RU2224337C1 - Method and installation for manufacturing high- temperature fuel cell - Google Patents

Abstract

FIELD: single-process manufacture of solid-oxide fuel cells. SUBSTANCE: proposed method includes manufacture of solid-oxide high-temperature fuel cells by pyrolysis of organometallic complexes based on 2-ethyl hexane acid. Functional layers of fuel cell are applied by rolling precursor organometallic complexes of each layer onto fuel-element blank which is heated to pyrolysis temperature of respective precursor. Blank surface heating provides for evaporation of precursor organic component when liquid precursor comes in contact with blank, this being accompanied by formation of oxide film of respective functional layer. Blank surface temperature is varied in the course of layer production between 240 and 600 C depending on layer being produced. Installation implementing proposed method has rotating device for blank cathode made of strontium lanthanum manganite and device for applying precursor onto cathode. Layers are applied by means of roller directly contacting fuel cell blank. Layers can be applied to fuel cell blank surface both over cathode generatrix and over helical line. All functional layers of fuel cell are applied on mentioned installation; proposed method and device may be likewise found useful for applying functional layers on anode used as fuel cell blank. EFFECT: enhanced safety and reduced cost of method; simplified design and enhanced reliability of installation. 14 cl, 12 dwg

Description

 The group of inventions relates to the field of direct direct conversion of chemical energy of fuel into electrical energy, and in particular, to high-temperature electrochemical devices with solid oxide electrolyte (TOE), and can be used for the manufacture of high-temperature fuel cells (VTTE).

 Currently, VTTE are one of the most promising types of converters of the chemical energy of fuel into electrical energy.

 The most important feature of VTE is a high efficiency, which theoretically can reach up to 80%. Currently, prototypes have achieved efficiency values of 50%. In addition, in comparison with traditional methods of generating electricity, VHFCs have a number of other advantages: modular design, high efficiency at partial electric load, the possibility of combined generation of electric and thermal energy, lower, by several orders of magnitude, output of polluting products, lack of moving parts and nodes.

 The main components of VTTE are the anode, electrolyte, cathode and current path. The components of the fuel cell must have high strength and durability in conditions of operating temperatures, low cost of manufacture.

 Currently, various technologies for the manufacture of VTTE are developed and widely used. VTTE components — electrodes, electrolytes, and current paths — are made of ceramic materials based on zirconium dioxide, cerium, thorium, barium, strontium, bismuth oxides, and perovskite-type compounds based on chromium, manganese, cobalt, nickel, and lanthanum oxides, which are modified with magnesium , calcium, strontium, barium, scandium, yttrium, cerium and other lanthanides.

 At the same time, the use of well-known technologies does not fully solve such problems as: providing the specified porosity of ceramic electrodes with sufficient structural strength and electrical conductivity; reducing the thickness of the electrolyte film while maintaining gas density; the formation of thin films of electrolyte on porous supporting electrodes with a maximum increase in the specific working surface per unit weight of VTTE.

 Particularly difficult is the task of manufacturing a gas-tight electrolyte layer (with a thickness of δ = 5 ÷ 15 μm) on a porous electrode, in which the open porosity should be at least 30%. At the same time, it is necessary to achieve a sharp decrease in the cost of manufacturing VTTE, which would ensure their mass mass production.

 Numerous attempts have been made to create thin oxide films on a porous electrode using CVD (EVD) electrochemical deposition, plasma spraying, sputtering, spray pyrolysis and the sol-gel method [1]. Among these methods, the latter is distinguished by improved homogeneity, greater purity of the obtained films, and is realized at lower temperatures. However, sol-gel precursors are very sensitive to moisture and have a relatively short shelf life.

Known methods for manufacturing a high-temperature fuel cell, the implementation of which this problem is solved by the fact that the precursor is applied to the substrate, which lead to rapid rotation of the order of 2000-3000 rpm, as a result of which the precursor spreads, forming a thin film. The film is then heated in the presence of oxygen at a temperature not exceeding 600 ^° C to convert the polymer film of the precursor into a polycrystalline metal oxide film, using a polymerizable organic solvent (e.g. ethylene glycol) precursor to form a polymer intermediate, free from sediment and including a polymer containing metal cations [2].

However, using this method it is practically impossible to produce films of functional layers on a complex substrate, to produce thin high-quality gas-tight oxide functional films for high-temperature electrochemical devices (VEHU). In addition, heating (up to 80 ^o C) aqueous solutions of compounds containing nitrates, chlorides, carbonates, alkoxides and hydroxides of the corresponding metals, together with a polymerizable organic solvent (e.g. ethylene glycol) does not remove mineral acid anions from the resulting precursor. As a result, nitrogen, chlorine, carbon fall into the formed polymer film and then into the functional oxide layer (electrolyte, current passage, etc.), which greatly distorts their electrochemical properties. Chlorine residues that are not removed even at the sintering temperature of the oxides are especially harmful. Chlorine forms a low-melting eutectic with metal oxides, as a result of which, upon calcination, melts (through holes) are formed, which makes the properties of the films unacceptable for HPLC. Also, the initial precursor after water removal has a high viscosity, which necessitates the provision of a high substrate rotation speed of up to 3000 rpm. Such speeds are not applicable for the manufacture of VTTE in the form of a long tube of doped lanthanum manganite due to the possibility of its destruction. When droplets of the precursor are deposited on a rotating flat porous surface of the cathode, its high viscosity does not allow it to penetrate (absorb) quickly into the pores. However, during the next stage of the process associated with stopping rotation and heating the surface to 80 ^° C, the polymer film sharply decreases its viscosity and is absorbed into the substrate, as a result of which the necessary film does not form on the surface of the substrate. By repeating this process many times, tens of times, gas density can be achieved, but at the same time, the cathode pores by a third or more of the thickness are filled with electrolyte. Thus, the actual thickness of the electrolyte may be an order of magnitude greater than expected.

The final annealing of the zirconium film deposited on the substrate is insufficient to carry out at 600 ^o C, since part of the zirconium acquires a cubic structure due to carbon remaining after decomposition of the organic radical. Further, during operation, such a cubic structure becomes monoclinic, since carbon is gradually removed. The properties of the electrolyte (coefficient of thermal expansion, specific gravity, electrical resistance) change in this case, which can lead to a loss in performance. Complete removal of carbon is possible at a temperature not lower than 1250 ^o C and exposure for 1 hour.

 There is also a known method of manufacturing VTEs having the form of a tube (or tubes with a large ratio of length to diameter), according to which the synthesis of an electrolyte on a cathode made in the form of a tube of doped lanthanum manganite is carried out by plasma spraying of stabilized zirconium yttrium, and then the process is conducted CVD in an atmosphere of gaseous zirconium and yttrium halides. In accordance with this method, the problem of the gas density of the electrolyte layer sprayed by the plasma method is solved [3].

 This method, being the closest to the proposed one, although it allows you to solve the problem of the gas density of the electrolyte layer, is unsafe, because the work is carried out with aggressive gaseous halides.

 An installation for manufacturing a high-temperature fuel cell is also known from said US patent, comprising a drive for rotating a hollow hollow cathode and a device for applying to the cathode precursors of the components of the layers of the fuel cell, made in the form of a plasma gun. However, this installation incorporates sophisticated equipment necessary both to ensure the electrolyte deposition process itself and to ensure the safety of the fuel cell manufacturing process.

 The task posed by the creation of the proposed group of inventions is that the method of manufacturing a fuel cell is safe and cheap, and the installation for its implementation is structurally simple and reliable.

In terms of the method of manufacturing a high-temperature fuel cell, the problem is solved by the use of organometallic complexes (IOC) that do not contain an aqueous component and anions of mineral acids as a precursor, and as the starting organic reagent used for the manufacture of organic complexes of all metals required in the precursor , use 2-ethylhexanoic acid, while all layers are applied to a rotating heated substrate by sequential (in one operation) knurling precursor ov. For various precursors, the required substrate temperature at the time of its application has an individual value. However, all these individual values fall within the range from 240 to 600 ^o C, while all precursors are applied in an atmosphere of atmospheric air or inert gases.

 In addition, the problem regarding the method is solved by conducting the process of creating a fuel cell by applying functional layers in a certain sequence. This sequence depends on the design of the current passage in the element selected for execution.

 For the construction of the current passage, which is removed from the cathode through the electrolyte and other functional layers, first a layer of the current passage is applied to the supporting cathode, then an antidiffusion layer with a gap with respect to the latter, and then an electrolyte layer. Next, the cathode with the deposited layers is subjected to heat treatment. After heat treatment, a cermet anode layer is also applied to the current passage layer with a gap, then the cathode with all deposited layers is subjected to vacuum heat treatment, after which the gap between the current passage and all other layers is filled with a layer of electrically insulating material. This layer is also applied by rolling the precursor.

 For the design of the fuel cell, in which the current passage is removed from the inner surface of the cathode and does not penetrate the functional layers, the manufacture of the fuel cell begins with the application of an anti-diffusion layer. In this case, there is no need to leave any gaps in the anti-diffusion layer, the electrolyte and all subsequent layers.

 As regards the installation for manufacturing a high-temperature fuel cell, this problem is solved by the fact that it is equipped with a carrier cathode heater, a mechanism for moving the device for applying precursors relative to the carrier cathode and a control unit, a device for applying precursors of layers of the fuel cell in the form of a cell placed in the housing with an open end face and protruding above the last cylindrical roller forcibly wetted by a precursor corresponding to the applied layer of the fuel cell as well as coming from an additionally installed feeder with a control device, the drive of rotation of the bearing cathode is made in the form of a stepper motor, the movement mechanism is in the form of a carriage in which the device for applying precursors is installed, and the mechanism for moving, the drive for rotation and the control device of the feeder are made controlled from the control unit.

In addition, the device for applying the precursors of the layers of the fuel cell has water cooling, and in its case a channel for supplying inert gas to the contact zone of the roller of the device for applying the precursors of the layers of the fuel cell with the supporting electrode (cathode) is made. The roller of the device for applying the precursors of the layers of the fuel cell can be installed in the housing with the possibility of rotation by 90 ^o relative to the vertical plane. The roller can be made of ceramic based on BeO, while the outer surface of the roller can be made with a concave radius corresponding to the radius of the bearing cathode.

The invention is illustrated in the drawings:
in FIG. 1 shows thermoanalytical curves of zirconium salt of 2-ethylhexanoic acid;
figure 2 - diagram of the manufacturing process of VTTE;
figure 3 is a diagram of the installation for the manufacture of VTTE (top view);
in FIG. 4 is a diagram of a device for heating the functional layers of VTTE operating on the principle of using ohmic resistance of the cathode;
figure 5 is a section along aa of figure 4;
in FIG. 6 is a diagram of an apparatus with reciprocating movement of a device for applying precursors of VTFC layers;
Fig.7 is a section along aa of Fig.6;
on Fig - a device for applying precursors of layers of VTTE;
Fig.9 is a section along aa of Fig.8
figure 10 is a diagram of the deposition of a layer of current passage on the cathode;
figure 11 is a diagram of the application of the antidiffusion layer;
in FIG. 12 is a photograph of the cleavage of the sample, which shows the deposited layers: anti-diffusion, consisting of (CeO ₂ ) _0.85 (Sm ₂ O ₃ ) _0.15 , and an electrolyte layer of 9YSZ on a MLS substrate.

The essence of the method of manufacturing HTFCs is to use organometallic complexes (IOC) during the formation of HTFC elements, or IOC mixtures, whose thermal decomposition (in atmospheric oxygen) or thermal dissociation of which (in an inert medium, without decomposition of organic radicals transforming into a gaseous state) Oxide materials are synthesized in the form of a film of the required phase and chemical composition directly on the substrate. The synthesis occurs at relatively low temperatures (240 ÷ 600 ^o C), i.e., in the range of the decomposition temperatures of the MOC, and, according to data confirmed by X-ray diffraction analysis, leads to the formation of materials with the necessary crystal structure.

 At the time of synthesis, the newly formed oxide materials have high chemical activity, which leads to their preliminary sintering at low temperatures in the process of formation of the components of HTFC.

It is proposed that 2-ethylhexanoic acid with a basic substance content of 97% be used as an organic component of IOC. The organometallic zirconium complex based on 2-ethylhexanoic acid has a decomposition termination temperature of 410 ^{° C.} (see FIG. 1).

 It is known the use of dimethylbutylacetic acid as the main substance for the IOC used for the manufacture of VTTE [4].

The main disadvantage of using this acid is that the decomposition temperature of the MOA based on it is 530 ^o C and does not coincide with the temperature of synthesis of zirconium dioxide (410 ^o C). To overcome this drawback, it is necessary to add zirconium alcoholate to the IOC, which reduces the temperature at which the electrolyte layer is formed. However, the alcoholate is difficult to manufacture and therefore expensive. Its introduction into the IOC sharply reduces the shelf life of the precursor (up to several hours), which must be used immediately after its preparation. The shelf life of IOC based on 2-ethylhexanoic acid is practically unlimited. In addition, the deposition processes of HTFC layers, which use dimethylbutylacetic acid-based MBC, are less stable due to the significant and unstable effect of the exothermic effect on the given process temperature.

For the manufacture of any of the above thin-film functional layers from the initial MOQs, mixtures of the type
M ^A [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ ] _A + M ^B [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ ] _B + M _C [. ...], etc.

where M ^A is a metal with a valency A;
M ^B is a metal with a valency B, etc.

 The prepared mixture, which under standard conditions (P = 101.3 kP, T = 298.16 K) is in the form of a liquid and is a precursor is brought into contact with the heated surface of the rotating substrate. When the heated surface of the substrate comes into contact with a liquid precursor, the organic part of the MOC is rapidly evaporated, and the metals from the MOC are oxidized and remain in the form of an oxide film on the surface of the substrate, forming the necessary structure of the functional layer.

The manufacturing process of VTTE is illustrated in figure 2. The first step in the production of VTTE is the application of a current passage (if this is due to the design feature of the fuel cell, see above) in the form of a longitudinal strip on the cathode, which has the form of a tube or tube. To do this, a current passage precursor is rolled onto the cathode using a roller. The precursor is an IOC of chromium, lanthanum, strontium, to which La _0.7 Sr _0.3 CrO ₃ powder is added. In this case, the ratio of the solid phase of the powder to the liquid phase of the MOC is from 1/100 to 5/100 parts by weight. The temperature of the cathode, on which the precursor is applied, is maintained in the range of 550-600 ^{° C.} , The application is carried out in air. The organic part of the MOC evaporates, and a gas-tight film of doped lanthanum chromite in the form of a longitudinal strip forms on the cathode surface. The growth rate of the thickness of the gas-tight film of the current passage on the surface of the supporting porous cathode is 20 ÷ 60 μm per hour. In Fig.2, this process is indicated by the letter "A". The second operation of the method, which is indicated by the letter "B" in FIG. 2, is the deposition of an anti-diffusion layer on the cathode, often also called an interface layer. The purpose of the anti-diffusion layer is to reduce the chemical interaction between the functional layers of VTE at operating temperatures. In addition, the anti-diffusion layer allows you to compensate for the difference in the linear expansion coefficients of the adjacent cathode and electrolyte layers. The thickness of the gas-tight anti-diffusion layer having the composition (CeO ₂ ) _0.85 (Sm ₂ O ₃ ) _0.15 or (CeO ₂ ) _0.85 (Gd ₂ O ₃ ) _0.15 is 3-5 microns. A mixture of organometallic complexes characterized by the general formula is used as a precursor
Ce [O ₂ C-CH (C ₂ H ₅ ) - (CH ₂ ) ₃ -CH ₃ ] ₄ , + Sm ₂ [O ₂ C- (C ₂ H ₅ ) - (CH ₂ ) ₃ -CH ₃ ] ₃
or
Gd ₂ [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₃ .

The anti-diffusion layer is applied with a gap relative to the current path by rolling onto the cathode, heated to a temperature of 350-380 ^o C, of the precursor, the application is carried out in air.

The next step in the manufacture of VTTE is to create an electrolyte layer. This operation is indicated in figure 2 by the letter "B". The electrolyte precursor is applied to the anti-diffusion layer by knurling with a gap with respect to the current passage strip. It is possible to apply an electrolyte with a conductivity of negative oxygen ions and an electrolyte with a conductivity of protons (positive hydrogen ions). To create a layer with a negative oxygen ion conductivity, a mixture of zirconium MOA - Zr [(O ₂ C-CH (C ₂ H ₅ ) - (CH ₂ ) ₃ -CH ₃ )] ₄ with at least organometallic complexes is used as a precursor , one of the elements: Mg, Ca, Sc, Y, Ce
Mg [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₂
Ca [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₂
Sc ₂ [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₃
Y ₂ [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₃
Ce [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₄
and / or other lanthanides
Ln ^A [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] _A ,
where Ln are lanthanides,
and the application of the prepared precursor is carried out in an atmosphere of air on an anti-diffusion layer heated to a temperature of 380-600 ^o C.

To create a layer with proton conductivity (positive hydrogen ions) in the form of a film having the composition SrCe _0.85 Gd _0.15 O ₃ or BaCe _0.85 Gd _0.15 O ₃ , a precursor is applied to the anti-diffusion layer, which is a mixture of MOC metals characterized by the formula
SrCe _0.85 Gd _0.15 [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ )] ₆
or
BaCe _0.85 Gd _0.15 [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ )] ₆ .

The surface temperature of the substrate, while maintaining in the range of 380 ÷ 400 ^o C.

After completion of the deposition of the electrolyte layer, the VTTE billet, which is a cathode with three deposited components — a current passage, an anti-diffusion layer, and an electrolyte layer — is subjected to heat treatment in a furnace at a temperature of 1250–1280 ^° С for 2–4 hours. In Fig.2, this process is shown by the letter "G".

The next operation is the manufacture of the anode (fuel electrode), this operation is indicated in figure 2 by the letter "D". In the process of manufacturing the anode, the problem of obtaining the anode layer with a given porosity and electrical conductivity is solved. As a precursor, a paste mixture is used, which is prepared by mixing powders of coarsely dispersed electrically conductive material selected from the group of metallic nickel and / or cobalt, coarsely dispersed ion-conductive material based on doped zirconia and / or doped cerium oxide, finely dispersed ion-conductive material based on doped cerium oxide and the liquid phase of the IOC of Nickel and / or cobalt, characterized by the General formula
Me ^{+ m} [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ )] _m ,
where Me is Ni and / or Co;
m is the valence of the metal.

 MOC during the heat treatment forms an electrically conductive porous multiphase layer, bonding together the coarse and finely dispersed phases that form the cermet of the fuel electrode.

 In addition, the ratio of solid to liquid phases in the manufactured paste mixture is in the range (1/3 ÷ 5/7) of the mass.

 The concentration of nickel and / or cobalt in liquid MOC is in the range from 20 to 70 g / kg, and nickel and / or cobalt powder is added in the ratio of the amount of metal powder to the amount of electrolyte powder as 1.1 / 1.0.

The coarse particles of nickel and / or cobalt powder should have a regular spherical structure with a diameter of 10 to 15 μm, and the synthesized coarse electrolyte powder should have a threadlike shape, and the ratio of the particle length to its diameter should be at least 10 with a particle diameter of 5 ÷ 10 μm. At the same time, fine powder of doped cerium oxide contains 90% of particles with a diameter of less than 1.0 microns. Application of the paste mixture is carried out in air at a temperature of 260-280 ^o C and atmospheric pressure.

After applying the anode layer, the VTTE billet is subjected to heat treatment in vacuum for 2-3 hours at a temperature not exceeding 380 ÷ 400 ^o C and a residual pressure of not more than 0.1 atm. This completes the conversion of the crude paste mixture into a solid anode layer with desired properties. This process is shown in figure 2 by the letter "E".

Complete the process of manufacturing the functional layers of VTTE by applying an electrical insulating layer that provides effective electrical insulation between the current passage and the anode, as well as between the electrolyte and fuel gas. An insulating layer is formed in the gap between the current passage, on the one hand, and the anti-diffusion layer, the electrolyte and the anode, on the other hand, by rolling the precursor at a temperature of 580-600 ^o C. As a precursor, a mixture of magnesia spinel powder with a mixture of IOC having the general formula is used
Me ^{+ A} [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ )] _A ,
where Me is Mg, Al, Zr, Y, Ca, La, and lanthanides;
A is the valency of the metal.

As a precursor, a dispersion consisting of 30% of the powder material and 70% of the liquid phase can be used. As a powder material, magnesia spinel of the composition MgAl ₂ O ₄ with 15% addition of 9YSZ powder is taken, and the liquid phase is a mixture of MOA Al and Mg, where the organic part of the MOA is represented by 2-ethylhexanoic acid. The weight ratio between aluminum and magnesium in the MOC mixture is designed to form, when they are calcined, a compound corresponding to MgAl ₂ O ₄ magnesia spinel.

After applying the insulating layer, the VTTE billet undergoes the final operation — annealing at a temperature of 1200 ÷ 1250 ^o C for 1 hour. Upon completion of annealing, the process of manufacturing VTFC is completed.

 Implementation of the proposed method, in which all the layers of HTFC are applied by the same method — by rolling the precursor, provided that the precursor is heated to its pyrolysis temperature — is carried out on the proposed installation.

 The installation (Fig. 3) comprises a bed 1 with a control unit 2 located on it, inside which there is a rotational drive 3 of the electrode 3 (cathode) of the VTTE blank and a drive 4 of the carriage displacement, in which the device 5 for applying the precursors of the VTFC layers is installed. The device 5 is equipped with a roller 6, which is wetted by the precursor. A heater 8 can be installed inside the hollow electrode through the collet clips 7. The carriage 4 is mounted with the possibility of reciprocating movement on the guides 9 between the stops 10. Inside the control unit 2 there is also a feeder for feeding the precursors, which is equipped with a syringe 11.

 Figure 4 illustrates the operating principle of the installation in the spiral deposition of precursors on the rotating cathode 3 by roller 6. In this case, the cathode is used as a resistance element to which voltage is supplied from the current source 12 through cables 13 and contact graphite rollers 14. Figure 4 shows a section of figure 3 along aa. Fig.6 illustrates the principle of operation of the installation during the reciprocating movement of the roller 6 of the carriage 4 relative to the surface of the cathode 3. The functional layer deposited as a result of the movement of the roller 6 is indicated by the position 15. In Fig.7 shows a section of Fig.6 on aa.

 For applying precursors to the surface of the VTTE billet, a device 5 (Fig. 8) is used, comprising a cylindrical roller 6 installed in the housing 16 with an end face open at the top 17. Gas is supplied to the contact zone of the roller with the cathode through the nozzle 18. The device has a cooling jacket 19, into which a cooling medium, such as water, is supplied through the fittings. To supply the IOC to the device, a nozzle 20 is used. Fig. 9 shows a section of Fig. 8 along AA.

 In the most difficult operating conditions, there is a roller 6 of the device 5, since during the deposition of layers it undergoes sharp temperature changes, and the number of its working cycles is many hundreds of thousands of heat exchanges. In the course of experiments on the production of HTFCs, we tested rollers from various materials: corundum, quartz, zirconium oxide stabilized with yttrium, and beryllium oxide. The best results were obtained on a roller made of beryllium oxide. In order to increase the contact area of the roller with the cathode surface, its outer surface is made with a radius equal to the radius of the supporting cathode.

 In order that the precursor entering the roller 6 does not solidify inside the housing 16 of the device 5 under the influence of high temperature in the knurling zone, the housing is cooled by passing a cooling medium through the jacket 19.

All rolling processes can be carried out both in air and inert gases. In the latter case, an inert gas under slight excess pressure is supplied from the source to the contact zone through the nozzle 18 of device 5. Nitrogen, argon, and carbon dioxide were used as the inert gas during the studies. The operation of the installation as a whole is automated, control of rolling modes is carried out in accordance with a computer program that provides control over the following parameters:
• The speed of the carriage along the VTTE blank;
• The angular velocity of rotation of the VTTE billet;
• The consumption of the precursor supplied to the knurling zone;
• The number of angular steps and the magnitude of the angular step of the VTTE blank;
• By the number of individual layers deposited on the VTTE billet during the formation of each of its functional layers (current passage, anti-diffusion layer, electrolyte, anode and electrical insulating layer).

The device operates as follows. The first applied layer is a current passage, which has the shape of a longitudinal strip on the surface of the cathode. To obtain a strip on the cylindrical surface of the cathode in a sector with an angle α (Fig. 10), the carriage 4 is driven in reciprocating motion, and the cathode using a drive, which uses a stepper motor, after each stroke of the carriage 4 of the device 5 is rotated by an angle equal to α / n, / n, where n is the number of working strokes of the carriage. In practice, this is achieved by moving the carriage between the stops 10. When the carriage reaches one of the stops, the direction of its movement automatically changes. At the moment of reversing the movement of the carriage, the cathode is rotated by a predetermined angle with the help of a stepper motor, after which the carriage starts moving in the opposite direction to the opposite limiter 10. Next, the cycle is repeated until the number of carriage strokes specified by the control program corresponding to the required thickness and bandwidth of the current passage. The precursor of the current passage layer to the point of contact of the roller 6 with the surface of the cathode 3 is transferred by the wetting forces. The part of the roller opposite the contact zone with the cathode surface is constantly washed by the precursor entering the housing 16 of the device 5 for applying the precursor through the nozzle 20. The latter is connected to the syringe 11 of the precursor supply device. The cathode is heated to the pyrolysis temperature of the precursor either using the heater 8 inserted inside it, or due to the ohmic resistance of the cathode when an electric current is passed through it, as illustrated in FIG. 4. As a precursor, a mixture of MOC La, Sr, Cr corresponding to the composition of La _0.7 Sr _0.3 CrO ₃ can be used. The surface temperature on which the precursor is applied is 580-600 ^o C. At this temperature, the precursor is pyrolyzed to form a film of doped lanthanum chromite. The growth rate of the gas-tight film thickness of doped lanthanum chromite is recommended to be maintained in the range of 20–60 μm / h. The width of the strip of the current passage 2 ÷ 3 mm

Next, an anti-diffusion layer 22 is applied to the cathode with the current passage (Fig. 11). To do this, as the source of organic reagents using a mixture of MOC necessary metals. The choice of a particular composition depends on the chemical properties of the metals in the mixture. For the manufacture of an anti-diffusion layer, which is a thin (3 ÷ 5 μm) gas-tight film of the composition (CeO ₂ ) _0.85 (Sm ₂ O ₃ ) _0.15 or (CeO ₂ ) _0.85 (Gd ₂ O ₃ ) _0.15 , a Ce / Sm or Ce / Gd MOC mixture may be used, where the organic part of the MOC is 2-ethylhexanoic acid.

The application process is carried out at a surface temperature in the range 350 ÷ 380 ^o With, rolling method and the same technological method as the current passage (see above). Only in this case does the sector changing the rotation of the stepper motor change; it increases to the angle β (Fig. 11). Thus, the sector where the current passage is applied becomes inaccessible for turning the drive mechanism of the stepper motor. When the roller of the precursor deposition device approaches the current passage, the stepper motor control program switches it to rotate the cathode in the opposite direction. Further, this cycle is repeated using an algorithm similar to the current passage application algorithm until the specified program for the application of the antidiffusion layer is exhausted.

The next operation is the deposition of an electrolyte layer on the surface of the anti-diffusion layer. The setup operation algorithm is similar to the current passage and anti-diffusion layer application. The layer is applied in a sector with an angle β. It is possible to deposit an electrolyte with conductivity by oxygen ions and with conductivity by protons. In the first case, the electrolyte is a 9YSZ layer 10–20 μm thick, which is formed as a result of 150–200 carriage strokes. As a precursor, mixtures of Zr / Y organometallic complexes based on 2-ethylhexanoic acid with a concentration of Zr and Y (in terms of the sum of oxides) (100 ÷ 120) g / kg are used. The process is carried out by heating the surface of the anti-diffusion layer to 410 ÷ 600 ^o C.

In the second case (obtaining a layer with proton conductivity), a mixture of MOK Ba, Ce, and Gd is used as a precursor and knurling is carried out at lower temperatures of 380 ÷ 400 ^o C. As a result, a gas-tight electrolyte film with proton conductivity of the composition BaCe _0.85 Gd _{0 is} obtained _{, 15} O ₃ .

After applying the electrolyte layer, the VTTE blank is removed from the installation and subjected to heat treatment for 2-4 hours in an electric furnace at a temperature of 1250 ÷ 1280 ^o C.

As a result of the operations, the cubic structure of the electrolyte layer is obtained, which is confirmed by measurements on an X-ray diffractometer. Electrochemical measurements showed that the number of transport of oxygen ions in the manufactured electrolyte is almost equal to unity. Figure 12 shows a photograph where an anti-diffusion layer (CeO ₂ ) _0.85 (Gd ₂ O ₃ ) _{0.15 of a} thickness of 3 μm and a 9YSZ electrolyte layer of 7-10 μm thickness are visible on an MLS cathode.

 After annealing, the VTTE billet is again mounted on the installation for applying the anode layer, and then the insulating layer.

As a precursor for obtaining a cermet anode electrode, a mixture obtained as follows is used: MOC - Ni [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] _{2 is} mixed, where Ni (60 g / kg ) with an electrolyte powder (ZrO ₂ ) _0.91 (Y ₂ O ₃ ) _0.09 with a ratio of solid substance / liquid = 1/3. Nickel powder is added to this mixture at a ratio of (T _YSZ / T _Ni ) = 1 / 1.1 and is processed in a mill. On the installation, the mixture is applied to the surface of the electrolyte with a gap with respect to the current passage according to the previously described algorithm at a surface temperature of 260 ÷ 280 ^o C.

Next, the VTTE billet is again removed from the installation and placed in a vacuum chamber, where it is kept at a temperature of 380 ÷ 400 ^o C and a pressure of 0.1 atm for 2 ÷ 3 hours. As a result of heating the MOC, nickel in the mixture decomposes to form metallic nickel, which binds the particles of electrolyte powder and previously mixed nickel powder with a single conductive framework.

After completion of the formation of the anode layer, the workpiece is mounted on the installation for the manufacture of the last functional layer of VTTE - electrical insulating layer. The purpose of this layer is to prevent spurious current bonds between the electrodes and eliminate the effect of the triple point "fuel gas-electrolyte-cathode" in the places where the current passage is output. The electrical insulating layer is applied to the gaps between the side surfaces of the current passage strip and the remaining functional layers of VTTE located opposite them. The electrolyte precursor is also applied to the gap using the roller of the device for applying precursors when moving the carriage along the VTTE blank. The precursor is a mixture consisting of 30% of the powder material and 70% of the liquid phase. The powder material is magnesia spinel of the composition MgAl ₂ O ₄ with 15% addition of 9YSZ powder, and the liquid phase is a mixture of MOA Al and Mg, where the organic part is 2-ethylhexanoic acid. The weight ratio between aluminum and magnesium in the MOC is designed to form, when they are calcined, a compound corresponding to the MgAl ₂ O ₄ magnesia spinel. The application of the precursor is carried out at a temperature of 580 ÷ 600 ^o C.

The final operation of the manufacture of VTTE is the heat treatment of the workpiece, which has all the functional layers (after the formation of the insulating layer), in a thermal furnace at a temperature of 1250 ÷ 1280 ^o C.

 The proposed group of inventions can be used for the production of VTE, when the layers are applied to a rotating anode. In this case, the same equipment and the same processes are used, which are, however, carried out in the reverse order.

 The use of the proposed group of inventions in industry will make it possible to establish serial production of VTTE for various power plants, since a single technological process is implemented using one installation for applying all functional layers, the precursors of which are based on the same organic reagent - 2-ethylhexanoic acid. Compared with currently used methods and installations, the proposed group of inventions allows the use of cheaper raw materials, less expensive equipment and fewer chemicals. Ultimately, as a result of reducing the cost of production of VTTE, it becomes possible to significantly reduce the cost of power plants based on fuel cells, and therefore, their widespread use in the national economy and everyday life.

Sources of information
1. US patent 5271955, IPC B 05 D 5/12, publ. 1992.

 2. US patent 5494700, IPC B 05 D 5/12, publ. 1996.

 3. US patent 5085742, IPC H 01 M 6/00, publ. 1992.

 4. PCT Application WO 98/21769, publ. 05/22/1998.

Claims (14)

1. A method of manufacturing a high-temperature fuel cell, comprising applying to the supporting cathode the functional layers of the fuel cell: current passage, electrolyte, cermet anode, anti-diffusion and electrical insulating layers, characterized in that all layers are applied by successive knurling of precursors, which are a mixture of organometallic complexes formed on based on 2-ethylhexanoic acid and metals included in the functional layers of the fuel cell, while applying a precursor to each of the fungi of national layers is carried out in the following sequence A) a current path in the form of a strip is applied to the heated bearing cathode by rolling the precursor in the form of a liquid mixture containing electrically conductive doped lanthanum chromite powder and an organometallic complex containing chromium, lanthanum cations and doping elements characterized by the formula Cr [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₆ + La ₂ [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₃ + Sr [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₂ , or Ca [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₂ or Mg [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₂ , while the bearing cathode is heated to a temperature providing a gas-tight film of doped lanthanum chromite; B) with a gap relative to the strip of the current path, an anti-diffusion layer is deposited by rolling onto a supporting cathode heated to a temperature providing a gas-tight film of this layer, a precursor, in the form of a liquid mixture of organometallic complexes Ce [O ₂ C-CH (C ₂ H ₅ ) - (CH ₂ ) ₃ -CH ₃ ] ₄ , + Sm ₂ [O ₂ C-CH (C ₂ H ₅ ) - (CH ₂ ) _3- CH ₃ ] ₃ or Gd ₂ [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₃ , C) with a gap relative to the current passage strip, an electrolyte layer is deposited by rolling onto an anti-diffusion layer, heated to a temperature that provides a gas-tight electrolyte layer, a precursor, while organometallic complexes are prepared on the basis of 2-ethylhexanoic acid to produce an electrolyte with oxygen ion conductivity, and organometallic complexes are characterized by the general formula Me ^{+ a} (O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ) _a , where Me is any of the metals included in the manufactured electrolyte of a high-temperature fuel cell, a is the valency of a given metal, and to obtain an electrolyte with proton conductivity, a precursor is applied, characterized by the following formula: SrCe _0.85 Gd _0.15 [O ₂ C-CH (C ₂ H ₅ ) - (CH ₂ ) ₃ -CH ₃ ] ₆ or BaCe _0.85 Gd _0.15 [O ₂ C-CH (C ₂ H ₃₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₆ ; D) a cathode with a current passage deposited on it, an anti-diffusion layer and an electrolyte layer is subjected to heat treatment at a temperature in the range of 1250-1280 ° C for 2-4 hours; E) with a gap in relation to the current passage, the cermet anode layers are applied to the heated electrolyte layer by rolling a precursor paste consisting of an electrically conductive material selected from a group of metal powders consisting of coarse-dispersed nickel and / or cobalt, coarse-dispersed ion-conducting material based on doped zirconia and / or doped cerium oxide and a finely dispersed electronically conductive porous multiphase layer consisting of a metal material selected from the group of nickel and / or cobalt, an ion-conductive doped material based on cerium oxide, moreover, mixtures of organometallic complexes of Ni and / or Co, characterized by the formulas, are used as a binder in the paste Ni [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₂ , and / or Co ₂ [O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₃ , which in the process of thermolysis form an electrically conductive porous multiphase layer, bonding together coarse and finely dispersed phases; E) the cathode with the applied current passage, anti-diffusion layer, electrolyte and cermet anode is subjected to heat treatment in vacuum at a residual pressure of not more than 0.1 atm and a temperature in the range of 380-400 ° C for 2-3 hours; G) the gaps between the current passage, the functional layers of the anti-diffusion electrolyte and the anode are filled with an electrically insulating layer by rolling a precursor consisting of a mixture of magnesia spinel powder and organometallic complexes with the general formula Me ^{+ a} [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ )] _a , where Me is Mg, Al, Zr, Y, Ca, La, and lanthanides; a is the valency of the metal, moreover, the filling is carried out at a temperature of 580-600 ° C. 2. The method according to claim 1, characterized in that the precursor for obtaining the current path strip is applied in an air atmosphere when the cathode is heated from 550 to 600 ° C. 3. The method according to p. 1 or 2, characterized in that the precursor for obtaining a gas-tight anti-diffusion layer is applied in an atmosphere of air at a cathode surface temperature of 350-380 ° C. 4. The method according to any one of claims 1 to 3, characterized in that the organometallic zirconium complex Zr [(O ₂ C-CH (C ₂ H ₅ ) - (CH ₂ ) is mixed to obtain an electrolyte with negative ion conductivity based on zirconium dioxide ) ₃ -CH ₃ )] ₄ with organometallic complexes of at least one of the elements selected from the group Mg, Ca, Sc, Y, Ce: Mg [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₂ , Ca [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₂ , Sc ₂ [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₃ , Y ₂ [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₃ , Ce [(O ₂ C — CH (C ₂ H ₅ ) - (CH ₂ ) ₃ —CH ₃ ] ₄ , and / or other lanthanides Ln ^a [(О ₂ С-СН (С ₂ Н ₅ ) - (СН ₂ ) ₃ -СН ₃ ] _a , where Ln are lanthanides, а is valency, and the prepared precursor is applied in air on the anti-diffusion layer heated to a temperature of 380-600 ° C. 5. The method according to any one of claims 1 to 3, characterized in that, to obtain a proton electrolyte, the precursor is applied to the anti-diffusion layer in an air atmosphere at a temperature of the last 380-400 ° C with the formation of a proton electrolyte film of the composition SrCe _0.85 Gd _0.15 O ₃ or BaCe _0.85 Gd _0.15 O ₃ . 6. The method according to any one of claims 1 to 5, characterized in that the precursor for the formation of the anode layer is applied in an atmosphere of air to an electrolyte heated to a temperature of 260-280 ° C. 7. Installation for the manufacture of a high-temperature fuel cell, comprising a drive for rotating the carrier hollow cathode and a device for applying components — layers of the fuel cell — to the last precursor, characterized in that the installation is equipped with a heater for the carrier cathode to the thermolysis temperature of the applied precursor, and a mechanism for moving the device for applying the precursors layers of the fuel cell relative to the cathode and the control unit, while the device for applying the precursors of the layers of the fuel cell nta is made in the form of a cylindrical roller located in the housing with an open end and protruding above the last one, forcedly wetted by a precursor corresponding to the applied layer of the fuel element and coming from an additionally installed feeder with a control device, the drive of rotation of the bearing cathode is made in the form of a stepper motor, the movement mechanism is in the form of a carriage in which a device for applying precursors is installed, and a mechanism for moving, a drive for rotation and a control device The feeder is made controllable from the control unit. 8. Installation according to claim 7, characterized in that the casing of the device for applying the precursors of the layers of the fuel cell has water cooling. 9. The apparatus according to claim 7 or 8, characterized in that an inert gas supply channel is made in the housing of the device for applying the precursors of the fuel cell layers to the contact zone of the roller of the device for applying the precursors of the fuel cell layers with the supporting cathode. 10. Installation according to any one of claims 7 to 9, characterized in that the roller of the device for applying the precursors of the layers of the fuel element is installed in the housing with the possibility of rotation by 90 ° relative to the vertical plane. 11. Installation according to claim 7, characterized in that the carrier electrode heater is made in the form of a spiral heater placed in a quartz tube placed inside the carrier cathode. 12. Installation according to claim 7, characterized in that the carrier cathode heater is made in the form of an electric current source and rotating contacts connected with it by a cable - graphite rollers pressed against the carrier cathode. 13. Installation according to any one of paragraphs.7-10, characterized in that the roller of the device for applying the precursors of the components of the fuel cell is made of ceramic based on BeO. 14. Installation according to any one of paragraphs.7-10, 13 and 14, characterized in that the outer surface of the roller is made with a concave radius corresponding to the radius of the bearing cathode.

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