JP2009245896A - Spacer for manufacturing solid oxide fuel cell, manufacturing method of member for solid oxide fuel cell using this, and manufacturing method of solid oxide fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spacer which is used when manufacturing a solid oxide fuel cell by sintering and of which the material cost can be reduced and in which the degradation of long term stability and performance of the solid oxide fuel cell can be prevented, and a manufacturing method of a member for solid oxide fuel cell using the same, and the solid oxide fuel cell. <P>SOLUTION: This is a spacer for manufacturing a solid oxide fuel cell having an electrolyte, a fuel electrode, and an air electrode and includes a porous substrate, a first covering layer which is formed on one face of the porous substrate and is composed of the same material as the electrolyte and a second covering layer which is formed on the other face of the porous substrate and is composed of the same material as the fuel electrode or the air electrode. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a spacer for producing a solid oxide fuel cell having an electrolyte, a fuel electrode, and an air electrode, a method for producing a member for a solid oxide fuel cell using the same, and production of a solid oxide fuel cell. Regarding the method.

  Various methods have been proposed for forming an electrolyte, a fuel electrode, and an air electrode constituting a solid oxide fuel cell. As one of the methods, a sheet-like or plate-like material called a green body is proposed. There is a method of sintering. When mass production of batteries is performed by this method, for example, a method of performing sintering after alternately laminating green bodies and porous plate-like spacers is generally performed. Such a method is disclosed in Patent Document 1, for example, and porous ceramics such as alumina and zirconia are used as the spacer. However, this method has a problem that during the sintering of the green body, the component contained, for example, in the case of the fuel electrode, the nickel component moves to the spacer and the content of the nickel component in the green body decreases. . As a result, the long-term stability and electrical characteristics of the produced solid oxide fuel cell may be deteriorated.

In order to solve this, in Patent Document 2, the green body is arranged on a plate-like jig called a setter to prevent the contained components from moving. This setter contains nickel oxide having a predetermined content in the ceramic material, thereby preventing the nickel component from scattering from the green body during sintering.
JP 2007-302515 A International Publication No. 99/59936

  However, the above setter contains a large amount of a nickel oxide component. As described above, when a large amount of the same material used in the solid oxide fuel cell is added, there is a problem that the material cost increases.

  The present invention has been made to solve the above problems, and is a spacer used when a solid oxide fuel cell is manufactured by sintering, and can reduce the material cost. It is an object of the present invention to provide a spacer capable of preventing long-term stability and deterioration in battery performance, a method for producing a member for a solid oxide fuel cell using the same, and a method for producing a solid oxide fuel cell. .

  The present invention is a spacer for producing a solid oxide fuel cell having an electrolyte, a fuel electrode, and an air electrode, and has been made in order to solve the above problem. A first coating layer formed on one surface of the substrate and made of the same material as the electrolyte; and a second coating layer formed on the other surface of the porous substrate and made of the same material as the fuel electrode or the air electrode. I have.

  This spacer is sintered by laminating a plurality of laminates in which an electrolyte green body and a fuel electrode green body are laminated or a laminate in which an electrolyte green body and an air electrode green body are laminated. Used when. That is, when laminating a plurality of laminated bodies, a spacer is interposed between them to perform sintering. Here, the spacer according to the present invention forms a first coating layer made of the same material as the electrolyte on one surface of the porous substrate, and a second material made of the same material as the fuel electrode or the air electrode on the other surface. A coating layer is formed. The first coating layer is disposed to face the electrolyte green body, and the second coating layer is disposed to face the air electrode or fuel electrode green body. By doing so, it is possible to prevent the contained components from scattering from the green body, and it is possible to prevent the long-term stability of the solid oxide fuel cell and the deterioration of the cell performance.

  In addition, since the first coating layer and the green body for electrolyte are arranged so as to face each other, the thermal stress load from the spacer can be reduced, and the electrolyte membrane is damaged or cracked after sintering. Can be prevented. Furthermore, since the coating layer of the same material as the electrolyte, fuel electrode, or air electrode constituting the green body is formed, there is an advantage that heat conductivity is good and it is easy to sinter uniformly. The green body can be used in various forms such as a sheet or plate, and the spacer of the present invention can be applied to these.

  Also, since the upper and lower surfaces of the spacer are coated with the same material as the electrolyte and any of the electrodes, there is no need to newly provide spacers coated with the same material for each material. As a result, space can be saved and productivity is improved.

  Moreover, the spacer which concerns on this invention coat | covers the 1st and 2nd coating layer on the porous board | substrate, and prevents scattering of the content component of the green body mentioned above by these coating layers. Therefore, the material constituting the substrate is not particularly limited except that it is porous and has heat resistance at the temperature at which the green body is sintered. For example, inexpensive and high mechanical strength alumina, etc. Can be selected. Further, since the material of the solid oxide fuel cell is not mixed in the spacer, but only on the porous substrate, the material cost can be reduced. Further, if the coating layer is formed again, it can be used repeatedly as a spacer, and therefore there is an advantage that the running cost can be reduced. In particular, since the spacer is used at the time of mass production of fuel cells, the use of the spacer of the present invention contributes particularly to cost reduction.

  The surface roughness Ra of the coating layer in the spacer is preferably 0.1 to 1.0 μm. Thus, when the surface roughness of the coating layer is made constant, it is possible to prevent the surface of the green body from being uneven during sintering. For example, when the green body of the electrolyte is sintered, breakage and cracks can be prevented and the denseness can be improved. In addition, surface roughness Ra can be made into the value when it measures using a ZYGO company (USA) non-contact three-dimensional surface roughness meter (New View5032).

  Moreover, it is preferable that the porosity of the coating layer in the said spacer is 30 to 70%. If the porosity is too low, for example, the binder contained in the green body is not sufficiently volatilized during sintering, and the green body may be cracked. On the other hand, if the porosity is too high, the mechanical strength decreases. Therefore, when the porosity of each coating layer is in the above range, the green body can be prevented from cracking and the mechanical strength can be maintained. The porosity can be measured by a known method such as Archimedes method, mercury intrusion method, and gas adsorption method.

  The material constituting the substrate can be at least one material selected from alumina, zirconia, mullite, and cordierite. As described above, the material constituting the substrate is not particularly limited. However, when the substrate is formed of these materials, it is inexpensive and sufficient mechanical strength can be expected.

  The method for producing a member for a solid oxide fuel cell according to the present invention has been made in order to solve the above-described problem, and a green body for a fuel electrode or a green body for an air electrode is formed on one surface of an electrolyte green body. A plurality of green body laminates having the same structure, the first coating layer formed of the same material as the electrolyte constituting the green body, and the same material as the fuel electrode or air electrode A step of preparing the plurality of spacers described above including the second coating layer, and a stacking of the plurality of spacers, and between them, the same kind of electrolyte, fuel electrode, or air electrode materials are provided. The step of disposing the green body laminate so as to face each other and the step of sintering the green body laminate together with the spacer are provided.

  According to this manufacturing method, a material having the same components as the electrolyte, fuel electrode, or air electrode is coated on the substrate as a coating layer, and the coating layer and the green body are brought into contact with each other before sintering. Therefore, it is possible to prevent the components contained in the green body from being scattered, and it is possible to prevent the long-term stability of the solid oxide fuel cell produced using the green body and the deterioration of the cell performance. At this time, since the spacer to be used can be selected at a low cost and with high mechanical strength, the material cost can be reduced. The “same material” in the above invention does not mean the same material as the green body, but means the same material as the electrolyte or electrode after the green body is sintered. That is, it is the same as the material after the components such as the binder are lost by sintering.

  In addition, a method for producing a solid oxide fuel cell according to the present invention has been made to solve the above-described problem, and a solid oxide fuel can be obtained by the above-described method for producing a member for a solid oxide fuel cell. Forming a battery member; and forming the other electrode on the surface of the sintered electrolyte of the laminate that is opposite to the surface on which the green body of the one electrode is disposed. ing.

  According to this manufacturing method, it is possible to obtain a solid oxide fuel cell having long-term stability and capable of preventing deterioration of battery performance.

  ADVANTAGE OF THE INVENTION According to this invention, the material cost can be reduced and the spacer which can prevent the fall of long-term stability of a solid oxide fuel cell and battery performance can be provided. In addition, the production of the solid oxide fuel cell can be performed at low cost.

  An embodiment of manufacturing a solid oxide fuel cell according to the present invention will be described with reference to the drawings. FIG. 1 is a front sectional view of a spacer used in the method for producing a solid oxide fuel cell according to this embodiment.

The spacer according to this embodiment is used when producing a solid oxide fuel cell including an electrolyte, a fuel electrode, and an air electrode. The electrolyte, fuel electrode, and air electrode constituting the battery can be formed by various methods. At least one of these members is made of a so-called green body (green sheet) containing these materials. A method of forming by sintering has been proposed. On the other hand, in this embodiment, the case where the laminated body which laminated | stacked the green body for electrolytes and the green body for fuel electrodes is sintered using a spacer is demonstrated.
As shown in FIG. 1, each spacer S is composed of a porous substrate 1 formed in a rectangular shape, a first coating layer 2 coated on the upper surface, and a second coating layer 3 coated on the lower surface. It is configured. The first coating layer 2 is formed of the same material as the electrolyte constituting the electrolyte green body E to be sintered. On the other hand, the 2nd coating layer 3 is formed with the same material as the fuel electrode which comprises the green body A for fuel electrodes to be sintered.

  The substrate 1 is not particularly limited as long as it is porous and has a certain degree of mechanical strength and heat resistance. For example, the substrate 1 is formed of at least one material selected from alumina, zirconia, mullite, or cordierite. can do. Here, when preparing a porous base by mixing two kinds of materials, for example, alumina and cordierite powder are mixed, a binder and a pore former are mixed, and the base is formed by sheet molding or press molding. It can be produced by sintering. However, even other methods are not particularly limited as long as two kinds of materials can be mixed. The porous porosity is preferably equal to or higher than that of each of the coating layers 2 and 3 described below, but is not necessarily limited thereto.

  As described above, the first coating layer 2 is the same material as the electrolyte, and the second coating layer 3 is the same material as the fuel electrode. Hereinafter, these materials will be described. In addition, below, the material of the air electrode which forms a solid oxide fuel cell is also demonstrated. The electrolyte, fuel electrode, and air electrode can be formed of a ceramic powder material. The average particle size of the powder used at this time is preferably 10 nm to 100 μm, more preferably 50 nm to 50 μm, and particularly preferably 100 nm to 10 μm. In addition, an average particle diameter can be measured according to JISZ8901, for example.

  As the electrolyte material, those known as electrolytes for solid oxide fuel cells can be used. For example, ceria oxide (GDC) doped with samarium or gadolinium, lanthanum doped with strontium or magnesium, etc. An oxygen ion conductive ceramic material such as a galide oxide, zirconia oxide (YSZ) containing scandium or yttrium can be used.

  As the fuel electrode, for example, a mixture of a metal catalyst and a ceramic powder material made of an oxide ion conductor can be used. As the metal catalyst used at this time, materials such as nickel, iron, and cobalt can be used. Examples of the oxide ion conductor include ceria-based oxides doped with samarium and gadolinium, and zirconia-based oxides containing scandium and yttrium. Further, lanthanum galade oxides doped with strontium or magnesium can be given. Among the above materials, it is preferable to form the fuel electrode with a mixture of an oxide ion conductor and nickel. Moreover, the ceramic material mentioned above can be used individually by 1 type or in mixture of 2 or more types. The fuel electrode can also be configured using a metal catalyst alone.

As the ceramic powder material forming the air electrode, for example, a metal oxide made of Co, Fe, Ni, Cr, Mn or the like having a perovskite structure or the like can be used. Specifically, (Sm, Sr) CoO ₃ , (La, Sr) MnO ₃ , (La, Sr) CoO ₃ , (La, Sr) (Fe, Co) O ₃ , (La, Sr) (Fe, Co , Ni) O _{3 and the} like, and (La, Sr) (Fe, Co) O ₃ is preferable. The ceramic material mentioned above can be used individually by 1 type or in mixture of 2 or more types.

  Each of the coating layers 2 and 3 formed of the same material as the electrolyte and the fuel electrode can be formed on the substrate by, for example, a wet coating method. Examples of the wet coating method include a screen printing method, an electrophoresis (EPD) method, a doctor blade method, a spray coating method, an ink jet method, a spin coating method, and a dip coating method. In that case, it is necessary to make these electrolytes, fuel electrodes, and pastes, which are formed by adding appropriate amounts of a binder resin, an organic solvent, a pore-forming agent, etc., with the above-described materials as the main components. More specifically, it is preferable to add a binder resin or the like so that the main component is 50 to 95% by weight in the mixing of the main component and the binder resin. For example, when screen printing is used, an electrolyte paste mixed with the binder as described above is prepared and printed on the upper surface of the substrate 1. Then, the printed paste is dried and sintered at a predetermined temperature for a predetermined time. Then, if the surface roughness is adjusted by polishing the surface, the first coating layer 2 is completed. Subsequently, the fuel electrode paste is printed on the lower surface of the substrate 1, dried and sintered at a predetermined time and at a predetermined temperature, and then the surface is polished to complete the second coating layer 3.

  Examples of the pore-forming agent include carbon powder. The amount of pore former added is 5 to 20% by weight. Since the added carbon powder burns and vaporizes during sintering, voids are formed at the locations where the carbon particles were present. The pore former is not limited to carbon powder, and any other material may be used as long as it is a material that can be vaporized and form pores during sintering.

  The coating layers 2 and 3 can also be produced by a dry coating method. Examples of dry coating methods include vapor deposition, sputtering, ion plating, chemical vapor deposition (CVD), electrochemical vapor deposition, ion beam, laser ablation, atmospheric pressure plasma deposition, and reduced pressure. It can also be formed by a plasma film formation method or the like. In these methods, since it is possible to directly form a coating layer formed of the same material as the electrolyte, fuel electrode, or air electrode, sintering may not be required unlike the above-described wet coating method. .

  It is preferable that the thickness of each coating layer 2 and 3 is 0.1-100 micrometers, for example. This is because if it is too thin, it will not be possible to prevent scattering of the components of the green body, and if it is too thick, the cost will increase. Moreover, since the porosity of each coating layer 2 and 3 disperses the binder contained in a green body, it is preferable that it is 30 to 70%. Such porosity can be adjusted, for example, by adjusting the particle size of the material or by increasing or decreasing the content of the pore-forming agent. Further, the surface roughness of each coating layer 2 is preferably 0.1 to 1.0 μm in average roughness Ra by polishing or the like, for example, but this is the surface of the coating layer in contact with the green body. This is because if the roughness is large, the green body is unevenly burned during sintering, and the entire surface of the green body cannot be made uniform. The air electrode can be formed in the same manner as the fuel electrode.

  The green bodies of the fuel electrode, the electrolyte, and the air electrode can be produced by various methods. A method for producing a sheet-like green body, that is, a green sheet by the doctor blade method is described below. The fuel electrode or air electrode green sheet is produced by the following method. A pore former is added to the fuel electrode or air electrode powder, a binder, a dispersant and a plasticizer are added, and a slurry dispersed in a dispersion medium composed of an alcohol solvent such as ethanol or 2-propanol is prepared. The addition amount of the pore former is preferably 5 to 20% by weight. Since the added pore former burns and vaporizes during sintering, pores are formed at the locations where the pore former was present. Examples of the pore former include carbon-based powder and resin-based powder, but other materials may be used as long as they can be vaporized during sintering to form pores.

Moreover, there is no restriction | limiting also in the kind of binder used when producing the said slurry composition or kneading | mixing composition, The organic or inorganic binder known conventionally can be used. Organic binders include ethylene copolymers, styrene copolymers, acrylate and methacrylate copolymers, vinyl acetate copolymers, maleic acid copolymers, vinyl acetal resins, vinyl formal resins, polyvinyl Examples include butyral resins, vinyl alcohol resins, celluloses such as ethyl cellulose, waxes, etc. Next, the prepared slurry is molded by a known doctor blade method to form a slurry layer on a film such as polyethylene terephthalate. Then, the dispersion medium is removed from the slurry layer to dry the fuel electrode or the air electrode green sheet. The dispersion medium is not limited to alcohol solvents, and other organic solvents such as toluene, xylene, and ketones may be used. In addition to the organic solvent, a slurry in which the mixed powder is dispersed in water may be used. For example, by using a predetermined dispersant, the mixed powder can be dispersed in water.

  The electrolyte green sheet is produced by the following method. A binder, a dispersant, and a plasticizer are added to the electrolyte electrode powder to prepare a slurry that is dispersed in a dispersion medium composed of an organic solvent. The produced slurry forms a slurry layer on a film such as polyethylene terephthalate by the doctor blade method in the same manner as the fuel electrode. The dispersion medium is removed from the slurry layer to dry the electrolyte green sheet.

  Next, a sintering method using the spacer formed as described above will be described with reference to FIG. First, the fuel electrode and the green sheets A and E for electrolyte are prepared by the above method. When such a green sheet is used, if the fuel electrode is used as a support, for example, the thickness of the green body for the fuel electrode is 100 to 3000 μm, and the thickness of the green sheet for the electrolyte is 0.5 to 100 μm. be able to. The material which comprises these green sheets is as above-mentioned, For example, it can produce with the method mentioned above. Next, as shown in FIG. 2, an electrolyte green sheet E is disposed on the fuel electrode green sheet A to form a laminate C, and a plurality of these are prepared. Subsequently, a plurality of spacers S and laminated bodies C are alternately laminated. At this time, the electrolyte green sheet E is disposed to face the first coating layer 2, and the fuel electrode green sheet A is disposed to face the second coating layer 3. In addition, as shown in FIG. 2, a plurality of stacked bodies C can be disposed on one spacer S. In this state, if sintering is performed at a predetermined temperature for a predetermined time, a so-called half-cell (solid oxide fuel cell member) in which a fuel electrode and an electrolyte for a solid oxide fuel cell are joined is completed.

  Here, since the electrolyte or fuel electrode material contained in the green sheet is the same as the material of the coating layer in contact with the same, the components contained in the green sheets E and A are prevented from being scattered during sintering. Can do. As a result, it is possible to prevent a decrease in electrical characteristics, for example, power density, of the produced solid oxide fuel cell. In particular, the laminate C is the same as the electrolyte or fuel electrode contained in the green sheet because the electrolyte green sheet E is disposed on the porous fuel electrode green sheet A and co-sintered. When the spacer S on which the coating layer of the material is formed is used, scattering of the material can be prevented particularly in a space saving. Each half cell thus formed is used as a member constituting a solid oxide fuel cell. For example, if an air electrode is formed on the surface of the half-cell electrolyte where no fuel electrode is formed, a solid oxide fuel cell is completed. At this time, the air electrode is formed by a method such as screen printing as described above. The solid oxide fuel cell thus completed generates power by supplying a fuel gas such as a hydrocarbon-based gas to the fuel electrode and an oxidant gas such as air to the air electrode. It can also be used as a single-chamber solid oxide fuel cell that generates power in a mixed gas of fuel gas and oxidant gas. Even if it does in this way, since each electrode selectively reacts with fuel gas or oxidizing agent gas, electric power generation can be performed.

As described above, when the stacked body C is held between the pair of spacers S, there is an advantage that the warpage of the stacked body C can be prevented. That is, the spacer S also serves as a weight. This is because the electrolyte green sheet E and the fuel electrode green sheet A are different in material and have a difference in thermal expansion coefficient during sintering, so that warpage is likely to occur. Therefore, it is possible to prevent the half cell from warping after sintering by sandwiching the laminate C with the spacer S and using the upper spacer S as a weight. In addition, when using the spacer S as a weight, a certain amount of weight is required, For example, a load with respect to the laminated body C can be 0.5-10 g / cm < ² >.

  As described above, according to the present embodiment, the first coating layer 2 made of the same material as the electrolyte is formed on one surface of the porous substrate 1, and the second coating made of the same material as the fuel electrode is formed on the other surface. Layer 3 is formed. Therefore, it is possible to prevent the contained components from scattering from the green sheet, and it is possible to prevent a decrease in electrical characteristics of the produced solid oxide fuel cell.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention. For example, in the above-described embodiment, the case where a laminate in which an electrolyte green sheet and a fuel electrode green sheet are laminated is described. For example, when an electrolyte-supported solid oxide fuel cell is manufactured, an electrolyte is used. The spacer can be used when the fuel electrode green sheet is laminated on the substrate and sintered. Moreover, after forming the calcined body by compacting the powder of the fuel electrode material and heating at about 1200 ° C., a laminate is formed by disposing a green sheet for electrolyte on the calcined body. You can also. And if this laminated body is sandwiched between the spacers and sintered, the same effect as described above can be obtained.

  In the above-described embodiment, the spacer in which the electrolyte material is coated on one surface of the substrate 1 and the fuel electrode material is coated on the other surface is used. However, the spacer in which the air electrode material is coated on the other surface of the substrate can also be used. . If it does in this way, it can use as a spacer at the time of sintering of the laminated body which laminated | stacked the green body for electrolytes, and the green body for air electrodes. The fuel electrode can be formed by the various methods described above.

  Examples of the present invention will be described below. In addition, this invention is not limited to a following example.

Here, a case where co-sintering is performed using a laminate in which an electrolyte green sheet is laminated on a fuel electrode green sheet will be described.
(Method for producing the first spacer)
First, the mass ratio of GDC (Ce: Gd: O = 0.9: 0.1: 1.9) powder (particle size range: 0.1 to 3 μm, average particle size 1 μm) and cellulose binder resin is 80: A paste was prepared by adding a solvent so as to be 20. Thereafter, the paste is printed on one surface of an alumina porous substrate having a porosity of 60% by screen printing, dried at 130 ° C. for 15 minutes, and then sintered at 1450 ° C. for 1 hour to obtain a first GDC electrolyte. A coating layer was formed. Then, the surface of the first coating layer was polished to a thickness of about 20 μm.

Subsequently, SDC (Ce: Sm: O = 0.8: 0.2: 1.9) powder (particle size range: 0.1 to 3 μm, average particle size 1 μm) and NiO (particle size range: 0.1) To 3 μm and an average particle size of 1 μm) were mixed so as to have a ratio of 4: 6, and a paste was prepared by adding a solvent to the powder and the cellulose-based binder resin so that the mass ratio was 80:20. Thereafter, the paste is printed on the other surface of the porous alumina substrate by screen printing, dried at 130 ° C. for 15 minutes, and then sintered at 1450 ° C. for 1 hour to form a second coating layer as a fuel electrode. did. Following this, the surface of the second coating layer was polished to a thickness of about 20 μm. Thus, the first spacer was completed.
(Method for producing second spacer)
Instead of the first coating layer of the first spacer, the following coating layer was formed. That is, a solvent was added so that the mass ratio of 8 mol% yttria-stabilized zirconia powder (YSZ) powder (particle size range: 0.1 to 3 μm, average particle size 1 μm) and cellulose binder resin was 80:20. A paste was prepared. Then, this paste is printed on one surface of the alumina porous substrate by screen printing, dried at 130 ° C. for 15 minutes, and then sintered at 1450 ° C. for 1 hour to form a first coating layer that is a YSZ electrolyte. did. Then, the surface of the first coating layer was polished to a thickness of about 20 μm. The second coating layer is the same as the first spacer.
(Green sheet for fuel electrode)
The fuel electrode green sheet was prepared by the following method. SDC (Ce: Sm: O = 0.8: 0.2: 1.9) powder (particle size range: 0.1 to 3 μm, average particle size 1 μm) and NiO (particle size range: 0.1 to 3 μm, Add a pore former made of carbon powder to an average particle size of 1 μm, add dibutyl phthalate as a polyvinyl binder and plasticizer, and make a slurry dispersed in a dispersion medium made of an organic solvent such as 2-propanol did. The amount of pore former added was 10% by weight of the total amount.

Next, the produced slurry is formed by, for example, a well-known doctor blade method to form a slurry layer on a film such as polyethylene terephthalate, and the dispersion medium is removed from the slurry layer, followed by drying. A fuel electrode green sheet was formed.
(Green sheet for GDC electrolyte)
GDC (Ce: Gd: O = 0.9: 0.1: 1.9) powder (particle size range: 0.1 to 3 μm, average particle size 1 μm) powder, polyvinyl binder and dibutyl phthalate as plasticizer And a slurry dispersed in a dispersion medium composed of an organic solvent such as 2-propanol was prepared. The prepared slurry forms a slurry layer on a film of polyethylene terephthalate or the like by the doctor blade method in the same manner as the fuel electrode, and is dried by removing the dispersion medium from the slurry layer to form a 20 μm GDC electrolyte green sheet. did.
(Green sheet for YSZ electrolyte)
8 mol% Yttria-stabilized zirconia powder (YSZ) powder (particle size range: 0.1 to 3 μm, average particle size 1 μm) is added with polyvinyl binder and dibutyl phthalate as a plasticizer, and organic such as 2-propanol A slurry dispersed in a dispersion medium composed of a solvent was prepared. The prepared slurry forms a slurry layer on a film of polyethylene terephthalate or the like by the doctor blade method in the same manner as the fuel electrode, and is dried by removing the dispersion medium from the slurry layer to form a 20 μm YSZ electrolyte green sheet. did.
(Preparation of air electrode paste)
LSCF (La: Sr: Co: Fe: O = 0.6: 0.4: 0.2: 0.8: 3) (particle size range: 0.1 to 3 μm, average particle size 1 μm) to ethyl carbitol ) And ethyl cellulose as a binder were added, and these were mixed by a ball mill to prepare an air electrode paste for forming an air electrode.
(Lamination of laminate)
Subsequently, a plurality of first laminated bodies in which green sheets for GDC electrolyte are laminated on the green sheets for fuel electrodes laminated so as to have the thickness of the substrate are prepared, and each is sandwiched between a plurality of first spacers. Sintering was performed at about 1450 ° C. (Sample 1). Also, a plurality of first laminated bodies were prepared, and each was sandwiched between a plurality of second spacers and sintered at about 1450 ° C. (Sample 2). Furthermore, a plurality of second laminated bodies in which a green sheet for a YSZ electrolyte was laminated on a green sheet for a fuel electrode were prepared, and each was sandwiched between a plurality of first spacers and sintered at about 1450 ° C. (sample) 3). A plurality of second laminates were prepared, and each was sandwiched between a plurality of second spacers and sintered at about 1450 ° C. (Sample 4). In the sintering step, the electrolyte green sheet was disposed to face the first coating layer, and the fuel electrode green sheet was disposed to face the second coating layer.

Thereafter, an air electrode paste was printed on the electrolyte of each sintered sample by screen printing. Then, these were dried in an oven at 130 ° C. for 15 minutes and baked at 1200 ° C. for 1 hour to form an air electrode having a thickness of about 20 μm on the electrolyte. In this way, four types of solid oxide fuel cells were produced.
(Evaluation test)
Then, the battery evaluation experiment which measures an electromotive force and an output density was conducted. The results are as follows.

この結果が示すように、同じ材料の電解質用グリーンシートと第１被覆層を接触させて焼結したサンプル１は異種材料を接触させて焼結したサンプル２よりも、４は３よりも出力密度が高いことが分かる。これにより、同種の材料を有するスペーサーを用いると、材料の飛散が防止され、また熱応力による電解質膜へのマイクロクラックの発生を防止することができるため電池性能が低下しないと考えられる。

As shown in this result, Sample 1 which is sintered by bringing the green sheet for electrolyte of the same material and the first coating layer into contact with each other is more powerful than Sample 2 which is sintered by bringing different materials into contact with each other. Is high. Thus, it is considered that the use of a spacer having the same kind of material prevents scattering of the material and prevents the occurrence of microcracks in the electrolyte membrane due to thermal stress, so that the battery performance is not deteriorated.

1 is a front sectional view showing an embodiment of a solid oxide fuel cell manufacturing spacer according to the present invention. It is front sectional drawing which shows sintering of the green body using the spacer of FIG.

Explanation of symbols

1 Substrate 2 First coating layer 3 Second coating layer

Claims (6)

A spacer for producing a solid oxide fuel cell having an electrolyte, a fuel electrode, and an air electrode,
A porous substrate;
A first covering layer formed on one surface of the porous substrate and made of the same material as the electrolyte;
A second coating layer formed on the other surface of the porous substrate and made of the same material as the fuel electrode or the air electrode;
It is equipped with a spacer.   The spacer according to claim 1, wherein the surface roughness Ra of each coating layer is 0.1 to 1.0 μm.   The spacer according to claim 1 or 2, wherein the porosity of each coating layer is 30 to 70%.   The spacer according to any one of claims 1 to 3, wherein the substrate is made of at least one material selected from alumina, zirconia, mullite, and cordierite. Preparing a plurality of green body laminates in which the green body of one electrode of the fuel electrode green body or the air electrode green body is disposed on one surface of the electrolyte green body;
The first coating layer formed of the same material as the electrolyte constituting the green body, and the second coating layer formed of the same material as the fuel electrode or air electrode constituting the green body, Providing a plurality of spacers according to any of claims 1 to 4, comprising:
Laminating a plurality of the spacers, and arranging each of the green body laminates so that the same kind of materials face each other,
Sintering the green body laminate with the spacer;
A method for producing a member for a solid oxide fuel cell. Forming a member for a solid oxide fuel cell by the method for producing a member for a solid oxide fuel cell according to claim 5;
In the sintered electrolyte of the laminate, forming the other electrode on the surface opposite to the surface on which the green body of the one electrode is disposed;
A method for producing a solid oxide fuel cell.

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