Solid oxide fuel cell and method for manufacturing a solid oxide fuel cell

Abstract

The present invention provides a solid oxide fuel cell which has an open cathode structure. This solid oxide fuel cell is configured by stacking a plurality of power generation modules, each of which is obtained by stacking a plurality of cell units; and each power generation module is provided with a module end plate that seals at least a cathode reaction surface that forms one end of the module in the stacking direction. In addition, the module end plate is provided with a bonding part, to which another power generation module that is adjacent thereto in the stacking direction is bonded, along the outer peripheral edge.

Description

Technical Field

[0001] The present invention relates to a solid oxide fuel cell and a method for manufacturing the same.

Background Art

[0002] In a fuel cell that operates at a high temperature, such as a solid oxide fuel cell (SOFC), there is a problem that the power generation part is deformed during operation. For example, in an SOFC formed by laminating a plurality of power generation modules, the central power generation part may be recessed, and there is a risk that the sealing performance between adjacent power generation modules cannot be ensured.

[0003] JP2014-93168A discloses a fuel cell stack in which a plurality of power generation modules each formed by laminating a plurality of single cells are laminated. In this fuel cell stack, the seal parts formed on the frame at the periphery of the single cell are arranged in a staggered pattern along the lamination direction, and by deflecting the periphery of the single cell, the periphery of the single cell follows the deformation in the lamination direction at the center of the single cell. Thereby, the sealing performance is ensured.

Summary of the Invention

[0004] In the fuel cell stack described in JP2014-93168A, since the seal parts are arranged in a staggered pattern, the rigidity of the periphery of the single cell is low, and even if the periphery of the power generation module is pressed to seal between the power generation modules, a sufficient reaction force cannot be received. Therefore, there is still a risk that the sealing performance between adjacent power generation modules cannot be ensured even by the technique described in JP2014-93168A.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a solid oxide fuel cell that ensures the sealing performance between power generation modules.

[0006] According to one aspect of the present invention, a solid oxide fuel cell having an open cathode structure is provided. The solid oxide fuel cell is composed of a plurality of stacked power generation modules, each of which is a stack of a plurality of cell units, and each power generation module is provided with a module end plate that seals the cathode reaction surface, which is at least one end in the stacking direction. The module end plate is also provided with a joint portion along its outer edge to which adjacent power generation modules in the stacking direction are joined. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is an exploded perspective view of a solid oxide fuel cell according to a first embodiment of the present invention. [Figure 2] Figure 2 is an exploded perspective view of the power generation module. [Figure 3] Figure 3 is an exploded perspective view of the cell unit. [Figure 4] Figure 4 is a perspective view of the cell unit. [Figure 5] Figure 5 shows a side view of two adjacent power generation modules. [Figure 6] Figure 6 is a top perspective view of a power generation module in a solid oxide fuel cell according to the second embodiment. [Figure 7] Figure 7 is a bottom perspective view of the power generation module. [Figure 8] Figure 8 illustrates the rib fitting of two adjacent power generation modules. [Figure 9] Figure 9 is a top perspective view of a power generation module in a solid oxide fuel cell according to a modified example of the second embodiment. [Figure 10] Figure 10 is a top perspective view of a power generation module in a solid oxide fuel cell according to the third embodiment. [Figure 11] Figure 11 is a schematic side view of the area near the junction of adjacent power generation modules in a solid oxide fuel cell according to the fourth embodiment. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to the drawings and other figures.

[0009] [First Embodiment] Figure 1 is an exploded perspective view of the solid oxide fuel cell (SOFC) 100 (hereinafter also referred to as the "fuel cell stack") according to this embodiment. While the solid oxide fuel cell 100 of this embodiment is primarily installed in vehicles and the like, it is not limited to this application.

[0010] As shown in Figure 1, the fuel cell stack 100 is constructed by stacking multiple power generation modules 10. In Figure 1, five power generation modules 10 are stacked to form the fuel cell stack 100, but the number of stacked power generation modules 10 is not limited to this. Although not shown, the fuel cell stack 100 is equipped with end plates at both ends of the power generation modules 10 in the stacking direction, and cover components that cover the entire stacked power generation modules 10.

[0011] Each power generation module 10 has a plurality of protrusions 11 extending from its outer edge, and manifolds 12, which are holes through which fuel gas flows in the stacking direction, are formed in the protrusions 11. In this embodiment, the power generation module 10 has two protrusions 11 on one longitudinal side and one protrusion 11 on the other side, but is not limited to this. The fuel cell stack 100 is made up of power generation modules 10 stacked such that the manifolds 12 of each power generation module 10 overlap. Manifold seal members 121 are provided around the manifolds 12 to seal the gaps between overlapping manifolds 12.

[0012] On the other hand, the cathode gas flowing in the stacking direction of the power generation module 10 passes through the space formed between the recess 13 corresponding to the protrusion 11 and the cover component that covers the entire power generation module 10.

[0013] Figure 2 is an exploded perspective view of the power generation module 10. As shown in Figure 2, the power generation module 10 is composed of multiple cell units 1 stacked on top of each other. Each cell unit 1 has one side that reacts with cathode gas (air) as the cathode reaction surface and the other side that reacts with anode gas (fuel gas) as the anode reaction surface. In this embodiment, the upper side of the cell unit 1 is the anode reaction surface and the lower side is the cathode reaction surface.

[0014] Furthermore, the power generation module 10 is provided with module end plates 2 at both ends of the cell unit 1 in the stacking direction. The module end plate 2 at one end of the cell unit 1 in the stacking direction (the upper end of the power generation module 10) seals the cathode reaction surface of the cell unit 1 at one end in the stacking direction (the cell unit 1 at the upper end in the stacking direction). The module end plate 2 at the other end of the cell unit 1 in the stacking direction (the lower end of the power generation module 10) seals the anode reaction surface of the cell unit 1 at the other end in the stacking direction (the cell unit 1 at the lower end in the stacking direction).

[0015] The module end plate 2 has a joint portion 21 along its outer edge to which adjacent power generation modules 10 in the stacking direction are joined. Adjacent power generation modules 10 are joined to each other by the joint portion 21 on the outer edge of the module end plate 2.

[0016] Furthermore, as shown in Figure 2, each cell unit 1 and module end plate 2 has multiple protrusions 14 extending from its outer edge, which form the protrusions 11 of the power generation module 10 when stacked. Holes 15 are formed in the protrusions 14, and when multiple cell units 1 are stacked, the holes 15 overlap to form the manifold 12 of the power generation module 10. An anode seal member 151 is provided around the holes 15 to seal the gaps between the overlapping holes 15.

[0017] Figure 3 is an exploded perspective view of cell unit 1.

[0018] As shown in FIG. 3, the cell unit 1 includes a power generation cell 3, a cell frame 31 surrounding the outer periphery of the power generation cell 3, a cell sealing member 32, a channel flow path 4, a separator 5, an anode spacer 33, an anode sealing member 151, a cathode spacer 35, and the like.

[0019] The power generation cell 3 is composed of a membrane electrode assembly in which an anode electrode is disposed on one surface of a solid electrolyte layer and a cathode electrode is disposed on the other surface. In this embodiment, the lower surface side of the power generation cell 3 is the anode electrode and the upper surface side is the cathode electrode. An anode gas (fuel gas) and a cathode gas (air) are supplied to the power generation cell 3, and the power generation cell 3 generates electricity based on electrode reactions at the anode electrode and the cathode electrode. Note that the power generation cell 3 may be configured to include a support layer that supports the anode electrode and / or the cathode electrode.

[0020] The cell frame 31 is a frame body that fixes the power generation cell 3 and is disposed so as to surround the outer periphery of the power generation cell 3. The cell frame 31 has a plurality of convex portions 311 that extend and project from the outer peripheral edge, and hole portions 312 are formed in the convex portions 311.

[0021] The cell sealing member 32 is disposed so as to surround the outer periphery of the power generation cell 3 and seals between the power generation cell 3 and the cell frame 31.

[0022] The channel flow path 4 is made of a conductive material such as metal and is disposed between both surfaces of the power generation cell 3 and a separator 5 described later, and is a member that forms an anode flow path on one surface side of the power generation cell 3 and a cathode flow path on the other surface side. The channel flow path 4 is formed in a so-called corrugated shape in which concavities and convexities extending linearly in the width direction of the power generation cell 3 are repeatedly provided in the longitudinal direction. Thereby, a plurality of anode flow paths are partitioned between one surface of the power generation cell 3 and the separator 5, and a cathode flow path is partitioned between the other surface of the power generation cell 3 and the separator 5 (of an adjacent cell unit 1). In this embodiment, an anode flow path is formed on the lower surface side of the power generation cell 3, and a cathode flow path is formed on the upper surface side.

[0023] The separator 5 is a conductive plate-shaped member, with one side electrically connected to the channel flow path 4. This electrically connects the separator 5 and the power generation cell 3 via the channel flow path 4. The other side of the separator 5 is connected to the channel flow path 4 of the adjacent cell unit 1.

[0024] Furthermore, the separator 5 has a plurality of protrusions 51 that extend from the outer edge and protrude at positions corresponding to the protrusions 311 of the cell frame 31, and holes 52 are formed in the protrusions 51 at positions corresponding to the holes 312 of the cell frame 31. The holes 52 of the separator 5 and the holes 312 of the cell frame 31 overlap to form the holes 15 (Figure 2) of the cell unit 1. As described above, an anode seal member 151 is provided around the holes 15.

[0025] The anode spacer 33 is a frame stacked on the outer circumference of the separator 5, positioned between the cell frame 31 and the separator 5, and ensuring the height of the anode flow path. The anode spacer 33 is positioned so that its outer shape overlaps with the cell frame 31 and the separator 5.

[0026] The cathode spacers 35 are positioned at both ends in the longitudinal direction of the cathode-side channel flow path 4, ensuring the height of the cathode flow path and sealing both ends in the longitudinal direction of the channel flow path 4.

[0027] Figure 4 is a perspective view of the assembled cell unit 1.

[0028] As shown in Figure 4, the cell unit 1 has a protrusion 14 with a hole 15 that constitutes a manifold 12 through which fuel gas flows, and the holes 15 between the cell units 1 are sealed by an anode seal member 151.

[0029] On the other hand, in the cell unit 1, the cathode gas flowing in the stacking direction passes through the space formed between the recess 16 corresponding to the protrusion 14 and the cover component that covers the entire power generation module 10. When multiple cell units 1 are stacked, the recesses 16 overlap, forming a recess 13 which is a channel for the cathode gas flowing in the stacking direction (Figure 1). In other words, the fuel cell stack 100 has an open cathode structure in which the channel for the cathode gas flowing in the stacking direction is formed by the cover component rather than within the cell unit 1.

[0030] Incidentally, because solid oxide fuel cells (SOFCs) operate at high temperatures, in SOFCs that consist of multiple stacked power generation modules, there is a risk that the power generation section in the center of the power generation module may sag during operation, making it impossible to ensure proper sealing between adjacent power generation modules.

[0031] In contrast, in the solid oxide fuel cell 100 of this embodiment, the power generation module 10 is equipped with module end plates 2 at both ends in the stacking direction of the cell unit 1, and adjacent power generation modules 10 are joined together by joints 21 at the outer edges of the module end plates 2. Therefore, even if the center of the power generation module 10 deforms, the joints 21 are set at the points where the deformation occurs, thus ensuring a seal between the power generation modules 10.

[0032] The following describes the details of how the module end plates 2 of adjacent power generation modules 10 are joined together.

[0033] Figure 5 is a side view of two adjacent power generation modules 10 in the stacking direction, viewed from the X direction in Figure 1. Here, the power generation module above in the stacking direction is referred to as power generation module 10A, and the power generation module below is referred to as power generation module 10B.

[0034] As shown in Figure 5, the module end plates 2 are provided at both ends in the stacking direction of the multiple stacked cell units 1, and seal the anode reaction surface and cathode reaction surface at the stacking direction ends of the cell units 1.

[0035] Furthermore, as shown in Figure 5, the module end plate 2 is formed to be larger than the outer shape of the cell unit 1 that constitutes the power generation module 10 in a plan view. A joint portion 21 is formed on the module end plate 2 along its outer peripheral edge at a position offset in the outer direction relative to the cell unit 1. The module end plate 2A that seals the anode reaction surface at the lower end of the power generation module 10A and the module end plate 2B that seals the cathode reaction surface at the upper end of the power generation module 10B are joined to each other at the joint portion 21 by a conductive joint such as welding.

[0036] In this way, because adjacent power generation modules 10 are joined together at the joint portion 21 along the periphery of the module end plate 2, even if the center of the power generation module 10 deforms, the joint portion 21 is formed at the point where the deformation occurs, thus ensuring airtightness (sealing) between the power generation modules 10.

[0037] Furthermore, since adjacent power generation modules 10 are joined by conductive junctions, conductivity is ensured between the power generation modules 10. In other words, airtightness and conductivity between the power generation modules 10 can be ensured simultaneously.

[0038] Furthermore, since the joint portion 21 that connects adjacent power generation modules 10 is formed at a position offset in the outer direction relative to the cell unit 1, no load is placed on the internal components of the power generation modules 10 (such as the components that make up the cell unit 1) when connecting adjacent power generation modules 10. Therefore, the load for joining can be applied at the joint portion 21 without considering the load on the internal components of the power generation modules 10, and better contact can be achieved between the power generation modules 10.

[0039] Furthermore, if the fuel cell stack has a closed cathode structure in which the flow path of cathode gas flowing in the stacking direction is sealed within the cell unit, sealing both ends of the cell unit in the stacking direction with module end plates may prevent access to the power generation module, potentially resulting in insufficient sealing of the anode gas. In contrast, this embodiment uses an open cathode structure, allowing access to the power generation module 10 even after joining the module end plates 2, and enabling sealing of the anode flow path.

[0040] According to the solid oxide fuel cell 100 of the first embodiment described above, the following effects can be obtained.

[0041] The solid oxide fuel cell 100 has a power generation module 10 equipped with module end plates 2 at both ends in the stacking direction of the cell unit 1. The module end plates 2 have joint portions 21 along their outer edges to which adjacent power generation modules 10 in the stacking direction are joined. The outer edges of the module end plates 2 of adjacent power generation modules 10 in the stacking direction are joined by the joint portions 21. Therefore, even if the center of the power generation module 10 deforms during operation of the solid oxide fuel cell 100, the joint portions 21 are set at the points where the deformation occurs, thus ensuring sealing (airtightness) between the power generation modules 10.

[0042] In the solid oxide fuel cell 100, each power generation module 10 is joined to adjacent power generation modules 10 in the stacking direction by conductive joints at joint portions 21 along the outer edge of each power generation module 10. This ensures both sealing (airtightness) between the power generation modules 10 and electrical conductivity between them. In other words, both airtightness and electrical conductivity between the power generation modules 10 can be ensured simultaneously.

[0043] In the solid oxide fuel cell 100, the module end plate 2 is formed to be larger than the outer shape of the cell unit 1 that constitutes the power generation module 10 in a plan view, and the joint portion 21 of the module end plate 2 is formed at a position offset in the outer direction relative to the cell unit 1. Therefore, when joining adjacent power generation modules 10, no load is placed on the internal components of the power generation module 10 (components of the cell unit 1, etc.). Consequently, the load for joining can be applied at the joint portion 21 without considering the load on the internal components of the power generation module 10, and better contact can be made between the power generation modules 10. Therefore, the power generation performance of the solid oxide fuel cell 100 is improved.

[0044] In this embodiment, the power generation modules 10 are joined by welding, but this is not limited to this method, and they may also be joined by brazing or other methods. Furthermore, while it is preferable to join the power generation modules 10 using a conductive joint, this is not necessarily limited to this method, and the power generation modules 10 may also be joined using a non-conductive joint such as a glass or ceramic adhesive. When a power generation module 10 is deformed into a curved shape, the module end plates 2 of adjacent power generation modules 10 come into contact with each other on the outside of the joint 21, so conductivity between the power generation modules 10 can be ensured even with a non-conductive joint.

[0045] Furthermore, in this embodiment, module end plates 2 are provided at both ends of the cell unit 1 in the stacking direction, but this is not necessarily the only configuration. The module end plate 2 may be provided only on the cathode reaction surface side, which is one end of the cell unit 1 in the stacking direction. In this case, the anode reaction surface at the other end of the cell unit 1 in the stacking direction of the adjacent power generation module 10 is joined to the joint 21 of the module end plate 2 that seals the cathode reaction surface. That is, one module end plate 2 is shared as an end plate that seals the cathode reaction surface and the anode reaction surface.

[0046] Furthermore, as in this embodiment, it is preferable that the joint portion 21 of the module end plate 2 be formed at a position offset in the outer peripheral direction relative to the cell unit 1, but it is not necessarily limited to this. Even if the joint portion 21 is formed at a position overlapping with the cell unit 1, as long as the joint portion 21 is formed along the outer peripheral edge of the module end plate 2, the joint portion 21 is set at a point where deformation occurs, and thus sealing (airtightness) between the power generation modules 10 is ensured.

[0047] [Second Embodiment] The solid oxide fuel cell 100 of the second embodiment will be described with reference to Figures 6 to 8. In this embodiment, the adjacent power generation modules 10 are rib-fitted together, which is different from the first embodiment. The same reference numerals are used for elements similar to those in the first embodiment, and their descriptions are omitted.

[0048] Figure 6 is a perspective view of the power generation module 10 viewed from above, and Figure 7 is a perspective view of the power generation module 10 viewed from below. Figures 6 and 7 show the state before the multiple power generation modules 10 are joined together.

[0049] As shown in Figures 6 and 7, the power generation module 10 is provided with a rib 17A that protrudes from the upper surface of the module end plate 2 at the upper end in the stacking direction of the cell unit 1, and a rib 17B that protrudes from the lower surface of the module end plate 2 at the lower end in the stacking direction in a direction substantially perpendicular to the rib 17A.

[0050] Furthermore, on the upper surface of the module end plate 2 at the upper end of the cell unit 1 in the stacking direction, the power generation module 10 has a fitting portion 18A formed at a position corresponding to the rib 17B that protrudes from the lower end of an adjacent power generation module 10 in the stacking direction (upward), into which the rib 17B fits. On the other hand, on the lower surface of the module end plate 2 at the lower end of the power generation module 10 in the stacking direction, the power generation module 10 has a fitting portion 18B formed at a position corresponding to the rib 17A that protrudes from the upper end of an adjacent power generation module 10 in the stacking direction (downward), into which the rib 17A fits. As a result, when the power generation modules 10 are stacked, the rib 17A at the upper end of the power generation module 10 and the fitting portion 18B at the lower end of the adjacent power generation module 10 fit together, and the rib 17B at the lower end of the power generation module 10 fits together.

[0051] Figure 8 is an enlarged view of the cross-section of the rib fitting portion between adjacent power generation modules 10.

[0052] As shown in Figure 8, adjacent power generation modules 10A and 10B in the stacking direction are connected by a rib 17A protruding from the upper end of power generation module 10B which fits into a fitting portion 18B formed at the lower end of power generation module 10A. Note that Figure 8 is a cross-sectional view of the portion where the rib 17A of power generation module 10B fits into the fitting portion 18B of power generation module 10A, but similarly, the rib 17B protruding from the lower end of power generation module 10A fits into the fitting portion 18B formed at the upper end of power generation module 10B.

[0053] In this way, because adjacent power generation modules 10 are rib-fitted together, the planar displacement of the solid oxide fuel cell (fuel cell stack) 100 is suppressed. As a result, the vibration resistance of the solid oxide fuel cell (fuel cell stack) 100 is improved.

[0054] In Figures 6 and 7, multiple ribs 17B extending in the longitudinal direction of the power generation module 10 are formed on the lower surface of the module end plate 2 at the lower end in the stacking direction, and ribs 17A in a direction approximately perpendicular to the ribs 17B are formed on the upper surface of the module end plate 2 at the upper end in the stacking direction, but this is not necessarily the only option. The position and number of ribs 17 formed on the module end plate 2 can be determined arbitrarily. The fitting portion 18 can be provided at a position corresponding to the ribs 17.

[0055] [Modified version of the second embodiment] Referring to Figure 9, a modified solid oxide fuel cell 100 of the second embodiment will be described. Elements similar to those in other embodiments are denoted by the same reference numerals, and their descriptions are omitted.

[0056] Figure 9 is a perspective view of the power generation module 10 from above. Note that Figure 9 shows the state before multiple power generation modules 10 are joined together.

[0057] As shown in Figure 9, in this modified example, the power generation module 10 has ribs 17 provided on the upper surface of the module end plate 2 at the upper end in the stacking direction of the cell unit 1, which are formed around the manifold 12 through which the fuel gas flows in the stacking direction. Although not shown, on the lower surface of the module end plate 2 at the lower end in the stacking direction of the cell unit 1, there is a fitting portion, which is a groove into which the ribs 17 fit, at a position corresponding to the ribs 17 of the adjacent power generation module 10 in the stacking direction (downward). As a result, when the power generation modules 10 are stacked, the ribs 17 at the upper end of the power generation module 10 and the fitting portion at the lower end of the adjacent power generation module 10 in the stacking direction fit together. This suppresses the planar displacement of the solid oxide fuel cell (fuel cell stack) 100 and improves the vibration resistance of the solid oxide fuel cell (fuel cell stack) 100.

[0058] Furthermore, because the ribs 17 that fit into the mating portion are formed around the manifold 12, the flow of fuel gas in the planar direction between adjacent power generation modules 10 is prevented. In other words, the airtightness of the manifold 12 is improved, and the power generation performance of the solid oxide fuel cell 100 is improved.

[0059] [Third Embodiment] The third embodiment of the solid oxide fuel cell 100 will be described with reference to Figure 10. Elements similar to those in the other embodiments are denoted by the same reference numerals, and their descriptions are omitted.

[0060] Figure 10 is a perspective view of the power generation module 10 from above. Note that Figure 10 shows the state before the power generation modules 10 are joined together.

[0061] In this embodiment, the power generation module 10 is equipped with a high thermal conductivity layer 7, which is different from other embodiments.

[0062] As shown in Figure 10, the power generation module 10 is equipped with a high thermal conductivity layer 7 in the central part of the module end plate 2 at the upper end in the stacking direction of the cell unit 1. The high thermal conductivity layer 7 is made of a material with high thermal conductivity, such as graphite, or metals such as silver, copper, aluminum, nickel, or ferritic stainless steel. This improves the thermal conductivity in the planar direction of the power generation section of the power generation module 10, thereby improving the power generation performance of the solid oxide fuel cell 100.

[0063] In this embodiment, the high thermal conductivity layer 7 is preferably provided in the central part of the module end plate 2, but it is not limited to this, and may be provided at any position on the module end plate 2.

[0064] [Fourth Embodiment] The fourth embodiment of the solid oxide fuel cell 100 will be described with reference to Figure 11. Elements similar to those in other embodiments are denoted by the same reference numerals, and their descriptions are omitted.

[0065] Figure 11 is a schematic side view of the vicinity of the joint 21 of adjacent power generation modules 10, illustrating the stacking process of adjacent power generation modules 10 in the stacking direction. Figure 11(a) shows the adjacent power generation modules 10 before stacking, (b) shows the adjacent power generation modules 10 during stacking, and (c) shows the adjacent power generation modules 10 after stacking is complete. Although Figure 11 shows the stacking process of two adjacent power generation modules 10 for convenience, each of the multiple power generation modules 10 to be stacked has the configuration shown in Figure 11.

[0066] As shown in Figure 11(a), the module end plate 2 of the power generation module 10 is bent at its longitudinal end. That is, the module end plate 2 has a flat portion 22 and a bent portion 23. Here, for each power generation module 10, the bending angle θ1 of the module end plate 2 at the upper end in the stacking direction of the cell unit 1 is smaller than the bending angle θ2 of the module end plate 2 at the lower end in the stacking direction. As a result, as shown in Figure 11(b), when the power generation modules 10 are stacked, the module end plates 2 of adjacent power generation modules 10 come into contact at the bent portion 23 before the flat portion 22. Here, the module end plates 2 of adjacent power generation modules 10 are joined (welded) at the point where they first come into contact at the bent portion 23 during stacking. That is, a joint portion 21 is formed at the point where they first come into contact during stacking.

[0067] As shown in Figure 11(c), when the stacking of the power generation modules 10 is complete, the module end plates 2 of adjacent power generation modules 10 are in contact with each other at least at the joint 21.

[0068] In this way, by bending the module end plate 2 at the upper end in the stacking direction so that the bending angle θ1 is smaller than the bending angle θ2 of the module end plate 2 at the lower end in the stacking direction before stacking the power generation modules 10, the longitudinal ends of the power generation modules 10 make contact first when stacking. Then, by joining (welding) the module end plates 2 of adjacent power generation modules 10 at the part that makes first contact, adjacent power generation modules 10 are in contact at least at the ends of the module end plates 2. Therefore, the joining of the power generation modules 10 is more reliably ensured, and the conductivity between the power generation modules 10 is improved. In other words, the power generation performance of the solid oxide fuel cell 100 is improved.

[0069] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0070] Although each of the embodiments described above has been explained as a standalone embodiment, they may be combined as appropriate.

Claims

1. A solid oxide fuel cell having an open cathode structure, It is composed of multiple stacked power generation modules, each consisting of multiple cell units stacked on top of each other. Each power generation module is equipped with module end plates at both ends in the stacking direction, sealing the cathode reaction surface and the anode reaction surface, respectively. The module end plate has a joint along its outer edge to which adjacent power generation modules in the stacking direction are joined, and adjacent power generation modules in the stacking direction are joined at the outer edges of the module end plate by the joint. Solid oxide fuel cell.

2. A solid oxide fuel cell according to claim 1, Each power generation module is joined to an adjacent power generation module in the stacking direction by a conductive bond at the joint. Solid oxide fuel cell.

3. A solid oxide fuel cell according to claim 2, The module end plate is formed to be larger than the outer shape of the cell unit constituting the power generation module in a plan view. The joint portion of the module end plate is formed at a position offset in the outer circumferential direction relative to the cell unit. Solid oxide fuel cell.

4. A solid oxide fuel cell according to claim 2, A rib is formed to protrude from the module end plate of one of the adjacent power generation modules. The module end plate of the other power generation module has a fitting portion formed therein that fits with the rib. Solid oxide fuel cell.

5. A solid oxide fuel cell according to claim 4, The power generation module has a manifold through which fuel gas flows in the stacking direction, The ribs are formed around the manifold. Solid oxide fuel cell.

6. A solid oxide fuel cell according to any one of claims 1 to 5, Each power generation module is provided with a high thermal conductivity layer between adjacent power generation modules in the stacking direction, the layer being made of a material containing at least one of the following: graphite, silver, copper, aluminum, nickel, or ferritic stainless steel. Solid oxide fuel cell.

7. A method for manufacturing a solid oxide fuel cell having an open cathode structure, A power generation module is constructed by stacking multiple cell units and sealing the cathode reaction surface at one end in the stacking direction and the anode reaction surface at the other end with module end plates. Multiple of the aforementioned power generation modules are stacked, The solid oxide fuel cell is constructed by joining each power generation module to the outer edge of the module end plate of an adjacent power generation module in the stacking direction at the outer edge of the module end plate of the module end plate. A method for manufacturing a solid oxide fuel cell.

8. A method for manufacturing a solid oxide fuel cell according to claim 7, A power generation module is constructed by stacking multiple cell units and sealing both ends in the stacking direction with module end plates. The longitudinal end of the module end plate is bent and formed, Multiple power generation modules, each having a bent module end plate, are stacked to form the solid oxide fuel cell. The bending angle of the aforementioned bending process is such that the module end plate at the upper end in the stacking direction is smaller than that of the module end plate at the lower end in the stacking direction. A method for manufacturing a solid oxide fuel cell.

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