Carbon electrodes with high pseudocapacitance for supercapacitors
Electrochemical properties of electrodes on the basis of CH900-20 activated carbon
(AC) cloth were studied in concentrated H 2 SO 4 solutions in a wide range of potentials
from− 0.8 to+ 1 V RHE. Cyclic voltammetric curves measured in two ranges of potentials
were analyzed: in the reversibility range (from 0.1 to 0.9 V) and in the deep cathodic
charging range (from− 0.8 to 1 V). Electric double layer (EDL) charging occurs in the
reversibility range, while faradaic processes of hydrogen chemisorption and its ...
Electrochemical behavior of electrodes on the basis of CH900-20 activated carbon (AC) cloth has been studied in concentrated sulfuric acid solution. Cyclic voltammetric curves have been studied in the reversibility range (from 0.1 to 0.9 V RHE) and in the deep cathodic charging potential range (from –0.8 to 1 V RHE). It has been shown that electric double layer (EDL) charging occurs in the reversibility range, while faradaic processes of hydrogen intercalation into AC carbon take place in the range of negative potentials (←0.1 V). The intercalation process is governed by slow solid-phase hydrogen diffusion. The specific charge value grows at an increase in concentrated sulfuric acid solution. The mechanism of double intercalation of sulfuric acid and hydrogen into the AC material is suggested. On the basis of the reached specific discharge capacitance of 1,560 C/g (or 1,110 F/g) and Faraday's law, it has been concluded that the compound of C6H is formed in the limiting case of deepest cathodic charging. The obtained data have been used in a mathematical charge–discharge model for an AC electrode taking into account the EDL charging and the hydrogen intercalation. The galvanostatic recharge curves have been calculated in the diapason of currents by the developed model.
Investigated the effect of annealing on the optical properties of metallic films obtained by setting the plasma-focus "PF-4" on glass substrates. The transmission spectra of these films before and after annealing in air at about 900 K for about 10 minutes. Shows the effect of carbon on the optical properties and electrical conductivity of the films.
Formation of carbon nanoparticles is an important type of complex non-equilibrium processes that require precise atomistic theoretical understanding. In this work, we consider the process of ultrafast cooling of pure carbon gas that results in nucleation of an onion-like fullerene. The model is based on molecular dynamics simulation with the interaction between carbon atoms described via a reactive ReaxFF model. We study the consecutive stages of fullerene-like nanoparticle formation and identify the corresponding temperature ranges. Analysis of hybridization and graphitization reveals the underlying microscopic mechanisms connected with rearrangements of dihedral angles and density changes.
The method of Rutherford backscattering of He + ions 2 MeV studied profiles of C, Cu and W in the films deposited on the PF-4 LPI. The films were deposited on glass substrates in gases Ar, D2. It is found that the profiles of the elements is significantly dependent on the kinetic energy of the particles and their sizes. At particle velocities ~ 100 km / s, the particles penetrate to a depth of ~ 500 nm. Profiles are inhomogeneous in nature. For each impurity, there are certain depth beneath the surface layers of the glass. A special feature is the location of the films produced impurity layers below the surface of the glass substrate and overlapping. This arrangement sputtered layers is significantly different from the traditionally used methods of film deposition.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.