Method for producing laminate, laminate, and solid oxide fuel cell

Abstract

To provide a method of manufacturing a laminate capable of exhibiting sufficient power generation performance while reducing the time required for manufacturing the laminate as compared with a conventional process.SOLUTION: A method for producing a laminate, the method comprising laminating two or more raw material layers selected from a first raw material layer 21 obtained by using a first raw material powder for producing a metal support layer 31, a second raw material layer 22 obtained by using a second raw material powder for producing a negative electrode layer 32, a third raw material layer 23 obtained by using a third raw material powder for producing an electrolyte layer 33, and a fourth raw material layer 24 obtained by using a fourth raw material powder for producing a positive electrode layer 34, and a compressing and solidifying step of simultaneously compressing and solidifying the material laminate at a temperature lower than a firing temperature of a material contained in each of the material layers to obtain laminates 20a to 20c including two or more layers selected from the metal-supporting layer, the negative electrode layer, the electrolytic layer, and the positive electrode layer. 30c 30a.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a laminate, a laminate, and a solid oxide fuel cell. [Background technology]

[0002] Conventionally, a laminate including a metal support layer, a fuel electrode layer (anode layer), an electrolyte layer, and an air electrode layer (cathode layer) has been known. Such laminates have been utilized, for example, in the field of solid oxide fuel cells. In solid oxide fuel cells, hydrogen contained in fuel gas reacts with oxygen ions that migrate from the cathode layer via the electrolyte layer to the anode layer, thereby generating electricity.

[0003] Various proposals have been made regarding this type of laminate. For example, a method for manufacturing a laminate in which a metal support (1), an electrode layer (2), an intermediate layer (3), an electrolyte layer (4), a reaction prevention layer (5), and a counter electrode layer (6) are stacked in this order has been proposed (see Patent Document 1, for example, Figure 1). Another proposal has also been made regarding a laminate in which a support (10), a mixed layer (20), a negative electrode (30), an electrolyte layer (40), a reaction prevention layer (50), and a positive electrode (60) are stacked in this order (see Patent Document 2, for example, Figure 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-158026 [Patent Document 2] Japanese Patent Publication No. 2021-036499 Summary of the Invention [Problem to be solved by the invention]

[0005] Both Patent Documents 1 and 2 include a process of firing and sintering the raw materials (e.g., raw material powders and dried pastes containing the raw material powders) that constitute each layer of the laminate. Sintering is a process in which powdered material is heated to a high temperature (above the sintering temperature but below the melting point) to bond the material particles together, thereby transforming the powder into a solid. Sintering promotes interparticle bonding without completely melting the material. However, conventional processes require repeated firing to sinter each layer of the laminate, which requires a long manufacturing time and makes it difficult to increase the productivity of the laminate. Furthermore, repeated firing processes result in excessive thermal loads on the materials and the laminate, which can lead to significant adverse effects (e.g., delamination between layers in the resulting laminate). If it is difficult to suitably prevent peeling between layers in the laminate, it is naturally impossible to ensure the desired power generation performance for a solid oxide fuel cell constructed using the laminate.

[0006] Therefore, an object of the present disclosure is to provide a method for producing a laminate that can reduce the time required for producing the laminate compared to conventional processes, while still providing sufficient power generation performance. Another object of the present disclosure is to provide a laminate produced by the production method, and a solid oxide fuel cell constructed using the laminate. [Means for solving the problem]

[0007] An example of an aspect provided by the present disclosure is as follows. [1] A method for manufacturing a laminate, comprising: The method comprises: A first raw material layer obtained using a first raw material powder for producing a metal support layer; a second raw material layer obtained using a second raw material powder for producing a negative electrode layer; a third raw material layer obtained using a third raw material powder for producing an electrolyte layer; a fourth raw material layer obtained using a fourth raw material powder for producing a positive electrode layer; a lamination step of laminating two or more raw material layers selected from the above to obtain a raw material laminate; a compression and solidification step of simultaneously compressing and solidifying the raw material laminate at a temperature lower than the sintering temperature of the material contained in each raw material layer to obtain a laminate including two or more layers selected from the metal support layer, the negative electrode layer, the electrolyte layer, and the positive electrode layer; A method for producing a laminate comprising the steps of: [2] In the lamination step, Item 2. The method according to item 1, wherein one or more raw material layers selected from the first raw material layer, the second raw material layer, and the fourth raw material layer included in the raw material laminate are formed using a mixed powder containing the raw material powder and a support powder different from the raw material powder. [3] In the method, after the compressive solidification step, 3. The method according to item 1 or 2, further comprising a removing step of removing the support powder from the obtained laminate. [4] In the compression and solidification step, 4. The method according to any one of items 1 to 3, wherein the compaction is carried out by explosive squeezing. [5] In the lamination step, 5. The method according to any one of items 1 to 4, wherein three or more raw material layers selected from the first raw material layer, the second raw material layer, the third raw material layer, and the fourth raw material layer are laminated. [6] In the method, The raw material laminate including the fourth raw material layer is simultaneously compressed and solidified to obtain the laminate including the positive electrode layer, or 6. The method according to any one of items 1 to 5, wherein a raw material laminate including two or more raw material layers selected from the first raw material layer, the second raw material layer, and the third raw material layer is simultaneously compressed and solidified, and then the fourth raw material layer is fired, thereby laminating the positive electrode layer on the compressed and solidified laminate. [7] In the lamination step, 7. The method according to any one of items 1 to 6, wherein the first raw material powder is a powder containing one or more selected from a pure metal, an alloy, and a combination thereof. [8] In the lamination step, 8. The method according to any one of items 1 to 7, wherein the second raw material powder is a powder containing at least one selected from nickel (Ni), nickel oxide (NiO), yttria-stabilized zirconia (YSZ), scandia-yttria-stabilized zirconia (ScYSZ), strontium-magnesium-doped tantalum gallate (LSGM), gadolinium-doped ceria (GDC), and / or scandium-stabilized zirconia (SSZ). [9] In the lamination step, 9. The method according to any one of items 1 to 8, wherein the third raw material powder is a powder containing at least one selected from yttria-stabilized zirconia (YSZ), scandia-yttria-stabilized zirconia (ScYSZ), strontium-magnesium-doped lanthanum gallate (LSGM), gadolinium-doped ceria (GDC), and scandium-stabilized zirconia (SSZ).

[10] In the lamination step, 10. The method according to any one of items 1 to 9, wherein the fourth raw material powder is a powder containing at least one selected from lanthanum strontium manganite (LSM), lanthanum strontium cobaltite (LSC), lanthanum strontium cobalt ferrite (LSFC), and samarium strontium cobaltite (SSC).

[11] A laminate, The battery includes two or more layers selected from a metal support layer, an anode layer, an electrolyte layer, and a cathode layer, A laminate in which the thickness of the diffusion layer between at least one layer is 10 μm or less.

[12] Item 12. The laminate according to item 11, wherein one or more layers selected from the metal support layer, the negative electrode layer, and the positive electrode layer are porous.

[13] Item 13. A solid oxide fuel cell constructed using the laminate according to Item 11 or 12. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a method for producing a laminate that can reduce the time required for producing the laminate compared to conventional processes, while still being able to exhibit sufficient power generation performance. Furthermore, the present disclosure can provide a laminate produced by the production method, and a solid oxide fuel cell constructed using the laminate. Here, the solid oxide fuel cell of the present disclosure can ensure the desired power generation performance. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of an apparatus for applying shock waves to powder using the uniaxial compression method. [Figure 2] FIG. 2 is a schematic diagram showing an example of an apparatus for applying shock waves to powder using the cylindrical convergence method (single tube). [Figure 3] FIG. 3 is a schematic diagram showing an example of an apparatus for applying shock waves to powder using the cylindrical convergence method (double tube). [Figure 4] FIG. 4 is a diagram illustrating an example of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail. In this disclosure, various measurements are performed based on the methods described in the examples unless otherwise specified. In the present disclosure, in numerical ranges described in stages, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages, or may be replaced with a value shown in the examples. In the present disclosure, the term "step" includes not only an independent step, but also a step that cannot be clearly distinguished from other steps, as long as the function of the step is achieved. In the contents shown in the drawings, the scale, shape, and length may be exaggerated for clarity.

[0011] [First embodiment] [Method of manufacturing laminate] One example of an aspect provided by the present disclosure is a method for producing a laminate. Such a method comprises: A first raw material layer obtained using a first raw material powder for producing a metal support layer; a second raw material layer obtained using a second raw material powder for producing a negative electrode layer; a third raw material layer obtained using a third raw material powder for producing an electrolyte layer; a fourth raw material layer obtained using a fourth raw material powder for producing a positive electrode layer; a lamination step of laminating two or more raw material layers selected from the above to obtain a raw material laminate; a compression and solidification step of simultaneously compressing and solidifying the raw material laminate at a temperature lower than the sintering temperature of the material contained in each raw material layer to obtain a laminate including two or more layers selected from the metal support layer, the negative electrode layer, the electrolyte layer, and the positive electrode layer; It has. This provides a method for producing a laminate that can exhibit sufficient power generation performance while reducing the time required for producing the laminate compared to conventional processes. Furthermore, a solid oxide fuel cell constructed using the laminate produced by the production method of the present disclosure can ensure desired power generation performance.

[0012] According to the manufacturing method of the present disclosure, a laminate is manufactured using a novel process that replaces the conventional process of repeatedly firing each layer to sinter them. That is, according to the manufacturing method of the present disclosure, the raw material stack is simultaneously compressed and solidified at a temperature below the sintering temperature of the material contained in each raw material layer to obtain a laminate. Therefore, according to the manufacturing method of the present disclosure, repeated firing steps as in the conventional process can be avoided, and therefore excessive heat load due to such firing steps and, ultimately, adverse effects associated with such excessive heat load can be avoided. Specifically, firing can cause phenomena such as diffusion of metal components constituting each layer of the laminate toward adjacent layers and the formation of unintended composites between layers. The adverse effects of such phenomena become more pronounced as firing is repeated. Therefore, in conventional laminates in which a metal support layer, a negative electrode layer, an electrolyte layer, and a positive electrode layer are fabricated in this order, the metal support layer fabricated first is prone to repeated firing each time a layer above it is fabricated. Therefore, it has been particularly difficult to effectively prevent diffusion of metal components constituting the metal support layer into other layers and, ultimately, interlayer delamination between the metal support layer and other layers. Conventional laminates fabricated by such repeated firing processes have resulted in a decline in the performance of solid oxide fuel cells constructed using the laminates. In conventional technologies, because they are based on the conventional firing process, a decline in the activity of the electrolyte and / or the electrode in the solid oxide fuel cell cannot be avoided. In contrast, the manufacturing method of the present disclosure can prevent the occurrence of the above-mentioned phenomenon.

[0013] As described above, the manufacturing method of the present disclosure can reduce the number of firing steps that were previously required, thereby significantly shortening the time required to manufacture the laminate. Furthermore, excessive thermal load due to the firing can be avoided, and thus adverse effects associated with such excessive thermal load can be avoided, thereby effectively preventing delamination between layers in the resulting laminate. Furthermore, by using the laminate manufactured by the manufacturing method of the present disclosure, a solid oxide fuel cell with desired power generation performance can be constructed. In addition, since the manufacturing method of the present disclosure omits the conventional process of repeatedly firing, there tends to be a wider range of options for materials to construct the laminate, compared to conventional technologies that required consideration of the excessive heat load caused by such firing.

[0014] <Raw material laminate> The raw material stack includes two or more raw material layers selected from the first raw material layer, the second raw material layer, the third raw material layer, and the fourth raw material layer. In one embodiment of the present disclosure, in the raw material stack, the two or more raw material layers selected from the first raw material layer, the second raw material layer, the third raw material layer, and the fourth raw material layer are in contact with each other. In one embodiment of the present disclosure, the raw material laminate includes: One or more raw material layers selected from the second raw material layer, the third raw material layer, and the fourth raw material layer may be disposed on the first raw material layer, On the second raw material layer, one or more raw material layers selected from the third raw material layer and the fourth raw material layer may be disposed, and The fourth raw material layer may be disposed on the third raw material layer.

[0015] The one or more raw material layers selected from the first raw material layer, the second raw material layer, the third raw material layer, and the fourth raw material layer included in the raw material laminate may be a single layer or multiple layers. When multiple raw material layers are configured, the compositions of the respective raw material layers are different from each other, and layers of different compositions are introduced into the laminate. In one embodiment, the third raw material layer can have a two-layer structure, and one of the third raw material layers can be configured to function as an electrolyte layer in the laminate, and the other third raw material layer can be configured to function as a reaction prevention layer in the laminate. Even in the case of such a raw material laminate in which some of the raw material layers are multiple layers, the raw material laminate can be compressed and solidified all at once in the method of the present disclosure.

[0016] Each raw material layer is obtained using raw material powder having a composition suitable for that layer. The raw material powder mainly contains metals and inorganic compounds, and may optionally contain support powder and / or organic binders. The composition suitable for each layer can be calculated based on, for example, the types of metal elements, nonmetal elements, and compounds, their ratios, and even the crystal structure. Based on this calculation, the raw material powder can be prepared by any method to form the desired composition. The metal elements here include those provided in the form of pure metals and alloys, as well as those provided in the form of inorganic compounds (e.g., metal oxides, metal nitrides, metal carbides, metal borides, etc.) described below.

[0017] The metal component that may be contained in each raw material layer is a metal belonging to Groups 1 to 14 of the periodic table, preferably Groups 2 to 13, and more preferably Groups 3 to 13. Examples of such metals include iron (Fe), nickel (Ni), yttrium (Y), zirconium (Zr), strontium (Sr), magnesium (Mg), gallium (Ga), copper (Cu), aluminum (Al), titanium (Ti), scandium (Sc), chromium (Cr), cobalt (Co), zinc (Zn), gold (Au), silver (Ag), and tungsten (W). Such metals are not limited to those that are pure or highly pure, but may contain some impurities, which may be other metallic elements or non-metallic elements such as carbon, phosphorus, and sulfur.

[0018] The metal component contained in each raw material powder may be one type of metal or two or more types of metals. When two or more types of metals are contained in each raw material powder, the mass ratio of the two metals may be selected appropriately.

[0019] Each raw material layer may further contain an inorganic compound. The inorganic compound is not particularly limited as long as it is an inorganic compound that is solid at room temperature, and preferable examples thereof include inorganic materials such as metal or non-metal oxides, nitrides, carbides, and borides. Specific examples of inorganic compounds include nickel oxide (NiO), silicon oxide (SiO), titanium oxide (TiO), aluminum oxide (AlO), zirconium oxide (ZrO), gadolinium-doped ceria (GDC), scandia-stabilized zirconia (SSZ), yttria-stabilized zirconia (YSZ), scandia-yttria-stabilized zirconia (ScYSZ), lanthanum strontium manganite (LSM), lanthanum strontium cobaltite (LSC), strontium-magnesium-doped lanthanum gallate (LSGM), samarium strontium cobaltite (SSC), ytterbium-doped barium zirconate (BZYb), titanium nitride (TiN), silicon carbide (SiC), and tungsten carbide (WC). In each raw material layer, one inorganic compound may be used alone, or two or more may be used in combination.

[0020] The raw material laminate can be converted into a laminate by undergoing a compression and solidification step described below. Here, the raw material laminate can be pressed as needed to obtain a pressed raw material laminate. The raw material laminate can also be dried as needed to obtain a dried raw material laminate. The pressed raw material laminate and the dried raw material laminate can also be converted into a laminate by undergoing the compression solidification process described below.

[0021] The laminate obtained using the raw laminate can be converted into a porous material by undergoing a removal step described below. Such a porous material is suitable for use as an electrochemical element in water electrolysis or a fuel cell, for example, as an electrochemical element in a metal-supported SOFC (solid oxide fuel cell). For example, the metal support layer corresponding to the first raw material layer, or the porous material thereof, can be suitably used as a metal support material (metal support layer) in a solid oxide fuel cell. For example, the negative electrode layer corresponding to the second raw material layer, and the porous material thereof, can be suitably used as a fuel electrode layer in a solid oxide fuel cell. For example, the electrolyte layer corresponding to the third raw material layer can be suitably used as an electrolyte layer in a solid oxide fuel cell. For example, the positive electrode layer corresponding to the fourth raw material layer, and the porous material thereof, can be suitably used as an air cathode layer in a solid oxide fuel cell.

[0022] ≪First raw material powder≫ The first raw material powder includes a material for producing the metal support layer. The first raw material powder is preferably a powder containing one or more metals selected from pure metals, alloys, and combinations thereof. The pure metals herein are preferably metals belonging to Groups 1 to 14 of the periodic table, preferably Groups 2 to 13, and more preferably Groups 3 to 13. Examples of metals belonging to these groups are as described above. The alloys herein are combinations of two or more of the above metals, for example, those containing two or more metals selected from the above-mentioned metals belonging to Groups 1 to 14 of the periodic table as the main component. The main component refers to the metal that accounts for the largest mass percentage in the metal composition of the alloy. Examples of alloys include stainless steel, brass, cupronickel, bronze, solder, duralumin, and nichrome, with stainless steel being preferred due to its excellent mechanical properties and corrosion resistance.

[0023] The first raw powder is in the form of a powder, and its average particle size is preferably 0.1 μm to 1000 μm. The upper limit of the average particle size may be, for example, 800 μm or less, 500 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, or 50 μm or less. The lower limit that can be combined with these upper limits is, for example, 0.5 μm or more, 1 μm or more, 5 μm or more, or 10 μm or more. The particle size distribution of the first raw powder preferably contains 30% or more of powder with an average particle size of 500 μm or less, and more preferably 30% or more of powder with an average particle size of 250 μm or less. If the proportion of powder with an average particle size larger than 500 μm is 30% or less, homogeneous mixing is facilitated, and therefore a denser laminate and, ultimately, a more homogeneous porous material can be obtained.

[0024] In the manufacturing method of the present disclosure, the term "average particle size" refers to the particle size at 50% cumulative value in the particle size distribution determined by particle size analysis - laser diffraction and scattering method according to JIS Z 8825.

[0025] ≪Second raw material powder≫ The second raw material powder contains materials for forming the negative electrode layer (for example, metals, oxygen ion conductors, etc.). The metal that may be contained in the second source layer preferably includes at least one metal selected from the group consisting of pure metals, alloys, and combinations thereof. The metal that may be contained in the second source layer may also be a metal oxide that changes to a conductive metal in a reducing atmosphere, and is preferably, for example, nickel (Ni) or nickel oxide (NiO).

[0026] The second raw material powder is in the form of a powder, and its average particle size is preferably 500 μm or less. The upper limit of the average particle size may be, for example, 100 μm or less, 50 μm or less, or 10 μm or less. The particle size distribution of the second raw material powder preferably contains 30% or more of powder with a particle size of 500 μm or less, and more preferably 30% or more of powder with a particle size of 250 μm or less. If the proportion of powder with an average particle size greater than 500 μm is 30% or less, homogeneous mixing is facilitated, and therefore a denser laminate and, ultimately, a more homogeneous porous material can be obtained.

[0027] The oxygen ion conductor contained in the second raw material powder is preferably strontium-magnesium-doped lanthanum gallate (LSGM), gadolinium-doped ceria (GDC), scandia-stabilized zirconia (SSZ), scandia-yttria-stabilized zirconia (ScYSZ) and / or yttria-stabilized zirconia (YSZ). The average particle size of the oxygen ion conductor here is preferably 500 μm or less, and the upper limit of the average particle size may be, for example, 100 μm or less, 10 μm or less, or 1 μm or less.

[0028] The mixing ratio of the oxygen ion conductor contained in the second raw material powder may be preferably more than 30% by volume and not more than 80% by volume, more preferably not more than 70% by volume, even more preferably not more than 60% by volume, and particularly preferably not more than 50% by volume, based on 100% by volume of the total volume of the second raw material powder.

[0029] In light of the above, the second raw material powder may contain powders of the following metals and / or powders of the following inorganic compounds in combination with one selected from Ni and NiO and one selected from YSZ, LSGM, GDC, and SSZ, specifically the following combinations: Ni, and YSZ, Ni, and LSGM, Ni, and GDC, Ni, and SSZ, Ni, and ScYSZ, NiO and YSZ, NiO and LSGM, NiO and GDC, NiO and SSZ, and NiO and ScYSZ It may be included in.

[0030] ≪Third raw material powder≫ The third raw material powder contains an oxygen ion conductor for forming the electrolyte layer. As the oxygen ion conductor, strontium-magnesium doped lanthanum gallate (LSGM), gadolinium-doped ceria (GDC), scandia-yttria stabilized zirconia (ScYSZ), scandia-stabilized zirconia (SSZ), scandia-yttria stabilized zirconia (ScYSZ) and / or yttria stabilized zirconia (YSZ) are preferred. The average particle size of the oxygen ion conductor here is preferably 500 μm or less, and the upper limit of the average particle size may be, for example, 100 μm or less, 10 μm or less, or 1 μm or less.

[0031] ≪Fourth raw material powder≫ The fourth raw material powder contains a composite oxide for forming the positive electrode layer. As the composite oxide, lanthanum strontium manganite (LSM), lanthanum strontium cobaltite (LSC), lanthanum strontium cobalt ferrite (LSFC), and samarium strontium cobaltite (SSC) are preferred. The average particle size of the oxygen ion conductor here is preferably 500 μm or less, and the upper limit of the average particle size may be, for example, 100 μm or less, 10 μm or less, or 1 μm or less.

[0032] ≪Support powder≫ In the manufacturing method of the present disclosure, the support powder is an optional particulate component that is added to impart characteristics to the structure of the laminate. The support powder is not particularly limited as long as it is solid at room temperature, and in one embodiment, it is a material that dissolves in a solvent (water or an organic solvent) (hereinafter also referred to as a "soluble material"), a material that decomposes when heated (hereinafter referred to as a "thermally decomposable material"), and a material that flows when heated (hereinafter referred to as a "thermoplastic material"), etc. The soluble material preferably includes water-soluble salts such as sodium chloride (NaCl), potassium chloride (KCl), potassium aluminum sulfate (alum: KAl(SO4)2), and magnesium sulfate (MgSO4). Examples of the thermally decomposable material include organic binders (for example, alkylacetalized polyvinyl alcohol, ethyl cellulose, acrylic resin, etc.). Examples of thermoplastic materials include thermoplastic resins (for example, polylactic acid (PLA), ABS resin, etc.). As the support powder, one of the above materials may be used alone, or two or more may be used in combination. The support powder may also be used in a mixed state (e.g., paste or slurry) with any fluid component such as an organic binder, solvent, or oil. When a laminate containing a thermally decomposable material and / or a thermoplastic material is heated and removed at a high temperature, the laminate can be easily converted into a porous material. This heating and removal is achieved at a temperature lower than the firing temperature in conventional processes, and therefore the thermal load on the laminate due to this drying is extremely low.

[0033] The support powder is in powder form, and its average particle size is preferably 0.01 μm to 1000 μm. The upper limit of the average particle size of the support powder may be, for example, 800 μm or less, 500 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, or 50 μm or less. The lower limit that can be combined with these upper limits is, for example, 0.005 μm or more, 0.01 μm or more, 0.05 μm or more, or 0.1 μm or more. By adjusting the average particle size of the support powder, the pore size of the porous material can be adjusted. The support powder may be used as it is, or may be dissolved in a solvent and then dried to re-precipitate.

[0034] ≪Mixed powder≫ The mixed powder contains the raw material powder and the support powder. The mixing ratio of the raw material powder and the support powder can be, for example, 5 to 95 volume % of the raw material powder and 10 to 90 volume % of the support powder, where the total volume of the mixed powder is 100 volume %. The upper limit of the mixing ratio of the raw material powder can be, for example, 80 volume % or less, 70 volume % or less, 60 volume % or less, 50 volume % or less, 40 volume % or less, 30 volume % or less, or 20 volume % or less. The lower limit that can be combined with these upper limits can be, for example, 20 volume % or more, 30 volume % or more, 40 volume % or more, 50 volume % or more, 60 volume % or more, 70 volume % or more, or 80 volume % or more. The upper limit of the mixing ratio of the support powder may be, for example, 80 vol.% or less, 70 vol.% or less, 60 vol.% or less, 50 vol.% or less, 40 vol.% or less, 30 vol.% or less, or 20 vol.% or less, and the lower limit that can be combined with these upper limits may be, for example, 20 vol.% or more, 30 vol.% or more, 40 vol.% or more, 50 vol.% or more, 60 vol.% or more, 70 vol.% or more, or 80 vol.% or more.

[0035] <Lamination process> In this process, Two or more raw material layers selected from the first raw material layer, the second raw material layer, the third raw material layer, and the fourth raw material layer are laminated to obtain the raw material laminate. In this step, for example, On the first raw material layer, one or more raw material layers selected from the second raw material layer, the third raw material layer, and the fourth raw material layer may be laminated; Furthermore, one or more raw material layers selected from the third raw material layer and the fourth raw material layer may be laminated on the second raw material layer, Moreover, the fourth raw material layer can be laminated on the third raw material layer. The first raw material layer, the second raw material layer, the third raw material layer, and the fourth raw material layer have different compositions from one another. Thus, this step forms a laminate (the raw material laminate) in which two or more raw material layers having different compositions are laminated.

[0036] The raw material layer can be easily produced by using a predetermined jig. For example, by charging a mixed powder into a predetermined jig, a raw material layer corresponding to the mixed powder can be easily produced. Two or more mixed powders having different compositions can also be charged sequentially into the same jig, which allows the raw material laminate to be suitably produced.

[0037] The raw material layer can also be easily produced by mixing the mixed powder with a solvent, applying a paste, and then drying the mixture. The raw material layers thus obtained can be stacked together, or the paste can be applied to other raw material layers already prepared and the resulting raw material layer with the paste can be dried. Examples of methods for applying the paste include, but are not limited to, screen printing and dip coating. Of course, the raw material layers may be made from the mixed powder as is, and for example, the mixed powder may be naturally filled into the jig as is, thereby easily making the raw material layers corresponding to the mixed powder. The paste method and the natural filling method may be combined, and thus some of the raw material layers in the raw material stack may be made by the paste method, and at this time, the remaining raw material layers in the raw material stack may be made by the natural filling method.

[0038] Here, examples of solvents suitable for preparing the paste include water and organic solvents. Among them, water is preferred as the solvent from the viewpoint of reducing the environmental load, while organic solvents with a boiling point of 300°C or less are preferred from the viewpoint of easy evaporation by subsequent drying. Examples of usable organic solvents include: Examples include NMP (N-methyl-2-pyrrolidone), GBL (γ-butyrolactone), DMSO (dimethyl sulfoxide), N,N-dimethylacetamide, N,N-dimethylformamide, tetramethylurea, ketones, esters, lactones, ethers, alcohols, halogenated hydrocarbons, and hydrocarbons. The mass ratio of the mixed powder to the solvent suitable for preparing the paste is, for example, 5 to 95 mass% of the mixed powder, with the total mass of the paste being 100 mass%. The upper limit of this mass ratio may be, for example, 95 mass% or less. The lower limit that can be combined with this upper limit may be, for example, 5 mass% or more.

[0039] When preparing the paste, an organic binder may be added to it. By mixing an organic binder, it is easy to impart an appropriate viscosity to the paste, and in this case, workability is easily improved. The mixing ratio of the paste containing the organic binder is preferably 5 to 95 mass % of the mixed powder, 0.5 to 50 mass % of the organic binder, and 5 to 95 mass % of the organic solvent, with the total mass of the paste being 100 mass %.

[0040] In this process, It is preferable to obtain a raw material laminate including a first raw material layer. Conventionally, in a metal support layer formed using a metal powder, in a conventional process in which repeated firing is performed, phenomena such as diffusion of metal components contained in the metal support layer into adjacent layers and formation of unintended composites between layers have occurred. In particular, in a conventional laminate in which the metal support layer, a negative electrode layer, an electrolyte layer, and a positive electrode layer are produced in this order, the metal support layer produced first is likely to be subjected to repeated firing each time a layer above it is produced. Therefore, it has been particularly difficult to suitably prevent diffusion of the metal components constituting the metal support layer into other layers and, ultimately, interlayer delamination between the metal support layer and other layers. In contrast, according to the manufacturing method of the present disclosure, repeated firing itself is avoided, and therefore, a laminate having a metal support layer can be suitably produced while preventing peeling between the metal support layer and its adjacent layer.

[0041] In addition, in this process, It is preferable that one or more raw material layers selected from the first raw material layer, the second raw material layer, and the fourth raw material layer contained in the raw material laminate are formed using a mixed powder containing a raw material powder and a support powder different from the raw material powder. A suitable embodiment of the support powder here is, for example, one that is soluble in a predetermined solvent. In this case, a raw material laminate containing the support powder, i.e., a laminate containing the support powder, is contacted with a solvent, thereby dissolving and removing the support powder from the laminate. However, the support powder usable in the manufacturing method of the present disclosure is not limited to one that is soluble in a predetermined solvent. As described above, examples of the support powder include a thermally decomposable material and / or a thermoplastic material. In this case, by subjecting the laminate containing the support powder to high temperatures, the thermally decomposable material in the laminate can be decomposed and / or the thermoplastic material can be fluidized and removed from the laminate. By dissolving and removing the support powder from the laminate, decomposing the organic polymer in the laminate, and / or fluidizing and removing the organic polymer from the laminate, pores are formed in the locations where the support powder was scattered, and a porous material can be obtained.

[0042] In addition, in this process, It is preferable to laminate three or more raw material layers selected from the first raw material layer, the second raw material layer, the third raw material layer, and the fourth raw material layer. Although the number of interlayer spaces increases as the number of layers in the raw material laminate increases, according to one embodiment of the present disclosure, the laminate can be manufactured in a shorter time than conventional processes. Furthermore, peeling between the layers is effectively prevented.

[0043] In addition, in this process, using a powder containing one or more selected from a pure metal, an alloy, and a combination thereof as the first raw material powder; using a powder containing nickel (Ni), nickel oxide (NiO), and / or yttria-stabilized zirconia (YSZ) as the second raw material powder; Using a powder containing yttria-stabilized zirconia (YSZ) and / or lanthanum gallate as the third raw material powder, and / or The fourth raw material powder is a powder containing at least one selected from lanthanum strontium manganite (LSM), lanthanum strontium cobaltite (LSC), and samarium strontium cobaltite (SSC). These are advantageous materials from the viewpoint of suitably producing each raw material layer, for example, from the viewpoint of improving various properties of the resulting laminate.

[0044] <Compression solidification process> In this process, The raw material stack is simultaneously compressed and solidified at a temperature below the sintering temperature of the material contained in each raw material layer to obtain a laminate. This process avoids the firing step required in conventional processes (as described above, the firing step is repeated each time each layer is produced), thereby avoiding the adverse effects associated with the heat load caused by such firing.

[0045] The compression consolidation method may be any method capable of compressing and molding the mixed powder into a predetermined shape at a temperature below the sintering temperature of the material. A preferred compression consolidation method is explosive compression. Explosive compression is a method of instantaneously compressing and consolidating using shock waves generated by explosives. Commonly used methods such as uniaxial compression and cylindrical consolidation can be used. Uniaxial compression is used to obtain a plate-shaped compressed body, while cylindrical consolidation is used to obtain a cylindrical or cylindrical compressed body. Furthermore, cylindrical consolidation, which places a core material in the center, can be used to obtain a cylindrical compressed body. Note that explosive compression utilizes the energy of explosives, and although an instantaneous thermal effect is expected, this effect is limited, and the entire compressed body does not reach the sintering temperature. For example, the temperature in explosive compression is approximately 80°C, which does not reach the sintering temperature of the various materials used in the laminate.

[0046] Explosives are explosives that generate detonation waves. Specific examples of explosives include ammonium nitrate; nitrate esters, such as PETN (pentaerythritol tetranitrate) and nitroglycerin; nitro compounds, such as TNT (trinitrotoluene); and nitramines, such as cyclotrimethylenetrinitramine and cyclotetramethylenetetranitramine. Explosives may be used alone or in combination with two or more other explosive components or components other than explosives.

[0047] In order to solidify the metal powder firmly, the detonation velocity is preferably 1,500 to 8,000 m / s, and more preferably 2,000 to 5,000 m / s. The detonation velocity is appropriately selected depending on the characteristics of the metal powder and the compression method.

[0048] When shock waves are used for compression solidification, they can be used with a liquid medium. Preferably, water is used as the liquid. When shock waves using water as the medium (hereinafter referred to as underwater shock waves) are used, the shock wave pressure itself lasts for a longer period of time than when air is used as the medium. Furthermore, when water is used as the medium, it is much easier to maintain a lower temperature (below the sintering temperature of the material) than when air is used as the medium.

[0049] Examples of methods for compressing and solidifying powder using shock waves are described below with reference to the drawings. The technical scope of the present disclosure is not limited to these specific examples. Figure 1 is a schematic diagram showing an example of an apparatus for applying shock waves to powder using the uniaxial compression method. In FIG. 1, a raw material stack 2 is placed in a metal concave jig 1. The raw material stack 2 here is, for example, The raw material stack 2 includes the first raw material layer, the second raw material layer, and the third raw material layer in this order. The raw material stack 2 may further include the fourth raw material layer on the third raw material layer. Each raw material layer in the raw material laminate 2 contains the mixed powder with a different composition. The raw material stack 2 placed in the metal concave jig 1 may be a pressed body 2 in which the raw material stack has been pressed in advance, or may be a dried body 2 in which the raw material stack has been dried in advance.

[0050] Fig. 1 is a schematic diagram showing an example of an apparatus for applying shock waves to powder using the uniaxial compression method. In Fig. 1, a raw material stack 2 to be compressed is placed on the bottom surface of a metal concave jig 1, and a metal jig 3 serving as a lid is placed on top of the raw material stack 2. An explosive 4 is placed directly on the metal jig 3 within the metal concave jig 1. A container filled with explosive 4 may also be placed on the metal jig 3. A detonator 5 is placed above the explosive 4, and when the explosive 4 is detonated by the detonator 5, the raw material stack 2 is compressed downward by the shock wave emitted by the explosive 4. At this time, a plurality of raw material stacks 2 may be laid one on top of the other, and then compressed at the same time.

[0051] Figure 2 is a schematic diagram showing an example of an apparatus for applying shock waves to powder using the cylindrical convergence method (single tube). Figure 2 shows a plan view and a top view of the apparatus. In Figure 2, a stainless steel rod 11 on which a raw material stack 2 is stacked is packed into a powder-filling metal pipe 8. Both ends of the powder-filling metal pipe 8 are sealed with metal plugs 6. The powder-filling metal pipe 8 is placed vertically on a resin base plate 10, and a buffer 7 is set on top of the metal plug 6 at the upper end, and is covered with a resin pipe 9. The buffer 7 prevents the powder-filling metal pipe 8 from breaking when the detonation pressure first reaches the upper part of the powder-filling metal pipe 8, which is located directly below the detonation point, and also guides the powder-filling metal pipe 8 to be subjected to uniform pressure in the radial direction. An explosive 4 is loaded in the space between the powder-filling metal pipe 8 and the resin pipe 9. A detonator 5 is installed above the explosive 4. When the explosive 4 is detonated by the detonator 5, the raw material stack 20 is compressed in the radial direction by the shock wave generated by the explosive 4.

[0052] Figure 3 is a schematic diagram showing an example of an apparatus for applying shock waves to powder using the cylindrical convergence method (double tube). Figure 3 shows a plan view and a top view of the apparatus. This apparatus is similar to the apparatus shown in Figure 2, except that the metal powder filling pipe 8 of the apparatus shown in Figure 2 is covered with a metal flight pipe 12, creating a double tube structure. In general, a substance (metal flight pipe 12) with a higher density than explosives is flown and collided at high speed, making it possible to compress it at a higher pressure than the apparatus shown in Figure 2. Furthermore, by filling the space between the double tubes with water, it is possible to compress and solidify the powder using water as a medium.

[0053] It is preferable to increase the shock wave to make the relative density of the mixed powder after compaction 80 to 99%. Here, the relative density is the actual density of the mixed powder after compaction expressed as a percentage, with the density (100%) assumed to be the standard when the target mixed powder is compressed so as to completely fill the void volume, and is expressed by the following formula. Relative density = (actual density) ÷ (reference density) × 100

[0054] <Preparation of the positive electrode layer> Here, in the method of the present disclosure, The raw material laminate including the fourth raw material layer is simultaneously compressed and solidified to obtain a laminate including a positive electrode layer, or a raw material laminate including two or more raw material layers selected from a first raw material layer, a second raw material layer, and a third raw material layer is simultaneously compressed and solidified, and then the fourth raw material layer is fired, thereby laminating a positive electrode layer on the compressed and solidified laminate; According to these methods, the positive electrode layer can be easily and suitably produced.

[0055] For example, the positive electrode layer may be produced by simultaneously compressing and solidifying the raw material laminate including the fourth raw material layer. This eliminates the need for a separate process for producing only the positive electrode layer, and the laminate including the positive electrode layer can be easily obtained by compacting (compressing and solidifying) the raw material laminate all at once.

[0056] Alternatively, for example, the positive electrode layer may be produced by simultaneously compressing and solidifying the raw material laminate, and then firing the fourth raw material layer, thereby laminating the positive electrode layer on the compressed and solidified laminate. This allows the laminate of the metal support layer, the negative electrode layer, and the electrolyte layer, or the laminate of the negative electrode layer and the electrolyte layer, and the positive electrode layer to be produced separately, making it easy to adjust various conditions in each step. The fourth raw material layer can be formed by applying and drying a paste prepared by mixing the fourth mixed powder, an organic binder, and a solvent, and the paste may be applied to the exposed surface of a pre-prepared laminate. Examples of application methods include screen printing and dip coating, and in one embodiment, screen printing is preferred. Here, the paste applied to the exposed surface and the laminate on which the paste is applied may be fired at a temperature of 850 to 1000° C. in a vacuum atmosphere or in the air atmosphere. Here, in the method of the present disclosure, firing is performed only once when a technique for producing a positive electrode layer by firing is adopted, and the thermal load on the laminate due to firing is extremely low compared to conventional processes in which firing itself is performed repeatedly. The calcination may be carried out during the evaluation of power generation performance, as described in the Examples.

[0057] When raw material layers are obtained using powders containing metals, the sintering temperature of the materials contained in each raw material layer is generally in the range of 70% to 90% of the melting point of the metal. Although the materials do not completely melt during the sintering process, exposure to high temperatures promotes diffusion of components between layers, which may result in the formation of undesirable intermediate layers and / or undesirable intercalation compounds. To prevent these phenomena, it is desirable to set the sintering temperature of the materials as low as possible. The sintering temperature of the material depends on the type of material and the physical properties of the powder, and is therefore difficult to determine in general, but is preferably less than 1200°C, more preferably less than 1100°C, even more preferably less than 1000°C, and preferably less than 900°C. The lower limit of the sintering temperature is preferably 200°C or higher, more preferably 300°C or higher. Within the above temperature range, delamination of the laminate is easily prevented, and further, the formation of a diffusion layer is also easily prevented. When sintering a laminate including a ceramic (inorganic compound) layer, the sintering temperature tends to be high. Setting a sintering temperature suitable for the ceramic layer increases the heat load on the other layers, which tends to make the laminate more susceptible to problems such as delamination. A typical example of a ceramic layer is an electrolyte layer. Therefore, in this embodiment, when the compression solidification step and the sintering step are used together, it is preferable to compress and solidify at least two layers including the electrolyte layer, then stack the other layers, and then perform firing and sintering. Firing may also be performed when evaluating power generation performance.

[0058] <Removal process (porous process)> In the method of the present disclosure, after the compression and solidification step, It is preferable to have a removal step of removing the support powder from the obtained laminate. In this step, for example, the compressed and solidified laminate is brought into contact with a solvent to dissolve and remove the support powder in the laminate, thereby forming pores in the locations where the support powder was scattered, thereby obtaining a porous material.

[0059] Methods for dissolving and removing the support powder include, but are not limited to, immersing the laminate in a solvent to dissolve the support powder. If necessary, physical stimulation may be applied, such as heating the solvent, causing the solvent to flow, or shaking the laminate. It is preferable that the temperature during processing does not exceed the sintering temperature of the materials in the laminate. Therefore, the upper limit of the temperature for removing the support powder is preferably 300°C or less, 200°C or less, or 100°C or less. The lower limit that can be combined with these upper limits is preferably 40°C or more, 70°C or more, or 90°C or more.

[0060] Another method for decomposing and removing the support powder is to heat the laminate and then remove the support powder. This method is suitable when an organic binder is used as the support powder; that is, the organic binder contained as the support powder in the laminate can be suitably removed by heating the laminate. The heating temperature here preferably does not exceed the sintering temperature of the materials in the laminate, and can be, for example, 500°C or less, or 45°C or less. The drying temperature here is significantly lower than the "firing temperature" used in conventional processes, and therefore the thermal load on the laminate due to drying here is extremely low.

[0061] <Example of this embodiment> An example of a preferred embodiment of the present disclosure will now be described. 4(a) to 4(c) each show an example of an embodiment of the present disclosure, with the flow of processes indicated by arrows. Note that in the figures, "compression and solidification" is carried out at a temperature below the sintering temperature of the material contained in each raw material layer.

[0062] Another example of a preferred embodiment of the present disclosure is a method of simultaneously compressing and solidifying three layers of raw material laminate 20a. For example, raw material laminate 20a including first raw material layer 21, second raw material layer 22, and third raw material layer 23 can be simultaneously compressed and solidified to produce laminate 30a including metal support layer 31, negative electrode layer 32, and electrolyte layer 33. A positive electrode layer 34 can be further laminated on the exposed surface of the electrolyte layer 33 in the same manner as above.

[0063] Another example of a preferred embodiment of the present disclosure is a method of simultaneously compressing and solidifying four layers of raw material laminate 20b. For example, raw material laminate 20b including first raw material layer 21, second raw material layer 22, third raw material layer 23, and fourth raw material layer 24 is pressed, and the resulting pressed body is simultaneously compressed and solidified to produce laminate 30b including metal support layer 31, negative electrode layer 32, electrolyte layer 33, and positive electrode layer 34.

[0064] Here, at least one of the layers in the laminate may be a multi-layer structure. Therefore, a method of simultaneously compressing and solidifying raw material laminate 20c, in which at least one of the layers in the raw material laminate is a multi-layer structure, is also a further example of a preferred embodiment of the present disclosure. Raw material laminate 20c here is a five-layer raw material laminate 20c including first raw material layer 21, second raw material layer 22, third raw material layer 23-2 on the anode layer side, third raw material layer 23-1 on the cathode layer side, and fourth raw material layer 24. By simultaneously compressing and solidifying the raw material laminate 20c, it is possible to produce a laminate 30c including a metal support layer 31, an anode layer 32, an electrolyte layer 33-2 on the anode layer side, an electrolyte layer 33-1 on the cathode layer side, and a cathode layer 34. In the laminate 30c, the electrolyte layer 33-2 on the anode layer side can be configured to function as an electrolyte layer in the laminate, and the third raw material layer 23-1 on the cathode layer side can be configured to function as a reaction prevention layer for the cathode layer.

[0065] [Second embodiment] A further example of an aspect provided by the present disclosure is a laminate. A preferred example of such a laminate is: The battery comprises two or more layers selected from a metal support layer containing at least one metal material selected from a pure metal, an alloy, and a combination thereof, an anode layer containing a mixed powder of a metal and an oxygen ion conductor, an electrolyte layer containing an oxygen ion conductor, and a cathode layer containing a composite oxide, The thickness of the diffusion layer between at least one layer is 10 μm or less, preferably 8 μm or less, more preferably 5 μm or less, and most preferably 1 μm or less. Such a laminate can suitably prevent peeling between layers.

[0066] The metal support layer, the negative electrode layer, the electrolyte layer, and the positive electrode layer may be referred to in the description of the first embodiment. The preferred aspects described in the first embodiment are also preferred in this embodiment.

[0067] The laminate of the present disclosure is provided by the manufacturing method of the present disclosure. The manufacturing method avoids the need for repeated firing in the conventional process, and the laminate of the present disclosure has a diffusion layer between at least one layer with a thickness of 10 μm or less. This type of diffusion layer can be formed by, among other things, the diffusion of metal components constituting each layer of the laminate toward adjacent layers, or the formation of unintended compounds between layers, which is caused by repeated firing in the conventional process. Examples of specific metal components constituting the metal support layer that can diffuse toward adjacent layers include iron (Fe), silicon (Si), nickel (Ni), chromium (Cr), manganese (Mn), molybdenum (Mo), tungsten (W), vanadium (V), cobalt (Co), titanium (Ti), copper (Cu), niobium (Nb), and aluminum (Al), and in one embodiment, chromium (Cr). When stainless steel is used as the metal support layer, these components can be added to the stainless steel. In the laminate of the present disclosure, the diffusion layer refers to a portion between any two layers where a component originally contained only in one layer has diffused into the other layer, resulting in a mixture of the components of the two layers. The thickness of the diffusion layer can be confirmed by analyzing the component distribution in the thickness direction of the laminate using a method such as energy dispersive X-ray spectroscopy (EDS).

[0068] As mentioned above, the meaning of the above explanation regarding the "diffusion layer" also applies mutatis mutandis to other interlayers. That is, Between the metal support layer and the electrolyte layer, Between the metal support layer and the positive electrode layer, Between the negative electrode layer and the electrolyte layer, Between the negative electrode layer and the positive electrode layer, and Between the electrolyte layer and the positive electrode layer, In the laminate of the present disclosure, the thickness of the diffusion layer between the layers selected from the above, in which the metal concentration contained in the layer constituting the interlayer is 5 atomic % or more, is 10 μm or less.

[0069] [Third embodiment] A further example of an aspect provided by the present disclosure is a porous material. Such a porous material can be obtained by carrying out the above-mentioned "removal step" on the laminate provided by the present disclosure. By carrying out the above-mentioned "removal step", the support powder can be removed from the laminate, and at this time, voids are formed in the locations where the support powder was scattered, thereby obtaining a porous material.

[0070] <Porosity> The porosity of the porous material is preferably 5% to 95%, more preferably 15% to 85%, and even more preferably 20% to 80%. When the porosity is 5% or more, the support powder can be easily removed, and when the porosity is 95% or less, the porous material can have sufficient mechanical strength. The porosity can be adjusted by adjusting the mixing ratio of the raw material powder and the support powder.

[0071] <Pore diameter> The pore size of the porous material is preferably 0.01 μm or more and 3000 μm or less. The upper limit of the pore size is, for example, 2000 μm or less, 1500 μm or less, 1000 μm or less, 800 μm or less, 500 μm or less, 250 μm or less, or 200 μm or less. The lower limit of the pore size is, for example, 0.5 μm or more or 1 μm or more. When the pore size is 0.01 μm or more, it is easy to remove the support powder, and when the pore size is 3000 μm or less, the porous material can obtain sufficient mechanical strength. The pore size can be adjusted by adjusting the average particle size and particle size content of the support powder.

[0072] [Fourth embodiment] A further example of an aspect provided by the present disclosure is a solid oxide fuel cell. Such a solid oxide fuel cell can be fabricated by a conventional method using the laminate provided by the present disclosure. The solid oxide fuel cell of the present disclosure includes a laminate that effectively prevents delamination between layers, thereby ensuring desired power generation performance. [Example]

[0073] Hereinafter, embodiments of the present disclosure will be described with reference to examples and comparative examples. However, the embodiments of the present disclosure are not limited to the following examples. Regarding the examples and comparative examples, various productions, measurements, evaluations, etc. were performed by the following methods.

[0074] [Measurement and Evaluation] <Presence or absence of delamination> The laminates obtained in the following Examples and Comparative Examples were evaluated for "presence or absence of delamination" as follows. (Observation (1) The laminate was compressed and solidified, and then the support powder was removed to make the laminate porous. The appearance of the porous laminate was visually observed to check for the presence or absence of delamination. (Observation (2)) Regarding the porous laminate, In Example 1, the following was performed within the scope that does not affect the firing of the air electrode and the evaluation of the power generation performance: In Examples 2 to 3 and Comparative Example, the following were performed within the scope that does not affect the evaluation of the power generation performance: The lamination surfaces of each laminate were polished, and the polished surfaces were observed (magnification: 100x) using a scanning electron microscope (hereinafter sometimes abbreviated as "SEM") to evaluate the presence or absence of peeling between each layer.

[0075] (Evaluation criteria) E (none): In both observations (1) and (2), no peeling was observed between any of the layers. P (present): Peeling was observed between any of the layers in at least one of observations (1) and (2).

[0076] <Presence or absence of diffusion layer> Each of the laminates shown in the following Examples and Comparative Examples was evaluated for the "presence or absence of a diffusion layer" as follows. The laminate was compressed and solidified, and then the support powder was removed to make the laminate porous. In Example 1, the following was performed within the scope that does not affect the firing of the air electrode and the evaluation of the power generation performance: In Examples 2 to 3 and Comparative Example, the following were performed within the scope that does not affect the evaluation of the power generation performance: The laminated surface of each laminate was polished, and the polished surface was subjected to line analysis in the thickness direction using energy dispersive X-ray spectroscopy (hereinafter sometimes abbreviated as "EDS") to evaluate the presence or absence of a diffusion layer of each metal component.

[0077] (Evaluation criteria) E (◯): No diffusion layer was observed. P(x): A diffusion layer was observed. Here, a "diffusion layer" was defined as a layer between layers in which the concentration of the diffusing component was less than 5 atomic % and the range was less than 10 μm. If no such layer was observed, it was determined that "a diffusion layer was not observed."

[0078] <Density of the electrolyte layer> Each of the laminates shown in the following Examples and Comparative Examples was evaluated for "density of the electrolyte layer" as follows. The laminate was compressed and solidified, and then the support powder was removed to make the laminate porous. In Example 1, the following was performed within the scope that does not affect the firing of the air electrode and the evaluation of the power generation performance: In Examples 2 to 3 and Comparative Example, the following were performed within the scope that does not affect the evaluation of the power generation performance: The laminated surface of each laminate was polished, and the polished surface was observed using an SEM (magnification: 1000 times), and the density of the electrolyte was evaluated.

[0079] (Evaluation criteria) E(〇): It was detailed. P(×): Not dense Here, when neither voids nor cracks were observed in the electrolyte upon SEM observation, it was determined to be "dense."

[0080] <Power generation performance> The solid oxide fuel cells constructed using the laminates shown in the following Examples and Comparative Examples were evaluated for "power generation performance" as follows. For a laminate having an air electrode layer, electrolyte layer, anode layer, and metal support layer in which the air electrode, anode, and metal support layer were made porous, air was supplied to the air electrode and combustion gas (H2) was supplied to the metal support layer. Then, the power generation performance as a solid oxide fuel cell was measured at an operating temperature of 700 to 850°C to confirm whether the open circuit voltage (OCV) was 0.5 V or higher. If the OCV is 0.5 V or higher, the density of the electrolyte is ensured, and the porosity of the air electrode, fuel electrode, and metal support layer, as well as the bonding between these layers, are good, so the battery was evaluated as "E: ◯." On the other hand, if the OCV is less than 0.5 V, there is a possibility of delamination, gas leakage due to poor density of the electrolyte layer, or reduced activity due to diffused components, and therefore the battery was evaluated as "P: ×."

[0081] (Evaluation criteria) E(◯): OCV was 0.5 V or higher. P(×): OCV was less than 0.5V.

[0082] [Examples and Comparative Examples] Example 1A (Preparation of raw material laminate)

[0083] A first raw powder containing the following powders was prepared. Metal powder: stainless steel (average particle size: 150 μm) Support powder: NaCl (sieved particle size: (250 μm or less) Volume ratio of metal powder / support powder: 70vol% / 30vol%

[0084] A second raw material powder containing the following powders was prepared. ·Metal powder: Ni (average particle size: 2μm) Oxygen ion conductor powder: YSZ (average particle size: 0.5 μm) ·Support powder: NaCl (average particle size: 20μm) Volume ratio of metal powder / oxygen ion conductor powder / support powder: 35 vol% / 35 vol%:30 vol%

[0085] A third raw powder was prepared containing the following powders: Oxygen ion conductor powder: YSZ (average particle size: 0.5 μm) Supporting powder: None

[0086] The third raw material powder and water were mixed (mass ratio of third raw material powder / water: 50 wt% / 50 wt%) and stirred to prepare a paste. The paste was applied (here, screen printed) onto a stainless steel plate to produce a paste layer (a third raw material layer in a paste state). The paste layer was dried at 110°C in an electric furnace to produce a third raw material layer. This resulted in a stainless steel plate on which the third raw material layer was printed.

[0087] The stainless steel plate on which the third raw material layer was printed was placed in a pressing jig, and then the second raw material powder was filled in to create a powder layer (the second raw material layer in powder form), and then the first raw material powder was filled in to create a further powder layer (the first raw material layer in powder form). A raw material stack comprising the third raw material layer, the second raw material layer, and the first raw material layer was produced. In this example, pressure was applied to the prepared raw material laminate in the lamination direction, thereby obtaining a pressed raw material laminate.

[0088] (Compression solidification) The pressed body obtained above was filled into a metal recessed jig 1 shown in Fig. 1. The pressed body was then compressed and solidified using an explosive with an explosion velocity of 3000 m / s, thereby producing a laminate including a metal support layer, a negative electrode layer, and an electrolyte layer (Example 1A). The laminate had a plate shape. According to this method for producing a laminate, multiple layers can be formed at once in a short time, and peeling between the layers can be suitably prevented.

[0089] ·(Porous) By immersing the laminate obtained above in water, NaCl could be suitably eluted, thereby making the metal support layer and the negative electrode layer porous.

[0090] Example 1 (Lamination of positive electrode layers) The following fourth raw material powder was prepared. Composite oxide: SSC (average particle size: 0.1 μm) The fourth raw material powder was mixed with an organic binder (ethyl cellulose) and an organic solvent (ethanol) (mass ratio of fourth raw material powder / organic binder / organic solvent: 58 wt% / 2 wt% / 40 wt%) and stirred to prepare a paste. The paste was applied (by screen printing) to the exposed surface of the electrolyte layer of a laminate fabricated in the same manner as in Example 1A, to fabricate a paste layer (a fourth raw material layer in a paste state). The paste layer was dried at 120°C in an electric furnace, thereby fabricating a fourth raw material layer.

[0091] Through the above steps, a laminate including a metal support layer, a negative electrode layer, an electrolyte layer, and a positive electrode layer was produced (Example 1). This laminate had a plate shape.

[0092] The organic binder of the resulting laminated cathode could be decomposed and removed during the temperature rise process when evaluating the power generation performance, and the cathode was made porous by sintering at 850°C for 1 hour.

[0093] <Example 2> (Preparation of raw material laminate) A first raw material powder and a second raw material powder were prepared in the same manner as in Example 1A.

[0094] The following third raw material powder for the negative electrode layer side was prepared. Oxygen ion conductor powder: YSZ (average particle size: 0.5 μm) Supporting powder: None

[0095] The following third raw material powder for the positive electrode layer side was prepared. Oxygen ion conductor powder: LSGM (average particle size: 0.4 μm) Supporting powder: None

[0096] A fourth raw powder was prepared containing the following powders: ·Composite oxide: LSC (average particle size: 0.1μm) ·Support powder: NaCl (average particle size: 1μm) Volume ratio of metal powder / support powder: 90vol% / 10vol%

[0097] The fourth raw material powder, an organic binder (ethyl cellulose), and an organic solvent ethanol were mixed (mass ratio of fourth raw material powder / organic binder / organic solvent: 60 wt% / 1 wt% / 39 wt%) and stirred to prepare a paste. The paste was applied (here, by screen printing) onto a stainless steel plate to produce a paste layer (fourth raw material layer in a paste state). The paste layer was dried at 120°C using an electric furnace, thereby producing the fourth raw material layer.

[0098] Furthermore, a paste was prepared by mixing a third raw material powder (third raw material powder for the positive electrode layer side) with an organic solvent (ethanol) (mass ratio of third raw material powder for the positive electrode layer side / organic solvent: 50 wt% / 50 wt%) and stirring the mixture. The paste was applied (by screen printing) to the exposed surface of the fourth raw material layer to prepare a paste layer (a paste-like third raw material layer for the positive electrode layer). The paste layer was dried at 120°C in an electric furnace to prepare a third raw material powder layer for the positive electrode layer.

[0099] In addition, a paste was prepared by mixing a third raw material powder (third raw material powder for the negative electrode layer side) with an organic solvent (ethanol) (mass ratio of third raw material powder for the negative electrode layer side / organic solvent: 50 wt% / 50 wt%) and stirring. The paste was applied (by screen printing) to the exposed surface of the third raw material layer (for the positive electrode layer side) prepared above to prepare a paste layer (a paste-state third raw material layer for the negative electrode layer side). The paste layer was dried at 120°C using an electric furnace, thereby preparing a third raw material powder layer for the negative electrode layer side.

[0100] By the above steps, a powder laminate including the fourth raw material layer, the third raw material layer for the positive electrode layer, and the third raw material layer for the negative electrode layer was produced. That is, by the above steps, a stainless steel plate on which the powder laminate was printed was obtained.

[0101] The stainless steel plate on which the powder laminate was printed was placed in a pressing jig, and then a second raw material powder was filled in to form a powder layer (a powdered second raw material layer), and then a first raw material powder was filled in to form a further powder layer (a powdered first raw material layer). In this way, a raw material laminate was produced that included a fourth raw material layer, a third raw material layer for the positive electrode layer, a third raw material layer for the negative electrode side, a second raw material layer, and a first raw material layer. In this example, pressure was applied to the prepared raw material laminate in the lamination direction, thereby obtaining a pressed raw material laminate.

[0102] (Compression solidification) The pressed body obtained above was filled into a metal recessed jig 1 shown in the apparatus of Fig. 1. The pressed body was then compressed and solidified using an explosive with an explosion velocity of 3000 m / s, thereby producing a laminate including a metal support layer, a negative electrode layer, an electrolyte layer for the negative electrode side, an electrolyte layer for the positive electrode side, and a positive electrode layer (Example 2). This laminate had a plate shape.

[0103] ·(Porous) The resulting laminate was immersed in water to effectively dissolve NaCl, thereby making the metal support layer, anode layer, and cathode layer porous. The organic binder remaining in the cathode layer was also eliminated during the temperature rise process during the evaluation of power generation performance.

[0104] Example 3 (Preparation of raw material laminate) A first raw powder containing the following powders was prepared. Metal powder: stainless steel (average particle size: 50 μm) ·Support powder: NaCl (average particle size: 10μm) Volume ratio of metal powder / support powder: 70vol% / 30vol%

[0105] A second raw material powder containing the following powders was prepared. ·Metal oxide powder: NiO (average particle size: 3μm) Oxygen ion conductor powder: YSZ (average particle size: 0.4 μm) Mass ratio in metal powder: NiO / YSZ=60wt% / 40wt% ·Support powder: NaCl (average particle size: 10μm) Volume ratio of metal oxide powder / oxygen ion conductor / support powder: 40 vol% / 40 vol% / 20 vol%

[0106] The following third raw material powder was prepared. Oxygen ion conductor powder: LSGM (average particle size: 0.3 μm)

[0107] A fourth raw powder was prepared containing the following powders: ·Composite oxide powder: SSC (average particle size: 0.3μm) ·Support powder: NaCl (average particle size: 1μm) Composite oxide powder / support powder volume ratio: 70 vol% / 30 vol%

[0108] The fourth raw material powder, an organic binder (ethyl cellulose), and an organic solvent (ethanol) were mixed (mass ratio of fourth raw material powder / organic binder / organic solvent: 40 wt% / 1 wt% / 59 wt%) and stirred to prepare a paste. This paste was applied (dip coated in this case) to the surface of a stainless steel support rod to prepare a paste layer (fourth raw material layer in a paste state). This paste layer was dried at 120°C using an electric furnace, thereby preparing a fourth raw material powder layer.

[0109] Furthermore, the third raw material powder, an organic binder (ethyl cellulose), and an organic solvent (ethanol) were mixed (mass ratio of third raw material powder / organic binder / organic solvent: 40 wt% / 1 wt% / 59 wt%) and stirred to prepare a paste. This paste was applied (here, dip coated) to the surface of the fourth raw material powder layer to prepare a paste layer (third raw material layer in a paste state). This paste layer was dried at 120°C using an electric furnace, thereby preparing a third raw material powder layer.

[0110] Similarly, the second raw material powder, organic binder (ethyl cellulose), and organic solvent (ethanol) were mixed (mass ratio of second raw material powder / organic binder / organic solvent: 40 wt% / 1 wt% / 59 wt%) and stirred to prepare a paste. This paste was applied (here, dip coated) to the surface of the third raw material layer to prepare a paste layer (second raw material layer in a paste state). This paste layer was dried at 120°C using an electric furnace, thereby preparing a second raw material powder layer.

[0111] Similarly, the first raw material powder, organic binder (ethyl cellulose), and organic solvent (ethanol) were mixed (mass ratio of first raw material powder / organic binder / organic solvent: 40 wt% / 3 wt% / 57 wt%) and stirred to prepare a paste. This paste was then applied (dip coated) to the surface of the second raw material powder layer to prepare a paste layer (first raw material layer in a paste state). This paste layer was dried at 120°C using an electric furnace, thereby preparing the first raw material layer.

[0112] Through the above steps, a raw material stack was produced, in which the stainless steel support rod was positioned at the axial core and which included the fourth raw material layer, the third raw material layer, the second raw material layer, and the first raw material layer. In this example, the obtained raw material laminate was heat-treated at 450° C. in an electric furnace to remove the organic binder from the raw material laminate, thereby obtaining a dried raw material laminate.

[0113] (Compression solidification) The support rod with the dried body obtained above was packed into a metal powder-packing pipe 8 shown in Fig. 2. The dried body was then compressed and solidified using an explosive with an explosion velocity of 2500 m / s, thereby producing a laminate including a metal support layer, a negative electrode layer, an electrolyte layer, and a positive electrode layer (Example 3). The laminate had a cylindrical shape.

[0114] ·(Porous) By immersing the obtained laminate in water, NaCl could be suitably eluted, thereby making the metal support layer, the negative electrode layer, and the positive electrode layer porous.

[0115] <Comparative Example 1> (Preparation of raw material laminate) A first powder mixture was prepared containing the following powders: Metal powder: stainless steel (average particle size: 100 μm)

[0116] A second powder mixture was prepared containing the following powders: ·Metal powder: Ni Oxygen ion conductor powder: YSZ (average particle size: 1 μm)

[0117] A third powder mixture was prepared containing the following powders: Oxygen ion conductor powder: YSZ (average particle size: 1 μm)

[0118] A fourth powder mixture was prepared containing the following powders: Composite oxide powder: SSC (average particle size: 1 μm)

[0119] The third raw material powder and water were mixed (mass ratio of third raw material powder / water: 50 wt% / 50 wt%) and stirred to prepare a paste. The paste was applied (here, screen printed) onto a stainless steel plate to produce a paste layer (a third raw material layer in a paste state). The paste layer was dried at 110°C using an electric furnace, thereby producing a third raw material layer. In other words, a stainless steel plate on which the third raw material layer was printed was obtained.

[0120] The stainless steel plate on which the third raw material layer was printed was placed in a pressing jig, and then the second raw material powder was filled in to create a powder layer (the second raw material layer in powder form), and then the first raw material powder was filled in to create a further powder layer (the first raw material layer in powder form). A raw material stack comprising the third raw material layer, the second raw material layer, and the first raw material layer was produced. In this example, pressure was applied to the prepared raw material laminate in the lamination direction, thereby obtaining a pressed raw material laminate.

[0121] (Firing: Preparation of laminate) The pressed body obtained above was fired in a reducing atmosphere at 1200° C. for 1 hour, thereby producing a laminate including a metal support layer, a negative electrode layer, and an electrolyte layer.

[0122] (Further firing: lamination of positive electrode layer) The fourth raw material powder, an organic binder (ethyl cellulose), and an organic solvent (ethanol) were mixed (mass ratio of fourth raw material powder / organic binder / organic solvent: 40 wt% / 1 wt% / 59 wt%) and stirred to prepare a paste. The paste was applied (here, by screen printing) to the exposed surface of the electrolyte layer to prepare a paste layer (fourth raw material layer in a paste state). The paste layer was dried at 120°C using an electric furnace to prepare a fourth raw material powder layer.

[0123] The laminate obtained by the above process was fired in a vacuum atmosphere at 850°C for 1 hour to produce a laminate having a metal support layer, a negative electrode layer, an electrolyte layer, and a positive electrode layer. The laminate had a plate shape.

[0124] The results of the above are shown in the table below. [Table 1]

[0125] According to the examples, it was possible to produce a laminate having sufficient power generation performance in a shorter time than with conventional processes. It was also confirmed that this process effectively prevented delamination between layers in the laminate. [Industrial Applicability]

[0126] According to the present disclosure, it is possible to obtain a laminate that can exhibit sufficient power generation performance while shortening the time required for manufacturing the laminate. This contributes to reducing manufacturing costs and GHG emissions during manufacturing. Furthermore, it is possible to effectively prevent delamination between layers of the laminate. The laminate provided by the present disclosure can be used to suitably produce porous materials. Such porous materials may be applicable to lightweight structures, filters, catalysts, heat exchangers, medical artificial bones and implants, electrode materials, buffer materials, sound-deadening materials, and the like. Furthermore, the laminate provided by the present disclosure can be used to suitably produce electrochemical elements for water electrolysis, electrochemical elements for fuel cells, and solid oxide fuel cells. Such electrochemical elements and solid oxide fuel cells can ensure desired power generation performance. [Explanation of symbols]

[0127] 1 Metal concave jig 2 Raw material laminate 3 Metal jig 4 Explosives 5 Detonator 6 Metal plug 7 Buffer 8. Metallic pipe for powder filling 9. Resin pipes 10 Resin base plate 11 Stainless steel rod 12 Metal Flying Pipe 20 Raw material laminate 20a to 20c Raw material laminate 21 1st raw material layer 22 2nd raw material layer 23 Third raw material layer 23-1 Third raw material layer on the positive electrode side 23-2 Third raw material layer on the negative electrode side 24 4th raw material layer 30a to 30c Laminate 31 Metal support layer 32 negative electrode layer 33 Electrolyte layer 33-1 Electrolyte layer on the positive electrode side 33-2 Electrolyte layer on the negative electrode side 34 Positive electrode layer

Claims

1. A method for manufacturing a laminate, comprising: The method comprises: A first raw material layer obtained using a first raw material powder for producing a metal support layer; a second raw material layer obtained using a second raw material powder for producing a negative electrode layer; a third raw material layer obtained using a third raw material powder for producing an electrolyte layer; a fourth raw material layer obtained using a fourth raw material powder for producing a positive electrode layer; a lamination step of laminating two or more raw material layers selected from the above to obtain a raw material laminate; a compression and solidification step of simultaneously compressing and solidifying the raw material laminate at a temperature lower than the sintering temperature of a material contained in each raw material layer to obtain a laminate including two or more layers selected from the metal support layer, the negative electrode layer, the electrolyte layer, and the positive electrode layer; A method for producing a laminate comprising the steps of:

2. In the lamination step, 2. The method according to claim 1, wherein one or more raw material layers selected from the first raw material layer, the second raw material layer, and the fourth raw material layer included in the raw material stack are formed using a mixed powder containing the raw material powder and a support powder different from the raw material powder.

3. In the method, after the compressive solidification step, The method according to claim 1 , further comprising a removing step of removing the support powder from the resulting laminate.

4. In the compression and solidification step, 2. The method of claim 1, wherein the compacting is performed by explosive compaction.

5. In the lamination step, The method according to claim 1 , wherein three or more types of raw material layers selected from the first raw material layer, the second raw material layer, the third raw material layer, and the fourth raw material layer are laminated.

6. In the method, The raw material stack including the fourth raw material layer is simultaneously compressed and solidified to obtain the stack including the positive electrode layer, or 2. The method according to claim 1, wherein a raw material laminate including two or more raw material layers selected from the first raw material layer, the second raw material layer, and the third raw material layer is simultaneously compressed and solidified, and then the fourth raw material layer is fired, thereby laminating the positive electrode layer on the compressed and solidified laminate.

7. In the lamination step, The method according to claim 1 , wherein the first raw material powder is a powder containing at least one selected from the group consisting of a pure metal, an alloy, and a combination thereof.

8. In the lamination step, 2. The method according to claim 1, wherein the second raw material powder contains at least one selected from nickel (Ni), nickel oxide (NiO), yttria-stabilized zirconia (YSZ), scandia-yttria-stabilized zirconia (ScYSZ), strontium-magnesium-doped tantalum gallate (LSGM), gadolinium-doped ceria (GDC), and / or scandium-stabilized zirconia (SSZ).

9. In the lamination step, 2. The method according to claim 1, wherein the third raw material powder is a powder containing at least one selected from yttria-stabilized zirconia (YSZ), scandia-yttria-stabilized zirconia (ScYSZ), strontium-magnesium-doped lanthanum gallate (LSGM), gadolinium-doped ceria (GDC), and scandium-stabilized zirconia (SSZ).

10. In the lamination step, 2. The method according to claim 1, wherein the fourth raw material powder is a powder containing at least one selected from lanthanum strontium manganite (LSM), lanthanum strontium cobaltite (LSC), lanthanum strontium cobalt ferrite (LSFC), and samarium strontium cobaltite (SSC).

11. A laminate, The battery includes two or more layers selected from a metal support layer, an anode layer, an electrolyte layer, and a cathode layer, A laminate in which the thickness of the diffusion layer between at least one layer is 10 μm or less.

12. The laminate according to claim 11 , wherein at least one layer selected from the metal support layer, the negative electrode layer, and the positive electrode layer is porous.

13. A solid oxide fuel cell constructed using the laminate according to claim 11.

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