Электрохимические конденсаторы

The work presents a comparative cyclic voltammetry analysis of all-solid-state mock-up cells based on potassium polytitanate. Most measurements were carried out at 25°C. Potassium polytitanate sample with 10 wt.% of phosphotungstic acid was studied at 0°C, followed by the Arrhenius estimate of its characteristics at 25°C. The study focuses on comparing integral capacitive characteristics, response stability at different scan rates and charge storage mechanisms determined using the Dunn and Trasatti methods.

In this paper, we compare electrode composites based on Li3V2(PO4)3 and carbon according to their initial characteristics in the galvanostatic cycling mode and structural features. The composites were synthesized using carbon black or starch as carbon sources. The electrode material obtained using starch demonstrates a higher specific capacity, the stability of which is lower during cycling, while characterized by a smaller unit cell volume and a larger crystallite size.

A method for forming electrode structured microsystems based on titanium foil was developed. These microsystems can be used in electrochemical energy storage devices. The method includes a three-stage chemical treatment of the titanium foil surface: etching in concentrated HCl to create a microrelief, processing in the aqueous solution of KOH to form a layer of potassium polytitanate and the subsequent modification in the solution of manganese sulfate with the following heat treatment at 750°C.

A method for producing nitrogen-doped carbon nanotubes was tested. Polyaniline, chemically synthesized on the surface of nanotubes with subsequent carbonization, was used as a source of nitrogen. The electrochemical characteristics of the electrodes based on the obtained carbon material for the hybrid supercapacitors with the acidic electrolyte were studied. It was shown that nitrogen doping of carbon nanotubes increases the capacitive characteristics of the electrodes. 

The results of the study of electrochemical reduction of multilayer graphene oxide in galvanostatic and potentiostatic modes are presented, the possibility of using the alkaline electrolyte KOH with the concentration of 0.01 M is shown. The identification of electrochemically reduced graphene oxide was carried out by XRD analysis, IR and Raman spectroscopy.

Manganese oxide was obtained by cathodic electrochemical deposition from the electrolyte solutions adding sodium nitrate or sulfate. The structural characteristics and the elemental composition of the MnO2 samples were studied by energy dispersive microanalysis, IR spectroscopy, and transmission electron microscopy. The electrochemical characteristics of the electrodes were determined by cyclic voltammetry, galvanostatic charge-discharge and impedance spectroscopy in 0.5M Na2SO4 solution.

The review of modern scientific and technical literature on supercapacitors produced by industrial companies is presented. The advantages of supercapacitors compared to batteries are: high power density, high cycleability, the ability to operate at extreme temperatures from –50 to +60°C, energy efficiency up to 100% and the ability to charge in a very short time.

The electrical and chemical characteristics of nanocomposite materials based on carbon black for double-layer supercapacitors were investigated. It was shown that the highest values of the specific capacitive characteristics were obtained for carbon material SP4 which has the largest specific surface area (total capacity 228 F/g, reversible capacity 162 F/g).