Водородная энергетика

The possibility of the use of impedance spectroscopy using an impulse method of step current change and recording voltage change in during time at the terminals of a cell with subsequent Fourier transform of the input signal and the response to it to assess the current state of Li-cell. It is proposed use of current pre-impulse in order to minimize the influence of passive film. It is substantiated an algorithm based on the measurements of impedance phase for determining of residual capacity.

The complex oxides Li_{1 + x}Ni_{1 / 3}Co_{1 / 3}Mn_{1 / 3}O₂ were obtained by solid state method. The conclusion about influence of lithium concentration on Ni²⁺ and Ni³⁺ ions ratio in Li_{1 + x}Ni_{1 / 3}Co_{1 / 3}Mn_{1 / 3}O₂ is made. Monotonous decrease of g-factor value identified by EPR method testifies the intensification of local exchange interactions with temperature descent.

Lithium ions intercalation into the laser-exposed nanodisperse ТiO₂ had been analyzed and its research results are given. The modes of laser treatment, when the degree of the ``quest'' load and, accordingly, specific energy capacity of the proper electrochemical current sources achieves a maximum, are experimentally set. Thermodynamical pecularities of current forming and lithium ions intrusion into the cathode material are set. Electrochemical source discharge capability analyzed in scope of laser-exposed ТiO₂ using.

Concentrated water-alkaline mixtures of sodium and potassium borohydrides and borates are used as fuel and a hydrogen source in hydrogen power engineering, including low-temperature fuel cells. The performance of such mixtures is determined by their physicochemical properties. An algorithm to calculate the density, viscosity, and specific electric conductivity of mixed solutions of the five-component water + salt system (Na,K)BH₄ + (Na,K)BO₂ + (Na,K)OH + H₂O based on the quasiadditivity of these properties is proposed.

The development of nickel-cadmium batteries with high energy capacious electrodes is described. Selection and development of technology of manufacturing nickel-oxide electrodes based on nickel-plated carbon and graphite felt materials are considered. Discharge characteristics of the electrodes are analysed.

The results of protons diffusion mathematical modeling in the crystalline lattice of NiOOH/ Ni(OH)₂ are caparisoned with data of experiments on thin (100 μm) porous electrodes. The criterion of nickel hydroxide activity is offered as product of proton diffusion coefficient in the crystalline lattice of NiOOH on the square of specific surface area. It was founded existence of protons migration mechanism in a crystalline lattice under action electric field.

Comparative results of capacity renewal of sealed nickel-cadmium batteries with asymmetric and direct currents after their long-term storage are represented. Capacity renewal with asymmetric current was carried out in an accelerated manner at average value of the charging current equal to 0,25C_rated. Capacity renewal with direct current was carried out at average value of the charging current equal to 0,1C_rated in accordance with Technical Conditions.

The results of nickel cadmium accumulators (NCA) formation with the asymmetric and constant currents are represented. Accumulators formation with the asymmetric current allowed to reduce one-half the time of technological cycle of placing these accumulators in service, comparing with the constant current mode, with maintenance of their operational characteristics. Comparative characteristics of NCA operational parameters are given.

The research results of the sealed lead-acid (SLA) batteries of domestic and foreign production are considered. The effect of temperature on the SLA batteries operational performances was investigated. The relationship between the open-curcuit voltage (OCV) and the SLA battery stage-of-charge as well as the relationship between the open-curcuit voltage (OCV) and the battery impedance were determined. The high accuracy of the stage-of-charge diagnosis method based on the battery OCV measuring was proven.

This article is dedicated to the investigation of sulfatation process of negative active mass. The authors showed a dependence of sulfatation degree of lead electrode from time of keeping in discharged station. It was studied the influence of addition of ammonium sulfate on desulfatation process.