RU2280297C2 - Using sulfur-containing fuels for directly oxidizing fuel cells - Google Patents

Abstract

FIELD: solid oxide fuel cells.

SUBSTANCE: proposed fuel cell has solid electrolyte incorporating electron conductor enabling anion transfer, composite cermet anode, and cathode. Fuel cell also has sulfur-containing hydrocarbon fuel whose sulfur content is approximately 1 to 5 000 ppm and oxygen source. Invention specification includes method for power generation in fuel cell and method for recovering serviceability of fuel cell deactivated due to sulfur poisoning. Invention specification also includes method for producing porous cermet used as directly oxidizing anode covered, like substrate, with electrolytic structure for solid oxide fuel cell using nickel cermet. Nickel cermet is leached out to remove at least some portion of nickel and to obtain porous oxide. The latter is then pre-impregnated with copper salt to elementary CuO state, then reduced to copper. Copper cermet or copper-nickel alloy cermet produced in the process can be used as directly oxidizing anode. Preferable source material for nickel cermet is strip molded from NiO-containing suspension and YSZ-containing ceramic powder. This strip is combined in stack with one or more additional strips molded from ceramic powder containing suspension.

EFFECT: ability of fuel cell to oxidize hydrocarbon fuel in environment of organic sulfur compounds.

73 cl, 20 dwg

Description

FIELD OF THE INVENTION

This invention relates to fuel cell technology and, more specifically, to a solid oxide fuel cell capable of operating with sulfur-containing hydrocarbon fuel, as well as to methods for producing such fuel cells and their use for generating electrical energy.

Description of the prototype.

Solid Oxide Fuel Cells ((SOFCs) (SOFCs)) are recognized as a viable high-temperature source of electrical energy. Since the operating temperature of said fuel cells is typically greater than ^about 600 C and may be as high as ^{1000 °} C, materials used for components of the fuel cell, are limited in that they must be resistant at such temperatures. The electrolyte of fuel cells is made mainly of dense ceramic materials. The electrolyte conducts oxygen anions (O ^2- ), but is an electronic non-conductor.

It is known to obtain anode materials for solid oxide fuel cells using nickel (Ni) cermets obtained from yttrium oxide stabilized zirconia powders (YSZ). NQMinch, Journal of the American Ceramic Socieety, 76 , 563 (1993), the entire disclosure of which is incorporated herein by reference. The high temperature calcination at 1200 ^{° C} is necessary to obtain the required ionic conductivity in the YSZ-anode portion.

In most conventional fuel cells, hydrogen gas is either supplied directly to the anode or obtained by steam conversion of hydrocarbons such as methane. Steam conversion is expensive and significantly complicates the system. Dry methane has been proposed, but Ni catalyzes the formation of carbon fibers in dry methane, leading to the formation of carbon on the anode. Ni-containing anodes can be used if only the fuel cells introducing them operate at steam / methane ratios greater than 1.7. However, there are significant benefits to working in dry conditions. These include easy heat control, the absence of the need for additional steam and the possibility of lower operating temperatures due to the fact that the equilibrium for direct oxidation is always favorable.

Some of the drawbacks of nickel-containing anode materials in SOFCs are eliminated by using copper-containing anodes. See, for example, R. Gorte et al., Advanced Materials , 12 , 1465-69 (2000), the full description of which is incorporated herein by reference. It is indicated that replacing nickel with copper in the anode material makes it possible to avoid carbon formation when using dry hydrocarbon fuels See S. Park et al., Nature, 404 , 265-57 (2000), the full description of which is incorporated herein by reference.

Fuel cells typically work with hydrogen as fuel. It has been proposed to replace hydrogen with commercially available and more economical hydrocarbon fuels such as natural gas, gasoline, diesel, oil, fuel oil, etc. Such crude fuels are not currently used as a fuel source suitable for a fuel cell because these fuels contain relatively high levels of sulfur, often in the form of natural complex organic sulfur compounds. For example, gasoline sold in the United States has an average sulfur level of 300 ppm. In addition, sulfur compounds such as mercaptans and thiols are introduced as odorants into natural gas at a level between 10 and 20 ppm, so that leaks can be detected.

Most conventional fuel cells run on hydrogen gas. Oxidation in the presence of sulfur leads to toxic effects on the catalyst used in the hydrogen generation system, often including the anode catalyst of the fuel cell. Accordingly, the hydrocarbon fuels currently used in fuel cells are typically desulfurized and then reformed to hydrogen gas.

In one such operation, conventional fuel processing systems used with stationary fuel cell power plants include a thermal steam reformer, such as described in US Pat. No. 5,516,344. In such a fuel processing system, sulfur is removed by conventional hydrodesulfurization technology, which is usually based on some kind of recycling process such as hydrogen source for the process. Recycled hydrogen combines with organic sulfur compounds to form hydrogen sulfide in the catalytic bed. Hydrogen sulfide is then removed using a layer of zinc oxide to form zinc sulfide. The conventional hydrodesulfurization process is described in detail in US Pat. No. 5,292,428. When such a system can be used in large stationary applications, it gives the systems significant complexity.

Other fuel processing systems, such as traditional autothermal reformers, which have a higher operating temperature than traditional thermal steam reformers, can produce hydrogen enriched gas in the presence of the above complex organic sulfur compounds without prior desulfurization. According to US Pat. No. 6,159,256, when using an autothermal reforming unit for processing crude fuels containing complex organic sulfur compounds, the result is a loss of catalyst efficiency of the autothermal reforming unit and the lifetime of the used catalyst of the rest of the fuel processing system. It is indicated that before the reforming product is fed to the fuel cell, the H ₂ S concentration should be reduced to 0.05 ppm. Work Y.Matsuzaki and I.Yasuda, SOFC VII, Proceeding of the 7 ^{th Intern.Symp, Electrochemical Society, Pennington,} NJ, 2001: A. 16 (2001), p. 769.

Alternatively, sulfur in the form of hydrogen sulfide can be removed from the gas stream by passing the gas stream through a liquid scrubber such as sodium hydroxide, potassium hydroxide or amines. Liquid scrubbers are large and heavy and therefore are used mainly only in stationary fuel cell power plants.

A brief description of the invention.

The objective of the invention is to overcome the problems associated with the presence of complex organic sulfur compounds in a hydrocarbon fuel stream for use in a fuel cell without increasing the complexity of fuel processing.

Another objective of this invention is to provide a fuel cell that can work with sulfur-containing hydrocarbon fuels.

Another objective of this invention is the creation of a fuel cell that can work with fuel, which should not be subjected to pre-treatment to remove complex organic sulfur compounds.

Another objective of the present invention is to provide a method in which a fuel cell that is contaminated with sulfur can restore full characteristics after decontamination by sulfur poisoning.

Another objective of the present invention is to provide a method for producing a porous direct oxidizing anode for a solid oxide fuel cell using nickel sintered metal as a starting material.

Another objective of this invention is to provide a method for producing a layered ceramic structure containing an oxidizing anode with an electrolyte deposited on it as a substrate, which can introduce an additional layer to give the structure a higher strength.

Another objective of this invention is to provide a method for producing a porous copper or Ni-Cu metal-ceramic alloy for use in a porous oxidative anode for a solid oxide fuel cell.

Another objective of the present invention is to provide a solid oxide fuel cell having a ceramic metal alloy composite anode that works efficiently using dry sulfur-containing hydrocarbon fuel.

Another objective of the present invention is to provide a method for producing electrical energy using the above SOFC.

These and other problems are solved according to the present invention, which contains a solid oxide fuel cell containing a solid electrolyte, which is an electronic non-conductor, which allows the transfer of anions, a ceramic-metal composite anode and cathode, and which operates using a fuel that contains sulfur-containing hydrocarbon and has a sulfur content from about 1 ppm to about 5000 ppm, and an oxygen source.

The hydrocarbon may be an oil distillate selected from the group consisting of gasoline, diesel, naphtha, JP-4, JP-5, JP-8, kerosene, autol, natural gas and fuel oil. Other preferred hydrocarbons and their derivatives are alcohols, including ethanol and methanol, and dry methane, butane, toluene and decane. Mixtures of hydrocarbons may also be used. Sulfur-containing fuels preferably have a sulfur concentration of from about 1 ppm to about 1000 ppm, and more preferably, a sulfur concentration of from about 1 ppm to about 500 ppm.

The invention also provides a method for producing electrical energy. The method of the invention comprises the creation of a solid oxide fuel cell containing an electrolyte, which is an electronic non-conductor, which allows the transfer of anions, a cermet composite anode and cathode, and additional steps of contacting the cathode of the fuel cell with an oxygen source and contacting the anode with a sulfur-containing hydrocarbon fuel having sulfur content from about 1 ppm to about 5,000 ppm

The invention further provides a method for restoring the characteristics of a fuel cell deactivated by sulfur poisoning by heating the anode in water vapor for a period of time sufficient to effectively remove sulfur.

The present invention further provides a method for producing porous copper cermet or cermet from a copper-nickel sintered nickel cermet alloy with a nickel content of between about 10% and about 60% for use as an oxidizing anode. The method comprises leaching at least a portion of nickel from cermets with an increase in porosity of cermets. Cu is then introduced back into the porous structure to form Cu-cermets. In one embodiment, the porous structure is impregnated with a soluble copper-containing impregnating agent, preferably a copper salt. The impregnated cermets are subjected to a temperature sufficient to convert the copper-containing impregnating substance to copper oxide, which, in turn, is reduced to elemental copper, resulting in the formation of cermet or cermet from a copper-nickel alloy depending on the amount of nickel removed during the leaching stage .

In a preferred embodiment, the multilayer ceramic part is obtained with one layer containing NiO and YSZ, and the other with YSZ only. These layers each can be formed by traditional tape casting technology. In carrying out this embodiment of the invention, a suspension suspension of the first tape casting containing a binder, carrier and ceramic powder containing nickel oxide and zirconia stabilized with yttrium oxide (YSZ) and optimally an organic blowing agent is applied to a substrate (such as a Mylar film) and formed in the first tape. The casting recipe of the second tape is obtained by forming a suspension containing a binder, a carrier and a ceramic powder, at least part of which is YSZ. The suspension of the casting of the second tape is applied to the substrate, which may be the first tape, and formed into a second tape. The specified second tape after sintering forms a dense YSZ, which serves as an electrolyte.

The first tape and the second tape are laid on top of each other to provide a laminate preform. The laminate preform is heated to a temperature sufficient to sinter the ceramic powder, after which nickel oxide is reduced to elemental nickel. The resulting laminate is then processed in the manner described above to convert the nickel cermet into an oxidizing anode material.

The present invention also provides a method of hardening the aforementioned oxidative anode with or without electrolyte deposited on it as a substrate. The method includes the formation of another tape casting formulation that is used to provide a reinforcing layer on the aforementioned laminate preform. The formulation is in the form of a suspension containing a binder, carrier and ceramic powder containing YSZ or another compound, the coefficient of thermal expansion of which during sintering is compatible with the coefficient of thermal expansion of sintered YSZ. A suspension of this formulation of the casting of the third tape is applied to the carrier substrate and formed into a third tape. The thickness of the third tape is relatively greater than the thickness of the second tape. The third tape is perforated to form at least one hole and, preferably, several holes through the thickness of the tape. A perforated third tape is applied to the porous first tape. The three-layer preform is then sintered and further processed to remove Ni in the above manner to obtain a hardened direct oxidizing anode with an electrolyte structure deposited on it as a substrate. The resulting three-layer structure has greater mechanical strength than a two-layer laminate.

The present invention also provides a solid oxide fuel cell comprising a solid electrolyte consisting of an electrical non-conductor that allows the transfer of anions, anode and cathode. Anode material, with or without an electrolyte deposited thereon, is prepared using the methods described above.

The present invention further provides a method for producing electrical energy. The method comprises the steps of providing a solid oxide fuel cell as described immediately above, contacting the cathode of such a fuel cell with an oxygen source, and contacting the anode of the fuel cell with fuel.

A brief description of the drawings.

Figure 1 presents a diagram of the solid oxide fuel cell of the invention.

Figure 2 presents a diagram of a fuel cell, which is suitable for use in the implementation of the present invention.

In FIG. 3, 4, 5, 6, and 7 are diagrams showing a preferred method for producing the anode of the invention.

On Fig presents a diagram illustrating the method of obtaining according to this invention.

Figure 9 presents a photograph of three crude tapes used to obtain a hardened direct oxidative anode with an electrolyte deposited on it as a substrate, together with the structure after firing.

Figure 10 presents a diagram of a side view of the components of a solid oxide fuel cell.

Figure 11 presents the current-voltage characteristics obtained with a fuel cell of the invention using sulfur-free decane, toluene and diesel fuel as fuel.

On Fig presents the current-voltage characteristics obtained from a fuel cell of the type shown in figure 2, using n-decane containing various concentrations of sulfur.

13 shows the maximum current density of a fuel cell operating with 40 wt.% N-decane containing 5,000 ppm sulfur in dry nitrogen in a fuel cell having a copper-yttrium stabilized zirconia anode without content cerium oxide.

On Fig presents the current-voltage characteristics of a fuel cell having a zirconia anode, stabilized copper-cerium oxide-yttrium oxide, and worked with 40 wt.% N-decane containing 5000 ppm sulfur in nitrogen gas.

On Fig presents x-ray for the anode of zirconia stabilized with copper-cerium oxide-yttrium oxide, after various processing conditions.

On Fig presents the current-voltage characteristics for a fuel cell that worked with 40% industrial gasoline in dry nitrogen gas.

On Fig presents the current-voltage characteristics for a fuel cell that worked with 10% industrial gasoline in dry nitrogen.

On Fig presents the current-voltage characteristics for a fuel cell that worked with a dean containing various concentrations of sulfur.

On Fig presents the change in the resistance of the anode obtained from Cu, in hydrocarbon fuel containing 5000 wt.% Sulfur, when the conductor is heated to 700 ^about C.

On Fig presents the main characteristics of the fuel cell in comparison with the current density curves for the operation of the solid oxide fuel cell of the invention at 700 ^about With the use of hydrogen and butane as fuels. Hydrogen is shown on the curves in a circle, and butane - in a square. The open circle and square indicate the results related to the voltage of the fuel cell. A shaded circle and a square indicate power-related results.

Description of preferred options.

In FIG. 1 and 2 show, respectively, a diagram of a solid oxide fuel cell and a diagram of a fuel cell of the invention. According to FIG. 1 and 2, molecular O ₂ from the oxygen source is reduced to O ^2– anions at the cathode, after which O ^2– diffuses through the electrolyte to the anode, where it oxidizes the fuel, in this case, hydrocarbon fuel. An external current is generated by the flow of electrons from the anode through the external circuit to the cathode. Water and carbon dioxide are also produced by the oxidation reaction at the anode and are removed from the fuel cell.

The electrolyte is an electronic non-conductor that allows the transfer of ions. The electrolyte is preferably an oxide ion conducting material. Suitable oxide ion conducting materials include doped ceria, such as cadmium doped with gadolinium, ceria, samarium doped, zirconia doped with zirconia, doped with zirconia, doped with yttria and zirconia with doped calcium, and doped lanthan gallate, such as strontium doped lanthan gallium oxide. Other suitable oxide ion conducting materials are bismuth or vanadate oxides, perovskites containing manganese, cobalt, iron, nickel, vanadium, chromium or other metals. Preferably, the electronic non-conductor is doped cerium oxide or doped zirconia, and most preferably, yttria stabilized zirconia. See, for example, US Patent Nos. 6,214,485 (Barnett et al.) And 6303098 (Kramarz et al.), Which are incorporated herein by reference, and US Patent No. 5,670,270 (Wallin).

The anode / electrolyte structure of the fuel cell of the invention can be obtained by any suitable methods, some of which are given as an example immediately below. For example, an unsintered mixture of electrically conductive and ion-conductive materials can be deposited on a layer containing sintered or unsintered ion-conductive electrolyte material before sintering, providing sufficient contact between the layers, as shown in the method of the second aspect of the invention. In one embodiment of such a method, a mixture of ion-conductive and electron-conductive materials is deposited on an unsintered layer of electrolyte material, and the mixture and the electrolyte layer are sintered simultaneously. In another embodiment, the mixture is applied to a pre-sintered electrolyte layer and then sintered.

A mixture of ion-conducting and electron-conducting particles can be deposited on a layer containing particles of electrolyte material (hereinafter “the electrolyte layer”) by any suitable methods, such as, for example, methods of casting a tape, screen printing or silk-screening of a suspension of material (materials) on an electrolyte structure.

Other methods of forming the electrode / electrolyte structure are tape calendering and slip casting. Calendering of a tape typically includes the steps of forming an electrically conductive tape from an electrically conductive component, as well as forming a tape from an electrolyte component. The tapes are then rolled along with the molding of a multilayer composite tape. In slip casting, a suspension of a conductive ceramic material and a liquid carrier, such as water, optionally with an organic binder and surfactants, is molded to form the desired molded product. The individual amounts of ceramic material, organic binder, and liquid carrier may vary depending on the density required in the cast product. The obtained cast product is dried and calcined in the traditional way to obtain the desired electrode. See also, for example, US patent No. 6270536 (Minh) and 5670270 (Wallin), the full description of which is given here by reference.

In a preferred embodiment of the present invention, the cermet composite anode of the fuel cell is preferably obtained as shown in FIG. 3, 4, 5, 6, and 7. In this method, yttrium oxide stabilized zirconia powder (YSZ) is mixed with a polymer and sprayed onto a suitable film material, for example Mylar, to produce a crude ribbon. Then, a similar polymer-YSZ-suspension is mixed with a blowing agent and applied to the treated surface of the first tape, which does not contain a blowing agent. The cast tapes are then co-sintered to form a porous layer consisting essentially of porous YSZ on a generally flat sheet of relatively dense YSZ. A pore former, for example, carbon particles, is consumed during the sintering step and essentially does not remain in the resulting porous YSZ layer.

Then the material is introduced into the anode impregnation with aqueous copper using a concentrated salt solution, for example Cu (NO _{3) 2,} followed by calcination at a temperature of about 600 ^C for a period of about two hours to give the nitrate decomposition and formation of oxides. The reduction of copper oxide gives an elemental form of copper. The resulting material has sufficient mechanical strength of the anodes with electrolyte deposited on it as a substrate.

The metal content in the anode material is at least 10 wt.%, Preferably 25 wt.%, And more preferably at least 35 wt.%.

Copper is the preferred metal for use in the anode, but the metal may be an alloy, such as an alloy of copper with a second conductive metal. The alloy contains between about 5 wt.% And about 95 wt.% Copper and about 5-95 wt.% The second metal and, more preferably, between about 50 wt.% And about 90 wt.% Copper and about 10-50 wt. % of the second metal. One hundred percent (100%) Cu is preferred.

Other components, including cerium oxide (CeO ₂ ), are preferably introduced using some impregnation methods. (CeO ₂ ) plays a dual role in the anode. Firstly, it provides ionic and electronic conductivity, increasing as a result the created reaction zone, where the gas phase, ionic conductor and electronic conductor go together, which is usually called a three-phase circuit, or TRV. Secondly, (CeO ₂ ) provides catalytic activity for the oxidation of hydrocarbons.

The term “consisting essentially of yttrium oxide stabilized zirconia”, as used in relation to a porous layer of a ceramic-metal composite anode, is intended to mean the absence of essentially any fibrous component in such a layer whose function is to impart porosity to the layer when it becomes component of the final anode material (as opposed to pore formers that are consumed in the sintering process), and, in particular, the absence of zircon fibers and the like, which Due to the silicon-containing surface coating, they have a deteriorating effect on the characteristics of SOFC.

The term "oxygen source", as used here, means air and oxygen in a more purified form than that present in the air.

The term "fuel", as used here, means hydrogen or any hydrocarbon fuel, in which a hydrocarbon is defined as any combustible compound that consists of or includes hydrogen, carbon and oxygen as main elements.

As indicated above, conventional fuel cells use hydrogen as fuel. The solid oxide fuel cells of the invention are intended to operate with a wide range of hydrocarbon fuels, including mixtures of these fuels. Sulfur-containing hydrocarbons may also be used. Sulfur-containing hydrocarbons include, but are not limited to, petroleum distillates such as gasoline, diesel, naphtha, JP-4, JP-5, JP-8, kerosene, motor fuel, natural gas, and fuel oil. Other preferred hydrocarbons and derivatives are alcohols, including ethanol and methanol, and dry methane, butane, toluene and decane. The fuel element of the invention typically operates at about 650-900 ° ^C.

A fuel cell of the invention can successfully operate with hydrocarbons containing between 1 ppm and 5,000 ppm of sulfur. As shown below, the fuel cell of the invention works successfully with hydrocarbons containing between 250 ppm and 5000 ppm of sulfur, including 500 ppm and 1000 ppm of sulfur. It is preferable to use hydrocarbons containing from 1 ppm to 1000 ppm of sulfur as a fuel, and more preferably from 1 ppm to 500 ppm of sulfur. Industrial gasoline is a suitable fuel. Depending on established rules and other requirements, industrial gasoline typically has about 300 ppm of sulfur, but may, for example, have sulfur concentrations of less than about 10 ppm, about 10 ppm, about 20 ppm, or approximately 100 ppm

As indicated above, there is no noticeable deterioration in the efficiency of the fuel cell when using hydrocarbons with sulfur concentrations below 1000 ppm for a method such as a cyclic method in which the fuel cell is operated for ten (10) hours or less. For a method involving continuous use of a fuel cell for one hundred (100) hours or more, there is no noticeable deterioration in fuel cell efficiency when using hydrocarbons with sulfur concentrations below 100 ppm. In the event that the fuel cell becomes deactivated sulfur poisoning, the characteristics of the fuel cell can be restored by heating the anode in pairs. In a preferred embodiment, the heating process is carried out in a mixture of steam and diluent, preferably N ₂ or CO _2. Preferred steam to CO ₂ ratios are between 100: 0 and 5:95. The anode is preferably heated for reactivation at a temperature between about 600 ^C and about 800 ^{° C,} and preferably at about 700 ^C for a period of one (1) to five (5) hours, and most preferably for about one (1) hour to about three (3) hours.

In accordance with the preferred characteristic of the invention shown in the diagram in Fig. 8, the starting material is nickel-cermet (Ni and YSZ composite containing at least 10% Ni so as to provide electronic conductivity) obtained by known technology. See, for example, NQMinh, Journal of American Ceramic Society, 76 : 563 (1993). The reduction of NiO to elemental nickel gives the cermet a porous nature. Cermets are in contact with the leaching agent to remove at least a portion of nickel with an increase in porosity of cermets. The cermet is then contacted with a copper-containing impregnating agent. The porous copper-containing cermets are then further processed to obtain porous copper cermets or cermets from a copper-nickel alloy (depending on the amount of nickel removed during the leaching process), which is used as an oxidizing anode material for a solid oxide fuel cell.

In the preferred embodiment above, the ceramic powder of the first tape casting formulation contains a ceramic powder containing NiO and YSZ, a binder and water as a carrier so as to form a suspension. The backing sheet is preferably a Mylar cellulose acetate film. The casting formulation of the first tape also preferably includes glycerin as a plasticizer and a blowing agent. The suspension of the casting of the first tape is applied to the carrier substrate and formed into the first tape.

Then, the casting of the second tape is obtained in the form of a suspension containing a binder, a carrier and YSZ powder. The casting recipe of the second tape does not contain any ingredient acting as a blowing agent. A suspension of the casting of the second tape is applied to the carrier substrate and formed into a second tape. The first tape can conveniently serve as a carrier substrate for the second tape, or a separate backing material can be used, if desired. In any case, the tapes are superimposed on each other with the formation of a packet, and after sintering, the first tape turns into a direct oxidizing anode, while the second tape becomes electrolyte deposited on it like on a substrate.

The amount of water used in the suspension for casting the tape is preferably about 20-40 wt.% In relation to the total weight of the composition. The formulations may additionally contain minor amounts of known processing aids, such as dispersants and anti-foaming agents. The amount of dispersant and antifoam can be about 1-5 wt.% And 0.05-0.5 wt.%, Respectively, relative to the weight of the ceramic powder.

In a preferred embodiment, the casting of the first tape also contains, in addition to NiO, another blowing agent. Preferably, the other blowing agent is organic material. Particularly preferred blowing agent is powdered graphite.

The multilayer tape is usually removed from the back sheet to allow sintering of the tape to form the ceramic product. Removing the back sheet may not be necessary if the sheet decomposes easily during sintering.

Casting can be carried out by any known tape casting technology. A preferred casting method is the traditional casting of a tape with a doctor blade, comprising the following steps. First, the suspension is poured onto the back sheet, which is usually supported by a flat plate. The back sheet and suspension are then passed through a squeegee apparatus at a height above the sheet corresponding to the desired tape thickness. The resulting tape is then dried to increase its strength and reduce thickness. The binder cures during casting and drying, after which it is cooled to room temperature. The dried tape preferably has a thickness of about 25-2500 microns.

In this preferred embodiment, the time and temperature of sintering the multilayer stack or laminate preform may vary, but sintering is preferably conducted at 1500 ^C for two hours. The sintering step consumes all or part of any organic blowing agent, resulting in a porous first ribbon.

After performing the sintering step, NiO is reduced to elemental nickel, as shown in FIG. Generally this step is carried out by reduction in hydrogen gas at a temperature above 500 ° ^C. Then, at least part of the elemental nickel is leached from the bag. The preferred way to carry out this step is to contact the bag with hot nitric acid, which effectively dissolves nickel with an inconspicuous dissolution of YSZ. Nitric acid can be replaced, if desired, with another leaching agent that selectively dissolves nickel. Preferably, all nickel is leached. In another preferred embodiment, approximately 50-99% of nickel is leached. Removing nickel results in an increase in porosity of the first tape.

After carrying out the leaching step, the bag is impregnated with a copper-containing impregnating substance, preferably Cu (NO ₃ ) ₂ . The amount of said material is preferably chosen so as to obtain an amount of elemental copper that is approximately equivalent to the mass of elemental nickel leached in the leaching stage. Material is converted to copper oxide by calcination at a temperature not lower than 600 ° ^C. The copper oxide is then reduced to elemental copper by reduction usually in hydrogen gas at about 500 ^{° C,} thereby obtaining a pryamookislitelnogo anode.

The copper content in the anode material is at least 15 wt.%, Preferably 25 wt.% And more preferably at least 35 wt.%. In an embodiment of the invention in which the metal is a copper-nickel alloy, the alloy preferably contains between about 5 wt.% And about 95 wt.% Copper and about 5-95 wt.% Nickel.

Other components, including CeO ₂ , can be introduced into the anode portion of the bag using the same impregnation method described above. CeO ₂ plays a dual role in the anode. Firstly, it provides ionic and electronic conductivity, increasing as a result the created reaction zone, where the gas phase, ionic conductor and electronic conductor go together, which is usually called a three-phase circuit, or TRV. Secondly, CeO ₂ provides catalytic activity for the oxidation of hydrocarbons.

The method of producing a two-layer laminate preform can be modified by introducing a third tape into the bag, which will serve as a reinforcing layer in the final structure, as shown in FIG. 9 and 10. According to this method, the casting of the third tape is obtained in the form of a suspension containing a binder, a carrier and ceramic powder, but without a blowing agent. The ceramic powder may contain YSZ, as before, or another material, such as MgAlO _2, which has a thermal expansion coefficient that is compatible with the thermal expansion coefficient of sintered YSZ. The thickness of the third tape is made relatively greater than the thickness of the second tape. The third tape is perforated to form at least one hole through the thickness of the tape to allow gas and liquid (for example, a solution of copper salt) to pass through the tape. Perforation preferably has a periphery with a continuous curved contour, i.e. without sharp corners that contribute to cracking or destruction of the material. A perforated third tape is applied to the laminate preform in contact with the porous first tape.

The resulting element is then heated to sinter the ceramic powder at 1500 ^{° C} for several hours. Any NiO in the middle layer is then removed by reducing it to Ni and removing it by leaching. Compared with the porous direct oxidizing anode in the two-layer package described above, with the introduction of the reinforcing layer, the three-layer package has a greater mechanical integrity.

After sintering a three-layer package, the element can be subjected to the additional steps described above with respect to the two-layer package, with the introduction of copper or a copper-nickel alloy as well as CeO ₂ as a metal conductor _. The layers of this package are shown in Fig. 9 together with the laminate structure after roasting. The final fuel cell (prior to the introduction of Cu) representing this aspect of the present invention is shown in FIG. 10. Preferably, the electrolyte layer has a thickness of <100 μm, the porous layer is between about 100 μm and about 1000 μm, and the substrate is between about 300 μm and about 5000 μm.

In a solid oxide fuel cell, the anode should catalyze the reaction of hydrocarbon fuel with O ^2- from the electrolyte. Since electrons are obtained in this reaction, the anode must be electrically conductive. Finally, the anode should have a coefficient of thermal expansion approaching the coefficient of thermal expansion of a dense YSZ electrolyte to minimize cracking. A copper or copper-nickel anode provides electrical conductivity or the necessary electrical connection of the anode. Copper also acts as an electronic or current collector for electrons obtained during the catalytic reaction of fuel with O ^2-.

The copper collector and the solid oxide fuel cell anode connection have a number of shapes, including (but not limited to) gratings, wire mesh, wires, plates (both flat and with corrugations or protrusions), tubes, and other structural and preformed shapes.

In addition to using collectors and compounds that are made of pure copper or copper-nickel alloys, other Cu-coated metals can be used. For example, stainless steel has better mechanical properties than Cu at high temperatures. One way to take advantage of the mechanical properties of stainless steel or other metals while maintaining the inert chemical properties of Cu is to deposit Cu on the structural metal. For these systems, the reactivity of the metal is passivated or excluded by coating non-reactive Cu. The Cu coating allows the use of a number of metals in addition to Ni, including (but not limited to) Fe, W and metal alloys such as (but not limited to) ferritic steels (e.g. FeCrAl alloys), nickel alloys (e.g. Inconel 617) and Cr alloys (for example, Cr ₅ FeY ₂ O ₃ ), as collectors and compounds in SOFCs that operate on dry hydrocarbons. In addition to improved heat resistance of Cu-coated metals, the use of copper-coated metals and alloys has the added benefit of reduced cost. Copper-coated metals and alloys that are used as collectors and compounds can take a wide range of forms, such as those indicated above for pure Cu.

The invention can be used in all SOFCs, for portable generators and for use, for example, in cars, ship engines and the generation of electrical energy.

The following examples are provided for illustration only, and not to limit the invention.

Example 1

A solid oxide fuel cell having a porous copper-ceramic composite anode is obtained by the double-strip casting technology described above, which is described in more detail in R. Gorte et al., Advanced Materials, 12 : 1465-69 (2000).

Example 2

A solid oxide fuel cell is prepared according to the present invention as follows. The tape of YSZ powder, polymeric binder and the carbon powder porogen is applied to one surface of YSZ-belt without porogens and calcined at 1500 ^C for two hours. The cathode is formed from 50 wt.% Physical mixture of Sr-LaMnO ₃ and YSZ powder, spread on the opposite surface of the electrolyte in the compressed glycerol suspension, and then heated at 1250 ^C for two hours. Then YSZ-porous layer is impregnated with an aqueous solution of Cu (NO _{3) 2} (Fisher Scientific) ₂ and Ce (NO _{3) 3.} After calcination at 950 ^{° C} for two hours, the copper salt is converted to metallic form by heating at 800 ^{° C.} in H ₂ .

Example 3 (comparative test).

The solid oxide fuel cells of examples 1 and 2 are tested to determine their characteristics when using sulfur-free hydrocarbon as fuel. The fuel element of Example 1 is operated with 40 wt.% Hydrocarbon in dry nitrogen at ⁷⁰⁰ ° C, and determine the values of voltage, current density and power density as a function of time. The hydrocarbons used are decane, toluene and diesel. The results, as shown in FIG. 11, are typical results obtained for such tests.

Example 4

In order to determine the sensitivity of the anodes to sulfur, fuels containing different levels of sulfur are obtained by mixing thiophene with n-decane to obtain sulfur concentrations (wt.% Sulfur) in n-decane 250, 500, 1000 and 5000 ppm. The n-decane / thiophene fuel mixture is used as fuel in the fuel cell under the conditions given in Examples 1 and 2 above. The concentration of the n-decane / thiophene fuel mixture is 40 wt.% With dry nitrogen gas constituting the remainder of the fuel. The results for voltage and current density measured over time for n-decane / thiophene fuel mixtures with the indicated various sulfur concentrations are shown in FIG. 12. These results show a very slight decrease in performance for n-decane / thiophene fuel from 250 ppm. 12 also shows that said n-decane / thiophene fuel slightly decreases its performance with increasing sulfur concentration. This result is consistent with FIG. 11, which shows no change in performance over time when using n-decane, which does not contain sulfur. 12 shows that the use of hydrocarbon fuel containing n-decane with a sulfur concentration of 250 ppm (obtained by the introduction of thiophene) gives only a very slight decrease in performance after twenty four (24) hours. 12 also shows that the use of hydrocarbon fuel with 1000 ppm sulfur gives a slightly higher degree of reduction in fuel cell performance, but that the fuel cell still works close to its original capacity for ten (10) hours. This result shows that the fuel cell can work very efficiently with hydrocarbons containing at least 1000 ppm sulfur, and it works even when the hydrocarbon fuel contains up to 5000 ppm sulfur.

Example 5

The test procedures used in Example 4 are repeated, except that the fuel cell contains an anode of zirconia stabilized with yttrium oxide not containing cerium oxide. The fuel used is n-decane with 5,000 ppm sulfur (obtained by the introduction of thiophene). The fuel cell operates with a shorted cell (i.e. at maximum current). The current density of the element is determined over time, and the results are shown in FIG. 13 shows that high sulfur levels are not affected by current density even after six (6) hours. The open circuit voltage (0.9 V) (not shown) also does not change. Visual inspection of the anode suggests that sulfur does not affect copper. This control, in combination with the data presented in FIG. 13, further shows that the use of hydrocarbon fuels containing very high levels (i.e., 5000 ppm) of sulfur does not affect the Cu component or the characteristics of the element, containing an anode in which copper is used for electrical conductivity. The general characteristic of a fuel cell that contains Cu but without cerium oxide, however, is not good, showing that incorporation of cerium oxide into the anode improves performance.

Example 6

The test conditions of Example 4 are repeated, except that the fuel cell used contains zirconia stabilized with yttrium copper oxide and cerium oxide. The fuel used again is n-decane with the introduction of thiophene to obtain a sulfur concentration of 5000 ppm. The fuel cell operates for 24 hours. The results are shown in Fig. 14. On Fig shows that the data on the characteristics are similar to the earlier results shown in example 4. On Fig shows that the characteristics of the fuel cell fall during the first five (5) hours, but then reach a stable state. It is believed that this result is due to the formation of a Ce ₂ O ₂ S phase after approximately five (5) hours.

Without the desire to be bound by a specific scientific theory, it is assumed that the results given in examples 5 and 6 take place for the following reasons. In order to understand the long-term effect of sulfur, and why the cerium oxide Cu-anode is stable under conditions containing sulfur, it is important to understand the mechanism of sulfur poisoning. At 700 ^° C, the equilibrium constant for the reaction 2Cu + H ₂ S = H ₂ + Cu ₂ S is 1500. This means that Cu will remain metallic in a mixture of H ₂ and H ₂ S, while the ratio of H ₂ : H ₂ S remains greater 1500. Although the equilibrium conditions for thiophene in a hydrocarbon will be somewhat different from this, the equilibrium conditions suggest that Cu will be resistant to sulfur poisoning until very high sulfur levels are obtained.

The equilibrium data for the reaction 2CeO ₂ + H ₂ + H ₂ S = Ce ₂ O ₂ S + 2H ₂ O, which most often leads to poisoning of the CeO ₂ catalyst, are given by D. Alan, R. Kay, WGWilson and V .Jalan, Journal of Alloys and Compounds , 1993, 192, the entire disclosure of which is incorporated herein by reference. The stability of the Ce ₂ O ₂ S phase depends on both the chemical potential of oxygen and the chemical potential of sulfur. For typical fuel cell anode conditions, where the chemical potential of oxygen is about 10 ^-20 - 10 ^-10 atmospheres, these equilibria suggest that a Ce ₂ O ₂ S phase will form if the chemical potential of H ₂ S is above 10 ^-3 - 10 ^-4 atm.

Example 7

Get a fuel cell with zirconia stabilized with yttrium copper oxide, which operates according to example 4 in the following additional test conditions. In the first test, the fuel cell operates with hydrocarbon fuel containing 250 ppm sulfur for twenty four (24) hours, then operates with hydrocarbon fuel containing 500 ppm sulfur for fourteen (14) hours, then works with hydrocarbon fuel containing 1000 ppm sulfur for twelve (12) hours and finally works with hydrocarbon fuel containing 5000 ppm sulfur for eight (8) hours. In the second test, the fuel cell operates with hydrocarbon fuel containing 5,000 ppm sulfur for seven (7) hours. In the third test, the fuel cell operates with hydrocarbon fuel containing 500 ppm sulfur for twenty (20) hours. After each of these three tests, the anode of the fuel cell made of zirconia stabilized with yttrium copper oxide is subjected to x-ray diffraction, the results of which are shown in Fig. 15 by curves under the letters "a-c". X-ray diffraction results shown by the letter "a", suggest that the new phase of cerium oxide with the diffraction peak ^of about 39 is formed at high levels of sulfur. The x-ray results from the third test (represented by the letter “c”) additionally show that average sulfur levels do not lead to the formation of a new sulfide phase as a result of the presence of sulfur-containing particles. In all three trials, a peak at approximately 43 ^o, due to copper metal phase is clearly visible. This result is consistent with the results in Example 6, which seek to show that sulfur does not affect copper.

Example 8

The fuel cells of Examples 1 and 2 are tested under the conditions described in Example 4 with industrial gasoline used as fuel. Fuel is 40 wt.% Gasoline in dry nitrogen gas. The results are presented in Fig.16. On Fig shows that the voltage and current density of the fuel cell are stable for twelve (12) hours. This test is repeated with 10 wt.% Gasoline in dry nitrogen for an additional forty-eight hours. The retest results, which are presented in FIG. 17, show that energy generation by the fuel cell remains stable for the indicated additional period. The indicated results show that the fuel cell is capable of operating for a considerable period of time with industrial gasoline.

After completion of this test, the anode of the fuel cell is again subjected to x-ray examination. The results of an X-ray study show the linear characteristics of copper, cerium oxide and zirconia stabilized with yttrium oxide. No lines are observed that would be characteristics of sulfur-containing particles. The indicated X-ray diffraction data show that the sulfur present in the commercial grade of gasoline does not affect the anode.

Example 9

Get a fuel cell with zirconia stabilized with copper-ceria-yttrium oxide, and operate according to example 4 at 700 ^about With various fuel mixtures. The original mixture used is a mixture (n-decane containing 100 ppm sulfur (represented as “thiophene”)): steam: nitrogen gas in a ratio of 2: 2: 2. The next mixture used is a mixture (n-decane containing 5000 ppm sulfur): steam: N ₂ in a ratio of 2: 2: 2. After replacing the mixture with steam, hydrocarbon mixtures of pure decane and decane containing 5000 ppm sulfur are used. The current density and voltage of the fuel cell for each of these mixtures are presented in Fig. 18. On Fig shows that the fuel cell continues to work after switching to n-decane containing 5000 ppm of sulfur, but that the current density decreases with time. On Fig also shows that the efficiency of the fuel cell is restored after treatment with steam and in the process of using n-decane fuel.

Example 10

In this example, freshly prepared employing fuel cell with an anode consisting of Cu ₂ O, CeO ₂ and YSZ, the anode was treated with gradual heating at 700 ^{° C} in hydrogen gas. During this heating step, the electrical resistance is measured over the entire anode in ohms over time and at temperature. The results are presented in Fig.19. On Fig shown that the resistance of the conductor of the fuel cell is reduced due to the restoration of Cu ₂ O to metallic Cu. The introduction of sulfur-containing fuel does not impair the resistance of the Cu-containing anode, showing the inertness of Cu to sulfur under the indicated conditions.

Example 11

In this example, Ni-YSZ cermets are prepared by mixing 40 wt.% NiO, 60 wt.%. YSZ with graphite blowing agent in a conventional slurry for casting a tape. The second layer is cast with pure YSZ on top of it, and the two layers was calcined at 1500 ^C. After heating the resulting ceramic plate at ⁷⁰⁰ ° C in H ₂ for recovery NiO to Ni plate is boiled in HNO ₃ to remove Ni. The change in mass indicates that Ni is completely removed. Then, a powder of 50% YSZ, 50% LaMnO ₃ doped with Sr is deposited on the dense side of the bilayer plate to form a cathode. Cu (NO _{3) 2} and Ce (NO _{3) 3,} then impregnated porous side of the wafer, is heated to decompose the nitrate and reduced in H ₂ at 700 ^C.

Example 12

The curves of the current-voltage characteristics of the fuel element described in Example 11, removed at ⁷⁰⁰ ° C in a stream of H ₂ and butane stream with the data presented in Figure 20.

These results show that the characteristics of fuel cells with hydrogen and hydrocarbon fuels are comparable to the characteristics of fuel cells obtained by other methods. In addition, the characteristics of the fuel cell in dry butane are stable. The operation of SOFC with a Ni-containing anode is impossible due to the rapid coke formation.

Example 13

Five nickel cermets are prepared by suspension casting of a tape from YSZ and NiO powders in the ratios of YSZ to NiO at 70:30 (twice), 80:20, 90:10 and 60:40. All formulations also contain graphite blowing agent.

The porosity and the metal weight is determined immediately after the calcination of raw strips in air at 1550 ^C. The following definitions porosity and mass operate cermet after heating in hydrogen gas (for the reduction of nickel oxide to nickel), and after leaching with boiling nitric acid. The results for porosity are shown in table 1A. The results for the mass are shown in table 1B. The data obtained show that essentially all of the Ni can be removed from the Ni-cermets.

Table 1A Mass
ratio
YSZ / NiO Introduced
graphite (%) Initial
porosity Porosity
after H ₂ Porosity
after higher
healing 70/30 22.2 0.362 0.431 0.455 80/20 32.9 0.414 0.474 0.460 90/10 32.9 0.405 0.432 0.430 70/30 15.2 0.425 0.472 0.564 60/40 - - 0.384 0.419 Table 1B Mass
ratio
YSZ / NiO Initial
weight (g) Weight
le N ₂ Weight
le vyschela-
chiva (g) Calculated
mass
(d) (a) Change
mass (%) 70/30 0.74 0.70 0.55 0.52 21 80/20 0.55 0.52 0.40 0.44 23 90/10 0.81 0.79 0.74 0.73 6 70/30 0.86 0.80 0.62 0.60 22 60/40 1.13 1.06 0.78 0.68 26 (a) Calculated mass based on the assumption that Ni could be fully leached.

Although the invention is described and illustrated in the above description with reference to certain preferred embodiments, and many details are given for purposes of illustration, it will be understood by those skilled in the art that the invention is capable of further variations, and that some of the details described herein may be significantly changed without departure from the basic principles of the invention.

Claims (76)

1. Solid oxide fuel cell containing (a) a solid electrolyte comprising an electronic non-conductor that allows the transfer of anions, a cermet composite anode containing at least cerium oxide and / or copper, and a cathode, wherein at least the solid electrolyte and anode are obtained by molding at least at least two layers to form a porous anode layer and a dense solid electrolyte layer, and then impregnate the porous anode layer with at least cerium oxide and / or copper; (b) a fuel containing a sulfur-containing hydrocarbon having a sulfur content of from about 1 ppm to about 5000 ppm; and (c) a source of oxygen. 2. The fuel cell according to claim 1, wherein the hydrocarbon is petroleum distillate. 3. The fuel cell according to claim 2, in which the oil distillate is selected from the group consisting of gasoline, diesel fuel, naphtha, JP-4, JP-5, JP-8, kerosene, autol, natural gas, fuel oil and mixtures thereof. 4. The fuel cell according to claim 2 or 3, in which the oil distillate is selected from the group consisting of JP-4, JP-5, JP-8 and mixtures thereof. 5. The fuel cell according to claim 2 or 3, in which the oil distillate is selected from the group consisting of naphtha, kerosene, autol and mixtures thereof. 6. The fuel cell according to claim 2 or 3, in which the oil distillate is selected from the group consisting of gasoline, diesel fuel, natural gas and mixtures thereof. 7. The fuel cell according to claim 1, in which the hydrocarbon contains alcohol. 8. The fuel cell according to claim 7, in which the alcohol is selected from the group consisting of methanol, ethanol and mixtures thereof. 9. The fuel cell according to claim 1 or 2, in which the hydrocarbon is selected from the group consisting of dry methane, butane, toluene, decane and mixtures thereof. 10. The fuel cell according to claims 1 to 9, in which the sulfur-containing hydrocarbon fuel has a sulfur content of from about 1 ppm to about 1000 ppm. 11. The fuel cell according to claims 1 to 10, in which the sulfur-containing hydrocarbon fuel has a sulfur content of from about 10 to about 1000 ppm. 12. The fuel cell according to claims 1-11, wherein the sulfur-containing hydrocarbon fuel has a sulfur content of from about 20 to about 1000 ppm. 13. The fuel cell according to claims 1-12, wherein the sulfur-containing hydrocarbon fuel has a sulfur content of from about 100 ppm to about 1000 ppm. 14. The fuel cell according to claims 1 to 13, wherein the sulfur-containing hydrocarbon fuel has a sulfur content of from about 250 ppm to about 1000 ppm. 15. The fuel cell according to claims 1-14, wherein the solid electrolyte is a material that conducts an oxide ion. 16. The fuel cell of claim 15, wherein the oxide ion conducting material is selected from the group consisting of doped cerium oxide, doped zirconia and doped lanthanum gallate. 17. The fuel cell according to clause 16, in which the doped cerium oxide is selected from the group consisting of cerium oxide doped with gadolinium, cerium oxide doped with samarium, and cerium oxide doped with yttrium oxide, and mixtures thereof. 18. The fuel cell of claim 15, wherein the material conducting the oxide ion is zirconia stabilized with yttrium oxide. 19. The fuel cell of claim 16, wherein the doped zirconia is scandium doped zirconia. 20. A method of producing electrical energy containing (a) providing a solid oxide fuel cell containing a solid oxide electrolyte that is an electronic non-conductor that allows the transfer of anions, a cermet composite anode containing at least cerium oxide and / or copper, and a cathode, at least a solid electrolyte and the anode is obtained by molding at least two layers to form a porous anode layer and a dense layer of solid electrolyte, and then impregnating the porous layer of the anode with at least cerium oxide and / or copper; (b) contacting the cathode with an oxygen source; and (c) contacting the anode with a fuel containing a sulfur-containing hydrocarbon having a sulfur content of from about 1 ppm to about 5000 ppm. 21. The method according to claim 20, in which the hydrocarbon is an oil distillate. 22. The method according to item 21, in which the oil distillate is selected from the group consisting of gasoline, diesel fuel, naphtha, JP-4, JP-5, JP-8, kerosene, autol, natural gas, fuel oil and mixtures thereof. 23. The method according to item 21 or 22, in which the oil distillate is selected from the group consisting of JP-4, JP-5, JP-8 and mixtures thereof. 24. The method according to item 21 or 22, in which the oil distillate is selected from the group consisting of naphtha, kerosene, fuel oil and mixtures thereof. 25. The method according to item 21 or 22, in which the oil distillate contains gasoline. 26. The method according to item 21 or 22, in which the oil distillate contains diesel fuel. 27. The method according to claim 20 or 21, in which the hydrocarbon is selected from the group consisting of alcohols, dry methanes, butane, toluene, decane and mixtures thereof. 28. The method according to item 27, in which the hydrocarbon contains alcohol. 29. The method according to p, in which the alcohol is selected from the group consisting of methanol, ethanol and mixtures thereof. 30. The method according to claims 20-29, wherein the sulfur-containing hydrocarbon has a sulfur content of from about 10 ppm to about 1000 ppm. 31. A method of restoring the health of a solid oxide fuel cell containing a solid electrolyte, including an electronic non-conductor, which allows the transfer of anions, a ceramic-metal alloy composite anode, and a cathode that has been deactivated by sulfur poisoning, said method comprising the step of heating the anode in a mixture containing steam. 32. The method according to p, in which the anode is heated in a gaseous mixture containing steam. 33. The method according to p, in which the anode is heated at a temperature between about 600 ° C and about 800 ° C for a period of from about 1 hour to about 3 hours 34. A method of obtaining a porous cermet as an oxidizing anode material for a solid oxide fuel cell, the method comprising (a) providing porous nickel-containing cermets with a Ni content between 10% and 60%; (b) contacting the cermets with a leaching agent to remove at least a portion of the nickel, resulting in an additional porous character of the cermets; (c) contacting the porous cermet with an impregnating substance containing a soluble copper salt, with the deposition of the copper salt in the pores of the cermet; (d) calcining the cermet impregnated with a copper salt at a temperature sufficient to convert the copper salt to copper oxide; f) reduction of copper oxide to elemental copper, resulting in an oxidative anode material. 35. The method according to clause 34, in which at stage (b) all of the Nickel is leached from cermets. 36. The method according to clause 34, wherein in step (b), from about 50% to about 99% nickel is leached from the cermet. 37. The method according to clause 36, in which the cermet is impregnated with a soluble copper salt, which gives an amount of elemental copper, which is approximately equivalent to the mass of elemental nickel leached from cermet in stage (b). 38. The method according to clause 34, which contains an additional stage of processing the oxidative anode material with a cerium salt, which is converted into cerium oxide. 39. A method for producing a porous multilayer ceramic laminate as a direct oxidizing anode with an electrolyte structure for a solid oxide fuel cell deposited on it as a substrate, the laminate comprising at least a first layer and a second layer, the second layer being relatively dense compared to the first layer, and the specified method contains the following stages: (a) preparing a first formulation in the form of a suspension containing a binder, a carrier and a ceramic powder, wherein at least a portion of the ceramic powder includes nickel oxide and YSZ; (b) forming said suspension in a first layer; (c) preparing a second formulation in the form of a suspension containing a binder, a carrier and YSZ; (d) molding said suspension into a second layer; (e) forming a bag containing a first layer and a second layer superimposed on each other, resulting in a laminate preform; (f) heating the laminate preform at a temperature sufficient to sinter the ceramic powder; (g) reducing at least a portion of the nickel oxide present in the sintered laminate to elemental nickel; (h) contacting the sintered laminate with a leaching agent to remove at least a portion of nickel, resulting in a porous nature of the first layer of the sintered laminate; (i) contacting the first layer of the sintered laminate with an impregnating substance containing a soluble copper salt, with the deposition as a result of this salt in the pores of the sintered laminate; (j) calcining a sintered laminate impregnated with a copper salt at a temperature of at least 600 ° C, thereby converting the copper salt into copper oxide; and (k) reduction of copper oxide to elemental copper, resulting in a direct oxidizing anode with an electrolyte structure deposited on it as a substrate. 40. A method of obtaining a porous multilayer ceramic laminate as an oxidizing anode with an electrolyte structure for a solid oxide fuel cell deposited on it as a substrate, the laminate comprising at least a first layer and a second layer, the second layer being relatively dense compared to the first layer, and the specified method contains (a) preparing a first tape formulation in the form of a suspension containing a binder, a carrier and a ceramic powder, wherein at least a portion of the ceramic powder includes nickel oxide and YSZ; (b) forming said suspension in a first ribbon; (c) preparing a second tape formulation in the form of a suspension containing a binder, a carrier and YSZ; (d) molding said suspension into a second ribbon; (e) forming a bag comprising a first anode tape and a second electrolyte tape superimposed on each other, resulting in a laminate preform; (f) heating the laminate preform at a temperature sufficient to sinter the ceramic powder; (g) reducing at least a portion of the nickel oxide present in the sintered laminate to elemental nickel; (h) contacting the sintered laminate with a leaching agent to remove at least a portion of nickel, resulting in a porous nature of the first layer of the sintered laminate; (i) contacting the first layer of the sintered laminate with an impregnating substance containing a soluble copper salt, with the deposition as a result of this salt in the pores of the sintered laminate; (j) calcining a sintered laminate impregnated with a copper salt at a temperature of at least 600 ° C, thereby converting the copper salt into copper oxide; and (k) reduction of copper oxide to elemental copper, resulting in a direct oxidizing anode with an electrolyte structure deposited on it as a substrate. 41. A method for producing a porous multilayer ceramic laminate as a direct oxidizing anode with an electrolyte structure for a solid oxide fuel cell deposited on it as a substrate, said laminate having at least a first layer and a second layer, the second layer being relatively dense in comparison with a first layer, said method comprising: (a) preparing a casting of the first tape in the form of a suspension containing a binder, a carrier and a ceramic powder, wherein at least a portion of said ceramic powder includes nickel oxide and YSZ; (b) applying a suspension of the casting formulation of the first tape to a carrier substrate and molding the suspension into a first tape; (c) preparing a molding of the second tape in the form of a suspension containing a binder, a carrier and YSZ; (d) applying a suspension of the casting formulation of the second tape to a carrier substrate and molding the suspension into a second tape; (e) forming a bag comprising a first anode tape and a second electrolyte tape superimposed on each other, resulting in a laminate preform; (f) heating the laminate preform at a temperature sufficient to sinter the ceramic powder; (g) reducing at least a portion of the nickel oxide present in the sintered laminate to elemental nickel; (h) contacting the sintered laminate with a leaching agent to remove at least a portion of nickel, resulting in a porous nature of the first layer of the sintered laminate; (i) contacting the first layer of the sintered laminate with an impregnating substance containing a soluble copper salt, with the deposition as a result of this salt in the pores of the sintered laminate; (j) calcining the sintered laminate impregnated with a copper salt at a temperature of at least 600 ° C, thereby converting said copper salt into copper oxide; and (k) reduction of copper oxide to elemental copper, resulting in a direct oxidizing anode with an electrolyte structure deposited on it as a substrate. 42. The method according to paragraph 41, wherein the suspension of the casting of the second tape is applied to the first tape with molding as a result of the anode and electrolyte. 43. The method according to paragraph 41, wherein in step (h), substantially all of the nickel is leached from the sintered laminate. 44. The method according to paragraph 41, wherein in step (h), 50 to 99% of nickel is leached from the sintered laminate. 45. The method according to item 44, in which the laminate is impregnated with a soluble copper salt, which gives an amount of elemental copper, which is approximately equivalent to the mass of elemental nickel leached from the laminate in stage (h). 46. The method according to paragraph 41, which contains an additional step of processing the oxidative anode with a cerium salt deposited on it as a substrate by an electrolyte structure, which is converted into cerium oxide. 47. The method according to paragraph 41, in which the formulation of the casting of the first tape further comprises an organic blowing agent. 48. The method according to clause 47, in which the organic blowing agent contains powdered graphite. 49. The method according to paragraph 41, in which the leaching agent selectively dissolves Nickel without noticeable dissolution of YSZ. 50. The method according to § 49, in which the leaching agent is heated nitric acid. 51. The method according to paragraph 41, further comprising prior to sintering the stage: (a) obtaining a formulation of the casting of the third tape in the form of a suspension containing a binder, a carrier and ceramic powder, wherein the coefficient of thermal expansion of the sintered ceramic powder is compatible with the coefficient of thermal expansion of the sintered YSZ; (b) applying a suspension of the casting formulation of the third tape to the carrier substrate and molding the suspension into a third tape, the thickness of the third tape being relatively greater than the thickness of the second tape; (c) punching the third tape to form as a result of at least one hole through the thickness of said tape; and (d) applying a perforated third tape to the laminate preform in contact with the first tape. 52. The method according to 51, wherein said at least one hole in the third tape has a periphery with a continuous curved contour. 53. The method according to paragraph 41, in which, after sintering, the contacting of the first layer of the sintered laminate with the impregnating substance is carried out while passing the impregnating substance through the specified at least one hole in the specified third tape. 54. A method of manufacturing a three-layer structure of a solid oxide fuel cell containing a perforated layer, an anode and an electrolyte, said method comprising producing a first anode tape for molding a first tape containing ceramic powder, comprising at least YSZ and a blowing agent; obtaining a second electrolyte tape for the formulation of the casting of the second tape, including at least YSZ; molding a laminate comprising a first anode tape and a second electrolyte tape; obtaining the formulation of the casting of the third tape in the form of a suspension containing a binder, a carrier and a ceramic powder, the coefficient of thermal expansion of the sintered ceramic powder is compatible with the coefficient of thermal expansion of the sintered YSZ; applying a suspension of the casting formulation of the third tape to the carrier substrate and molding the suspension into a third tape, the thickness of the third tape being relatively greater than the thickness of the second tape; punching the third tape with molding as a result of at least one hole through the thickness of the specified tape; and applying a perforated third tape to the laminate in contact with the first anode tape to form a three-layer structure; sintering a three-layer structure to form a perforated third layer, a porous anode layer containing at least YSZ, and a relatively dense electrolyte layer containing at least YSZ; impregnation of the porous anode layer with an aqueous solution containing a salt of an electrically conductive material to obtain an impregnated three-layer structure; calcining the impregnated three-layer structure at a temperature sufficient to produce oxide of the electrically conductive material; and reducing the oxide of the electrically conductive material to obtain a three-layer structure containing a perforated layer, a porous anode containing at least YSZ and an electrically conductive material, and an electrolyte containing at least YSZ. 55. The method according to item 54, in which the specified at least one hole in the third tape has a periphery with a continuous curved path. 56. The method according to item 54, in which the electrically conductive material is selected from the group consisting of nickel, copper, cerium oxide and mixtures thereof. 57. The method according to p, in which the electrically conductive material is copper. 58. The method according to p, in which the electrically conductive material is a mixture of copper and cerium oxide. 59. The method according to item 54, in which the calcination is carried out at a temperature of at least 600 ° C. 60. The method according to item 54, in which the sintering is carried out at a temperature of approximately 1500 ° C for two hours. 61. The method according to item 54, in which the reduction of oxide of the conductive material is carried out by reduction in hydrogen gas at a temperature of approximately 500 ° C. 62. A three-layer anode structure of a solid oxide fuel cell containing a perforated ceramic layer containing at least ceramic material having a coefficient of thermal expansion during sintering, compatible with the coefficient of thermal expansion of sintered YSZ; a porous anode layer adjacent to the perforated ceramic layer and containing porous ceramics containing at least YSZ and an electrically conductive material dispersed at least partially within the pores; and a relatively dense electrolyte layer comprising at least YSZ located adjacent to the porous anode layer. 63. The three-layer anode structure of claim 62, wherein the electrically conductive material is selected from the group consisting of nickel, copper, cerium oxide, and mixtures thereof. 64. The three-layer anode structure of claim 63, wherein the electrically conductive material is copper. 65. The three-layer anode structure of claim 63, wherein the electrically conductive material is a mixture of copper and cerium oxide. 66. The three-layer anode structure of claim 62, wherein the ceramic material in the perforated ceramic layer is selected from the group consisting of YSZ, MgAlO _2, and mixtures thereof. 67. The three-layer anode structure of claim 62, wherein the perforated ceramic layer has a thickness in the range of from about 300 microns to about 5000 microns. 68. The three-layer anode structure of claim 62, wherein the porous anode layer has a thickness in the range of from about 100 microns to about 1000 microns. 69. The three-layer anode structure of claim 62, wherein the electrolyte layer has a thickness of less than about 100 microns. 70. A solid oxide fuel cell containing a three-layer anode structure according to claim 62 and a cathode located adjacent to a relatively dense electrolyte layer. 71. A method of manufacturing a three-layer structure of a solid oxide fuel cell, comprising: molding a first anode layer; forming a second electrolyte layer containing ceramic electrolyte material, and placing a second electrolyte layer near the first anode layer; forming a third layer on the side of the first anode layer opposite the second electrolyte layer, the third layer containing a binder, a carrier and ceramic powder having a coefficient of thermal expansion during sintering compatible with the coefficient of thermal expansion of the sintered ceramic electrolyte material; perforating the third layer, thereby forming at least one hole through the thickness of the third layer; sintering the third layer, the first anode layer and the second electrolyte layer to form a perforated third layer, a porous anode layer and a relatively dense electrolyte layer; impregnation of the porous anode layer with an aqueous solution containing a salt of an electrically conductive material; and molding a three-layer structure of a solid oxide fuel cell. 72. The method according to p, in which the specified at least one hole in the third layer has a periphery with a continuous curved path. 73. The method according to p, in which the electrically conductive material is selected from the group consisting of nickel, copper, cerium oxide and mixtures thereof. Priorities: 11/09/2000 - claims 1-19, 21-26, 30-33; 02/19/2001 - pp. 20, 27, 28, 29; 07.27.2001 - pp. 34-73.

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