Водородная энергетика

Currently, a large number of studies on alkaline water electrolysis are being carried out with the aim of reducing the specific energy costs for the hydrogen evolution reaction and the oxygen evolution reaction. This work is devoted to the methods of synthesis of highly dispersed composite coating on the surface of nickel foam and the methods of the formation of bi- and ternary catalytic alloys based on molybdenum using electrochemical deposition.

The electrochemical activity of nickel mesh cathodes activated by electrocatalysts of chemically deposited coatings Ni-S-Fe is investigated. The maximum reduction of overvoltage at current density 6 kA/m² and temperature 70°C is 0.34 V. Comparison of the electrochemical activity of such cathodes with similar cathodes described in the scientific literature revealed that at the same temperature and same overvoltage the current density is twice higher than for the known electrodes.

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.

Mass-transfer processes are considered in a double-chamber running electrolyzer for the synthesis hydroxide of nickel (ІІ) from solution of NiSO₄. The product of Ni(ОН)₂ appears at co-operation of ions of Ni²⁺ the ions of ОН^-, which are generated on a cathode. The mathematical model of processes is formulated. Decisions show dependence of concentrations of ions in a reactionary area from the managed parameters of process and current.

With the help of the polarization curves method (E-lgI_a) there are investigated the anode processes at Co₂O₃ anode deposition together with the doping additives – nickel (NiO, Ni₂O₃) and chromium (Cr₂O₃) oxides at the electrolysis from the mixed sulfate solutions. The possible mechanisms of these processes interconnection with nucleation and crystal growth of binary oxide compounds of Co-Ni and Co-Cr and crystal structure formation of anode deposits are considered.

Results of field trials of the prototype energy installation system of navigational equipment (SNE) with computer control are presented. The energy installation SNE is based on friendly environmentally photovoltaic battery, rechargeable lead-acid battery and a new predictive controller.

Features of lithiated iron phosphate behavior (PH/P1, Phostech Lithium Inc, Canada) used as positive electrode of lithium-ion battery with LiPF₆-based electrolyte were investigated. It was shown that lihiated iron phosphate potential does not depend of lithium contents in active material. It was shown that cycle life of the positive electrode strongly depends on charge/discharge current. Fast degradation of the positive electrode takes place at low current rates (0.25 and 0.5C). At the same time degradation is considerably lower at 1 and 2.5C rates.

Corrosion behavior of niobium current leads of fluorocarbon-lithium cells are studied. Polarization measurements at plain niobium leads and at such leads in a contact with fluorocarbon cathode in an electrolyte of fluorocarbon-lithium cell were carried out. Besides, behavior of niobium lead directly in a feedthrough of real cells was studied. The contact of niobium with fluorocarbon cathode is shown to result in toughening of corrosion conditions and in possible niobium depassivation.