The electrochemical energy converters are described which, depending on the type, can be used both for generating electric energy and its accumulation in the form of chemical energy of active substances. An alternative scheme of the guaranteed supply of electricity and heat is considered for a region remote from the centralized energy supply but with a high potential of wind energy generation and hydrogen energy storage without using any imported or local fuel. The scheme includes a wind energy complex, i.e., a farm of wind turbines localized in sites with the high wind potential, which guarantees the electricity supply even during low wind periods. All surplus electricity is consumed in the thermoelectric heating of water in storage tanks and the hydrogen production by water electrolysis. Hydrogen is either stored or supplied to the fuel cell plant (used in windless periods or as an alternative power source) and to the hydrogen condensing boiler in heat-deficiency periods. The annual hydrogen energy balance, the necessary number of wind turbines, the parameters of the equipment scheme are calculated, and the capacity factors of the installed equipment are estimated for a real autonomous region (Novikovo village, Sakhalin island). The main prerequisites for the implementation of the alternative scheme of electricity and heat supply that uses no imported fuel but operates on wind power and electrochemically converted energy are shown.

The results of the development and study of catalysts for the anodes of water splitting electrolyzers with a proton exchange membrane are presented. To deposit catalytic layers on a titanium support, the method of magnetron sputtering of composite targets in a vacuum was used. Iridium and ruthenium are used as the principal catalysts; molybdenum, chromium, and titanium, as functional additives. The electrochemical and structural characteristics of catalytic coatings are studied. Using voltammetry methods, cyclic voltammograms and anodic characteristics of the catalytic compositions are obtained, in particular, at different temperatures of the subsequent heat treatment in air, as well as at different measurement temperatures. The Tafel slopes of the current–voltage characteristics of the composite anodes, as well as the currents at a potential of 1.55 V (RHE) are determined. The minimal slopes are obtained for the Ir–Ru–Mo–Ti catalytic composition (b = 40–63 mV/decade); the maximal currents, for the Ir–Mo–Cr catalytic composition (i = 100–110 mA/cm2 at E = 1.55 V (RHE)). The magnitude of adsorption currents in the anodic potential region of cyclic voltammograms is shown to correlate with the coefficient b of the Tafel equation (E vs. logi); it determines the number of catalytic centers for the deprotonation stage in the oxygen evolution reaction. However, the catalyst activity in the oxygen evolution reaction is determined not only by the number of these centers but mainly by the functional features of the catalyst proper, i.e., the composition of the catalyst and the conditions for its preparation (including the temperature of the catalyst subsequent heat treatment in air). The iridium-based catalytic compositions added with molybdenum and chromium have higher activity in the oxygen evolution reaction. Structural studies showed that during the magnetron sputtering of the composite targets, even with small catalyst loading, dispersed structures are formed; in the real porous titanium anodes, these structures must form on the front surfaces with higher catalyst content.

The results of R&D of electrochemical components of an energy system based on hydrogen–air open cathode fuel cells with proton-exchange membrane are presented. The scheme is shown being capable of realizing electrical power system with high specific energies (up to 700 W h/kg) on the condition that it contains no humidifiers and heaters, light metals are used as the material of bipolar plates, and the fuel cell operates in the mode of self-humidification of the membrane using only the reaction water therefor. Under these conditions, at operating temperatures up to 50°C, the air consumption is 50–100 times higher than the stoichiometric value; there appears a danger of the membrane drying-out. To improve the current–voltage characteristics, a combined method of manufacturing membrane–electrode assembles is used, according to which the catalytic layer was applied by screen printing, and the membrane is formed by direct application of an ionomer to the electrode. The properties of C–Pt- and TiN-based protective coatings on the surface of a titanium bipolar plate are also investigated. The dynamics of changes in the potentials of the electrodes is investigated at “critical” modes of the fuel cell operation and the process stabilization at the nominal mode. Using the experimental data for a fuel cell stack with a power of 1.2 kW and the specific enthalpy–temperature–air humidity diagram, the fuel-cell-operating temperature limits are calculated, at which the process of the membrane self-humidification with reaction water is maintained. The improving of electrochemical components of an open-cathode fuel cell stack is shown to allow achieving a specific power of the power modulus as high as 1 kW/kg.

Catalytic coatings for electrodes of fuel cells and water electrlyzers with a polymeric proton-exchange membrane were prepared by magnetron sputtering of composite targets and studied. The noble metals platinum and iridium were used as inserts into the base targets made of graphite, molybdenum, titanium, or nickel. The effects that parameters of different processes occurring in magnetron sputtering have on the electrochemical behavior and structural properties of catalytic compositions are investigated. The prepared coatings display high catalytic activity. We discuss the feasibility to use magnetron sputtering for fabrication of thin nanostructured catalytic compositions as part of industrial technology of fuel cells and electrolyzers with proton-exchange membrane and low noble metal contents.

Open‐cathode PEMFCs for unmanned aerial vehicles operate at a near‐ambient temperature, which requires high super‐stoichiometric air flow rates to remove heat. This, in turn, makes the stack vulnerable to drying out. Using a combination of experimental measurements with a 1.2 kW stack and 3D multiphysics modelling, we show that the design of the corrugated metal bipolar plate with a height above the commonly used 1.05 mm and with cathode cooling channels wider than air‐suppling channels allows for a more efficient heat removal at lower air flow rates, thus assuring a wider range of operating parameters, while maintaining adequate hydration. The self‐humidifying stack attains 1000 W kg −1 power, and the full system with a nominal runtime of 4 h attains specific energy of 700 Wh kg −1 .

The study is aimed at obtaining a sparse carbon nanotube (CNT) array for using it in experiments on amplifying the surface-enhanced Raman scattering (SERS) signal. A procedure for synthesizing CNTs on Si/SiO2 and on glass-ceramic (sitall) substrates using the CVD method has been developed. The substrates were covered with a thin Ni layer in a magnetron sputtering unit. The subsequent annealing of the substrates in a high-temperature furnace at a temperature of 800-1000 оС resulted in that the Ni film became decomposed into an array of Ni islands that served as CNT growth catalysts. The CNTs were synthesized in the Planar Tech unit’s automated high-temperature furnace in a quartz glass tube, which was placed in the furnace and streamlined by flow of Ar with admixture СН4, Н2 and NH The synthesis temperature was equal to 900 оС, and the total synthesis process took more than 200 min. Owing to the system’s being fully automated, the synthesis operating parameters could be set up, including the temperature and duration of each stage and composition of gas mixture blown through the quartz tube. The microimages of the CNT arrays grown on different substrates were analyzed, and it has been found from that analysis that the synthesis yielded horizontally oriented multilayer CNTs ranging from 26 to 60 nm in diameter, depending both on the substrate type and condition and the surface annealing conditions. These factors also determine the CNT array density on the substrate. The synthesis conditions under which a sparse CNT array is obtained, which seems to be the most suitable for carrying out experiments on amplifying the SERS signal, have been established. Peculiarities of the Raman signal enhancement as a result of interaction between plasmon oscillations in CNTs and polyatomic molecules in the presence of laser radiation are discussed. It is pointed out that neighboring nanotubes have a screening effect on the radiation, for avoiding which sparse CNT arrays need to be used.

The development of energy systems based on high specific power hydrogen–air fuel cells using domestic nanostructured materials and technologies is an urgent task. The technologies used for manufacturing proton-exchange membrane fuel cells (PEM FC) by the Russian company BMPower using Pt/C-electrocatalysts of the PM series produced by another Russian company, Prometheus R&D, are presented. It has been shown that, in terms of their functional characteristics, catalysts of the PM series are superior to imported analogues. The use of the PM40 catalyst, as well as other innovative solutions in the field of nanotechnology (nanostructured coatings of bipolar plates, formation of an ionomer on the catalytic layer) makes it possible to achieve a specific power of more than 1 kW/kg in the PEM FC power module with air cooling.

The paper considers the various types of bipolar elements and materials which are used for their manufacture in fuel cell technology. They play an important role in switching individual fuel cells in a battery, and make up the largest fraction of its mass (up to 80%), which affects the specific mass power characteristics of the power system. Bipolar cells based on thin titanium foil and a corrugated duct have high mechanical strength with minimum weight, are important elements of a fuel cell battery, and their use can significantly improve the mass specific characteristics of a power system based on fuel cells with a solid polymer electrolyte and direct air supply. Protective coatings should provide low-resistance contact when switching individual fuel cells and prevent its change during prolonged operation of the fuel cell. Coating in a magnetron setup allows preliminary coatings on large surfaces to produce thin coatings with reproducible composition and properties. For research, we have used graphite and platinum targets, as well as composite graphite targets with platinum inserts in the spray zone. Using generally accepted procedures, we have studied the influence of the composition and conditions of applying composite coatings on the corrosion resistance and surface contact resistance of bipolar elements. The use of a graphite target and segments made of platinum is shown to allow obtaining protective coatings close to the requirements of technical targets for coatings in terms of corrosion resistance and surface contact resistance. Such titanium coatings have better conductive and protective properties than thin-film coatings based on platinum and thin films of gold. The production of protective coatings based on titanium carbides have a high surface resistance, and based on titanium nitride – lower protective properties. Thus, magnetron technology can be recommended as industrial for the production of bipolar elements.

The paper proposes an alternative scheme of guaranteed electricity and heat supply of an energy-insulated facility with a high potential of wind energy without the use of imported or local fuel. The scheme represents a wind power complex containing the park of wind generators located at the points with high wind potential. The wind generators provide guaranteed power supply even in periods of weak wind. For heat supply of the consumer, all surplus of the electric power goes on thermoelectric heating of water in tanks of accumulators, and also on receiving hydrogen by a method of electrolysis of water. The current heat supply is carried out with the use of hot water storage tanks, and the heat supply during the heat shortage is carried out by burning the stored hydrogen in condensing hydrogen boilers. We have developed the algorithm of calculation and the program "Wind in energy" which allows calculating annual balance of energy and picking up necessary quantity of the equipment for implementation of the scheme proceeding from the annual schedule of thermal and electric loading, and also potential of wind energy in the chosen region. The calculation-substantiation of the scheme proposed in relation to the real energy-insulated object Ust-Kamchatsk (Kamchatka) is carried out. The equipment for the implementation of an alternative energy supply scheme without the use of imported fuel is selected and compared with the traditional energy supply scheme based on a diesel power plant and a boiler house operating on imported fuel. With the introduction of an alternative power supply scheme, the equipment of the traditional scheme that has exhausted its resource can be used for backup power supply. Using climate databases, a number of energy-insulated facilities in the North and East of Russia with high wind energy potential are considered and the conditions for the successful implementation of the energy supply scheme are analyzed. This requires not only a high average annual wind speed, but also a minimum number of days of weak wind. In addition, it is necessary that the profile of the wind speed distribution in the annual section coincides with the profile of the heat load consumption.

Thin silicon films were deposited on surface-modified copper foil by magnetron sputtering; Si mass loading varied from 0.013 to 0.400 mg/cm. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to characterize the structure, morphology, and composition of the Si films as a function of mass loading. It was established that Si films repeated the hill-like morphology of Cu foil surface and consisted of nearly spherical agglomerates of amorphous silicon; the average size and packing of agglomerates varied as the Si mass loading changed. Galvanostatic half-cell electrochemical measurements were carried out within the range of 0.04–2.0 V with a lithium foil as the counter electrode and 1M solution of LiPF 6 in 1:1 (v/v) mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) as the electrolyte. According to the results obtained, the highest value of the reversible capacity of about 1200 mAh/g after 50 charge-discharge cycles at 0.1 C was observed in the electrodes with a Si mass loading of 0.293 mg/cm. The non-monotonic dependence of the reversible capacity vs. Si mass loading is likely to be caused by the structural evolution of the amorphous Si thin films.

Disperse catalytic compositions for water electrolysis in electrolyzers with a solid polymer electrolyte were obtained by magnetron sputtering of C–Pt and Mo–Ir sectional targets. The catalysts were studied by X-ray diffraction analysis, electron microscopy, and voltammetry. The synthesized Pt–С and Ir–Mo catalysts with lowered contents of the precious component were subjected to prolonged trials in an electrolysis cell with a solid polymer electrolyte and showed high activity and stability.

An aqueous suspension of a reduced composite of graphene oxide and humic acid has been prepared and used as ink to print conductive films and electrodes for supercapacitors. The dry powders of the composite ink before and after hydrazine reduction were characterized by IR and Raman spectroscopies and XPS. The surface areas of the reduced composite measured using the Brunauer-Emmett-Teller (BET) and standard contact porosimetry (SCP) methods were 6.5 and 200 m(2)/g, respectively. Moreover, the composite thin films obtained by printing exhibited island-like character. Further, the specific capacitance and other electrochemical properties of the supercapacitor using the composite electrode were studied. (C) 2017 Elsevier B.V. All rights reserved.

Highly disperse platinum film were vacuum-plasma-deposited onto titanium foil and gas-diffusion layers. The platinum deposits have complicated structure. By measuring hydrogen desorption peaks, the catalysts’ active specific surface area was determined and the roughness factor calculated. The electrochemical activity of the electrodes on gas-diffusion layers in the oxygen reduction and hydrogen oxidation reactions was determined. It was shown that the catalysts’ specific activity depends on the platinum content and the Nafion-ionomer additive. The high-activity electrodes were tested in Membrane Electrode Assemblies of low-temperature fuel cells.

Research of catalytic compositions based on noble metal black received by magnetron deposition of metal in vacuum thickness-control disclosed. Such blacks have unique bush-like structure formed by thin filaments of platinum with diameter near 10 nm and 200-300 nm long. This structure compared with structure of platinized platinum received by electrochemical deposition from solution. On basis of electrochemical research disclosed that vacuum platinum blacks (VPB) based on titan nickel and carbon provide high activity in anode hydrogen oxidation reaction and cathode hydrogen restoration in low temperature electrochemical devices.

Adsorption of certain long-chain aliphatic amines with 6–18 carbon atoms is studied on a stationary mercury drop electrode using the impedance method. It is found that adsorption of amines with C6–C12 results in the formation of an adsorption layer with the limiting capacitance of about 5 μF/cm2. In the case of amines with C14–C16, the limiting capacitance is approximately 0.5–0.7 μF/cm2. The most probable reason for such abrupt decrease in the adsorption layer capacitance is the formation of condensed layers of adsorbate molecules at the electrode surface. The adsorption parameters are calculated for hexylamine. The surface activity is estimated for amines with 10–14 carbon atoms in their chains.