Lithium electrochemical systems

Properties of LiFePO4-based cathode material with additions of conducting polymer for Li–ion batteries

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.

Study of influence of structural parameters of cathode materials of \alpha -NaFeO2 type on electrochemical characteristics of positive electrode of lithium-ion battery

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.

Influence of additives of EMIBF4 and BMIBF4 ionic liquids on the properties of network polymer electrolytes for lithium power sources

The effect of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF4) ionic liquids on the properties of the polymer electrolyte based on polyethylene glycol diacrylate (PEG-DA) and LiBF4 salt was studied. Research was carried out by spray-mass spectroscopy, differential scanning calorimetry, and electrochemical impedance spectroscopy technique in the temperature range from -40 to 120 °C.

Modern power sources for cardioelectronics

Cell with electrochemical system «lithium – fluorinated carbon» intended for electrical pacemakers have been developed. Their significant advantages over traditional lithium – iodine cells for pacemakers are shown. Discharges characteristics, a shelf-life, and reliability, as well as an effect of various additives in fluorinated carbon cathode on discharge characteristics have been studied.

Effect of feedstock on the characteristics of cathodes fluorinated carbon

The electrode behavior of various fluorinated graphite materials and different conductive additives in various electrolytes are studied. Fluorocarbon materials based on graphite fibers are shown to have the best discharge characteristics. The advantage of thin cathodes based on fluorinated nanomaterials with a solid polymer electrolyte in comparison with the similar electrodes with traditional fluorocarbon active material is demonstrated. The use of fluorinated nanomaterials results in increased discharge characteristics of the cells.

The kinetic of lithium ions intercalation in the anatase synthesized by sol-gel methods

Possibility of ultradispersed TiO22 (anatase modification) using as the base of the lithium power sources cathode material obtained by chloride-acid hydrolysis of titanium tetrachloride has been studied. The researches of Li+ ions electrochemical intercalation kinetics and phasic model of the process was suggested. The cathode material phase composition changes during discharge were fixed and interpreted.

Electrodes of lithium-ion batteries: some simple method for diagnostics of degradation at cycling

It is shown that an examination of reduced galvanostatic charge-discharge curves allows making preliminary conclusion on degradation mechanism upon cycling. If such degradation is due to loss of active material all normalized curves coincide. In the case of insulating films building up normalized curves are shifted along potential axis. Various structure changes result in qualitative change of curves shape.

Improvement of electrochemical behavior of amorphous silicon via preliminary heat treatment

Thin-film amorphous silicon electrodes, subjected to various pretreatment have been tested in galvanostatic and potenciodynamic modes. Preliminary heat treatment of silicon electrodes in nitrogen atmosphere was established to lead to some decrease in discharge capacity and insignificant decrease in degradation upon cycling. Preliminary annealing of silicon electrodes in vacuum at 480°C results in increase of discharge capacity and some decrease of degradation upon cycling. Silicon electrodes with thickness about 1 micron annealed in vacuum have discharge capacity about 1200 mA·h/g.

Development of high-capacity lithium-ion battery asstmblies

This paper describes the state-of-the-art and areas of application for lithium-ion batteries. Their competitiveness in comparison with conventional alkaline and acid based batteries is shown. System approaches and circuit configurations used for designing high-capacity energy storage batteries with microprocessor battery managemmt systems (BMS) are considered, including the main functions of BMS. Based on the given examples, the modular design approach of batteries with 2-3 levels of control has been proved. A comparative analysis of different hardware schemes for voltage leveling in storage batteries is carried out.

The earth rare metall nature influence on electrochemical processes on MnO2-electrode in aprotic organic solutions

The influence of rare earth elements nature on Mn02 electrode electrochemical modification process in solutions of their salts in aprolic organic solvents was investigated. It was proved that periodicity of properties inherent in the lanthanides lakes place in the products of their interactions with MnO, and it is connected with characteristics of their structure. It was shown that the choice of metal as a modifying agent may be decisive in choosing the conditions of synthesis of cathode materials.