Литиевые электрохимические системы

The study of the internal resistance of the lithium-ion battery designed and manufactured by JSC «Saturn» as the original, and after a long cycle life by pulse chronopotentiometry and electrochemical impedance was carried out. It is shown that the higher the hexagonal ordering of the material and the closer the degree of cation mixing to the optimal value, the less polarization resistance of the battery as original, and after a long cycle life. It was found that the less the original polarization resistance of the battery, the more its cyclic life.

УДК 544.65+621.355.9

DOI:  https://doi.org/10.18500/1608-4039-2016-16-1-3-9

The brief review of the processes arising in Li-ion cells in the cases of abuse is presented. The results of tests on overcharge, overdischarge, short circuit inside the cell and external short circuit for Li-ion cell having capacity of 150 A·h are shown and discussed. The recommendations to minimize the aftergrowths are suggested.

A pulse method at which a tested chemical power source is discharged by a pulse generated by constant current of special shape, and voltage on a cell is measured before and after pulse action has been developed to determine the degree of dicharge of chemical power sources. The degree of dicharge of a chemical power source is determined using a specially developed algorithm from the values of these voltages and other electrical parameters calculated.

The problem of use discharge and noise characteristic of primary power sources system of thionyl chloride/lithium for definition of their operative conditions (first of all, depth of discharge) is considered. On the basis of the analysis of features of discharge curves of Li/SOCl2 cells both bobbin and wound (rolled) type, and also intensity of voltage fluctuations and power-density spectrum of electrochemical noise of above mentioned cells it is drawn a conclusion on an opportunity of carrying out their correct diagnostics.

Multichannel instrument to study batteries and electrochemical cells during charge-discharge cycling, and open-circuit conditions is described. Each channel is a programmable potentiostat-galvanostat operating by an independent program. The accuracy of the stabilization current and potential is 0.01%. The additional sensors with analog output, such as temperature, can be plugged to each channel. The proposed hardware and software solution allows to control experiments, receive measurement data and remote administer the instrument via Ethernet.

In this study, the electrochemical behavior and properties of the novel LiFePO4-based composite cathode material with a water-soluble binder LA-133 and a conductive polymer PEDOT:PSS (poly-3,4-ethylenedioxythiophene: polystyrenesulfonate) as an aqueous dispersion were studied. Using the conductive polymer in combination with a water-soluble binder LA-133 allows to reduce the proportion of electrochemically inactive components (up to 10\%) and thus to increase its specific capacity for a given weight of the active material.

The relationship between the structural parameters of layered materials such as \alpha -NaFeO2 used as positive electrode materials of lithium-ion battery, and electrochemical characteristics were investigated. The dependence of charge transfer resistance on the ratio of cobalt to lithium mole fractions in layered oxides was studied.

It is shown that the performance of lithium-ion battery is significantly affected by the component structure of the electrodes, electrode fabrication technology, forming the battery mode. It is shown that in the production of lithium-ion batteries can be used the following materials: as a binder – polymer dispersion of water-based СНР 500, the negative electrode material – synthetic graphite 131181008–1 brands and 20130905.

Produced a new lithium power sources based on an electrochemical system Li/Ag₂O with a solid polymer electrolyte, investigated his discharge characteristics.