy.Field of application: energy, electronics, materials science.