JP2005317241A - Supporting film type solid oxide fuel cell stack, and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a supporting film type solid oxide fuel cell stack of which, the problem arisen when laminating and stacking sub-assemblies for a supporting film type SOFC stack is solved, and to provide the manufacturing method of the same. <P>SOLUTION: The sub-assembly is formed by wrapping whole unit cells of the supporting film type solid oxide fuel cell by alloy foil plates having an opening for an air electrode, a gas lead-in hole, and gas lead-out hole, of which, the part contacting a fuel electrode of the unit cell is formed so as to fit with the shape of the fuel electrode in advance. The supporting film type solid oxide fuel cell stack is formed by laminating the plurality of the sub-assemblies through an interconnector for gas flow and electric connection, and a jig having a shape corresponding to the shape of lower face of the sub-assembly is intercalated at the lower face of the sub-assembly at the lowest part. The manufacturing method of the supporting film type solid oxide fuel cell stack is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a support membrane type solid oxide fuel cell stack and a manufacturing method thereof, and also relates to a jig for constituting the support membrane type solid oxide fuel cell stack.

  A single cell of a solid oxide fuel cell (hereinafter abbreviated as SOFC as appropriate), that is, a single cell, has an anode (fuel electrode) and a cathode (air electrode, oxygen as an oxidizing agent) with a solid oxide electrolyte in between. When used, an oxygen electrode) is disposed, and is composed of a fuel electrode / electrolyte / air electrode three-layer unit. In the present specification and drawings, the single cell is also referred to as “cell” as appropriate, and the solid oxide electrolyte is also referred to as “electrolyte” or “electrolyte membrane” as appropriate. In addition, the cathode is an oxygen electrode when oxygen is used as an oxidant. However, in the present specification and claims, the cathode includes an air electrode including a case where oxygen or oxygen-enriched air is used as an oxidant. say.

As the electrolyte material, for example, a sheet-like sintered body such as yttria stabilized zirconia (YSZ) is used, and as the fuel electrode, a porous body such as a mixture of nickel and yttria stabilized zirconia (Ni / YSZ cermet) is used. As the air electrode, for example, a porous body such as Sr-doped LaMnO ₃ is used, and a single cell is usually formed by baking a fuel electrode and an air electrode on both surfaces of the electrolyte material. During the operation, oxygen in the air introduced into the air electrode becomes oxide ions (O ²⁻ ) at the air electrode, and reaches the fuel electrode through the electrolyte. Here, it reacts with the fuel introduced into the fuel electrode and emits electrons to generate reaction products such as electricity, water, and carbon dioxide. Used air at the air electrode is discharged as an air electrode off gas, and used fuel at the fuel electrode is discharged as a fuel electrode off gas.

  By the way, a conventional SOFC has a high operating temperature of about 1000 to 800 ° C., but recently, an SOFC operating at a temperature of about 800 to 650 ° C., for example, about 750 ° C. is being developed. FIG. 1 is a diagram illustrating an example of the SOFC cell mode. FIG. 1A is a cross-sectional view of a single cell, and FIG. 1B is a perspective view seen from the air electrode side. As shown in FIGS. 1A to 1B, the cell is configured by disposing an electrolyte membrane on the fuel electrode and an air electrode on the electrolyte membrane.

For example, a zirconia-based or LaGaO ₃ -based electrolyte material is used as the solid oxide electrolyte, which is configured to be supported by a thick fuel electrode, and is called a support membrane type. In the support membrane type, the thickness of the electrolyte membrane can be reduced. The thickness of the membrane is, for example, about 10 μm, and it can be operated at a low temperature of 800 to 650 ° C. For this reason, it is possible to use a heat-resistant alloy, for example, an inexpensive material such as stainless steel as the constituent material, and there are various advantages such as being able to reduce the size.

  FIG. 2 is a configuration example of an SOFC stack incorporating a single cell configured as described above. Here, air flows between the air electrode and the separator A, and the air electrode and the separator A need to be in electrical contact. For this reason, a conductive interconnector having a groove for air circulation is provided between the air electrode and the separator A, but the illustration is omitted. The interconnector may be provided separately from the separator A or may be provided integrally therewith.

  As shown in FIG. 2, in the support membrane SOFC stack, the separator A, the separator B, the separator C, the cell, and the separator D are sequentially arranged from the upper part to the lower part. Among these, the separator C is also called a cell support foil. A current collector plate and the like are disposed on the upper part of the separator A, but the illustration is omitted. Separators A to D are made of a heat-resistant alloy such as stainless steel. In FIG. 2, a gap is provided between the fuel electrode and the current collector plate. However, both need to be in electrical contact. For this reason, the lower surface of the fuel electrode and the current collector plate may be in direct contact with each other, or nickel felt or the like may be interposed therebetween. Since the fuel electrode is a porous body, the fuel contributes to power generation while circulating in the fuel electrode and its lower surface.

  By the way, also in the support membrane type SOFC operated at a low temperature as described above, since the voltage of one single cell is low, the single cell is usually configured by stacking a plurality of layers electrically in series. A single cell is joined to a cell support foil (ie, separator C in FIG. 2), and is placed and joined so as to fit in a manifold (separators B and D in FIG. 2). A stack is formed by joining to the next unit via a connector. In addition, since the fuel, air, fuel electrode off-gas, and air electrode off-gas flowing through the SOFC stack are all gases, gas sealing is performed. In order to improve the sealing performance, a sealing material is sandwiched between the members. In order to construct an SOFC stack, for example, it is necessary, in addition to a large number of members, a large number of processes are required.

  The inventors of the present invention have a sub-assembly for supporting membrane type SOFC stack (hereinafter referred to as “hereinafter referred to as“ subassembly ”) which can be configured without many processes with such a large number of members and chains, and which has a significantly reduced gas sealing portion. A ”), a supporting membrane type SOFC stack (hereinafter referred to as“ B ”) and a module using the same have been developed (Japanese Patent Application No. 2003-112202: filed on April 16, 2003). The outline of these subassemblies, stacks, and modules will be sequentially described below.

Japanese Patent Application No. 2003-112202

<A: Sub-assembly for supporting membrane SOFC stack configuration>
The sub-assembly for the support membrane type SOFC stack structure comprises a single cell of the support membrane type solid oxide fuel cell, an opening for the air electrode, a hole for introducing gas (opening), and a hole for opening (opening). It is a sub-assembly for constituting a support membrane type SOFC stack, which is wrapped with the provided alloy foil plate. 3 to 4 are diagrams showing examples of the configuration. 3 (a) is a diagram showing the first alloy foil plate 1, FIG. 3 (b) is a diagram showing the second alloy foil plate 2, and is an example in which the alloy foil plate is formed in a strip shape. The alloy foil plate may have a rectangular shape, a square shape, or any other appropriate shape.

  As shown in FIG. 3 (a), the first strip-shaped alloy foil plate 1 is provided with an opening (window) 3 for an air electrode at the center thereof and openings 4 and 4 for fuel circulation at both ends in the longitudinal direction. Joining portions 5 and 5 with the second strip-shaped alloy foil plate 2 shown in FIG. 3B are provided at both left and right ends with respect to the longitudinal direction. The second strip-shaped alloy foil plate 2 is provided with fuel flow openings 7 and 7 at both ends in the longitudinal direction, and the first strip shown in FIG. 3 (a) at the left and right ends with respect to the longitudinal direction of the strip-shaped alloy foil plate. The joint portions 6 and 6 with the strip-shaped alloy foil plate 1 are provided.

  Here, the joint portions 6 and 6 of the second strip-shaped alloy foil plate 2 are formed by bending the end portions thereof, and the joint portions 5 and 5 of the first strip-shaped alloy foil plate 1 have two end portions thereof. Although it is configured to be bent and locked at the joints 6 and 6 of the second strip-shaped alloy foil plate 2, the shape thereof is the joints 6 and 6 of the second strip-shaped alloy foil plate 2. And the first strip-shaped alloy foil plate 1 can be formed in an appropriate shape that can be joined to the joint portions 5 and 5. The joining can be joined by welding or a joining material. As the bonding material, a metal brazing material, a glass bonding material, or the like is used.

  FIG. 3C shows the first strip-shaped alloy foil plate 1 and the second strip-shaped alloy foil plate 2 configured as described above, and the single membrane 10 of the support membrane type SOFC as shown in FIG. FIG. 5 is a view showing an example in which a sub-assembly for supporting membrane SOFC stack configuration is configured using spacers 8 and 8. Here, the SOFC single cell 10 is disposed with the air electrode facing upward. The spacers 8, 8 are openings 4, 4 provided at both ends in the longitudinal direction of the first strip-shaped alloy foil plate 1 and openings 7 provided at both ends in the longitudinal direction of the second strip-shaped alloy foil plate 2, 7 and an alloy member similar to both strip-shaped alloy foil plates. The spacers 8 and 8 are provided with a plurality of holes 9 on the side surface of the opening so that the gas passes inward.

  As shown in FIG. 3C, first, the single cell 10 is placed in the center of the second strip-shaped alloy foil plate 2. And between the 1st strip-shaped alloy foil board 1 and the 2nd strip-shaped alloy foil board 2, both ends opening 4 and 4 of the longitudinal direction of the 1st strip-shaped alloy foil board 1, and 2nd strip shape Spacers 8 and 8 are disposed at positions corresponding to both end openings 7 and 7 in the longitudinal direction of the alloy foil plate 2. Thereafter, the joint portions 5 and 5 of the first strip-shaped alloy foil plate 1 are locked by the joint portions 6 and 6 of the second strip-shaped alloy foil plate 2, and the portion is joined by a joining material.

  FIG. 4 shows the sub-assembly 11 for constructing the support membrane type SOFC stack constructed as described above, FIG. 4 (a) is a perspective view seen from the air electrode side, that is, the front surface side, and FIG. It is the perspective view seen from the side. As shown in FIG. 4, this subassembly is an alloy foil plate having an air electrode opening, a gas introduction hole (opening), and a discharge hole (opening) for the entire single cell of the support membrane type SOFC. Wrapped and configured. The sub-assembly for supporting membrane SOFC stack construction as shown in FIG. 4 can also be produced by folding a single alloy foil plate and wrapping a single cell. According to the configuration in which a single cell is wrapped by folding a single alloy foil plate, the only part to be joined is the end portion facing the bent portion of the alloy foil plate, and the work is simple and easy. A sub-assembly for constructing a support membrane type SOFC stack having better gas sealing performance can be obtained.

<B: Stack using sub-assembly A for supporting SOFC stack configuration>
A stack is constructed using the sub-assembly A for constructing the support membrane SOFC stack. As the constituent members, the support membrane SOFC stack constituent subassembly, the insulator member, and the interconnector manufactured as described above are used. The insulator member has an opening corresponding to the opening of the stack subassembly, and is made of a heat resistant material such as mica, and the interconnector is made of a heat resistant alloy such as stainless steel.

  The interconnector is normally configured in a wave shape, and air flow (that is, gas flow) and electrical connection are performed by the wave-shaped portion. That is, the interconnector is configured to include a wave-like portion for air circulation and electrical connection, and this is disposed at a portion corresponding to the air electrode of the single cell. The interconnector is based on that point, and is constructed by extending the corrugated part for air flow and electrical connection to both sides and having openings corresponding to the opening of the insulator member and the opening of the subassembly at both ends. May be. Also in this case, the corrugated portion for air circulation and electrical connection is arranged at a portion corresponding to the air electrode of the single cell.

  FIG. 5 is a diagram showing a configuration process of a support membrane SOFC stack using the support membrane SOFC stack configuration subassembly 11 as shown in FIG. As an interconnector, an interconnector is used which extends in a planar shape on both sides from the airflow and electrical connection corrugated portion and has openings corresponding to the opening of the insulator member and the opening of the subassembly at both ends thereof. Shows the case. As shown in FIG. 5, the interconnector 13 includes openings 14 and 14 corresponding to the openings of the insulator members 12 and 12 and the openings 4 (7) and 4 (7) of the subassembly 11 at both ends. A corrugated portion (groove) 15 for air circulation and electrical connection is provided at a portion corresponding to the air electrode of the single cell 10.

Insulator members 12 and 12 having openings corresponding to the openings 4 (7) and 4 (7) at both ends in the longitudinal direction are placed on the support membrane type SOFC stack constituting subassembly 11, and the interconnector is mounted thereon. By mounting 13, a support membrane type SOFC stack is formed. In FIG. 5, an arrow (↓) indicates the mounting direction. The support membrane type SOFC stack produced in this way is used by arranging current collecting plates on both the upper and lower surfaces and placing it in a casing. FIG. 6 is a cross-sectional view of the central portion in the longitudinal direction of the support membrane SOFC stack constructed as described above.
The above is a stack in which one single cell is arranged. A support membrane SOFC stack having a plurality of single cells is formed by stacking a plurality of the stacks. In the above-mentioned Japanese Patent Application No. 2003-112202, such a laminated structure is called a support membrane type SOFC module.

  However, the support membrane SOFC stack subassembly as described above and the support membrane SOFC stack using the subassembly also have the following problems. If a single cell of a support membrane type SOFC is schematically shown, it becomes a plane as shown in FIG. However, a single cell requires a firing step for its production, and it becomes a flat surface that is acceptable for stacking from a complete flat surface due to a difference in thermal expansion coefficient between members such as a fuel electrode and an electrolyte. It is difficult to cause warping or distortion as shown in FIGS. 7 is a cross-sectional view, FIG. 8 is a perspective view seen from the air electrode side, that is, the front surface, and FIG. 9 is a perspective view seen from the fuel electrode side, that is, the back surface.

<Problem 1>
First, as shown in FIGS. 7 and 9, the fuel cell side of the single cell, that is, the back surface thereof, has a central portion that is recessed (dented) and gradually curves toward the peripheral portion, causing warping or distortion. Then, in the stack structure subassembly in which the single cell of the support membrane type SOFC is wrapped with the alloy foil plate, if the alloy foil plate disposed on the back surface is a flat plate, uneven electrical contact occurs and the contact resistance is reduced. It increases and power generation performance decreases.

<Problem 2>
On the other hand, on the air electrode side of the single cell, that is, the surface thereof, as shown in FIGS. 7 to 8, the central portion swells and gradually curves toward the peripheral portion, causing warping or distortion. When stacking the cells via the interconnector, the corrugated portion 15 of the interconnector is brought into contact with the air electrode surface as shown in FIGS. Contact between the corrugated portions 15 of the interconnector is obstructed, resulting in uneven electrical contact, increasing contact resistance, and reducing power generation performance.

<Problem 3>
When cells are stacked via an interconnector, a gap formed by the corrugated portion 15 of the interconnector serves as an air flow path. Of the undulating portion 15, the air flowing through the flow passage on the side facing the air electrode of the cell (the flow passage on the air electrode surface side) contributes to power generation, but does not face the air electrode of the cell in the undulating portion 15. The air flowing through the flow path on the side (the flow path on the side opposite to the air electrode surface) does not flow through the air electrode surface and does not contribute to power generation.

  The present inventors have previously developed a sub-assembly for supporting a solid oxide fuel cell stack structure that solves the above problems 1 to 3 (Japanese Patent Application No. 2003-329197: 2003). Filed September 19). 10 to 12 are diagrams for explaining the subassembly formed by solving the first problem among the first to third problems.

Japanese Patent Application No. 2003-329197

  As described above, the fuel electrode side, that is, the back surface of the support membrane type SOFC single cell has a concave central portion, and gradually curves toward the peripheral portion, causing warping or distortion. Therefore, as shown in FIGS. 10B to 10C, the alloy foil plate in contact with the fuel electrode of the single cell, that is, the second alloy foil plate 2 is preliminarily matched with the shape of the fuel electrode, and the central portion is recessed (recessed). Then, it is processed so as to be gradually curved toward the peripheral edge. Then, the processed surface is disposed in contact with the fuel electrode surface.

  Thereby, a fuel electrode surface and an alloy foil board surface are made to contact | abut uniformly, and an equal electrical contact can be achieved between both. Other processes and configurations are the same as those described with reference to FIGS. FIG. 11 is a perspective view of the sub-assembly for supporting membrane type SOFC stack configured as described above, as viewed from the back side (that is, the fuel electrode side), and FIG. 12 is a perspective view of the sub-assembly for supporting membrane type SOFC stack configured as described above. It is the perspective view seen from the air electrode side. As shown in FIGS. 11 to 12, since the alloy foil plate that has been preliminarily matched to the shape of the fuel electrode is disposed in contact with the fuel electrode surface, the fuel electrode surface and the alloy foil plate surface are contacted uniformly, An even electrical contact can be achieved.

  The sub-assembly for supporting membrane type SOFC stack construction thus configured may constitute a stack, but the supporting membrane type SOFC is formed by stacking a plurality of them through an interconnector that performs gas flow and electrical connection. Configure the stack. 13-14 is a figure explaining the aspect, and in order to show the arrangement | positioning relationship of each member, it has shown each member at intervals. 13 to 14 show a case where three subassemblies are stacked, the same applies to a case where two subassemblies or four or more subassemblies are stacked.

  As shown in FIG. 13, the subassembly 11, the interconnector 23, the subassembly 11, the interconnector 23, the subassembly 11, and the interconnector 23 are sequentially arranged on the lower base 20 via the insulating spacer 22. The SOFC stack is configured by applying a load from the top. Further, in the embodiment of FIG. 14, a current collecting current terminal 21 is placed at the center of the lower base 20, and the SOFC stack is configured in the same manner. In this case, as described above, since the sub-assembly 11 is arranged in contact with the fuel electrode surface in advance with the alloy foil plate that has been matched to the shape of the fuel electrode, even when the sub-assembly 11 is stacked and stacked, In addition to contacting the fuel electrode surface and the alloy foil plate surface evenly, even between the sub-assembly 11-interconnector 23-sub-assembly 11... Electrical contact can be achieved.

  However, a close observation of the SOFC stack constructed in this way revealed that there was room for further improvement. That is, when the subassemblies 11 are stacked and stacked as shown in FIG. 13, the lowermost layer is different from the upper sublayer 11-interconnector 23-subassembly 11. It was found that the current collection resistance was high. Further, in the embodiment of FIG. 14, there is only a gap S and a current terminal 21 for current collection in the gap S. Therefore, the load on the current collector current terminal 21 is not sufficiently applied from above, It turned out that current collection resistance becomes high. Therefore, if an excessive load is applied to correct the warpage of the cell in order to bring the lower surface of the lowermost subassembly 11 into contact with the current collecting current terminal 21, the cell will break.

  The present invention has been made in order to solve the above-described problems that occur when stacking and stacking support membrane SOFC stack constituent subassemblies, and between the lower surface and the lower base of the lowermost subassembly, It is another object of the present invention to provide a SOFC stack that can uniformly contact the lower surface, the current collecting current terminal, and the lower base, a manufacturing method thereof, and a jig for the SOFC stack.

  The present invention includes (1) an entire single cell of a support membrane type solid oxide fuel cell, which is provided with an opening for an air electrode, a hole for introducing a gas, and a hole for deriving a gas. A plurality of subassemblies in which the alloy foil plate in contact with the alloy foil plate, which is processed in advance according to the shape of the fuel electrode, is wrapped with an interconnector having a corrugated portion that performs gas flow and electrical connection. A stacked support membrane solid oxide fuel cell stack, characterized in that a jig having a shape corresponding to the surface of the lower surface of the subassembly is interposed on the lower surface of the lowermost subassembly. A supported membrane solid oxide fuel cell stack is provided.

  The present invention includes (2) an entire single cell of a support membrane type solid oxide fuel cell having an opening for an air electrode, a hole for introducing a gas, and a hole for leading out, and the fuel electrode of a single cell. A plurality of subassemblies in which the alloy foil plate in contact with the alloy foil plate, which is processed in advance according to the shape of the fuel electrode, is wrapped with an interconnector having a corrugated portion that performs gas flow and electrical connection. And a support membrane type solid oxide fuel cell stack in which a current collecting current terminal is disposed under the lowermost subassembly, and the lower surface of the current collecting current terminal is formed on the lower surface of the subassembly. Provided is a support membrane type solid oxide fuel cell stack comprising a jig having a shape corresponding to a surface.

  The present invention comprises (3) an entire single cell of a support membrane type solid oxide fuel cell having an opening for an air electrode, a hole for introducing gas, and a hole for leading out, and the fuel electrode of the single cell A plurality of sub-assemblies, in which the alloy foil plates in contact with each other are wrapped with an alloy foil plate that has been processed according to the shape of the fuel electrode in advance, are stacked via an interconnector that performs gas flow and electrical connection. A method of manufacturing a support membrane type solid oxide fuel cell stack, characterized by laminating a lower surface of a lowermost subassembly with a jig having a shape corresponding to the surface of the lower surface of the subassembly. A method for producing a supported membrane solid oxide fuel cell stack is provided.

  The present invention provides (4) an entire single cell of a support membrane type solid oxide fuel cell having an opening for an air electrode, a hole for introducing a gas, and a hole for deriving a gas. Laminating a plurality of subassemblies encased in an alloy foil plate in which the alloy foil plate in contact with the shape of the fuel electrode is processed in advance through an interconnector that performs gas flow and electrical connection, A method of manufacturing a support membrane type solid oxide fuel cell stack in which a current collecting current terminal is disposed under a lowermost subassembly, wherein a lower surface of the subassembly is disposed on a lower surface of the current collecting current terminal. A support membrane type solid oxide fuel cell stack is produced by interposing a jig having a shape corresponding to the above.

  The present invention provides (5) an entire single cell of a support membrane type solid oxide fuel cell having an opening for an air electrode, a hole for introducing a gas, and a hole for leading out, and the fuel electrode of a single cell. A plurality of sub-assemblies for supporting membrane type solid oxide fuel cell stacks, in which the alloy foil plates in contact with each other are encased in an alloy foil plate that has been processed according to the shape of the fuel electrode in advance, are used for gas flow and electrical A jig for constructing a support membrane type solid oxide fuel cell stack that is laminated via an interconnector for connection, and having a shape corresponding to the lower surface of the lowermost subassembly There is provided a jig for constituting a support membrane type solid oxide fuel cell stack.

  The present invention provides (6) an entire single cell of a support membrane type solid oxide fuel cell having an opening for an air electrode, a hole for introducing a gas, and a hole for leading out, and the fuel electrode of a single cell. A plurality of sub-assemblies for supporting membrane type solid oxide fuel cell stacks, in which the alloy foil plates in contact with each other are encased in an alloy foil plate that has been processed according to the shape of the fuel electrode in advance, are used for gas flow and electrical A jig for constructing a support membrane type solid oxide fuel cell stack in which current collector terminals are arranged under the lowermost subassembly while being stacked via interconnectors for connection. A jig for forming a support membrane type solid oxide fuel cell stack, characterized in that it is a jig having a shape corresponding to the lower surface of the subassembly.

  According to the present invention, an opening for the air electrode, a hole for introducing and a hole for introducing the gas, and a portion of the alloy foil plate in contact with the fuel electrode of the single cell are processed in advance according to the shape of the fuel electrode. A plurality of sub-assemblies for supporting membrane type solid oxide fuel cell stacks, which are wrapped with an alloy foil plate, are stacked through an interconnector for gas flow and electrical connection, and supporting membrane type solid oxidation When the physical fuel cell stack is configured, the lower surface and the lower base of the lowermost subassembly, or the lower surface, the current collecting current terminal, and the lower base can be uniformly contacted. The present invention is useful in putting a support membrane type solid oxide fuel cell stack into practical use.

  The present invention (1)-(2) includes a single cell of a support membrane type solid oxide fuel cell, comprising an opening for an air electrode, a hole for introducing gas, and a hole for leading out, and a single cell. A plurality of sub-assemblies for constituting a support membrane type solid oxide fuel cell stack, in which an alloy foil plate in contact with the fuel electrode is wrapped with an alloy foil plate previously processed according to the shape of the fuel electrode, A support membrane type solid oxide formed by stacking via an interconnector for distribution and electrical connection, and by arranging a current collecting current terminal on the lower surface of the lowermost subassembly or under the lowermost subassembly It is a fuel cell stack. A jig having a shape corresponding to the surface of the lower surface of the subassembly is interposed on the lower surface of the lowermost subassembly or the current collector current terminal.

  In the present invention (3) to (4), the entire single cell of the support membrane type solid oxide fuel cell is provided with an opening for the air electrode, a hole for introducing gas, and a hole for leading out, and the single cell A plurality of sub-assemblies for constituting a support membrane type solid oxide fuel cell stack, in which an alloy foil plate in contact with the fuel electrode is wrapped with an alloy foil plate previously processed according to the shape of the fuel electrode, A support membrane type solid oxide formed by stacking via an interconnector for distribution and electrical connection, and by arranging a current collecting current terminal on the lower surface of the lowermost subassembly or under the lowermost subassembly This is a method for producing a fuel cell stack. The lower assembly of the lowermost subassembly or the current collector current terminal is laminated with a jig having a shape corresponding to the surface of the lower surface of the subassembly.

  The present inventions (5) to (6) comprise an entire single cell of a support membrane type solid oxide fuel cell, comprising an opening for an air electrode, a hole for introducing gas, and a hole for leading out, and a single cell. A plurality of sub-assemblies for constituting a support membrane type solid oxide fuel cell stack, in which an alloy foil plate in contact with the fuel electrode is wrapped with an alloy foil plate previously processed according to the shape of the fuel electrode, A support membrane type solid oxide formed by stacking via an interconnector for distribution and electrical connection, and by arranging a current collecting current terminal on the lower surface of the lowermost subassembly or under the lowermost subassembly It is a jig | tool for comprising a fuel cell stack. And the said jig | tool is a jig | tool of the shape corresponding to the surface of the lower surface of the lowermost subassembly.

<Structure aspect of jig having a shape corresponding to the lower surface of the sub-assembly>
The lower surface of the subassembly becomes a curved recess as shown in FIG. The jig of the present invention is configured to have a curved convex portion corresponding to the curved concave portion. 15A and 15B are views showing the structure of the jig 24. FIG. 15A is a plan view, FIG. 15B is a cross-sectional view taken along line AA in FIG. 15A, and FIG. It is. As shown as 25 in FIG.15 (b)-(c), it comprises in the shape swelled in the upper part curvedly. And the curved convex part 25 turns into a surface corresponding to the surface of the lower surface of a subassembly. The lower surface 26 of the jig is planar and is disposed on the upper surface of the lower base 20. The constituent material of the jig may be an electrically conductive material or an insulating material, and for example, a heat resistant alloy such as stainless steel is used.

<Structure aspect of support membrane type SOFC stack with jig having a shape corresponding to the lower surface of the sub-assembly>
FIGS. 16 to 17 show a support membrane type SOFC stack by stacking a plurality of sub membrane assembly for supporting membrane type SOFC stack through an interconnector for gas flow and electrical connection, using the jig of the present invention. It is a figure explaining the aspect to comprise. In FIGS. 16 to 17, each member is shown with an interval in order to show the arrangement relationship of each member, and the case where three subassemblies are stacked is shown. However, two, four or more subassemblies are shown. The same applies to the case of stacking layers.

  As shown in FIG. 16, the jig 24 is placed at the center of the lower base 20. A subassembly 11, an insulating spacer 22, an interconnector 23, a subassembly 11, an insulating spacer 22, an interconnector 23, a subassembly 11, an insulating spacer 22, and an interconnector 23 are sequentially disposed thereon. And a SOFC stack is comprised by applying a load from the upper part. In the embodiment of FIG. 17, the current collecting current terminal 21 is placed on the jig 24, and the SOFC stack is configured in the same manner.

  In the embodiment of FIG. 16, since the jig 24 is configured to be a surface corresponding to the surface of the lower surface of the lowermost subassembly, contact with the lower surface of the subassembly even at a load that does not break the cell. The contact resistance during power generation is reduced. In this embodiment, a current terminal cable is connected to the lower surface of the lowermost subassembly. Further, in the aspect in which the current collecting current terminal 21 is arranged on the lower surface of the lowermost subassembly as shown in FIG. 17, the contact between the lower surface of the subassembly and the current collecting current terminal 21 is improved, and the contact during power generation is improved. Resistance is reduced. In this embodiment, a cable is connected to the current collecting current terminal 21. In the present invention, this improves the power generation output of the entire SOFC stack. Even when a load is applied during lamination, the jig 24 prevents the cell from being deformed, so that the cell can be prevented from cracking.

<Constituent Member of Support Film Type SOFC Stack Related to Jig According to the Present Invention>
When a support membrane SOFC stack is configured using the jig according to the present invention, it is useful to use an interconnector having a configuration corresponding to the shape of the support membrane SOFC. Hereinafter, the configuration of the interconnector will be sequentially described.

  The wavy shape of the waved portion of the interconnector can take various shapes. FIG. 18 is a diagram showing an example of the shape. 18A is a cross-sectional wave shape, FIG. 18B is a cross-sectional zigzag shape, FIG. 18C is a cross-sectional marshmallow shape, FIG. 18D is a cross-sectional trapezoidal shape, and FIG. e) is a U-shaped cross-section, and these deformation shapes can be adopted. Here, the wavy portion of the interconnector or the wavy shape of the interconnector in the present specification and claims means not only the wavy shape of the cross section as shown in FIG. 18 (a) but also includes the wavy shape of the cross section. Also used in a comprehensive sense of the above-mentioned various shapes.

  As shown in FIGS. 7 to 9, the surface of the support membrane SOFC single cell, that is, the air electrode surface, bulges at the center and gradually curves toward the peripheral edge, causing warping or distortion. Then, when the stack is manufactured, when the corrugated portion of the interconnector is brought into contact with the air electrode surface as shown in FIGS. 13 to 14 and FIGS. 16 to 17, it is shown as a non-contact portion in FIG. As described above, the contact between the air electrode surface and the corrugated portion of the interconnector is obstructed, causing uneven electrical contact, increasing the contact resistance, and reducing the power generation performance. Therefore, a slit is formed in the corrugated portion of the interconnector in parallel with the wave direction. FIG. 20 is a diagram showing this aspect.

  As shown in FIG. 20, a slit is made in the wavy portion in parallel with the wave direction. As a result, the air electrode surface of the support membrane SOFC single cell and the corrugated portion of the interconnector can be brought into contact evenly, and uniform electrical contact can be achieved between them. This slit is not limited to the corrugated shape shown in FIG. 20, but has a zigzag cross section, a marshmallow cross section, a trapezoidal cross section, and a U-shaped cross section as shown in FIGS. In addition to the wavy portion, the present invention can also be applied to the wavy portions having these deformed shapes.

  When stacking single cells of a support membrane type SOFC via an interconnector, the positional relationship between the air electrode surface and the corrugated portion of the interconnector is as shown in FIGS. And the air gap of the corrugated part of the interconnector becomes the air flow passage, but as shown in FIG. 21 (a), the air flowing through the flow path on the side facing the air electrode surface of the cell is generated for the power generation. Although it contributes, as shown in FIG. 21 (b), the air flowing through the flow path on the side of the wavy portion that does not face the air electrode surface of the cell does not flow through the air electrode surface, and does not contribute to power generation. Become. Therefore, a plurality of holes are provided in the corrugated portion of the interconnector. 22-23 is a figure which shows the aspect.

  As shown in FIGS. 22 to 23, a plurality of holes are provided in the corrugated portion of the interconnector. FIG. 22 is a mode in which a plurality of holes are provided in a wave-like portion without a slit, and FIG. 23 is a mode in which a plurality of holes are provided in a wave-like portion having a slit as shown in FIG. With this hole, the air flowing through the flow path on the side of the undulating portion that does not face the air electrode surface of the cell can be circulated to the air electrode side and brought into contact with the air electrode to contribute to power generation. The plurality of holes are not limited to the corrugated shape shown in FIGS. 22 to 23, but are a zigzag cross section, a marshmallow cross section, a trapezoidal cross section, and a U-shaped cross section as shown in FIGS. 18 (b) to 18 (e). In addition to the wavy portions having a shape, the present invention can also be applied to the wavy portions having these deformed shapes.

  A heat-resistant alloy such as stainless steel is used as the constituent material of the support membrane type SOFC stack constituting subassembly, the alloy foil plate constituting the stack, and the interconnector in the present invention. Moreover, hydrocarbons, city gas, LP gas, natural gas, gasoline, light oil, kerosene, diesel oil, alcohols (methyl alcohol, ethyl alcohol, etc.), dimethyl ether (DME), etc. are used as fuel to be supplied to the stack. .

The figure explaining the example of the aspect of the cell of SOFC Diagram showing a configuration example of a SOFC stack incorporating a single cell The figure which shows the sub-assembly for supporting membrane type SOFC stack which encloses the whole single cell of supporting membrane type SOFC with the alloy foil board provided with the opening for air electrodes, the hole for gas introduction, and the hole for extraction. The figure which shows the sub-assembly for supporting membrane type SOFC stack which encloses the whole single cell of supporting membrane type SOFC with the alloy foil board provided with the opening for air electrodes, the hole for gas introduction, and the hole for extraction. FIG. 4 is a diagram showing a configuration process of a support membrane SOFC stack using a support membrane SOFC stack configuration subassembly as shown in FIG. FIG. 5 is a cross-sectional view of the central portion in the longitudinal direction of the support membrane SOFC stack configured as shown in FIG. Diagram explaining problems that occur in a single cell of a support membrane SOFC Diagram explaining problems that occur in a single cell of a support membrane SOFC Diagram explaining problems that occur in a single cell of a support membrane SOFC The figure explaining the subassembly which solves the problem which arises with the single cell of support membrane type SOFC The figure explaining the subassembly which solves the problem which arises with the single cell of support membrane type SOFC The figure explaining the subassembly which solves the problem which arises with the single cell of support membrane type SOFC The figure explaining the aspect which comprises a support membrane type SOFC stack using the subassembly for support membrane type SOFC stack composition The figure explaining the aspect which comprises a support membrane type SOFC stack using the subassembly for support membrane type SOFC stack composition The figure which shows the structure of the jig concerning this invention The figure explaining the aspect which laminates | stacks the subassembly for support membrane type | mold SOFC stack structure, and comprises a support membrane type | mold SOFC stack using the jig | tool of this invention. The figure explaining the aspect which laminates | stacks the subassembly for support membrane type | mold SOFC stack structure, and comprises a support membrane type | mold SOFC stack using the jig | tool of this invention. The figure which shows the example of a wave-like shape in the wave-like part of the interconnector used for support membrane type SOFC stack structure of this invention The figure explaining the problem resulting from the air electrode surface shape of a support membrane type SOFC cell The figure which shows the aspect of the interconnector which solves the problem resulting from the air electrode surface shape of a support membrane type SOFC cell The figure explaining the problem resulting from the air electrode surface shape of a support membrane type SOFC cell The figure which shows the aspect of the interconnector which solves the problem resulting from the air electrode surface shape of a support membrane type SOFC cell The figure which shows the aspect of the interconnector which solves the problem resulting from the air electrode surface shape of a support membrane type SOFC cell

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st alloy foil board 2 2nd alloy foil board 3 Opening (window) for air electrodes
4, 4 Openings for fuel flow 5, 5 Joints 6, 6 Joints 7, 7 Openings 8, 8 Spacers 9 Multiple holes 10 Single cell 11 Sub-assembly for supporting membrane type SOFC stack 12, 12 Insulator member 13 Inter Connector 14, 14 Opening 15 Waved part (groove)
DESCRIPTION OF SYMBOLS 20 Lower stand 21 Current collecting current terminal 22 Insulating spacer 23 Interconnector 24 Jig of shape corresponding to the surface of the lower surface of the subassembly 25 Curved bulging portion of the upper portion of the jig 24 26 Lower surface of the jig 24

Claims (19)

  The entire single cell of the support membrane type solid oxide fuel cell is provided with an opening for the air electrode, a hole for introducing gas, and a hole for leading out, and an alloy foil plate in a portion in contact with the fuel electrode of the single cell. A support membrane type in which a plurality of subassemblies wrapped with an alloy foil plate previously processed according to the shape of the fuel electrode are laminated via an interconnector having a wave-like portion for gas flow and electrical connection A support membrane type solid oxide comprising a solid oxide fuel cell stack, wherein a jig having a shape corresponding to a surface of a lower surface of the subassembly is interposed on a lower surface of a lowermost subassembly Fuel cell stack.   The entire single cell of the support membrane type solid oxide fuel cell is provided with an opening for the air electrode, a hole for introducing gas, and a hole for leading out, and an alloy foil plate in a portion in contact with the fuel electrode of the single cell. A plurality of subassemblies wrapped with an alloy foil plate that has been processed to match the shape of the fuel electrode in advance are stacked via an interconnector having a wave-like portion for gas flow and electrical connection, and A support membrane type solid oxide fuel cell stack in which current collecting current terminals are arranged under a subassembly, the lower surface of the current collecting current terminals having a shape corresponding to the surface of the lower surface of the subassembly A support membrane type solid oxide fuel cell stack comprising a jig.   3. The support membrane type solid oxide fuel cell stack according to claim 1 or 2, wherein the constituent material of the jig having a shape corresponding to the lower surface of the subassembly is a heat resistant alloy. Type solid oxide fuel cell stack.   The support membrane type solid oxide fuel cell stack according to any one of claims 1 to 3, wherein the alloy foil plate is a strip-like foil plate. Battery stack.   The support membrane type solid oxide fuel cell stack according to any one of claims 1 to 4, wherein a constituent material of the alloy foil plate is a heat resistant alloy. Fuel cell stack.   The support membrane type solid oxide fuel cell stack according to any one of claims 1 to 5, wherein the shape of the wavy portion of the interconnector is a zigzag cross section, a marshmallow cross section, a trapezoidal cross section, or a U-shaped cross section. A supported membrane solid oxide fuel cell stack, characterized in that   The support membrane type solid oxide fuel cell stack according to claim 6, wherein the interconnector includes a corrugated portion in a portion in contact with the air electrode, and a slit is formed in the corrugated portion in parallel with the wave direction. A support membrane type solid oxide fuel cell stack characterized by being a connector.   7. The support membrane type solid oxide fuel cell stack according to claim 6, wherein the interconnector includes a corrugated portion in a portion in contact with the air electrode and a plurality of holes in the corrugated portion. A supported membrane solid oxide fuel cell stack.   The entire single cell of the support membrane type solid oxide fuel cell is provided with an opening for the air electrode, a hole for introducing gas, and a hole for leading out, and an alloy foil plate in a portion in contact with the fuel electrode of the single cell. A support membrane type in which a plurality of subassemblies wrapped with an alloy foil plate previously processed according to the shape of the fuel electrode are laminated via an interconnector having a wave-like portion for gas flow and electrical connection A method for producing a solid oxide fuel cell stack, comprising a lower membrane of a lowermost subassembly, and a stack having a shape corresponding to the surface of the lower surface of the subassembly, and laminating the support membrane type A method for producing a solid oxide fuel cell stack.   The entire single cell of the support membrane type solid oxide fuel cell is provided with an opening for the air electrode, a hole for introducing gas, and a hole for leading out, and an alloy foil plate in a portion in contact with the fuel electrode of the single cell. A plurality of subassemblies wrapped with an alloy foil plate that has been processed to match the shape of the fuel electrode in advance are stacked via an interconnector having a wave-like portion for gas flow and electrical connection, and A method of manufacturing a support membrane type solid oxide fuel cell stack in which a current collecting current terminal is arranged under a subassembly, corresponding to a lower surface of the subassembly on a lower surface of the current collecting current terminal A support membrane type solid oxide fuel cell stack manufacturing method characterized by interposing a jig having a shape.   11. The method of manufacturing a support membrane type solid oxide fuel cell stack according to claim 9 or 10, wherein the constituent material of the jig having a shape corresponding to the lower surface of the subassembly is a heat resistant alloy. A manufacturing method of a support membrane type solid oxide fuel cell stack.   The method for producing a support membrane type solid oxide fuel cell stack according to any one of claims 9 to 11, wherein the alloy foil plate is a strip-like foil plate. A method for manufacturing a physical fuel cell stack.   The method for producing a support membrane type solid oxide fuel cell stack according to any one of claims 9 to 12, wherein the constituent material of the alloy foil plate is a heat resistant alloy. A method for manufacturing an oxide fuel cell stack.   14. The method for manufacturing a support membrane solid oxide fuel cell stack according to claim 9, wherein the wavy portion of the interconnector has a zigzag cross section, a marshmallow cross section, a trapezoidal cross section, or a cross section. A manufacturing method of a support membrane type solid oxide fuel cell stack characterized by being U-shaped.   15. The method of manufacturing a support membrane type solid oxide fuel cell stack according to claim 14, wherein the interconnector includes a corrugated portion in a portion in contact with the air electrode, and a slit is formed in the corrugated portion in parallel with the wave direction. A method of manufacturing a support membrane type solid oxide fuel cell stack, characterized by comprising:   15. The manufacturing method of a support membrane type solid oxide fuel cell stack according to claim 14, wherein the interconnector includes a corrugated portion in a portion in contact with the air electrode and a plurality of holes in the corrugated portion. A manufacturing method of a support membrane type solid oxide fuel cell stack, which is a connector.   The entire single cell of the support membrane type solid oxide fuel cell is provided with an opening for the air electrode, a hole for introducing gas, and a hole for leading out, and an alloy foil plate in a portion in contact with the fuel electrode of the single cell. A plurality of sub-assemblies for supporting membrane type solid oxide fuel cell stack construction, which are encased in an alloy foil plate that has been previously processed according to the shape of the fuel electrode, have corrugated portions for gas flow and electrical connection. A jig for constructing a support membrane type solid oxide fuel cell stack laminated through an interconnector, and having a shape corresponding to the lower surface of the lowermost subassembly. A jig for constituting a support membrane type solid oxide fuel cell stack.   The entire single cell of the support membrane type solid oxide fuel cell is provided with an opening for the air electrode, a hole for introducing gas, and a hole for leading out, and an alloy foil plate in a portion in contact with the fuel electrode of the single cell. A plurality of sub-assemblies for supporting membrane type solid oxide fuel cell stack construction, which are encased in an alloy foil plate that has been previously processed according to the shape of the fuel electrode, have corrugated portions for gas flow and electrical connection. A jig for constructing a support membrane type solid oxide fuel cell stack in which a current collecting current terminal is disposed under a lowermost subassembly while being stacked via an interconnector. A jig for constituting a support membrane type solid oxide fuel cell stack, characterized in that the jig has a shape corresponding to the surface of the lower surface of the fuel cell. 19. A jig for constituting the support membrane type solid oxide fuel cell stack according to claim 17 or 18, wherein the constituent material of the jig is a heat resistant alloy. Jig for configuring the fuel cell stack.

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