Lithium-ion capacitor with carbon-based electrodes

The present article considers work principle of lithium-ion capacitor (LIC) and methods of negative electrode pre-lithiation. The effect of application of different active materials of positive and negative electrodes, electrolyte and separator on the specific power and energy of LiC is shown.

Comparison of traditional organic solvents with phosphoric acid esters in lithium-ion and supercapacitor technologies

This work is dedicated to phosphoric acid esters working as solvents for lithium-ion and supercapacitor (SC) electrolyte. The electrical conductivity of electrolytes based on phosphoric acid esters, lithium salts, commonly used in lithium-ion batteries (LIB), and salts used in SC technology was measured. The thermodynamic stability of new electrolytes in comparison with other solvents used in chemical power sources technology was also estimated. It was shown that the thermodynamic stability of phosphoric acid ester increases in a homologous series.

Conductivity and permittivity of potassium polytitanate, modified ferrous (III) sulphate

In the temperature range from 25 to 100 °C, the behavior of the conductivity and the electrical characteristics of potassium polytitanate modified iron sulfate at a pH modifying solution from 2.0 to 9.0. The temperature dependence of ac-conductivity, permittivity, conductivity activation energy evaluated.

Impedance spectroscopy potassium polytitanate, modified sulfate cobalt (II). High temperatures

The behavior of the conductivity and of electrophysical characteristics of potassium polytitanate modified by cobalt (II) sulphate was investigated under the temperature from 100 to 800 °C. The temperature dependence of AC and DC-conductivity was found, activation energy was appreciated in the low and high temperature phases. A equivalent circuit describing the transport processes in the studied composite based on potassium polytitanate was proposed.-

Supercapacitor based on electrochemically reduced graphene oxide

This article show results of research work which focused on a new electrodes for symmetrical supercapacitor which made from electrochemically reduced graphene oxide films.

The recovery process illustrated by experimental recordings С-V curves. Was identified the dependence of the reduced graphene oxide specific capacity from rate of charge/discharge, for symmetric and unipolar working voltage range. Was identified supercapacitor power density when it was tested in cyclic charge-discharge duty of the potentiostat with different speeds.

The nature conductivity in the amorphous potassium polytitanate

The work is devoted to investigation of the anisotropy of conductivity and determination of the most likely charge carriers in the amorphous polytitanate potassium. Defined ac – and dc-conductivity, dielectric permittivity, dielectric loss tangent in mutually perpendicular directions compacted potassium polytitanate.
An increase in the shift of the peak and the dielectric loss tangent in a frequency region when measured along the preferred direction location lamellae potassium polytitanate.

Electrochemical behavior of superfine carbon in electrolytes based on ionic liquid 1-methyl-3-butylimidazol tetrafluorborate

A various features of the electrochemical behavior of number superfine carbon materials in electrolyte based on an ionic liquid 1-methyl-3-butilimidazolium tetrafluorineborate (1Me3BuImBF4) were determined by voltammetry and impedance methods. A comparative analysis of the effect of the type and nature of the electrolyte material on the main electrochemical characteristics of carbon electrodes which may be used in supercapacitors was done.

Impedance spectroscopy of potassium polytitanate modified with cobalt salts

The new composite materials based on potassium polytitanate modified in the Co salt aqueous solutions were synthesized and characterized. On the bases of impedance research the high dielectric permittivity and ionic conductivity were reviled.

Impedance spectroscopy of polymer composites based on base potassium polytitanate

Work is devoted to the study of electrochemical and dielectric properties of the base potassium polytitanate and polymer composite based on it. The temperature dependence of ac-conductivity, permittivity, dielectric loss tangent. An increase in the dielectric constant of the composite with respect to the values of the dielectric constant of the base potassium polytitanate. The values of the dc-conductivity.

Electrochemical properties of activated carbon in alkaline electrolyte

We have studied the capacitance and kinetic properties of nanoporous carbon material which was obtained from wood. The maximum radius pore distribution of the investigated material was 1.37 nm. The data from X-ray scattering and electrochemical impedance spectroscopy was used to investigate the influence of porous structure change and electronic structure of activated carbon material on the mechanism and kinetics of charge-discharge at 7.6m KOH solution. It was proved that depending on the electrode potential and chemical potentials of electrolyte ions there are two different mechanisms of the charge of the porous structure of investigated material. The first mechanism is a process of electrostatic adsorption of hydrated electrolyte ions, and the second is a process electrosorption of H+ or OH. It was shown the cycle of charge-discharge capacity of 95 F/g can be made for two seconds and this is half of the maximum capacity of the material under study.