Özet:

Nickel hydroxide is widely used as an active material for hybrid supercapacitors. The most electrochemically active is a-Ni(OH)2, synthesized using template homogeneous precipitation. In order to achieve maximum characteristics, it was necessary to study the influence of the template concentration on structural, surface and electrochemical properties of Ni(OH)2 samples. For this purpose, Ni(OH)2 samples were prepared using template homogeneous precipitation, with Culminal C8564 (template) concentrations of 0 %, 0.5 %, 1 %, 2 %, 3 % and 4 %. Structural properties of the samples were studied by means of X-ray diffraction analysis, size and particle morphology – by means of Scanning Electron Microscopy, the electrochemical characteristic – galvanostatic charge-discharge cycling in the supercapacitor regime. It has been demonstrated that an increase of the template concentration to 0.2 % leads to a decrease of crystallinity and particle size. However, a further decrease of concentration leads to increase of crystallinity and aggregation of nickel hydroxide particles. The influence of the template concentration on the electrochemical properties is different for different concentration ranges. At low template concentrations (below 0.2 %), the specific capacity of the samples is almost independent of cycling current density. The optimal concentration for this range is 0.1 %, with the maximum specific capacity of 499 F/g. Nickel hydroxide prepared with 0.1 % of Culminal C8564, is recommended for use at low and medium current densities (below 80 mA/cm2). At high template concentrations (0.3–0.5 %), the specific capacity increases significantly with an increase of current density. The optimal concentration for the ranges was 0.4 %, with the maximum specific capacity of 525 F/g. Nickel hydroxide samples prepared with 0.4 % of Culminal C8564, is recommended for use in high-speed supercapacitors with high discharge current densities (120 mA/cm2 and above). Author Biographies Vadym Kovalenko, Ukrainian State University of Chemical Technology Gagarina ave., 8, Dnipro, Ukraine, 49005 Federal State Educational Institution of Higher Education "Vyatka State University" Moskovskaya str., 36, Kirov, Russian Federation, 610000 PhD, Associate Professor Department of Analytical Chemistry and Food Additives and Cosmetics Department of Technologies of Inorganic Substances and Electrochemical Manufacturing

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