conductivity

The methods for the synthesis of lithium iron phosphate LiFePO4 with olivine structure have been developed. New materials based on lithium iron phosphate, including doped with metals, the «LiFePO4 + carbon» composites obtained by pyrolysis of organic compounds have been synthesized. Crystallographic characterization of the synthesized materials was carried out; their electrochemical characteristics of the extraction and intercalation of lithium have been identified.

Properties of Dye Solar Cells with quasi solid electrolytes based on PEG have been investigated. The attempts to enhance the electrolyte conductivity was made with Li electrolyte introduction. 

The new composite material on the basis of polytitanates of potassium and the ionic conductor of iodide of silver with extremely high dielectric permeability is synthesized. Impedance and dielectric characteristics of the received material are investigated.

The possibility of using organic esters of phosphoric acid as a solvents for the electrolyte for lithium-ion systems and supercapacitors was investigated. Supercapacitors based on activated carbon Norit Supra and on the electrolyte being studied showed fine electrochemical performance which is comparable with standard electrolytes based on propylene carbonate. Lithium-ion batteries (Li4Ti5O12-LiNiO2 system) also showed a good performance.

In this work, the effect of humidity on the microstructural degradation of nickel-based metal– ceramic composite materials containing 0, 10, 20, 40, and 60 wt.% of cobalt in the metallic phase was investigated. The increase in cobalt concentration was found to have a beneficial effect on the stability of the microstructure and the long-term electrical conductivity, indicating the perspective of cobalt alloying as an approach to improve the performance and durability of SOFC anodes.

The electrochemical properties of a ceramic composite material in which a hollandite-like potassiumchromium titanate solid solution is presented as the main phase were studied using impedance spectroscopy. The dependences of the conductivity of the obtained composites on temperature in the range from 250 to 800°C were studied. The activation energies of volumetric, intergranular and grain volume conductivity were determined. The phase composition of the material and the crystallographic structures of individual phases were also established. 

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.

The electrochemical and electrophysical properties of basic and protonated potassium titanates in contact with the graphite electrodes were studied using the method of impedance spectroscopy. The characteristics of potassium titanates are given depending on the methods of modification and on the methods of their processing. The activation energies for some compositions were determined.

The new materials obtained in the potassium polytitanate (PPT)–MnSO₄ system by modifying PPT in aqueous solutions of manganese sulfate of various concentrations, followed by thermal treatment and annealing at 1080°C, were synthesized and studied. The phase composition of the obtained materials was determined. Their electrochemical and electrophysical properties in the temperature range from 250 to 700°C were studied.

The electrochemical and electrophysical properties of the protonated and modified with silver iodide potassium titanates, which can be applied in energy storage units, have been investigated by impedance spectroscopy. It has been shown that the dielectric losses at medium and high frequencies are weakly dependent on the polarizing voltage. It has also been established that transfer in modified potassium titanate can be made through potassium and silver ions.