Водородная энергетика

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.

The phenomenological model of transition ``low-conductive phase – electrolytic phase'' in crystals with own structural disordering is offered. The application of this model allowed to describe the behavior of thermodynamical characteristics of such crystals in the transition area and to propose an expression for the baric dependence of transition temperature. Analytical expressions for thermocinetical coefficients and for correlation between electric and thermal conductivity of solid electrolyte are obtained.

A study of the solubility in the ternary systems NaBH₄–NaOH–H₂O, KBH₄–KOH–H₂O, NaOH–NaBO₂–H₂O и KOH–KBO₂–H₂O is of special fundamental and practical interest. The first two systems are used as a fuel and as a hydrogen source in hydrogen power engineering that includes the low-temperature fuel cells; borohydrides are converted into metaborates. Hence, the last two systems represent the discharged by-product.

The phase composition, conductivity and corrosion resistance under the Molten Carbonate Fuel Cell (MCFC) operating conditions of synthesized using common ceramic and cocrystallization techniques samples of LaLi_0.1Со_0.1Fe_0.8O_{3 – δ} have been studied. It was found, that the phase composition of synthesized by ceramic technique sample differed from the nominal composition.

In this work the main principles used in the development of portable power source based on fuel cells with indirect oxidation of sodium borohydride are described, the general arrangement of this power source is shown, and its operating mechanism is described. The proposed power source has a number of advantages over existing portable power sources. The application of alkaline fuel cells enables to discard expensive solid-polymer electrolyte, catalysts and constructional materials that will lead to significant decrease of the power source cost.

Melts based on lithium salts are applied in various branches of engineering and scientific research. This requires improved methods to search for low-melting compounds and data on phase equilibria in systems of three or more components. We developed computational and experimental method for determining the composition of ternary eutectic for inorganic systems, which is tested on twenty systems of lithium salts, as well as three-component systems containing lithium iodide.

By cyclic voltammetry in alkaline solution investigatied electrochemical and electrocatalytic properties of polymeric phthalocyanines and Macroheterocyclic compounds with cobalt. Influence of change of potentials in area from 0,5 to-1,4 B and speeds of scanning from 5 to 100 mV/s on cyclic I-E-curves and redox-transformations of catalysts is studied.

To increase the specific characteristics of the surface electrodes, used in the lead accumulators it is necessary to exclude the influence of the internal stress in the paste which is obtained by the electrochemical way. One of the variants of the solutions of this problem is the electrochemical obtaining the paste under the pressure directed to the surface of the forming paste.

The manufacturing techniques nickel oxide electrode with a basis from a nickelized carbon fibre are offered. Comparative research of electrochemical characteristics (specific electric capacity, the self-category) pre-production models with a control industrial sample an nickel oxide electrode with a ceramic-metal basis carried out. It is established, that application of a basis from a nickelized carbon fibre allows to reduce the charge of nickel and his alloys, to simplify manufacturing techniques of an electrode.