JP2006351253A - Solid oxide fuel cell stack, solid oxide fuel cell module using this, and manufacturing method of solid oxide fuel cell stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid oxide fuel cell stack, a solid oxide fuel cell module using it, and a manufacturing method of the solid oxide fuel cell stack. <P>SOLUTION: The fuel cell stack is provided with a laminate having a first unit cell 11, a second unit cell 12, and a ceramic interconnector 2, has a fuel gas passage between a first fuel electrode 112 and an opposed face of the interconnector 2, has a combustion supporting gas passage between a second air electrode 123 and the opposed face of the interconnector 2, and the first fuel electrode 112 and the second air electrode 123 are connected through a via-conductor 21 penetrating the interconnector 2. The module has a plurality of stacks integrated. The manufacturing method of the stack comprises a forming process of lamination sheet for unbaked unit cell, a forming process of lamination sheet for unbaked interconnector, a forming process of compound sheet for unbaked unit cell, a forming process of compound unit, a forming process of crimped unit, a forming process of unbaked stack to cut the crimped unit, and a forming process of stack to bake the unbaked unit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid oxide fuel cell stack, a solid oxide fuel cell module using the same, and a method for manufacturing a solid oxide fuel cell stack. More specifically, the present invention has a structure in which single cells are stacked by ceramic interconnectors, and one fuel electrode and the other air electrode of adjacent single cells are formed in the ceramic interconnector. The present invention relates to a solid oxide fuel cell stack connected via a conductor, a solid electrolyte fuel cell module in which a plurality of stacks are integrated, and a method of manufacturing the solid oxide fuel cell stack.

  A solid oxide fuel cell (hereinafter sometimes referred to as “SOFC”) has an output voltage of a single cell of less than 1V. Therefore, for example, in order to obtain a preferable input voltage of the power conditioner (usually 120 V or more), it is necessary to use a large number of single cells connected in series. Therefore, as a practical SOFC, a so-called stack structure in which single cells are stacked in series in the vertical direction is proposed. In such a stack structure, an interconnector for connecting single cells in series is used, and a metal felt such as nickel felt and a metal plate are interposed between the interconnector and a fuel electrode and an air electrode to Continuity is ensured (see, for example, Patent Document 1 and Patent Document 2).

JP 2004-146129 A JP 2004-319187 A

  However, in the structure as described above, the conduction becomes unstable with time due to the thermal cycle when the SOFC is repeatedly started and stopped, and the function of the SOFC may be greatly deteriorated. Further, in the conventional stack structure, in order to stack a large number of single cells and hold them as a structure, the area of the single cells must be increased. As a result, although a predetermined output voltage can be obtained, there is a problem that the electric power is remarkably excessive from several kW, which is a normal required electric power for home cogeneration systems and in-vehicle SOFC. On the other hand, if the power is set to several kW, the number of stacked single cells is reduced, and a preferable input voltage such as a power conditioner is not reached. Therefore, the voltage conversion mechanism becomes complicated, the system becomes expensive, and There is also a problem that power loss increases.

  The present invention has been made in view of the above situation, and a via conductor in which a fuel electrode of one unit cell and an air electrode of the other unit cell among adjacent unit cells are formed in a ceramic interconnector. Because these single cells and ceramic interconnectors are firmly joined and integrated with each other, stable conduction even after undergoing a thermal cycle when SOFC is repeatedly started and stopped Is provided, and a solid oxide fuel cell stack (hereinafter, also referred to as “SOFC stack”) in which predetermined performance is maintained and a manufacturing method thereof are provided. The SOFC stacks are arranged in parallel at a predetermined interval, and a solid oxide fuel cell module (hereinafter referred to as “hereinafter referred to as“ fuel cell ”) including an isolation member for isolating the fuel gas supplied to each SOFC stack and the combustion-supporting gas. It is an object to provide “SOFC module”.

The present invention is as follows.
1. A first solid electrolyte body 111, a first fuel electrode 112 provided on one surface of the first solid electrolyte body 111, and a first air electrode 113 provided on the other surface of the first solid electrolyte body 111. Single cell 11, second solid electrolyte body 121, second fuel electrode 122 provided on one surface of second solid electrolyte body 121, and second air electrode provided on the other surface of second solid electrolyte body 121 The second unit cell 12 having the first solid electrolyte body 111, one surface side being joined to both sides of the first fuel electrode 112 on the one surface of the first solid electrolyte body 111, and the other surface side being the other of the second solid electrolyte body 121. And a ceramic interconnector 2 joined to both sides of the second air electrode 123 on the surface, between the opposing surfaces of the first fuel electrode 112 and the ceramic interconnector 2. A fuel gas flow path f, A combustion-supporting gas flow path s is provided between the opposing surfaces of the electrode 123 and the ceramic interconnector 2, and the first fuel electrode 112 and the second air electrode 123 are connected to the ceramic interconnector 2. A solid oxide fuel cell stack, which is connected via a via conductor 21 formed on the substrate.
2. A direction in which the first single cell 11 and the second single cell 12 are connected by the ceramic interconnector 2 is a length direction, and a cross section in a direction perpendicular to the length direction is a square or a rectangle. Above 1. A solid oxide fuel cell stack according to 1.
3. When the cross section is square, the dimension of one side is 5 to 20 mm, and the dimension in the length direction is 20 to 100 mm, or when the section is rectangular, the short side is 5 to 20 mm and the long side is 5 mm. 2 to 100 mm, and the dimension in the length direction is 20 to 100 mm. A solid oxide fuel cell stack according to 1.
4). The distance between the opposing surfaces of each of the first fuel electrode 112 and the second air electrode 123 and the ceramic interconnector 2 is 0.2 to 2 mm. To 3. The solid oxide fuel cell stack according to any one of the above.
5. The ceramic interconnector 2 is mainly composed of alumina. To 4. The solid oxide fuel cell stack according to any one of the above.
6). The first solid electrolyte body 111 and the second solid electrolyte body 121 are each made of zirconia containing alumina, and when the total of the alumina and the zirconia is 100% by mass, the alumina is 0. The above 5. which is 1 to 20% by mass. A solid oxide fuel cell stack according to 1.
7). The first solid electrolyte body 111 and the second solid electrolyte body 121 are each composed of zirconia, or zirconia containing 0.1 to 20% by mass of alumina when the total of alumina and zirconia is 100% by mass. The solid electrolyte body 111 and the solid electrolyte body 121 are joined to the ceramic interconnector 2 via intermediate ceramic layers each containing alumina and zirconia. A solid oxide fuel cell stack according to 1.
8). 2. To 7. A solid oxide fuel cell module in which the solid oxide fuel cell stack according to any one of the above is integrated, wherein a fuel gas flow path of each solid oxide fuel cell stack is opened. A plurality of the solid oxide fuel cell stacks arranged in parallel so that the side surfaces and / or the side surfaces where the combustion-supporting gas flow paths are open are opposed to each other with a predetermined interval therebetween, In order to isolate the fuel gas and the combustion-supporting gas supplied to the solid oxide fuel cell stack, an isolation member disposed in a gap between the solid oxide fuel cell stacks is provided. Solid electrolyte fuel cell module.
9. 7. The fuel gas flow direction intersects with the combustion-supporting gas flow direction. 2. A solid oxide fuel cell module according to 1.
10. Above 1. To 7. A method for manufacturing a solid electrolyte fuel cell stack according to any one of the above, wherein a plurality of unfired first fuel electrodes are respectively provided on one side and the other side of the unfired first solid electrolyte sheet 111 ′. A belt-shaped sheet 112 ′ and a plurality of unfired first air electrode belt-shaped sheets 113 ′ are formed so that their directions intersect to produce a fired first single-cell laminated sheet 11 ′. A plurality of unfired second fuel electrode strips 122 ′ and a plurality of unfired second air electrode strips 123 ′ are respectively disposed on one side and the other side of the second solid electrolyte sheet 121 ′. Are formed so as to intersect with each other, and a non-fired single cell laminated sheet preparation step for producing a non-fired second single cell laminated sheet 12 ′, one surface of the non-fired ceramic sheet 22 ′, and the non-fired first ceramic apertured sheet 231 'And the unfired ceramic sheet The direction of the strip-shaped opening of each of the other surface 22 ′ and the unfired second ceramic opening sheet 232 ′ of the unfired first ceramic opening sheet 231 ′ and the unfired second ceramic opening sheet 232 ′ The interconnector side via hole is provided in a portion where the unfired ceramic sheet 22 ′, the unfired first ceramic opening sheet 231 ′, and the unfired second ceramic opening sheet 232 ′ are stacked. A laminate sheet manufacturing process for an unfired ceramic interconnector in which the interconnector side via hole is filled with a conductive material to form an unfired via conductor 21 ′ to produce an unfired ceramic interconnector laminate sheet 2 ′; A plurality of unfired single cell laminate sheets including the fired first single cell laminate sheet 11 ′ and the unfired second single cell laminate sheet 12 ′. And an unfired first ceramic opening sheet having an unfired ceramic interconnector laminated sheet that is one less than the unfired single cell laminated sheet including the unfired ceramic interconnector laminated sheet 2 ′. The non-sintered air electrode is fitted into the non-sintered second ceramic apertured sheet so that the unsintered fuel electrode is fitted in the opening, and the end surface sheet 31 ′ and the end surface sheet 31 ′ An unsintered ceramic end face sheet 3 ′ composed of an end face opening sheet 32 ′ having a strip-like opening laminated on one surface of the end face sheet 31 ′ is formed on each end face in the opening. The air electrode or the unfired fuel electrode is stacked so that the unfired ceramic end face sheet 3 ′ is the bottom or top surface of the solid oxide fuel cell stack. Otherwise, the unfired ceramic end face sheet 3 ′ is provided with an end face sheet side via hole that communicates with the interconnector side via hole, and the end face sheet side via hole is filled with a conductive material to form the unfired end face sheet side via conductor 33 ′. An unfired unit cell composite sheet preparation step for producing an unfired unit cell composite sheet a formed by forming a plurality of the unfired unit cell composite sheets, The unfired air electrode formed on the end face side of one of the unfired unit cell composite sheets is opposed to the unfired fuel electrode formed on the end face side of the other unfired unit cell composite sheet. And forming a composite by laminating so that the direction of the unfired air electrode and the direction of the unfired fuel electrode intersect, and the composite Pressure bonding body forming step of pressure bonding in the laminating direction to form a pressure bonding body b, and the pressure bonding body between the openings included in the unfired first ceramic opening sheet and the above described structure of the unfired second opening ceramic sheet. An unsintered solid electrolyte fuel cell stack manufacturing step for cutting an unsintered solid electrolyte fuel cell stack by cutting in the pressure-bonding direction between the openings, and firing a plurality of the unsintered solid electrolyte fuel cell stacks to form a solid And a solid electrolyte fuel cell stack manufacturing step of manufacturing an electrolyte fuel cell stack.
11. The above-mentioned 10. The cutting is performed by a wire saw. A method for producing a solid oxide fuel cell stack according to 1.
12 In the unfired single cell laminated sheet manufacturing step, the unfired solid electrolyte sheet is provided on the unfired fuel electrode strip and the unfired ceramic interconnector laminated sheet to be laminated on the one surface. The conductive material filled in the interconnector-side via hole is connected to the fuel electrode-side unfired conductive pattern 41 ′, and on the other surface of the unfired solid electrolyte sheet, a band for the unfired air electrode is formed. The air electrode side unfired conductive pattern 42 is connected so that the sheet and the conductive material filled in the interconnector side via hole provided in the unfired ceramic interconnector laminated sheet to be laminated on the other surface are connected. 10. Forming ' Or 11. A method for producing a solid oxide fuel cell stack according to 1.

In the solid oxide fuel cell stack of the present invention, each single cell and the ceramic interconnector are firmly joined and integrated with each other, and stable even after a thermal cycle when starting and stopping are repeated. The continuity is ensured and the predetermined power generation performance is maintained.
Further, when the first unit cell 11 and the second unit cell 12 are connected in the length direction with the ceramic interconnector 2 and the cross section in the direction orthogonal to the length direction is square or rectangular, The SOFC stack is small and easy to handle.
Furthermore, when the cross section is square, the dimension of one side is 5 to 20 mm, and the dimension in the length direction is 20 to 100 mm, or when the section is rectangular, the short side is 5 to 20 mm, and the long side is 5 to 5 mm. When the length is 100 mm and the length is 20 to 100 mm, the SOFC stack can be made smaller and have sufficient power generation performance.
Moreover, when the distance between each opposing surface of each of the 1st fuel electrode 112 and the 2nd air electrode 123 and each ceramic interconnector 2 is 0.2-2 mm, it is the dimension of a length direction especially. Can be made smaller, and the SOFC stack can be made smaller and useless.
Furthermore, when the ceramic interconnector 2 is mainly composed of alumina, an SOFC stack having sufficient strength can be obtained.
The first solid electrolyte body 111 and the second solid electrolyte body 121 are each composed of zirconia containing alumina, and when the total of alumina and zirconia is 100 mass%, the alumina is 0.1-20. In the case of the mass%, the ceramic interconnector 2 made of alumina, the first solid electrolyte body 111 and the second solid electrolyte body 121 can be bonded more firmly.
Furthermore, the first solid electrolyte body 111 and the second solid electrolyte body 121 are each made of zirconia, or zirconia containing 0.1 to 20% by mass of alumina when the total of alumina and zirconia is 100% by mass. Even when each of the solid electrolyte body 111 and the solid electrolyte body 121 and the ceramic interconnector 2 are joined via an intermediate ceramic layer containing alumina and zirconia, the ceramic made of alumina. The made interconnector 2, the first solid electrolyte body 111, and the second solid electrolyte body 121 can be joined more firmly.
The solid oxide fuel cell module of the present invention can be easily miniaturized, has little unnecessary space, and has sufficient power generation performance.
In addition, when the flow direction of the fuel gas and the flow direction of the combustion-supporting gas intersect, the structure of a manifold or the like for supplying and discharging each of the fuel gas and the combustion-supporting gas is simplified. can do.
According to the method for manufacturing a solid oxide fuel cell stack of the present invention, it is possible to easily manufacture an SOFC stack in which each single cell and a ceramic interconnector are firmly joined to each other and integrated.
Furthermore, when cutting is performed with a wire saw, a SOFC stack with high dimensional accuracy can be obtained.
Also, in the process for producing a laminated sheet for unfired single cells, it is provided on the unfired solid electrolyte sheet on the unburned fuel electrode strip and the unfired ceramic interconnector laminated sheet to be laminated on this face. The conductive material filled in the interconnector-side via hole is formed, and a fuel electrode-side unfired conductive pattern 41 'is formed, and on the other surface of the unfired solid electrolyte sheet, a band shape for the unfired air electrode The air electrode side unfired conductive pattern 42 is connected so that the sheet and the conductive material filled in the interconnector side via hole provided in the unfired ceramic interconnector laminated sheet to be laminated on the other surface are connected. In the case of forming ', the fuel electrode of one unit cell and the air electrode of the other unit cell can be easily conducted.

Hereinafter, the present invention will be described in detail with reference to FIGS.
[1] Solid electrolyte fuel cell stack The “solid electrolyte fuel cell stack” includes a first solid electrolyte body 111, a first fuel electrode 112 provided on one surface thereof, and a first air electrode 113 provided on the other surface thereof. The “second unit cell” having the “first unit cell 11”, the second solid electrolyte body 121, the second fuel electrode 122 provided on one surface thereof, and the second air electrode 123 provided on the other surface thereof. 12 ”, one side is joined to both sides of the first fuel electrode 112 on one side of the first solid electrolyte body 111, and the other side is joined to both sides of the second air electrode 123 on the other side of the second solid electrolyte body 121. The laminated body which has the ceramic interconnector 2 joined is provided (refer FIG. 1, 2).

  The “first solid electrolyte body 111” and the “second solid electrolyte body 121” are one of the fuel gas introduced into the fuel electrode or the combustion-supporting gas introduced into the air electrode during battery operation. It has ionic conductivity that can move the part as ions. Although what kind of ion can be conducted is not particularly limited, examples of the ion include oxygen ion and hydrogen ion. Further, the “first fuel electrode 112” and the “second fuel electrode 122” are in contact with the fuel gas serving as a reducing agent and function as a negative electrode in the cell. Furthermore, the “first air electrode 113” and the “second air electrode 123” are in contact with a combustion-supporting gas serving as an oxidant and function as positive electrodes in the cell.

The material used for forming the first solid electrolyte layer 111 and the second solid electrolyte body 121 can be appropriately selected depending on the use conditions of the fuel cell. Examples of this material include ZrO ₂ ceramics, LaGaO ₃ ceramics, BaCeO ₃ ceramics, SrCeO ₃ ceramics, SrZrO ₃ ceramics, and CaZrO ₃ ceramics. Among these materials, preferably ZrO ₂ based ceramic, Sc, at least ZrO ₂ based ceramic is preferably stabilized by one of rare earth elements such as Y, the ZrO ₂ based ceramic stabilized with Sc Particularly preferred.

  When the ceramic interconnector 2 is mainly composed of alumina, the first solid electrolyte body 111 and the second solid electrolyte body 121 are each made of zirconia containing alumina, and the total of alumina and zirconia is 100 mass%. In this case, the alumina content is preferably 0.1 to 20% by mass, particularly 0.5 to 10% by mass, and more preferably 1 to 6% by mass. As the zirconia, zirconia stabilized by at least one of rare earth elements such as Sc and Y is preferable, and zirconia stabilized by Sc is particularly preferable. Thus, by making zirconia contain alumina, the 1st solid electrolyte body 111 and the 2nd solid electrolyte body 121, and the ceramic interconnector 2 can be joined more firmly.

Furthermore, when the ceramic interconnector 2 is mainly composed of alumina, the first solid electrolyte body 111 and the second solid electrolyte body 121 are each composed of zirconia, or the total of alumina and zirconia is 100% by mass. 0.1 to 20% by mass, particularly 0.5 to 10% by mass, and further 1 to 6% by mass of zirconia containing 1 to 6% by mass of alumina, and each of the solid electrolyte body 111 and the solid electrolyte body 121, and ceramic inter The connector 2 is preferably bonded via an intermediate ceramic layer containing alumina and zirconia, respectively.
The above “mainly composed of alumina” means that 70% by mass or more of alumina when the total amount of ceramic constituting the ceramic interconnector 2 is 100% by mass.
In particular, it means 80% by mass or more, and further 90% by mass (may be 100% by mass).

The content of alumina in the intermediate ceramic layer is not particularly limited, and can be set according to the content of alumina in each of the first solid electrolyte body 111 and the second solid electrolyte body 121, for example, 30 to 60% by mass. In particular, it can be 40 to 50% by mass. By using the intermediate ceramic layer in this manner, the first solid electrolyte body 111 and the second solid electrolyte body 121 and the ceramic interconnector 2 can be bonded more firmly. As the zirconia in this case, the same stabilized zirconia as described above is preferable.
Although the thickness of each of the first solid electrolyte body 111 and the second solid electrolyte body 121 is not particularly limited, it can be set to 100 to 3000 μm, particularly 150 to 2000 μm in consideration of electric resistance and strength.

The material used for forming the “first fuel electrode 112” and the “second fuel electrode 122” can also be appropriately selected depending on the use conditions of the fuel cell. Examples of this material include metals such as Ni and Fe and ZrO ₂ ceramics such as zirconia stabilized by at least one of rare earth elements such as Sc and Y, CeO ₂ ceramics, manganese oxides, and the like. The mixture with at least 1 sort (s) of ceramics etc. are mentioned. Moreover, metals, such as Pt, Au, Ag, Pd, Ir, Ru, Rh, Ni, and Fe, are mentioned. These metals may be used alone or in an alloy of two or more metals. Furthermore, a mixture (including cermet) of these metals and / or alloys and at least one of each of the above ceramics may be mentioned. Moreover, the mixture of metal oxides, such as Ni and Fe, and at least 1 type of each of the said ceramic etc. are mentioned. Among these materials, a mixture of a metal such as Ni and Fe and at least one of each of the ceramics is preferable, and a mixture of Ni and Sc stabilized with a ZrO ₂ ceramic is particularly preferable.
The thickness of each of the first fuel electrode 112 and the second fuel electrode 122 is not particularly limited, but may be 10 to 50 μm, particularly 20 to 40 μm.

Materials used for forming the “first air electrode 113” and the “second air electrode 123” can also be appropriately selected depending on the use conditions of the fuel cell. As this material, for example, various metals, metal oxides, metal double oxides, and the like can be used. Examples of the metal include metals such as Pt, Au, Ag, Pd, Ir, Ru, and Rh, or alloys containing two or more metals. Further, examples of the metal oxide include oxides such as La, Sr, Ce, Co, Mn and Fe (La ₂ O ₃ , SrO, Ce ₂ O ₃ , Co ₂ O ₃ , MnO ₂ and FeO). It is done. As the double oxide, a double oxide containing at least La, Pr, Sm, Sr, Ba, Co, Fe, Mn, etc. (La _1-x Sr _x CoO ₃ -based double oxide, La _1-x Sr _x FeO ₃ -based double oxide, La _1-x Sr _x Co _1-y Fe _y O ₃ -based double oxide, La _1-x Sr _x MnO ₃ -based double oxide, Pr _1-x Ba _x CoO ₃ -based double oxide Oxides and Sm _1-x Sr _x CoO ₃ -based double oxides).

Preferably mixed oxide Of _{these, Ln 1-x M x CoO} 3 -based mixed _{oxide, Ln 1-x M x FeO} 3 -based mixed oxide and _{Ln 1-x M x Co 1} -y Fe y O 3 More preferred are system double oxides (Ln is a rare earth element and M is Sr or Ba). The first air electrode 113 and the second air electrode 123 made of a double oxide containing Co and / or Fe, particularly a double oxide containing Co and Fe, have a SOFC of 500 to 850 ° C., more preferably 500 to 750. Even when operated at a low temperature in the temperature range of ° C., it has excellent performance as an electrode. These double oxides may further contain other substitution elements in addition to the Ln element and the M element. These _{Ln 1-x} M x CoO _3-based mixed _oxide, among Ln _1-x M x FeO _3-based mixed oxide and _{Ln 1-x M x Co 1} -y Fe y O 3 based mixed oxide, Ln _1-x M _x CoO _{3 ± δ} , Ln _1-x M _x FeO _{3 ± δ} and Ln _1-x M _x Co _1-y Fe _y O _{3 ± δ} , 0.2 ≦ x ≦ 0. 8, 0.5 ≦ y ≦ 0.9 and 0 ≦ δ <1 (δ is oxygen excess or oxygen deficiency) is particularly preferable, and Ln is selected from La, Pr and Sm. More preferably, it is at least one of the above.

Examples of the above-described Ln _1-x M _x CoO ₃ -based double oxide include La _0.6 Sr _0.4 CoO _{3 ± δ} , Pr _0.5 Ba _0.5 CoO _{3 ± δ,} and Sm _{0. 5} Sr _0.5 CoO _{3 ± δ and the} like. Further, as the Ln _1-x M _x FeO ₃ -based double oxide, for example, La _0.6 Sr _0.4 FeO _{3 ± δ} , Pr _0.5 Ba _0.5 FeO _{3 ± δ} and Sm _0.5 Sr _0.5 FeO _{3 ± δ and the} like. _As the _{Ln 1-x M x Co 1} -y Fe y O 3 based mixed oxide, for _{example, La 0.6 Sr 0.4 Co 0.2 Fe} 0.8 O 3 ± δ, Pr 0.5 Ba _0.5 Co _0.2 Fe _0.8 O _{3 ± δ,} Sm _0.5 Sr _0.5 Co _0.2 Fe _0.8 O _{3 ± δ and the} like.
The thickness of each of the first air electrode 113 and the second air electrode 123 is not particularly limited, but may be 10 to 100 μm, particularly 20 to 50 μm.

  The above-mentioned “ceramic interconnector 2” (hereinafter sometimes referred to as interconnector 2) has one surface joined to both sides of the first fuel electrode 112 provided on one surface of the first solid electrolyte body 111, and the other. The surface side is joined to both sides of the second air electrode 123 provided on the other surface of the second solid electrolyte body 121 (see FIGS. 1 and 2). One side of the interconnector 2 is joined over the entire length of both side portions of the first fuel electrode 112, and the first fuel electrode 112 is provided in a portion excluding the both side portions. The first fuel electrode 112 may be provided on the entire surface of the portion excluding the both side portions to which the interconnector 2 is joined, or may be provided on a part of the first fuel cell 112. From the viewpoint, it is preferably provided on the entire surface. Furthermore, the other surface side of the interconnector 2 is joined over the entire length of both side portions of the second air electrode 123, and the second air electrode 123 is provided in a portion excluding the both side portions. The second air electrode 123 may also be provided on the entire surface of the portion excluding the both side portions to which the interconnector 2 is joined, or may be provided on a part thereof, but the power generation efficiency of the second single cell 12 may be increased. From the viewpoint, it is preferably provided on the entire surface.

  A space is formed between at least the opposing surfaces of the outer surface of the first fuel electrode 112 and the inner surface of the interconnector 2, and this is the “fuel gas flow path f” (see FIG. 2). ). On the other hand, a space is formed between at least the facing surfaces of the outer surface of the second air electrode 123 and the inner surface of the interconnector 2, and this is the “flammable gas passage s”. (See FIG. 2). These fuel gas passages and combustion-supporting gas passages allow gas to flow with lower resistance as the cross-sectional area is larger. On the other hand, when the distance between the opposing surfaces is increased, the dimension in the stacking direction is increased and the SOFC stack becomes large, which is not preferable. Therefore, the distance between each opposing surface of each of the first fuel electrode 112 and the second air electrode 123 and the inner surface of the interconnector 2 is 0.2 to 2 mm, particularly 0.4 to 1 mm, and more preferably 0. It is preferable that it is 5-0.8 mm. If this distance is 0.2 to 2 mm, the fuel gas and the combustion-supporting gas can be circulated with low resistance. In addition, the SOFC stack can be reduced in size.

The first fuel electrode 112 and the second air electrode 123 are connected via the “via conductor 21” formed through the interconnector 2, whereby the first unit cell and the second unit cell are connected. The cells are connected in series (see FIG. 1). The via conductor 21 can be formed by filling an interconnector-side via hole provided in a required portion of the interconnector 2 with a conductive material and firing it. At least one via conductor 21 may be formed, but from the viewpoint of electrical conduction between the first fuel electrode 112 and the second air electrode 123, a plurality of via conductors 21 are preferably formed. It is preferable that ~ 8 are formed. The via conductor 21 is made of metal, conductive ceramic, or the like. Examples of the metal include silver, copper, palladium, platinum, nickel, gold, and tungsten. This metal may be a simple substance or an alloy containing two or more kinds of metals. Furthermore, examples of the conductive ceramic include La _1-x M _x CrO ₃ (M is an alkaline earth metal such as Ca and Sr), and the like may be used alone or in combination with the above metal. Further, the contact resistance is reduced by forming the via conductor 21 from a conductive ceramic and providing a metal layer made of platinum or the like on the contact surface between the first fuel electrode 112 and the second air electrode 123. You can also.

  The interconnector 2 is made of ceramic. The ceramic is not particularly limited, and various ceramics can be used. As this ceramic, various ceramics such as oxide ceramics, nitride ceramics, and carbide ceramics can be used. Examples of the oxide ceramic include alumina, mullite, zirconia, and spinel. Examples of the nitride ceramic include silicon nitride, sialon, titanium nitride, and aluminum nitride. Further, examples of the carbide-based ceramic include silicon carbide, titanium carbide, and aluminum carbide.

  As the ceramic, alumina, silicon nitride, zirconia, spinel and the like are preferable, and alumina is particularly preferable. Alumina has high strength and excellent electrical insulation. By using the interconnector 2 made of alumina, an SOFC stack having excellent durability can be obtained. In the case of the interconnector 2 containing alumina, when the total amount of ceramic contained in the interconnector 2 is 100% by mass, the alumina content is 70% by mass or more, particularly 80% by mass or more, and further 90%. The content is preferably at least mass%, more preferably 100 mass%. The interconnector 2 is preferably densified. For example, in the case of alumina, the relative density is preferably 90% or more, particularly 93% or more, and more preferably 95% or more. Thus, if the interconnector 2 has high density and high strength, a more durable SOFC stack can be obtained.

  The outer shape of the SOFC stack is preferably square or rectangular in cross section. That is, the planar shape of the “laminate” is preferably a square or a rectangle. If it is a columnar SOFC stack in which single cells and interconnectors are further laminated on one side and / or the other side of the laminate having such a planar shape, by arranging a plurality of SOFC stacks in parallel, It is possible to provide an SOFC module that has less unnecessary space and has excellent power generation performance.

  The dimensions of this SOFC stack are not particularly limited. When the cross section is square, the dimension of one side is 5 to 20 mm, particularly 7 to 15 mm, more preferably 8 to 12 mm, and the dimension in the length direction is 20 to 100 mm. In particular, an SOFC stack of 30 to 80 mm, further 40 to 60 mm can be obtained. Further, when the cross section is rectangular, the short side is 5 to 20 mm, particularly 7 to 15 mm, further 8 to 12 mm, the long side is 5 to 100 mm, particularly 30 to 80 mm, further 40 to 60 mm, and the length direction. The SOFC stack has a size of 20 to 100 mm, particularly 30 to 80 mm, and more preferably 40 to 60 mm. If the SOFC stack has such dimensions, the SOFC module using the SOFC stack can be easily downsized.

[2] Method for Manufacturing Solid Electrolyte Fuel Cell Stack The method for manufacturing the SOFC stack is not particularly limited, and for example, it can be manufactured by the method for manufacturing the SOFC stack of the present invention.
The manufacturing method of the SOFC stack of the present invention includes a non-fired single cell laminated sheet production step, an unfired ceramic interconnector laminated sheet production step, an unfired unit cell composite sheet production step, a composite formation step, and a crimped body formation step. , An unfired SOFC stack manufacturing process, and an SOFC stack manufacturing process.

(A) Laminated sheet manufacturing process for unsintered single cells The formation method of unsintered 1st solid electrolyte sheet 111 'and unsintered 2nd solid electrolyte sheet 121' is not specifically limited. For example, a slurry containing the above-mentioned ceramic powder that is a solid electrolyte is applied to the surface of a support material such as a resin sheet, a rubber sheet, and glass, then dried, further heated as necessary, and contained in the slurry It can be formed by removing the organic binder and the like. The coating method is not particularly limited, and various methods such as a screen printing method, a doctor blade method, a squeegee method, and a spin coating method can be used.

  The formation method of the unfired first fuel electrode strip sheet 112 ′ and the unfired second fuel electrode strip sheet 122 ′ is not particularly limited. For example, a slurry containing a mixed powder of a metal oxide powder such as Ni and Fe and a ceramic powder such as a zirconia ceramic, various metal powders, and a mixed powder of a metal powder and a ceramic powder is not used. It can form by apply | coating to each one surface of baking solid electrolyte sheet 111 ', 121', drying after that, and also heating as needed, and removing the organic binder etc. which are contained in a slurry. The coating method is not particularly limited, and various methods such as a screen printing method, a doctor blade method, a squeegee method, and a spin coating method can be used. This unburned fuel electrode belt-like sheet may be formed by previously forming a sheet using the slurry and laminating the sheet on one surface of the unfired solid electrolyte sheet.

The method for forming the unfired first air electrode strip sheet 113 ′ and the unfired second air electrode strip sheet 123 ′ is also not particularly limited. For example, a slurry containing the various metal powders, metal oxide powders, metal double oxide powders and the like is applied to the other surface of each of the unfired solid electrolyte sheets 111 ′ and 121 ′, and then dried. Furthermore, it can form by heating as needed and removing the organic binder etc. which are contained in a slurry. The coating method is not particularly limited, and various methods such as a screen printing method, a doctor blade method, a squeegee method, and a spin coating method can be used. This unfired air electrode belt-like sheet can be formed by previously forming a sheet using the slurry and laminating the sheet on one surface of the unfired solid electrolyte sheet.
In this way, the unfired first single cell laminated sheet 11 ′ and the unfired second single cell laminated sheet 12 ′ can be produced (see FIG. 4).
In addition, other unfired single cell laminated sheets 13 ′ and the like that are further laminated in the unfired unit cell composite sheet producing step can be produced in the same manner (see FIGS. 7 to 10).

(B) Laminated sheet manufacturing process for unfired ceramic interconnectors The respective formation methods of unfired ceramic sheet 22 ′, unfired first ceramic opening sheet 231 ′, and unfired second ceramic opening sheet 232 ′ are not particularly limited. For example, each green sheet is prepared by preparing a slurry containing the above-mentioned various ceramic powders, sintering aids, organic binders, solvents, plasticizers, etc., and using this slurry by a doctor blade method or the like. Can do. Thereafter, the direction of the band-shaped opening portion of each of the unfired first ceramic opening sheet 231 ′ and the unfired second ceramic opening sheet 232 ′ intersects with one side and the other side of the unfired ceramic sheet. It can be set as the laminated sheet integrally laminated | stacked by pressurizing, heating as needed and heating.

  Next, an interconnector-side via hole is provided in a portion of the laminated sheet formed as described above where the respective unfired sheets are laminated and overlapped. The via hole forming method is not particularly limited, and examples thereof include a laser irradiation method, a drill method, a punching method, an etching method, and a combination of these methods. Among these methods, a laser irradiation method that can more accurately form a via hole having a required diameter at a predetermined position is preferable. Moreover, according to this laser irradiation method, a small-diameter via hole can be easily formed. The diameter and shape of the via hole are not particularly limited, but usually the opening diameter on the surface of the substrate is 100 to 1000 μm, particularly 250 to 750 μm, and the shape is substantially a cylinder.

The interconnector side via hole is filled with a conductive material, and an unfired via conductor 21 'is formed. Examples of the conductive material to be filled include powder of at least one metal selected from silver, copper, palladium, platinum, nickel, gold, and tungsten. This metal powder is usually filled into a via hole using a via conductor paste prepared by blending with a resin, a solvent or the like. As the resin, a cellulose resin, an acrylic ester resin, or the like can be used. Various solvents such as alcohols and ketones can be used as the solvent. The method of filling the paste into the via hole is not particularly limited, and can be filled by screen printing or the like. Thereafter, the solvent is removed by drying, and then the unfired via conductor 21 ′ can be formed by removing the resin by heating at a required temperature.
In this way, a laminated sheet 2 ′ for an unfired ceramic interconnector can be produced (see FIGS. 5 and 6).
In addition, other unfired ceramic interconnector laminated sheets 24 ′ and the like that are further laminated in the unfired unit cell composite sheet producing step can be similarly produced (see FIGS. 7 to 10).

  Further, in the case where the solid electrolyte body and the ceramic interconnector are bonded more firmly through the intermediate ceramic layers each containing alumina and zirconia as described above, the intermediate layer containing alumina powder and zirconia powder is used. The slurry is used to form an unfired sheet that becomes the unfired intermediate ceramic layer 5 ′, and this sheet is interposed at the laminated interface between the unfired solid electrolyte sheet and the unfired ceramic interconnector laminated sheet. Preferred (see FIG. 10).

(C) Composite sheet manufacturing process for unfired unit cells A plurality of unfired single cell laminated sheets and an unfired ceramic interconnector laminated sheet that is one less than the unfired single cell laminated sheet are alternately laminated. And unfired ceramic end surface sheet | seat 3 'is laminated | stacked on the both end surfaces of the lamination direction, and the composite sheet for unfired unit cells is produced. The unsintered ceramic end face sheet 3 ′ is composed of an unsintered end face sheet 31 ′ and an unsintered end face opening sheet 32 ′ laminated on one surface, and these unsintered sheets are used for the unsintered ceramic interconnector described above. Using the same slurry as in the case of the laminated sheet, it can be formed by the same method, and by laminating these and applying pressure while heating, a composite sheet laminated integrally can be obtained. it can. When the unfired ceramic end face sheet 3 ′ is the lowermost surface or the uppermost surface of the SOFC stack, this composite sheet can be used as it is as the unfired unit cell composite sheet a.

On the other hand, when the unfired ceramic end face sheet 3 ′ is not the lowermost surface or the uppermost face of the SOFC stack but the unfired single cell laminated sheet is further laminated on at least one end face, the unfired ceramic end face sheet 3 ′ Is provided with an end face sheet side via hole communicating with the interconnector side via hole, and the end face sheet side via hole is filled with a conductive material to form an unfired via conductor 33 ′. The end face sheet side via hole can be formed in the same manner as the interconnector side via hole, and the diameter and shape of the via hole can be the same as the interconnector side via hole. Further, the unfired via conductor 33 ′ can be formed in the same manner using the same paste as that of the unfired via conductor 21 ′.
In this way, the unfired unit cell composite sheet a can be produced (see FIGS. 7 to 10).

  The unfired via conductor 21 ′ and the unfired via conductor 33 ′ do not necessarily have to be made of the same material. However, in order to reduce the resistance at the joint surface and ensure good conduction, the same material is used. Preferably it consists of. Furthermore, the end faces of the unfired via conductor 21 ′ and the unfired via conductor 33 ′ are preferably overlapped in more parts in order to ensure good conduction, and at least one of the end faces is in contact with the other entire surface. It is particularly preferred that they overlap.

  The number of laminated layers of the unfired single cell laminated sheet and the unfired ceramic interconnector laminated sheet constituting the unfired unit cell composite sheet a is not particularly limited. As the number of stacked layers increases, the output voltage of the SOFC stack can be increased. However, the greater the number of stacked layers, the lower the workability in crimping and cutting when producing the unfired SOFC stack. Moreover, it is not easy to ensure good conduction by making more portions of the end faces of the unfired via conductor and the unfired via conductor overlap. Therefore, the laminated sheet for unfired single cells is preferably 2 to 10 layers, particularly 3 to 5 layers. In addition, the lamination sheet for unfired ceramic interconnectors is one layer less than the lamination sheet for unfired single cells.

(D) Composite Forming Step A plurality of unfired unit cell composite sheets a are formed on the end face side of one unfired unit cell composite sheet, and the other unfired unit. The direction of the unburned air electrode strip and the direction of the unburned fuel electrode strip cross so that the unburned fuel electrode strip formed on the end surface side of the cell composite sheet faces each other. In this way, a composite is formed. Further, in this step, when the unfired unit cell composite sheet is not the lowermost surface or the uppermost surface of the unfired SOFC stack, the unfired via conductor 33 ′ on the surface of each unfired ceramic end face sheet 3 ′ to be laminated is used. However, it is preferable to confirm that they are at positions facing each other.

(E) Press-bonding body formation process A composite is crimped | bonded to the lamination direction, and it is set as the crimping | compression-bonding body b (refer FIG. 11). Although the method of this crimping is not particularly limited, in order to obtain a SOFC stack having high dimensional accuracy and a predetermined shape, the composite is placed in an elastic mold made of silicon rubber or the like, and the stacking direction is It is preferable to perform the pressure bonding so that the applied pressure is evenly distributed. Although the pressure at the time of pressure bonding is not particularly limited, it can be 20 to 1000 MPa, particularly 50 to 300 MPa, and further 80 to 120 MPa. When the pressure is 20 to 1000 MPa, deformation due to an excessive load or the like is not caused, and each composite can be sufficiently adhered.

(F) Unsintered solid electrolyte fuel cell stack manufacturing process Between the openings of the unfired first ceramic opening sheet constituting the laminated body for the unfired ceramic interconnector and the unfired second opened ceramic sheet A non-fired SOFC stack is manufactured by cutting in the pressure-bonding direction between the openings included in (see FIG. 12). The cutting method is not particularly limited, and various methods such as a method using a wire saw, a method using a rotating grindstone, a method using a water jet, a method using a hot wire, and a method using ultrasonic waves can be used. Among these, a method using a wire saw capable of cutting the crimped body b, which is a long unfired ceramic laminate, in the length direction with high dimensional accuracy and quickly and efficiently is preferable.

  A wire saw is an apparatus which can cut | disconnect the crimping | compression-bonding body b by abutting the crimping | compression-bonding body b and a wire, making a wire run in a predetermined cutting direction, or reciprocating, supplying grinding fluid. In this wire saw, since the stress at the time of cutting is applied in the stacking direction, the residual stress is suppressed and deformation and distortion caused by cutting are suppressed as compared with the case of using a cutting device having an outer peripheral blade or the like. The wire saw may include a plurality of wires. In this case, the crimped body can be efficiently made into a predetermined number of unfired SOFC stacks. Although the wire diameter of the wire used is not particularly limited, it is preferably 200 μm or less. If the wire diameter is 200 μm or less, the residual stress can be sufficiently suppressed. Further, the traveling speed of the wire is not particularly limited, but the average speed is preferably 100 m / min or more, particularly 250 m / min or more, and more preferably 360 m / min or more. Further, it is more preferable that the traveling speed does not vary greatly.

  The type of the grinding liquid is not particularly limited, but usually a liquid containing abrasive grains is used. Although the kind of abrasive grain is not limited, the abrasive grain which consists of SiC, diamond, etc. is used. These may use only 1 type and may use 2 or more types together. Furthermore, the particle diameter of the abrasive grains is not particularly limited, and any appropriate one can be used depending on the material and dimensions of the pressure-bonded body b. In particular, when the wire diameter is 200 μm or less and the average grain size of the abrasive grains is 50 μm or less, the residual stress can be sufficiently suppressed. Also, the type of the dispersion medium is not particularly limited, and may be water, an organic solvent, or a mixed solvent thereof. Furthermore, the grinding fluid may contain other components in addition to the abrasive grains and the dispersion medium. Examples of other components include a dispersant, a rust inhibitor, and a cleaning agent. The abrasive grains are preferably contained in 0.01 to 5.0 kg, particularly 0.5 to 2.0 kg in 1 liter of the grinding fluid.

  The grinding fluid may be continuously supplied while the wire saw is reciprocating or the like, may be supplied in advance before the operation, and may be stopped at the time of cutting. Moreover, you may supply intermittently as needed. Furthermore, the supply location of the grinding fluid is not limited, and for example, it may be supplied to the crimped body or may be supplied to the wire. Further, the supply amount of the grinding liquid is not limited, and the appropriate supply amount depends on the material and dimensions of the crimped body to be cut, the wire diameter, the wire speed, the type of abrasive grains, the abrasive grain content in the grinding liquid, and the like. can do.

(G) Solid-electrolyte fuel cell stack production process A SOFC stack can be produced by firing a plurality of unfired SOFC stacks obtained by cutting the pressure-bonded body b as described above. The unfired SOFC stack can be heated at a predetermined temperature to remove an organic binder or the like (generally referred to as a degreasing process), and then heated at a higher temperature to be fired. Further, this degreasing step is not provided, and the firing can be performed by continuously raising the temperature to the firing temperature. The firing conditions are not particularly limited, but the unfired SOFC stack has various members of different materials and dimensions, such as unfired solid electrolyte bodies, unfired fuel electrodes, unfired air electrodes, and unfired ceramic interconnectors. Therefore, it is preferable to perform firing under conditions that allow them to be sintered to a predetermined density without degrading them.

  The firing temperature can be a temperature suitable for each member, for example, 1300 to 1600 ° C, particularly 1400 to 1550 ° C. The firing time can also be appropriately set depending on the material of each member, the firing temperature, and the like, and can be set to 1 to 5 hours, particularly 2 to 3 hours, for example. Furthermore, the firing atmosphere contains an oxidizing atmosphere such as an air atmosphere, an inert atmosphere such as an inert gas atmosphere such as a nitrogen gas atmosphere and an argon gas, and a small amount of hydrogen gas in consideration of the ease of oxidation of each member. Reducing atmosphere or the like.

  The connection between the via conductor 21 and the first fuel electrode 112 in the first unit cell 11 and the via conductor 21 and the second air electrode 123 in the second unit cell 12 is the fuel electrode side conductive pattern 41 and the air electrode side, respectively. The conductive pattern 42 is used (see FIG. 1). The fuel electrode side conductive pattern 41 and the air electrode side conductive pattern 42 form a fuel electrode side unfired conductive pattern 41 ′ on one surface of one unfired solid electrolyte sheet in the unfired single cell laminated sheet manufacturing step, In addition, the air electrode side unfired conductive pattern 42 'is formed on the other surface of the other unfired solid electrolyte sheet (see FIG. 4), and these unfired conductive patterns are formed by sintering at the same time as the firing. be able to. Each unfired conductive pattern can be formed by applying a slurry containing a conductive powder such as platinum to a predetermined position of the unfired solid electrolyte sheet and drying it.

[3] Solid Oxide Fuel Cell Module The SOFC stack of the present invention has a square or rectangular cross section, and these are arranged in parallel and integrated to reduce unnecessary space and have excellent power generation performance. It can be an SOFC module.
In this SOFC module, the side surfaces of each SOFC stack where the fuel gas passages are opened and / or the side surfaces where the combustion-supporting gas passages are opened are opposed to each other with a predetermined interval. A plurality of SOFC stacks arranged in parallel, and a separation member 6 disposed in a gap between the SOFC stacks to isolate the fuel gas and the combustion-supporting gas supplied to each SOFC stack. (See FIG. 14).
As shown in FIG. 14, the separating member 6 is disposed at the corner of each SOFC stack so that the flow of the fuel gas and the combustion-supporting gas is not hindered and the gases are not mixed. Is done.
The material of the isolation member 6 is not particularly limited. Examples of the isolation member 6 include a molded body using various ceramics, a metal molded body made of stainless steel or the like, a surface of which a ceramic such as spinel is spray-coated, and a glass fiber. In addition, a molded body using a heat-resistant material such as ceramic wool can be used. Examples of the ceramic include the above-described various ceramics used for forming an interconnector, and alumina, spinel, and the like having sufficient strength are preferable. Moreover, it is preferable that the isolation member 6 is made of the same material as that of the ceramic interconnector 2, and in this way, the isolation member 6 can be efficiently formed.

  In this SOFC module, when the SOFC stack is composed of only one row in the vertical direction or the horizontal direction, the side surfaces of the fuel gas flow paths or the combustion-supporting gas flow paths of each SOFC stack are open to each other. Are arranged in parallel so as to face each other at a predetermined interval. On the other hand, when two or more SOFC stacks are arranged in parallel in at least one of the horizontal direction and the vertical direction, the side surfaces of each SOFC stack where the fuel gas flow paths and the combustion-supporting gas flow paths are open They are arranged in parallel so as to face each other at a predetermined interval.

  In this SOFC module, each SOFC stack may be connected in series or in parallel. If more SOFC stacks are connected in series, the output voltage of the SOFC module will be higher, and if more SOFC stacks are connected in parallel, the power obtained from the SOFC modules will increase. Therefore, the number of SOFC stacks to be used and whether to connect them in series or in parallel may be determined according to the required voltage and required power of the SOFC module. As described above, since the setting of the output voltage and power is easy, an optimum SOFC module can be obtained depending on the purpose and purpose.

  Specifically, for example, in the structure of FIGS. 13 to 15, a total of 25 SOFC stacks are integrated in the horizontal direction and the vertical direction, but in the case of FIGS. 13 and 14, Five in the horizontal direction are connected in series, and five arranged in the horizontal direction are connected in parallel in the vertical direction. On the other hand, in the case of FIG. 15, 25 SOFC stacks are similarly integrated, but 5 in the horizontal direction are connected in series, and 5 in each column in the vertical direction are also connected in series. ing. That is, all 25 SOFC stacks are connected in series. Therefore, more power can be obtained with the structures of FIGS. 13 and 14, and the power of the structure of FIG. 15 is lower than that of the structures of FIGS. 13 and 14, but the output voltage is higher.

  Also, in this SOFC module, if any one of the integrated SOFC stacks fails, just remove the SOFC stack from the SOFC module and insert the normal SOFC stack there. Can function. Therefore, maintenance during use is extremely easy.

  Further, in this SOFC module, a columnar SOFC stack having a square or rectangular cross section is arranged in parallel and accumulated, whereby the outer shape can be a rectangular parallelepiped (in some cases, a cube). Further, since the side surfaces where the fuel gas passages are opened and / or the side surfaces where the combustion-supporting gas passages are opened are arranged in parallel, the fuel gas passages are arranged in one direction. And the direction intersecting with this can be used as a combustion-supporting gas flow path. That is, the flow direction of the fuel gas and the flow direction of the combustion-supporting gas can be crossed. For example, a manifold for supplying fuel gas to one surface of a rectangular parallelepiped, a manifold for discharging fuel gas to a surface opposite to the one surface, and supplying combustion-supporting gas to another surface in a direction orthogonal to the one surface And a manifold for discharging combustion-supporting gas on the surface opposite to the other surface, and these four manifolds provide fuel gas and combustion-supporting gas to all single cells. And can be discharged. Therefore, the SOFC module having an extremely simple structure can be obtained.

[4] Extraction of electric power from the SOFC module The SOFC stack is heated to a predetermined operating temperature, and a fuel gas such as hydrogen is introduced into the fuel gas channel and brought into contact with the fuel electrode, By introducing a combustion-supporting gas such as air and bringing it into contact with the air electrode, an electromotive force is generated between the fuel electrode and the air electrode, and this power can be taken out to function as a battery. In the SOFC module 102 in which the SOFC stacks are integrated, the output voltage and the power can be adjusted by connecting the SOFC stacks in series or in parallel. be able to. Further, in each SOFC stack, for example, an end face sheet side via conductor may be formed on the uppermost and lowermost ceramic end face sheets 3 and power may be taken out from the end face sheet side via conductor. Further, a conductive material such as nickel felt is interposed between the ceramic end face sheet 3 on the uppermost surface or the lowermost surface and the fuel electrode, or a conductive material such as Inconel fiber mesh is interposed between the air electrode, Electric power can be taken out from the nickel felt or the like and the Inconel fiber mesh or the like.

As described above, the SOFC module can have a rectangular parallelepiped shape (in some cases, a cube). Although the dimension is not specifically limited, For example, it can be set as the cube whose one side is 20-250 mm, especially 80-120 mm. Furthermore, the output voltage and power vary depending on the capacity of each single cell and the connection method thereof. For example, the power generation capacity of the solid electrolyte body of each single cell is about 0.3 W / cm ^2. In this case, the output voltage can be 12 to 500 V, particularly 24 to 240 V, and the power can be 0.2 to 10 kW, particularly 0.5 to 3 kW. When the above-mentioned one side is a cube of 80 to 120 mm, particularly about 100 mm, for example, when the SOFC stack is connected as in the examples described later, an SOFC module with an output voltage of 300 V and a power of 1 kW can be obtained.

[5] Fuel gas and combustion-supporting gas When power is generated using the SOFC module, fuel gas is introduced to the fuel electrode side, and combustion-supporting gas is introduced to the air electrode side. As fuel gas, hydrogen, hydrocarbon as a reducing agent, mixed gas of hydrogen and hydrocarbon, fuel gas obtained by passing these gases through water at a predetermined temperature and humidified, and fuel obtained by mixing these gases with water vapor Gas etc. are mentioned. The hydrocarbon is not particularly limited, and examples thereof include natural gas, naphtha, and coal gasification gas. Further, the main components are saturated hydrocarbons having 1 to 10, preferably 1 to 7, more preferably 1 to 4 carbon atoms such as methane, ethane, propane, butane and pentane, and unsaturated hydrocarbons such as ethylene and propylene. Those having a saturated hydrocarbon as a main component are more preferable. The fuel gas is preferably hydrogen. These fuel gas may use only 1 type and can also use 2 or more types together. Moreover, you may contain inert gas, such as nitrogen and argon of 50 volume% or less.

  Examples of the combustion-supporting gas include a mixed gas of oxygen and another gas. Further, the mixed gas may contain 80% by volume or less of an inert gas such as nitrogen and argon. Among these combustion-supporting gases, air (containing about 80% by volume of nitrogen) is preferable because it is safe and inexpensive.

Hereinafter, the present invention will be described specifically by way of examples.
(A) Production of unfired single cell laminated sheet (a) Formation of unfired solid electrolyte sheet 100 parts by mass of 8YSZ (ZrO ₂ stabilized with 8 mol% Y ₂ O ₃ ) powder as a solid electrolyte "Parts"), 1 part of alumina powder, polyvinyl alcohol as an organic binder, and butyl carbitol as an organic solvent were mixed to prepare a slurry for an unfired solid electrolyte sheet. Thereafter, the slurry is used to form the unfired first solid electrolyte sheet 111 ′ and the unfired second solid electrolyte sheet 121 ′ each having a size of 96 mm × 96 mm × 150 μm (thickness) on the surface of the polyester film by a doctor blade method. did.

(B) Formation of unburned fuel electrode strip sheet 80 parts of nickel oxide (NiO) powder, 20 parts of the above 8YSZ powder, diethylamine as a dispersant, and toluene and methyl ethyl ketone as an organic solvent, and then dibutyl as a plasticizer Polyvinyl alcohol as a phthalate and an organic binder was further blended and mixed to prepare a slurry for an unfired fuel electrode. Next, this slurry is screen-printed on one surface of each of the unfired first solid electrolyte sheet 111 ′ and the unfired second solid electrolyte sheet 121 ′ formed in (a) above, and is 12 mm × 90 mm × 10 μm (thickness). The unfired first fuel electrode belt-like sheet 112 ′ and the unfired second fuel electrode belt-like sheet 122 ′ having the dimensions of 5 were respectively formed in parallel. In addition, the space | interval of each strip | belt-shaped unbaking sheet | seat was 6 mm.

(C) Formation of unsintered strip for air electrode Commercially available La _0.6 Sr _0.4 (Co _0.2 Fe _0.8 ) O ₃ having an average particle diameter of 2 μm (hereinafter referred to as “LSCF”) 100 parts of powder was mixed with 13 parts of polyvinyl alcohol as a binder and 35 parts of butyl carbitol as an organic solvent to prepare a slurry for an unfired air electrode. Thereafter, this slurry is screen-printed on the other surface of each of the unfired first solid electrolyte sheet 111 ′ and the unfired second solid electrolyte body 121 ′ formed in (a) above, and is 12 mm × 90 mm × 10 μm (thickness). The unsintered first air electrode belt-like sheet 113 ′ and the unfired second air electrode belt-like sheet 123 ′ having the dimensions of 5) were formed in parallel. These unfired air electrode strips were arranged in a direction orthogonal to the unburned fuel electrode strips formed in (b) above. Further, the interval between the respective strip-shaped unfired air electrode sheets was set to 6 mm.
Thus, unfired 1st single cell laminated sheet 11 ′ and unfired 2nd single cell laminated sheet 12 ′ were produced.
Further, another unfired single cell laminated sheet 13 ′ to be further laminated at the time of producing the unfired unit cell composite sheet was similarly produced.

(B) Preparation of laminated sheet for unfired ceramic interconnector (a) Formation of unfired laminated sheet 100 parts of alumina powder, 20 parts of the above 8YSZ powder, 2 parts of magnesia powder and 2 parts of silica powder are mixed, and 10 hours by a ball mill. Wet milled, then dehydrated and dried. Next, this mixed powder is blended with isobutyl methacrylate and nitrocellulose as organic binders, dioctyl phthalate as plasticizer, trichlorethylene and n-butanol as organic solvents, and mixed by a ball mill for unfired interconnectors. A slurry was prepared. This slurry was degassed under reduced pressure, and then cast into a sheet, and then the organic solvent was volatilized to form an unfired ceramic sheet 22 ′ having dimensions of 96 mm × 96 mm × 100 μm (thickness).

  On the other hand, two unfired ceramic sheets having the same dimensions (however, the thickness is 150 μm) are formed in the same manner, and each of the two unfired ceramic sheets is punched (punched) to perform the above (A ), 5 openings of 12 mm × 90 mm having the same dimensions as those of the unfired first fuel electrode belt-like sheet 112 ′ and the unfired second air electrode belt-like sheet 123 ′ formed in (c). The unfired first ceramic opening sheet 231 ′ and the unfired second ceramic opening sheet 232 ′ were formed. Then, the direction of the strip-shaped opening part which each has unfired 1st ceramic opening sheet 231 'and unbaking 2nd ceramic opening sheet 232' orthogonal to each of one side and other side of unfired ceramic sheet 22 ' Laminated so that.

(B) Formation of Via Conductor Each of the unfired laminated sheets formed as described above, that is, the unfired ceramic sheet 22 ′ and the unfired first and second ceramic apertured sheets 231 ′ and 232 Via holes having an opening diameter of 500 μm on the surface were formed by punching (punching) at predetermined portions of the portions where “′” was stacked and overlapped. Thereafter, a via conductor paste containing 80% by mass of platinum powder as a conductive powder was filled in the via hole by hole-filling printing. Next, the organic solvent contained in the paste was removed by drying at 120 ° C. for 30 minutes, thereby forming an unfired via conductor 21 ′.
In this manner, a laminated sheet 2 ′ for an unfired ceramic interconnector was produced.
In addition, the other laminated sheet 24 ′ for the unfired ceramic interconnector, which is further laminated at the time of producing the unfired unit cell composite sheet, was produced in the same manner.

(C) Production of composite sheet for unfired unit cell (a) Lamination of laminate sheet for unfired ceramic interconnector and laminate sheet for unfired single cell Laminated sheet 2 for unfired ceramic interconnector produced in (B) above The unfired second air electrode belt-like sheet 123 ′ of the unfired second single cell laminate sheet 12 ′ produced in (A) is fitted on the unfired first ceramic opening sheet 231 ′. Laminated. In addition, on the side of the unfired second ceramic opening sheet 232 ′ of the unfired ceramic interconnector laminated sheet 2 ′, the unfired first single cell laminated sheet 11 ′ produced in (A) above is unfired. The fuel electrode strips 112 ′ were laminated so as to be fitted. Further, the unfired second single electrode laminate sheet 12 ′ of the unfired second single cell laminate sheet 12 ′ is laminated so as to be fitted into the opening on one side of the unfired ceramic interconnector laminate sheet 24 ′. The laminated sheet 24 ′ for the unfired ceramic interconnector was laminated so that the non-fired single cell laminated sheet 13 ′ was fitted into the opening on the other surface side of the unfired ceramic interconnector laminated sheet 24 ′.

(B) Formation of unsintered ceramic end face sheet 3 ′ In the same manner as in (B) and (a) above, unsintered end face sheet 31 ′ having the same dimensions (the same thickness is 100 μm) was formed. Similarly, an unfired sheet having the same dimensions (however, the thickness is 150 μm) is formed, and openings having the same dimensions are formed in the unfired sheet in the same manner as in the above (B) and (a). Are provided at equal intervals to form an unfired end face opening sheet 32 ′. Thereafter, an unfired end face opening sheet 32 ′ was laminated on one face of the unfired end face sheet 31 ′. Next, in the same manner as in (B) and (b), an end sheet side via hole is formed in the unfired ceramic end sheet 3 ′ at a position corresponding to the unfired via conductor 21 ′. In the same manner, a conductive material was filled to form an unfired via conductor 33 ′.

(C) Lamination of unfired ceramic end face sheet on both end surfaces of a laminate of unfired single cell laminate sheet and unfired ceramic interconnector laminate sheet Unfired single cell laminate sheet and unfired ceramic interconnector laminate The laminated body with the sheet and the one unfired ceramic end face sheet 3 ′ are formed on the unfired first air electrode belt-like sheet of the unfired first single cell laminated sheet on the one end face of the laminated body. It laminated | stacked so that it might fit in the opening part of baking ceramic end surface sheet 3 '. Moreover, it laminated | stacked so that the strip | belt-shaped sheet | seat for unbaked fuel electrodes which unstacked single cell laminated sheet 13 'of the other end surface of a laminated body might be fitted in the opening part of the other unfired ceramic end surface sheet 3'.
In this way, the three laminated sheets for unfired single cells and the two laminated sheets for the unfired ceramic interconnector are alternately laminated on one end face and the other end face. An unfired unit cell composite sheet a in which the fired ceramic end face sheet 3 ′ was laminated was produced.

(D) Formation of composite 30 composite sheets a for unfired unit cells produced in (C) above are formed on the end face side of one unfired unit cell composite sheet laminated adjacently. The direction of the belt-like sheet for the unfired air electrode so that the belt-like sheet for the unfired air electrode and the belt-like sheet for the unfired fuel electrode formed on the end face side of the other unfired unit cell composite sheet face each other. Were laminated so that the direction of the unburned fuel electrode belt-like sheet intersected, and temporarily bonded to form a composite. Since each unfired unit cell composite sheet a has three layers of unfired single cell laminate sheets, the composite includes a total of 90 unfired single cell laminate sheets.

(E) Press-bonded body forming step The composite formed in (D) above is placed in a mold made of silicon rubber, then heated to 85 ° C., and pressed under reduced pressure at a pressure of 98 MPa in the stacking direction. A crimped body b was formed.

(F) Production of unfired solid electrolyte fuel cell stack Between the openings of the unfired first ceramic opening sheet and the opening of the unfired 2nd opening ceramic sheet with the crimped body b formed in (E) above In the meantime, it cut | disconnected in the crimping | compression-bonding direction, and produced the unbaking SOFC stack. The crimping body b fixes the crimping body b to the stage of the wire saw cutting device, and then raises the stage to bring the cutting wire into contact with the upper end surface of the crimping body b. While feeding, the wire is run at an average speed of 400 m / min and cut in one direction, and then the stage is lowered and rotated 90 degrees, and then orthogonal to this one direction as in the case of the one direction. 25 columnar unfired SOFC stacks having a cross section of 18 × 18 mm and a length of 50 mm were produced.

(G) Production of solid electrolyte fuel cell stack The 25 unfired SOFC stacks produced in (F) above are housed in a firing furnace and held at 260 ° C. for 5 hours in an air atmosphere to remove the organic binder. Subsequently, the temperature in the furnace was raised to 1430 ° C., and the temperature was maintained at this temperature for 2 hours to perform firing, thereby producing 25 SOFC stacks.

(H) Production of Solid Electrolyte Fuel Cell Module The 25 SOFC stacks produced in (G) above were arranged in parallel in the horizontal direction and 5 in the vertical direction at equal intervals to produce an SOFC module. Five in the horizontal direction are connected in series, and in the vertical direction, each of the five in the horizontal direction is connected in parallel.
Each SOFC stack is brazed to the lower end side substrate provided with the wiring pattern to be connected as described above by using silver solder so that the interval between the SOFC stacks becomes 5 mm. To stand. Thereafter, in order to isolate the fuel gas and the combustion-supporting gas supplied to each SOFC stack from the upper end side, an alumina separating member 6 was inserted into the gap between each SOFC stack. Next, an upper end side substrate similarly provided with a predetermined wiring pattern was disposed on the upper end side.

Thereafter, a fuel gas supply manifold for supplying fuel gas is disposed on the first row side of the five SOFC stacks arranged in parallel in the horizontal direction, and the fuel gas is disposed on the fifth row side. A fuel gas discharge manifold for discharge was provided. Further, a combustion-supporting gas supply manifold for supplying combustion-supporting gas is provided on one side of five SOFC stacks arranged in parallel in the vertical direction, and the combustion-supporting gas is supplied on the other side. A combustion-supporting gas discharge manifold for discharging was provided (none of these manifolds are shown).
In this way, an 80 mm × 80 mm × 55 mm (length) SOFC module was produced.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention depending on the purpose, application, and the like. For example, the number of SOFC stacks arranged in the horizontal direction and the vertical direction can be changed to make the SOFC module a rectangular parallelepiped.

It is a typical perspective view which shows an example of the laminated body which comprises the solid electrolyte form fuel cell stack of this invention. It is a schematic diagram which shows the cross section of the laminated body of FIG. It is a typical perspective view which shows an example of the lamination sheet for unbaked single cells. It is a typical top view which decomposes | disassembles and shows the lamination sheet for unbaked single cells of FIG. It is a typical perspective view which shows an example of the laminated sheet for unbaking ceramic interconnectors. It is a typical top view which decomposes | disassembles and shows the lamination sheet for unbaking ceramic interconnectors of FIG. It is a typical perspective view which decomposes | disassembles and shows an example of the composite sheet for unfired unit cells. It is a schematic diagram which shows the cross section of the composite sheet for unfired unit cells of FIG. It is typical sectional drawing showing the state by which each structural member of the composite sheet for unbaking unit cells of FIG. 8 shown decomposed | disassembled was laminated | stacked. FIG. 3 is a schematic cross-sectional view of a composite sheet for an unfired unit cell in which an unfired intermediate ceramic layer is interposed on a joint surface between an unfired solid electrolyte sheet and an unfired ceramic interconnector laminated sheet. It is a typical perspective view of the crimping | compression-bonding body by which the composite_body | complex in which the some composite sheet for unbaking unit cells was laminated | stacked was crimped | bonded. It is a perspective view which shows typically a mode that the crimping | compression-bonding body of FIG. 11 was cut | disconnected in the crimping direction in the position of the broken line of an upper surface. It is a perspective view which shows typically a mode that the solid electrolyte fuel cell stack was connected in series in the horizontal direction and 5 each in parallel in the vertical direction. 13 schematically shows a solid oxide fuel cell module in which an isolation member for isolating the fuel gas and the combustion-supporting gas is disposed at opposing corners of each solid oxide fuel cell stack in FIG. It is a perspective view shown. It is a perspective view which shows typically a mode that five solid electrolyte fuel cell stacks were connected in series with each of the horizontal direction and the vertical direction.

Explanation of symbols

  101; solid electrolyte fuel cell stack, 101 ′; unfired solid electrolyte fuel cell stack, 102; solid electrolyte fuel cell module, 11; first single cell, 111; first solid electrolyte body, 112; Fuel electrode 113; First air electrode 12; Second single cell 121; Second solid electrolyte body 122; Second fuel electrode 123 123 Second air electrode 2; Ceramic interconnector 21; Via conductor 3; Ceramic end face sheet, 41; Fuel electrode side conductive pattern, 42; Air electrode side conductive pattern, f; Fuel gas flow path, s; Combustion gas flow path, 11 '; Lamination for unfired first single cell Sheet 111 ′; unfired first solid electrolyte sheet 112 ′; unfired first fuel electrode strip sheet 113 ′; unfired first air electrode strip sheet 12 ′; unfired second single cell laminate Sheet, 121 ' Unsintered second solid electrolyte sheet, 122 ′; Unsintered second fuel electrode strip, 123 ′; Unsintered second air electrode strip, 2 ′; Unsintered ceramic interconnector laminated sheet, 21 ′; Sintered via conductor, 22 ′; unsintered ceramic sheet, 231 ′; unsintered first ceramic opening sheet, 232 ′; unsintered second ceramic opening sheet, 3; ceramic end face sheet, 3 ′; unsintered ceramic end face sheet, 31 ': Unsintered end face sheet, 32'; Unsintered end face opening sheet, 33 '; Unsintered end face sheet side via conductor, 41; Fuel electrode side conductive pattern, 42; Air electrode side conductive pattern, 41'; Fuel electrode side conductive pattern, 42 '; Air electrode side unfired conductive pattern, 5': Unfired intermediate ceramic layer, a: Composite sheet for unfired unit cell, b: Press-bonded body, c Cutting line, 6; isolating member.

Claims (12)

A first solid electrolyte body 111, a first fuel electrode 112 provided on one surface of the first solid electrolyte body 111, and a first air electrode 113 provided on the other surface of the first solid electrolyte body 111. Single cell 11, second solid electrolyte body 121, second fuel electrode 122 provided on one surface of second solid electrolyte body 121, and second air electrode provided on the other surface of second solid electrolyte body 121 The second unit cell 12 having the first solid electrolyte body 111, one surface side being joined to both sides of the first fuel electrode 112 on the one surface of the first solid electrolyte body 111, and the other surface side being the other of the second solid electrolyte body 121. A laminated body having a ceramic interconnector 2 joined to both sides of the second air electrode 123 on the surface,
A fuel gas flow path f is provided between the opposing surfaces of the first fuel electrode 112 and the ceramic interconnector 2, and is supported between the opposing surfaces of the second air electrode 123 and the ceramic interconnector 2. It has a flammable gas flow path s, and the first fuel electrode 112 and the second air electrode 123 are connected via a via conductor 21 formed in the ceramic interconnector 2. Solid oxide fuel cell stack.   A direction in which the first single cell 11 and the second single cell 12 are connected by the ceramic interconnector 2 is a length direction, and a cross section in a direction perpendicular to the length direction is a square or a rectangle. The solid oxide fuel cell stack according to claim 1.   When the cross section is square, the dimension of one side is 5 to 20 mm, and the dimension in the length direction is 20 to 100 mm, or when the section is rectangular, the short side is 5 to 20 mm and the long side is 5 mm. The solid oxide fuel cell stack according to claim 2, wherein the length direction dimension is 20 to 100 mm.   The distance between each facing surface of each of the first fuel electrode 112 and the second air electrode 123 and the ceramic interconnector 2 is 0.2 to 2 mm. The solid oxide fuel cell stack according to any one of the above.   The solid electrolyte fuel cell stack according to any one of claims 1 to 4, wherein the ceramic interconnector 2 contains alumina as a main component.   The first solid electrolyte body 111 and the second solid electrolyte body 121 are each made of zirconia containing alumina, and when the total of the alumina and the zirconia is 100% by mass, the alumina is 0. The solid oxide fuel cell stack according to claim 5, which is 1 to 20% by mass.   The first solid electrolyte body 111 and the second solid electrolyte body 121 are each composed of zirconia, or zirconia containing 0.1 to 20% by mass of alumina when the total of alumina and zirconia is 100% by mass. The solid electrolyte body 111 and each of the solid electrolyte body 121 and the ceramic interconnector 2 are joined to each other through an intermediate ceramic layer containing alumina and zirconia. The solid oxide fuel cell stack described. A solid oxide fuel cell module in which the solid oxide fuel cell stack according to any one of claims 2 to 7 is integrated,
In each of the solid oxide fuel cell stacks, the side surfaces where the fuel gas passages are opened and / or the side surfaces where the combustion-supporting gas passages are opened face each other with a predetermined interval therebetween. In order to isolate the plurality of solid electrolyte fuel cell stacks arranged in parallel and the fuel gas and the combustion-supporting gas supplied to each solid electrolyte fuel cell stack, each of the solid oxide fuel cells A solid oxide fuel cell module, comprising: a separating member 6 disposed in a gap of the stack.   The solid oxide fuel cell module according to claim 8, wherein a flow direction of the fuel gas and a flow direction of the combustion-supporting gas intersect each other. A method for producing a solid oxide fuel cell stack according to any one of claims 1 to 7,
A plurality of unfired first fuel electrode strips 112 ′ and a plurality of unfired first air electrode strips 113 ′ are respectively formed on one side and the other side of the unfired first solid electrolyte sheet 111 ′. Are formed so as to intersect with each other, to produce a non-fired first single-cell laminated sheet 11 ′, and a plurality of unfired second fuels are formed on each of one side and the other side of the non-fired second solid electrolyte sheet 121 ′. An electrode strip 122 ′ and a plurality of unfired second air electrode strips 123 ′ are formed so that their directions intersect with each other to produce an unfired second single cell laminated sheet 12 ′. Laminated sheet manufacturing process for firing single cell;
One side of the unfired ceramic sheet 22 ′ and the unfired first ceramic apertured sheet 231 ′ and the other side of the unfired ceramic sheet 22 ′ and the unfired second ceramic apertured sheet 232 ′ are combined with the unfired first ceramic apertured sheet 231. ′ And the unfired second ceramic apertured sheet 232 ′ are laminated so that the directions of the strip-shaped openings included in each of the unfired second ceramic apertured sheet 232 ′ and the unfired ceramic sheet 22 ′, the unfired first ceramic apertured sheet 231 ′, and An interconnector-side via hole is provided in a portion where the unfired second ceramic opening sheet 232 ′ is laminated, the interconnector-side via hole is filled with a conductive material, and an unfired via conductor 21 ′ is formed to form an unfired ceramic interface. A laminated sheet producing process for an unfired ceramic interconnector for producing a laminated sheet 2 ′ for a connector;
A plurality of unfired single cell laminate sheets including the unfired first single cell laminate sheet 11 ′ and the unfired second single cell laminate sheet 12 ′, and the unfired ceramic interconnector laminate sheet 2 ′. An unfired air electrode is fitted into an opening of the unfired first ceramic opening sheet, and the unfired ceramic interconnector laminated sheet is one less than the unfired single cell laminated sheet. Stacked alternately so that the unfired fuel electrodes are fitted into the openings of the sheet, and stacked on one surface of the unfired end surface sheet 31 ′ and the unfired end surface sheet 31 ′ on both end surfaces in the stacking direction. An unfired ceramic end face sheet 3 ′ composed of an unfired end face opening sheet 32 ′ having a strip-like opening is formed in the unfired air electrode or each formed on each end face. Are laminated so that the unfired fuel electrode is fitted, and when the unfired ceramic end face sheet 3 ′ is not the lowermost surface or the uppermost face of the solid oxide fuel cell stack, the unfired ceramic end face sheet 3 ′ An end sheet side via hole communicating with the interconnector side via hole is provided, and the end sheet side via hole is filled with a conductive material to form an unfired end sheet side via conductor 33 '. A composite sheet manufacturing process for a green unit cell to be manufactured;
A plurality of the unfired unit cell composite sheets a, the unfired air electrode formed on the end face side of one unfired unit cell composite sheet among the stacked unfired unit cell composite sheets, and the other Laminated so that the unfired fuel electrode formed on the end face side of the unfired unit cell composite sheet faces and the direction of the unfired air electrode and the direction of the unburned fuel electrode intersect And forming a complex to form a complex,
A crimping body forming step of crimping the composite in the stacking direction to form a crimped body b;
An unfired solid electrolyte fuel obtained by cutting the crimped body b in the crimping direction between the openings of the unfired first ceramic opening sheet and between the openings of the unfired second opening ceramic sheet. An unfired solid electrolyte fuel cell stack manufacturing process for manufacturing a battery stack;
A solid electrolyte fuel cell stack manufacturing step comprising: baking a plurality of the unfired solid electrolyte fuel cell stacks to produce a solid electrolyte fuel cell stack; .   The method for manufacturing a solid oxide fuel cell stack according to claim 10, wherein the cutting is performed by a wire saw.   In the unfired single cell laminated sheet manufacturing step, the unfired solid electrolyte sheet is provided on the unfired fuel electrode strip and the unfired ceramic interconnector laminated sheet to be laminated on the one surface. The conductive material filled in the interconnector-side via hole is connected to the fuel electrode-side unfired conductive pattern 41 ′, and on the other surface of the unfired solid electrolyte sheet, a band for the unfired air electrode is formed. The air electrode side unfired conductive pattern 42 is connected so that the sheet and the conductive material filled in the interconnector side via hole provided in the unfired ceramic interconnector laminated sheet to be laminated on the other surface are connected. The method for producing a solid oxide fuel cell stack according to claim 10 or 11, wherein 'is formed.

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