Щелочные аккумуляторы

УДК 541.136

DOI: https://doi.org/10.18500/1608-4039-2016-16-2-62-76

The work is devoted to the development of methods for input and current monitoring of the active mass components of electrophoretic cadmium electrodes in order to improve the stability of the discharge characteristics of nickel-cadmium batteries of the NKM series.

The use of heat of low-temperature sources dissipated into the environment for the production of useful energy is an urgent scientific and technical task. The article discusses the electrochemical principle of collecting the heat of low potential sources (temperature less than 100°C) and converting it into electricity using a thermoelectrochemical cell based on complex salts of potassium ferri/ferrocyanide redox electrolyte. The efficiency of converting low-grade heat into useful energy in the studied cell type largely depends on the electrolyte concentration.

It is experimentally established that the use of Ni-Zn batteries as positive oxide-Ni electrodes of metal-cell electrodes on porous polymer bases leads to a significant decrease in their capacity. Reduce zincate poisoning of positive electrodes of this type is possible with the introduction of cobalt hydroxide into the active substance. Various methods of introducing an activating additive into the active mass of the electrode have been studied.

The paper presents the results of the study of phase composition and electrochemical performance of lithium-manganese oxide spinel with excess lithium of nominal composition of Li_{1 + x}Mn₂O₄ obtained by solid-phase method. It was established that samples with x = 0.1 and 0.2 were composite materials with LiMn₂O₄ being the basic phase and Li₂MnO₃ being the impurity (3 and 7 mas.%, respectively) also comprising trace amounts of MnO₂.

This paper is the conclusion to the series of the articles devoted to the problem of accelerated charging of a lead-acid battery. In this paper we investigated the possibility of increasing the charge efficiency by applying the asymmetric current at the second stage. In addition, the effect of using admissible charging rates on the resource, the admissible number of consecutive cycles, and gas release were studied.

The energetic properties of the new composite electrode materials suitable for electrochemical capacitors were investigated. Composite electrodes were made using Norit A activated carbon and synthesized sparingly soluble copper salts such as copper iodide(I) and hexacyanoferrates (II), etc. (III). The composition of the salts was confirmed by elemental analysis and the particle size was determined by the Scherrer equation using the data of X­-ray phase analysis.

The current situation in technology and developments in the field of polymer binders for composite electrodes of lithium electrochemical systems are discussed. A wide range of synthetic and natural polymers used for this purpose is considered. Emphasis is placed on commercially available materials, which form aqueous solutions or dispersions. The advantages of multifunctional polymer binders are demonstrated.

The paper considers the most significant properties of moulding solutions based on a mixture of polyvinylidene fluoride and polystyrene for the process of capillary-free electrospinning nonwoven materials. It has been shown that the material obtained from the mixed solution of polyvinylidene fluoride and polystyrene in the ratio of components 0.75 : 0.25 is the largest porous, the diameter of the fibers is in the widest range from 0.14 to 2.8 ?m, and branching of the fibers is observed.

The methodological issues of noise research in electrochemical systems are considered. The problem of reducing the spread of statistical estimation of the noise signal is solved. The study was conducted using specific stationary noises of a lithium battery. The analysis was performed using the two-sample dispersion method. It is shown that if the stationary conditions are met, noise measurements of electrochemical systems can provide the quality of results of high precision.

The effect of cathodic polarization on the rate of hydrogen sorption from an aqueous organic electrolyte on an Al-Sm alloy using the potentiostatic and potentiodynamic methods were studied. The obtained data allowed us to calculate the diffusion-kinetic characteristics of this process, such as the interstitial constant, diffusion constant $C_{\text{Н}}\!\!\sqrt{D}$, constant current iconst, diffusion coefficient D and adsorption of hydrogen atoms G. The number of nuclei decreases, but their mass and radius increase in the potential range from –2.0 V to –2.4 V.