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Mathematical model of the subdiffusion impedance in multilayer nanostructures is considered on the basis of the Cattaneo-type diffusion equation in fractional derivatives. The Nyquist diagrams are calculated for different values of subdiffusion coefficient and time parameter (time for which the flow delays concerning the gradient of charge carriers concentration). A qualitative agreement is obtained for the GaSe system with encapsulated β-cyclodextrin.

A novel flexible electrospun nanofiber/γ-Fe₂O₃ composite has been obtained from suspension of γ-Fe₂O₃ nanoparticles in polyvinylpyrolidone solution in dimethylformamide. The impedance spectroscopy of the synthesized nanofiber/γ-Fe₂O₃ composite was carried out. Negative magnetoresistance and giant magnetocapacitance effects, as well as phenomenon of a "negative capacitance" at room temperature were observed in magnetic field (2.75 κOe) in infra-low frequency range. The polarization properties and volt-ampere characteristics of the nanocomposite in the applied magnetic field indicate the increase in the dielectric permittivity ɛ and the emergence of spin electromotive force, which enables us to accumulate of electric energy at quantum level. A quantum-mechanical model, which explained the non-monotonous behaviour of the volt-ampere characteristic of the novel nanofiber based composite, has been suggested.

We have discovered a huge enhancement of the supercapacity (up to 4 times) under sun illumination of electrodes fabricated from cavitated nanoporous carbon being carbonized from an iodine doped β–cyclodexryn. This effect was achieved even without a frequently used KOH treatment and is caused by enhancement of effective activated surfaces. The synthesized cavitated nanoporous carbon exhibits principally different accumulative features at the carbon/electrolyte interface. Relationship between the porous structure, electronic properties of supramolecular nanoporous carbon and enhanced supercapacitance is explored. The impedance spectroscopy measurements (Nyquist diagram) apparently suggest a capacitance mechanism for the energy accumulation. Enhancement of the supercapacity is explained by light-generated carriers in low-dimensional nano-interfaces in relevant mechanism an increasing concentration of delocalized electrons resulting in unlocking of the Helmholtz layer capacity.

The surface of microporous Norit® GAC 830 W carbon was fluoroalkylated by heating in 1,1,1,2-tetrafluoroethane and 1,1,1,2,2-pentafluoroethane at 400 and 500 °C. Elemental analysis, FTIR ATR spectroscopy, and TG studies showed the presence of ∼0.1–0.7 mmol g−1 of the fluorine-containing groups. Nitrogen adsorption measurements and quenched solid density functional theory simulations proved an increase in the mesoporosity. By combining the results of solid-state 19F NMR and XPS analyses, we determined the functionalization of the carbon surface with CF, CF3, and CF2 fluorine-containing groups. Supercapacitor electrodes prepared from these materials were subjected to the charge-discharge tests and electrical impedance measurements. During galvanostatic cycling in the aqueous 30% KOH, they showed an enhanced charge capacitance compared to the parent (830 W) and the reference (Supra 30) carbons. These observations suggest that the fluoroalkylated surface and the modified microporous structure have an additive effect on capacitance parameters of carbon electrodes studied in symmetric, negative and positive modes. The fluoroalkylation caused an increase in the surface capacitance up to 38%. Herein, we demonstrate the fluoroalkylation is a simple way to increase a capacitance of carbon electrodes.

Physical and technological principles of formation of clathrate structures for supramolecular electronics are given in this paper. It has been established that supramolecular nature of the “host–guest” conjunction, in general, and hierarchical architecture of the corresponding clathrates, in particular, provide realization of such an extraordinary effect as an optically or a magnetically controlled phenomenon of colossal “negative capacity” with a predicted frequency interval of manifestation, magnitude, and multiplicity. For the first time, the experimental confirmation of the behavior of the electretized fractal clathrate GaSe⟨β-CD⟨FeSO4⟩⟩ as a dissipative element, which accumulates inductive energy, is demonstrated. A general approach for obtaining the generalized transport equations with fractional derivatives by using the Liouville equation with fractional derivatives for a system of classical particles and the Zubarev nonequilibrium statistical operator method within Renyi statistics is presented. N...

Context. The task for electric energy accumulation in non-electrochemical way but by means of electrons and spins was developed on the basis of quantum accumulators and spin capacitors. Synthesized clathrates of 4 folds expanded GaSe matrix with guest component sodium nitrite NaNO2, Iron II Sulfate FeSO4 and combination of them NaNO2⊕FeSO4 are the object of research.Objective. Synthesis of heterostructured nanocomposite materials with large developed interface, anisotropic electric conductance and high values of dielectric permittivity in combination with loss tangent less than 1.Method. The intercalation approach to heterostructured nanocomposite materials formation was proposed. It allows creating developed atomic-molecular complexes of host-guest type and hierarchical structures of subhost-host-guest type. The X-ray diffractometry data show the structural changes in macro composite NaNO2⊕FeSO4 at the transition to the guest nanoscale geometry. With the help of frequency dependence of specific complex impedance the main features of current flow and charge accumulation processes in synthesized nanohybrids and effect of cointercalation were determined. Impedance photo- and magneto- responses show a gigantic photodielectric, magnetoresistive and magnetocapacitive effects at room temperature. These effects open up a new possibilities of theirs application as highly sensitive sensors of constant magnetic and light wave field.Results. Clathrates GaSe , GaSe та GaSe were synthesized. Electric charge accumulation at the interface was determined. The effects of negative photoconductivity and giant magnetoresistance, drastic increase in photo-EMF, giant photodielectric and magnetocapacitive effects were registered at room temperature.Conclusions. Cointercalation of NaNO2⊕FeSO4 modifies the energetic specter of GaSe more than individual intercalation. Synthesized clathrates are promising materials for novel approaches in thechnology of highly sensible sensors of capacitive type for magnetic and light wave field at room temperatures as well as for quantum accumulators and quantum capacitors as a new alternative of chemical power sources

Two-dimensional nanofiber mats based on a mixture of polybenzimidazole with telechelic oligoperoxide are obtained by the method of electrospinning. It is shown that the reactive peroxide groups on the surface of nanofibers can be modified by the initiation of radical polymerization and grafting of various polymeric chains. The phenomenon of “negative” capacitance is detected for the impedance dependences of synthesized nanofibers. The influence of grafting of various polymeric chains to the surface of nanofibers on the polarization characteristics of nanocomposites is investigated. It is shown that some of the obtained structures are characterized by a combination of a low (< 1) tangent of dielectric losses in the infralow-frequency region (0.001–0.1 Hz) and high values of the dielectric permittivity (∼106). The possibilities of application of materials of this kind in the production of quantum batteries are discussed.

A new technological approach to the synthesis of multilayer nanostructures which allows their use in high-performance storage of electrical energy at the nanoscale level is discussed in this paper. In particular, the effect of co-intercalation of histidine (his), water and a solution of KOH into layered semiconductors of GaSe and InSe on the charge accumulation are studied. Based on the data of the cyclic current-voltage characteristics (CVC) a power storage mechanism (capacitive/pseudocapacitive) in each of these structures is described. This mechanism is in a good accord with the results of galvanostatic studies. The simulation of the parameters of the impedance equivalent circuit has been carried out, proving the possibility of using the described structures for nanoelectronics and nanoenergy devices. The observed values of tangent of electrical losses tgδ (

This paper deals with an electric energy storage system (ESS) of distributed structure composed from the hybrid energy storage modules (HESM). Each module consists of the lead acid battery and the supercapacitor (SC) pack, which are connected to each other by the bidirectional DC-DC converter. The uniqueness of the proposed structure is that the DC-bus of whole ESS is formed by means of adding the SC pack voltages of all modules. For low voltage modules, it is proposed to use an ecologically acceptable SC with aqueous solution of KOH. Such SC has a low production cost, but also low voltage, no more than 1.2 V. For increasing specific characteristics of the SC with nonorganic electrolyte, the technology of its production was developed. This technology includes the next stages: receiving the biocarbon material from flax fibers with a developed specific surface area, carbonization and activation of the flax biocarbon at optimum regimes, its doping with iron, folding the electrodes, filling them with electrolyte, and sealing the cells. A control system was developed for the created HESM. The proposed HESM is built by Matlab/Simulink to verify its feasibility. Finally, a prototype of HESM is also set up to test the performance.

The model of impedance subdiffusion based on the Cattaneo equation in fractional derivatives in applications to multilayer nanostructures is considered. Nyquist diagrams with changes of the parameter (time for which the flow is delayed with respect to the concentration gradient) and the subdiffusion coefficient D are calculated. Розглянуто модель субдифузiйного iмпедансу на основi рiвняння Кеттано у дробових похiдних у застосуваннi до мультишарових наноструктур. Розраховано дiаграми Найквiста iз змiною параметрiв (час, на який потiк затримується вiдносно градiєнта концентрацiї) та субдифузiйного коефiцiєнта D.

The purpose of this work is to expand the class of electrical energy storage devices with non-conjugate functional hybridity. Cyclodextrins of β- and γ-modifications has used as a starting material for research. These materials containing intramolecular voids, which are able to accommodate guest components by molecular recognition on the "lock-key" principle. Methods of precision porometry and impedance spectroscopy has used to study the obtained carbon structures, electrochemical and magnetic measurements has performed to study the obtained carbon structures. Data of the precision porometry has indicated a bimodal porous structure of the synthesized chars. The total specific surface area of active surface of the β-cyclodextrin carbonizate was about 72 m2/g. After KOH-modification, the specific capacity for β-cyclodextrin char was 158 F/g, and in the negative potential range – 203 F/g. The last value for γ-cyclodextrin carbon was 162 F/g. The ability of β-cyclodextrin to molecular recognition of ferrocene (FC) has used and this cavitat has subjected to activation carbonation according to the same modes as β-cyclodextrin. The specific capacity of the obtained char of the β-CD complex after the KOH-modification was 110 F/g, the specific capacity of the cavitate carbon synthesized on γ-CD has dropped twice. The study of complexes host-guest inclusions β-cyclodextrin with molecular iodine has indicated a slight increase of capacity. However, their interface with 30 % aqueous electrolyte solution has shown high photosensitivity. The specific capacitance of the cavitate carbon without KOH-modification has increased four times when it was illuminated with integral and monochromatic light from LEDs of the same intensity. Magnetic studies of the synthesized carbonates have shown that they all demonstrate ferromagnetic properties. Measurement under normal conditions and in a constant magnetic field of cells of symmetric configuration on carbon-based electrodes synthesized with γ-CD and γ-CD has showed that their capacitance practically does not change, but their reactance parameters change significantly. Supercapacitors based on these carbonates can serve as sensors of a weak magnetic field at room temperature. Magnetovarionistors is a new class of devices, which are forming on such kind of supercapacitors.

Molybdenum disulfide is obtained by the template method. Its structure and electrochemical properties are investigated. It was found that the working voltage of the LPS for molybdenum disulfide obtained by template method reaches 3 V, the specific capacitance is 180.9 F/g. It was identified that the electric energy storage device the positive electrode of which is molybdenum disulfide obtained by the template method has the discharge specific capacity of 238.9 F/g at a scan rate of 0.001 V/c.

Nanofiber based polymer-inorganic composites filled with superparamagnetic nanoparticles were synthesized via electrospinning technique from the suspension of γ-Fe 2 O 3 nanoparticles in dimethylformamide solution of poly(vinylpyrrolidone) (PVP). On the basis of the magnetometric analysis, it was shown that γ-Fe 2 O 3 nanoparticles were in a superparamagnetic state in the nonmagnetic PVP matrix and its content was 10% weight. TEM, EDX analysis and impedance spectroscopy were conducted. It was found that the applied magnetic field (MF) of 2.75 kOe caused a negative giant magnetoresistive effect (GMRE) in the infra-frequency range. For both under normal conditions, and in MF nanofiber (NFM) composite, filled with functionalized maghemite γ-Fe 2 O 3 nanoparticles, NFM/γ-Fe 2 O 3 , the phenomenon of “negative” capacity was detected In addition, the polarization properties of the synthesized material were analyzed. It was proved that applied MF during the measurements increased the dielectric constant ∊ of the material and the magneto-capacitive effect reached 4000% in the infra-frequency range at room temperature. Spin electromotive force (EMF) and 〈spin-battery〉 effect were detected. The possibility of using the synthesized material as high-quality magneto varicaps (in the frequency range of 50÷106 Hz) and quantum batteries (in the frequency range 10−3÷210−2 Hz) was proved.

Within the framework of the Kronig-Penny model, changes in the electron spectrum of a layered crystal caused by intercalation are analyzed. Special attention is paid to both the geometric changes of the crystal and its energy characteristics during intercalation. The extraordinary behavior of the spectrum caused by the geometric intercalation factor is observed.

A new technological approach to the synthesis of multi-layer nanostructures is suggested; it enables us to ensure them unique properties and extraordinary possibilities of their practical application. In particular, it is shown that the synthesis of nanostructures of GaSe⟨β-cyclodextrin⟨FeSO4⟩⟩ hierarchy architecture in superposed electric and light-wave fields causes especially strong changes in their magnetic impedance response. In this case, the impedance response of the synthesized clathrate takes inductive character in the frequency range of 10−3–105 Hz. The relationship between the impedance behaviour of such hierarchical structures and frequency fractionality is investigated on the basis of Cettano equations. The prospect of application of the synthesized nanohybrids for active elements of gyrator-free nanolines of delay, for super-sensitive capacitance sensors of magnetic field and of light-wave field, and for quantum batteries at room temperature is shown.