Stack, hot module, and hydrogen production device

Abstract

Provided are: a stack (10, 80) with which it is possible to ensure a flow of gas between a passage and a cell; a hot module (71); and a hydrogen production device (70). This stack comprises: cells (30) including an electrolyte (31) that isolates a fuel electrode (32) and an air electrode (33) from each other in the thickness direction; first separators (27) fixed to the cells; inter-connectors (34) in contact with the air electrodes; second separators (29) fixed to the inter-connectors; electrically insulating frames (28) disposed between the first separators and the second separators; and gas passages (24, 25) extending in the thickness direction of the first separators, the frames, and the second separators. The passages are connected to spaces (37) between the first separators and the second separators. The stack also comprises insulators (50) disposed between the passages and the cells within the spaces. The spaces in which the insulators are disposed each include a gas passage part (52) through which gas passes between the passages and the cells.

Description

Stack, hot module and hydrogen production device

[0001] The present invention relates to a stack in which cells are stacked, a hot module, and a hydrogen production device.

[0002] Patent Document 1 discloses a stack including a cell containing an electrolyte that separates an anode and an cathode in the thickness direction, a first separator fixed to the cell, an interconnector in contact with the cathode, a second separator fixed to the interconnector, an electrically insulating frame disposed between the first separator and the second separator, and a gas passage extending in the thickness direction of the first separator, the frame, and the second separator, the passage connecting to a space between the first separator and the second separator. In the prior art disclosed in Patent Document 1, a flow path connecting the passage and the space is provided in the frame.

[0003] International Publication No. 2011 / 148769

[0004] In the prior art, when the stack is in use, the first separator or the second separator may deform, shortening the distance between the first separator and the second separator, making it difficult for gas to flow through the space between the passages and the cells, which can result in a decrease in stack performance.

[0005] The present invention has been made to solve this problem, and has as its object to provide a stack, a hot module, and a hydrogen production device that can ensure the flow of gas between the passages and the cells.

[0006] A first aspect of the present invention to achieve this object is a stack comprising: a cell containing an electrolyte separating an anode and a cathode in a thickness direction, a first separator fixed to the cell and extending beyond the outer periphery of the cell, an interconnector in contact with the cathode, a second separator fixed to the interconnector and extending beyond the outer periphery of the interconnector, an electrically insulating frame disposed between the first separator and the second separator in the thickness direction, and a gas passage extending in the thickness direction of the first separator, the frame, and the second separator, the passage connecting to a space between the first separator and the second separator. An insulator is disposed between the passage and the cell in the space, and the space in which the insulator is disposed includes a gas passage portion through which gas passes between the passage and the cell.

[0007] A second aspect is a stack comprising: a cell containing an electrolyte separating an anode and a cathode in a thickness direction, a first separator fixed to the cell and extending beyond the outer periphery of the cell, an interconnector in contact with the cathode, an electrically insulating frame disposed between the first separator and the interconnector in the thickness direction, and a gas passage extending in the thickness direction of the first separator, the frame, and the interconnector, the passage communicating with a space between the first separator and the interconnector, an insulator disposed between the passage and the cell in the space, and the space in which the insulator is disposed includes a gas passage portion through which gas passes between the passage and the cell.

[0008] In a third aspect, in the first or second aspect, the flexural modulus of the insulator is smaller than the flexural modulus of the frame.

[0009] In a fourth aspect, in any one of the first to third aspects, the insulating material is ceramic felt.

[0010] In a fifth aspect, in any one of the first to fourth aspects, the gas passage includes a groove provided in the insulator.

[0011] A sixth aspect is any one of the first to fifth aspects, wherein the first separator and the second separator include stress buffering portions that are curved in the same direction in the thickness direction in the space, and the insulator is disposed in the stress buffering portions.

[0012] A seventh aspect is the fuel cell according to any one of the first to sixth aspects, wherein the insulator is continuous around the entire periphery of the cell.

[0013] In an eighth aspect, in any one of the first to seventh aspects, the cell has a function of electrolyzing a fuel gas.

[0014] A ninth aspect is a hot module comprising the stack of the eighth aspect, a vaporizer that generates steam as fuel gas, a heat exchanger that exchanges heat with the gas supplied to the stack, a heater for heating the stack, and insulation within which the stack, vaporizer, heat exchanger, and heater are disposed.

[0015] A tenth aspect is a hydrogen production device comprising the hot module of the ninth aspect.

[0016] According to the present invention, an insulator is arranged in the space between the passage and the cell, and the space in which the insulator is arranged includes a gas passage portion through which gas passes between the passage and the cell, thereby ensuring the flow of gas between the passage and the cell.

[0017] 1 is a perspective view of a stack in a first embodiment; FIG. 2 is a cross-sectional view of the stack taken along line II-II; FIG. 3 is a cross-sectional view of the stack taken along line III-III; (a) is a cross-sectional view of an insulator taken along line IVa-IVa, (b) is a cross-sectional view of an insulator in a modified example, (c) is a cross-sectional view of an insulator in another modified example, and (d) is a cross-sectional view of an insulator in another modified example; and (d) is a block diagram of a hydrogen production device. FIG. 4 is a cross-sectional view of a stack in a second embodiment.

[0018] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Fig. 1 is a perspective view of a stack 10 according to a first embodiment. The stack 10 includes a reaction unit 11, a stack 12 formed by stacking a plurality of reaction units 11 in the thickness direction, conductive plates 13 and 15 electrically connected to the stack 12, and end plates 17 and 18 sandwiching the stack 12 and the conductive plates 13 and 15 in the thickness direction. The stack 12 is formed by stacking, for example, approximately 10-30 reaction units 11.

[0019] Conductive plate 13 is disposed between laminate 12 and end plate 17, and conductive plate 15 is disposed between laminate 12 and end plate 18. Terminals 14 and 16 are connected to conductive plates 13 and 15, respectively. The conductive plates 13 and 15 and terminals 14 and 16 are made of, for example, stainless steel.

[0020] An insulator 19 is disposed between the conductive plate 13 and the end plate 17, and provides electrical insulation between the conductive plate 13 and the end plate 17. An insulator 20 is disposed between the conductive plate 15 and the end plate 18, and provides electrical insulation between the conductive plate 15 and the end plate 18. Bolts 21 are disposed around the periphery of the stack 10, passing through the end plates 17, 18, insulators 19, 20, conductive plates 13, 15, and laminate 12 in the thickness direction. The stack 10 is fastened together by the bolts 21.

[0021] The four spaces that penetrate the periphery of the stack 10 in the thickness direction function as a passage 22 that supplies fuel gas from outside the stack 10 to a fuel chamber 36 (described later) of the reaction unit 11, a passage 23 that discharges gas from the fuel chamber 36 to outside the stack 10, a passage 24 that supplies oxidant gas from outside the stack 10 to an air chamber 37 (described later) of the reaction unit 11, and a passage 25 that discharges gas from the air chamber 37 to outside the stack 10, respectively.

[0022] 2 is a cross-sectional view of the stack 10 taken along line II-II in FIG. 1, passing through the passages 24 and 25, and shows a portion of the laminate 12. The thickness of each portion is exaggerated in FIG. 2.

[0023] 2, the reaction unit 11 includes, in order in the thickness direction, an anode frame 26, a first separator 27, a cathode frame 28, and a second separator 29. Holes (passages 22-25) penetrate the anode frame 26, the first separator 27, the cathode frame 28, and the second separator 29. Cells 30, interconnectors 34, and current collectors 35 are arranged inside the anode frame 26, the first separator 27, the cathode frame 28, and the second separator 29.

[0024] The cell 30 includes an electrolyte 31, and an anode 32 and cathode 33 separated in the thickness direction by the electrolyte 31. In this embodiment, a flat-plate type cell 30 is described, but the present invention is not limited to this. The cell 30 may be a metal-supported type (metal-supported flat-plate type) in which the electrodes and electrolyte are supported by a porous body of a metal such as an Fe—Cr system. The cell 30 may be an electrode-supported type or an electrolyte-supported type.

[0025] The material of the electrolyte 31 is a solid oxide, and examples thereof include stabilized zirconia, ceria-based solid solution, and a solid solution of alumina with one or more selected from stabilized zirconia and ceria-based solid solution. The stabilizer for stabilized zirconia is CaO, MgO, Y ２ O ３ , Sc ２ O ３ , Yb ２ O ３ Examples of elements that dissolve in ceria in the ceria-based solid solution include Gd, Sm, and Y.

[0026] Examples of the material for the fuel electrode 32 include a material containing a catalyst containing Ni and zirconia with Y dissolved therein, and a material containing a catalyst containing Ni and ceria with Gd dissolved therein. Examples of the catalyst include Ni, Ni-based alloys, and cermets, which are composites (sintered bodies) of NiO and oxides (solid electrolytes).

[0027] The material of the cathode 33 is a perovskite oxide, La １－Ｘ Sr Ｘ MnO ３－δ , La １－Ｘ Sr Ｘ CoO ３－δ , La １－Ｘ Sr Ｘ Co １－Ｙ Fe Ｙ O ３－δ , Pr １－Ｘ Sr Ｘ MnO ３－δ is exemplified.

[0028] The fuel electrode frame 26 is a frame-shaped member that is disposed between the conductive plate 15 or the second separator 29 and the first separator 27, and surrounds the cells 30 and the current collectors 35. The material of the fuel electrode frame 26 is, for example, stainless steel.

[0029] The first separator 27 is a frame-shaped member, and is airtightly joined to the electrolyte 31 by brazing material or the like, avoiding the air electrode 33. The material of the first separator 27 is, for example, stainless steel.

[0030] The cathode frame 28 is a frame-shaped member that is disposed between the first separator 27 and the second separator 29 and surrounds the interconnector 34. The material of the cathode frame 28 is exemplified by an insulator such as mica.

[0031] The second separator 29 is a frame-shaped member, and is airtightly joined to the interconnector 34 by brazing material or the like. The material of the second separator 29 is, for example, stainless steel.

[0032] The current collector 35 electrically connects the interconnectors 34 and the anode 32 adjacent to each other in the thickness direction. The current collector 35 includes, for example, a bent conductor and a spacer such as mica disposed within the conductor. Examples of the conductor material include nickel, a nickel-based alloy, and stainless steel.

[0033] The interconnector 34 electrically connects the current collectors 35 adjacent in the thickness direction to the air electrode 33. The material of the interconnector 34 is, for example, stainless steel.

[0034] A fuel chamber 36 is provided inside the anode frame 26, and an air chamber 37 is provided inside the cathode frame 28. The fuel chamber 36 is connected to the passages 22 and 23 (see FIG. 1), and the air chamber 37 is connected to the passages 24 and 25 through a slit 38. The first separator 27 and the second separator 29 isolate the fuel chamber 36 from the air chamber 37, preventing the fuel gas in the fuel chamber 36 and the oxidizer gas in the air chamber 37 from mixing.

[0035] The first separator 27 has a curved portion 40 that is curved in an arch shape toward the fuel chamber 36, along the entire periphery. The second separator 29 has a curved portion 41 that is curved in an arch shape toward the air chamber 37, along the entire periphery, at a position corresponding to the curved portion 40. The stress buffering portion 39, including the curved portions 40 and 41, is more easily deformed than the portions of the first separator 27 and the second separator 29 other than the stress buffering portion 39. As a result, when the stack 10 is fastened with the bolts 21 (see FIG. 1 ), the stress buffering portion 39 deforms, reducing the force applied to the cells 30 and reducing damage to the cells 30.

[0036] When the stack 10 is a fuel cell, examples of the fuel gas include hydrogen, carbon monoxide, and hydrocarbon, and examples of the oxidant gas include oxygen and air. When the stack 10 is an electrolysis device (the cell 30 is an electrolysis cell having the function of electrolyzing the fuel gas), examples of the fuel gas include water vapor, carbon dioxide, and a mixed gas thereof, and examples of the oxidant gas include oxygen and air. The stack 10 also includes one that is capable of reversible operation as a fuel cell and an electrolysis device.

[0037] The multiple cells 30 are electrically connected in series between terminals 14, 16 via interconnectors 34 and current collectors 35. When the stack 10 is an electrolysis device, the positive electrode of a power supply (not shown) is connected to terminal 14, and the negative electrode of the power supply is connected to terminal 16, causing electrons to flow toward the fuel electrode 32 of the cell 30. The fuel gas that enters the fuel chamber 36 is reduced at the fuel electrode 32. Because electrons are removed at the air electrode 33, oxide ions that have migrated to the air electrode 33 via the electrolyte 31 are oxidized at the air electrode 33. As a result, energy carriers such as hydrogen and hydrocarbons are generated in the fuel chamber 36. The energy carriers generated in the fuel chamber 36 pass through the passage 23 and exit the stack 10.

[0038] If the pressure in the fuel chamber 36 where energy carriers are generated becomes higher than the pressure in the air chamber 37, the cathode frame 28 may deform, and the first separator 27 and the second separator 29 may bend toward the air chamber 37. If the distance between the first separator 27 and the second separator 29 in the air chamber 37 becomes shorter and it becomes difficult for gas to flow through the air chamber 37, the performance of the stack 10 will deteriorate. Furthermore, if the first separator 27 and the second separator 29 bend more, and the first separator 27 and the second separator 29 come into contact inside the air chamber 37, a short circuit will occur.

[0039] When the stack 10 is a fuel cell, when fuel gas is flowed through the fuel chamber 36 and oxidant gas is flowed through the air chamber 37, gas-phase oxygen reacts with electrons at the air electrode 33 of the cell 30 to generate oxide ions, and the oxide ions that have migrated through the electrolyte 31 react with the fuel gas at the anode 32 to generate electrons. This causes a current to flow through a load (not shown) connected to terminals 14 and 16 (see FIG. 1 ). In this case, the air electrode frame 28 also deforms, and the first separator 27 and the second separator 29 each bend toward the air chamber 37. If the distance between the first separator 27 and the second separator 29 in the air chamber 37 becomes shorter, it becomes difficult for gas to flow through the air chamber 37, and the performance of the stack 10 deteriorates.

[0040] In the stack 10, in order to ensure gas flow between the passages 24, 25 connected to the air chamber 37 and the cells 30, an insulator 50 is disposed between the first separator 27 and the second separator 29 of the air chamber 37, and between the passages 24, 25 and the cells 30. In this embodiment, the insulator 50 is disposed in a stress buffering portion 39 provided in the first separator 27 and the second separator 29.

[0041] 3 is a cross-sectional view of the stack 10 taken along line III-III in FIG. 2. The insulator 50 includes a pair of front portions 51 facing the openings of the slits 38 connecting to the passages 24, 25, and a pair of side portions 53 disposed between the front portions 51. In this embodiment, the front portions 51 and the side portions 53 are connected, and the insulator 50 is continuous around the entire periphery of the interconnector 34 and the cells 30 (see FIG. 2). This eliminates the need to separately dispose the front portions 51 and the side portions 53 between the first separator 27 and the second separator 29 when assembling the stack 10, facilitating the work of disposing the insulator 50.

[0042] Grooves 52 (gas passages) are provided in the front portion 51. Therefore, even if the first separator 27 and the second separator 29 come into contact with the front portion 51, gas can pass through the front portion 51, allowing the gas to reach the air electrode 33 (see FIG. 2). The provision of the side portion 53 reduces the amount of gas that passes through the air chamber 37, bypassing the air electrode 33. This ensures the amount of oxidant gas that reacts at the air electrode 33.

[0043] There are no particular limitations on the material of the insulator 50 as long as it has electrical insulating properties. Examples of the material of the insulator 50 include minerals such as mica, glass, ceramics, and ceramic felt formed into a sheet by intertwining inorganic fibers.

[0044] The insulator 50 preferably has a flexural modulus smaller than that of the cathode frame 28. This is because when the stack 10 is fastened with the bolts 21 (see FIG. 1 ), the insulator 50 also deforms in accordance with the bending deformation of the first separator 27 and the second separator 29, thereby reducing the force applied to the cells 30 and reducing damage to the cells 30. Therefore, an insulator 50 that does not interfere with the bending deformation of the first separator 27 and the second separator 29 is preferred. An example of a material for such an insulator 50 is ceramic felt.

[0045] 4(a) is a cross-sectional view of the insulator 50 taken along line IVa-IVa. A plurality of grooves 52 are provided in the front surface portion 51. There are no restrictions on the shape, size, or number of the grooves 52. The grooves 52 are provided so as to ensure the flow of gas even when the first separator 27 or the second separator 29 comes into contact with the front surface portion 51.

[0046] 4(b) is a cross-sectional view of the insulator 54 in the modified example taken along line IVa-IVa (see FIG. 3). The insulator 54 has a front portion 55 that is lower in height than the side portion 53 (see FIG. 3). The entire front portion 55 is a groove 56 (gas passage portion) of the insulator 54. Even when the second separator 29 is deformed so as to contact the front portion 55, gas passes through the gap formed between the corner of the groove 56 and the second separator 29.

[0047] 4(c) is a cross-sectional view of an insulator 57 according to another modification taken along line IVa-IVa (see FIG. 3). The insulator 57 is divided into a front portion 58 and a side portion 53 (see FIG. 3), and the front portion 58 is further divided into multiple portions. Gas passes through gaps 58a (gas passages) formed between the front portions 58. There is no limitation on the number or size of the gaps 58a. Instead of providing gaps 58a between the front portions 58, gas may pass through gaps (gas passages) formed between the front portions 58 and the side portions 53.

[0048] FIG. 4( d ) is a cross-sectional view of an insulator 59 according to another modification taken along line IVa-IVa (see FIG. 3 ). The insulator 59 has holes 61 (gas passages) in its front surface 60, which connect the passages 24 and 25 (see FIG. 3 ) with the cells 30. The holes 61 may be open pores in the insulator 59, or, if the insulator 59 is formed into a sheet by intertwining fibers, the gaps between the fibers may be the holes 61. There are no limitations on the shape, size, or number of the holes 61. The holes 61 are provided so as to ensure gas flow even when the first separator 27 or the second separator 29 contacts the front surface 60.

[0049] 5 is a block diagram of a hydrogen production device 70 including the stack 10. The hydrogen production device 70 is a device that produces hydrogen from water and includes a hot module 71.

[0050] The hot module 71 includes the stack 10, a vaporizer 72 that generates steam to be supplied to the stack 10, a heat exchanger 73 that exchanges heat between the gas supplied to the stack 10 and the gas generated by the stack 10, and a heater 74 that heats the stack 10. In the hot module 71, the stack 10, the vaporizer 72, the heat exchanger 73, and the heater 74 are arranged inside a heat insulating material 75 to reduce heat radiation.

[0051] The vaporizer 72 includes a heat exchanger that exchanges heat with the high-temperature gas containing oxygen produced by the stack 10, and heats water to produce steam. The steam produced by the vaporizer 72 contains hydrogen, which reduces oxidation of the catalyst contained in the anode 32. The hydrogen-containing steam exchanges heat with the hydrogen and oxygen produced by the stack 10 in a heat exchanger 73, is heated to the operating temperature of the stack 10 by a heater 74, and is supplied to the fuel chamber 36 of the stack 10. The air exchanges heat with the hydrogen and oxygen produced by the stack 10 in the heat exchanger 73, is heated to the operating temperature of the stack 10 by a heater 74, and is supplied to the air chamber 37 of the stack 10.

[0052] Examples of the heat insulating material 75 include heat-resistant fibers such as ceramic wool, refractory ceramic fiber (RCF), and biosoluble fiber (AES), and a heat-resistant container made of heat-resistant fibers. The heat-resistant fibers fill gaps between the stack 10, the vaporizer 72, the heat exchanger 73, and the heater 74. The condenser 76 is a device that cools the hydrogen gas, and liquefied water is supplied to the vaporizer 72 as raw water.

[0053] A stack 80 according to a second embodiment will be described with reference to Fig. 6. In the first embodiment, the stack 10 in which the insulator 50 is disposed between the first separator 27 and the second separator 29 is described. In the second embodiment, a stack 80 in which the insulator 50 is disposed between the first separator 27 and the interconnector 82 is described. In the second embodiment, the same parts as those described in the first embodiment are denoted by the same reference numerals, and some of the following description will be omitted.

[0054] Fig. 6 is a cross-sectional view of a stack 80 according to the second embodiment. Similar to Fig. 2, Fig. 6 is a cross-sectional view of the stack 80 taken along line II-II (see Fig. 1) passing through the passages 24 and 25, and shows a part of the laminated body 12. In Fig. 6, the thickness of each part is exaggerated.

[0055] 6, a reaction unit 81 of a stack 80 includes, in order in the thickness direction, an anode frame 26, a first separator 27, a cathode frame 28, and an interconnector 82. Inside the anode frame 26, the first separator 27, and the cathode frame 28, a cell 30 and a current collector 35 are arranged.

[0056] The interconnector 82 includes a connection portion 83 interposed between the air electrode 33 and the current collector 35 adjacent to each other in the thickness direction, and an overhanging portion 84 overhanging from the periphery of the connection portion 83. The connection portion 83 electrically connects the air electrode 33 and the current collector 35. The thickness of the overhanging portion 84 is smaller than the thickness of the connection portion 83 and larger than the thickness of the first separator 27.

[0057] The entire periphery of the extension 84 is sandwiched between the fuel electrode frame 26 and the air electrode frame 28. Holes (passages 22-25) penetrate the fuel electrode frame 26, the first separator 27, the air electrode frame 28, and the interconnector 82 (extension 84).

[0058] The insulator 50 is disposed between the first separator 27 and the inside of the portion of the overhanging portion 84 that is sandwiched between the fuel electrode frame 26 and the air electrode frame 28. The insulator 50 reduces the deflection of the first separator 27 that deforms toward the air chamber 37, so as in the first embodiment, the flow of gas in the air chamber 37 is ensured and the occurrence of a short circuit between the first separator 27 and the interconnector 82 (overhanging portion 84) can be reduced.

[0059] As in the first embodiment, the stack 80 can be provided with insulators 54, 57, and 59 instead of the insulator 50. Furthermore, the stack 80 can be provided instead of the stack 10 that constitutes the hydrogen production device 70 or the hot module 71.

[0060] The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and it can be easily inferred that various improvements and modifications are possible within the scope of the present invention.

[0061] In the embodiment, the insulators 50, 54, 57, and 59 include the side surface portions 53, but this is not necessarily limited to this. It is of course possible to omit the side surface portions 53 of the insulators 50, 54, 57, and 59 and arrange only the front surface portions 51, 55, 58, and 60 in the air chamber 37. In this case, too, the flow of gas between the passages 24 and 25 and the cell 30 can be ensured.

[0062] In the embodiment, the insulators 50, 54, 57, and 59 are disposed inside the stress buffering section 39, but this is not necessarily limited to this. If the width of the insulators 50, 54, 57, and 59 is wide, some of the insulators 50, 54, 57, and 59 are disposed inside the stress buffering section 39, and the rest are disposed outside the stress buffering section 39.

[0063] In the first embodiment, the first separator 27 and the second separator 29 include the stress buffering portion 39, but this is not necessarily limited to this. It is of course possible to omit the stress buffering portion 39 of the second separator 29 or to omit the stress buffering portion 39 of the first separator 27 and the second separator 29.

[0064] In the embodiment, the case where the shape of the cells 30 is a rectangle has been described, but this is not necessarily limited to this. The shape of the cells 30 may be a circle or an ellipse, or may be a polygon other than a rectangle, such as a triangle or a pentagon.

[0065] In the embodiment, the gas passages 22, 23, 24, and 25 are built into the stacks 10 and 80, but this is not necessarily limited to this. It is of course possible to provide manifolds serving as the gas passages 22, 23, 24, and 25 outside the cells by joining them to the cells. Examples of materials for the manifolds include ceramics with high high-temperature strength.

[0066] In the embodiments, the stacks 10 and 80 including the solid oxide type cells 30 have been described, but this is not necessarily limited to this. It is of course possible to apply the technology according to the embodiments to stacks including other types of cells, such as molten carbonate type cells.

[0067] 10, 80 Stack 24, 25 Passage 27 First separator 28 Air electrode frame (frame) 29 Second separator 30 Cell 31 Electrolyte 32 Fuel electrode 33 Air electrode 34, 82 Interconnector 37 Air chamber (space) 39 Stress buffer 50, 54, 57, 59 Insulator 52, 56 Groove (gas passage) 58a Gap (gas passage) 61 Hole (gas passage) 70 Hydrogen production device 71 Hot module 72 Vaporizer 73 Heat exchanger 74 Heater 75 Heat insulator

Claims

1. A cell containing an electrolyte that separates the fuel electrode and the air electrode in the thickness direction, A first separator fixed to the cell and extending outwards from the outer circumference of the cell, The interconnector in contact with the aforementioned air electrode, A second separator is fixed to the interconnect and extends outwards from the outer circumference of the interconnect, An electrically insulating frame disposed between the first separator and the second separator in the thickness direction, The first separator, the frame, and the gas passage extending in the thickness direction of the second separator are provided, The passage is a stack that connects to the space between the first separator and the second separator, The space includes an insulator disposed between the passage and the cell, The space in which the insulator is arranged includes a gas passage through which the gas passes between the passage and the cell. A stack in which the bending modulus of the insulator is smaller than that of the frame.

2. A cell containing an electrolyte that separates the fuel electrode and the air electrode in the thickness direction, A first separator fixed to the cell and extending outwards from the outer circumference of the cell, The interconnector in contact with the aforementioned air electrode, An electrically insulating frame disposed between the first separator and the interconnect in the thickness direction, The interconnect comprises the first separator, the frame, and a gas passage extending in the thickness direction of the interconnect, The passage is a stack that connects to the space between the first separator and the interconnector, The space includes an insulator disposed between the passage and the cell, The space in which the insulator is arranged includes a gas passage through which the gas passes between the passage and the cell. A stack in which the bending modulus of the insulator is smaller than that of the frame.

3. A cell containing an electrolyte that separates the fuel electrode and the air electrode in the thickness direction, A first separator fixed to the cell and extending outwards from the outer circumference of the cell, The interconnector in contact with the aforementioned air electrode, A second separator is fixed to the interconnect and extends outwards from the outer circumference of the interconnect, An electrically insulating frame disposed between the first separator and the second separator in the thickness direction, The first separator, the frame, and the gas passage extending in the thickness direction of the second separator are provided, The passage is a stack that connects to the space between the first separator and the second separator, The space includes an insulator disposed between the passage and the cell, The space in which the insulator is arranged includes a gas passage through which the gas passes between the passage and the cell. The gas passage portion is a stack provided on the insulator.

4. A cell containing an electrolyte that separates the fuel electrode and the air electrode in the thickness direction, A first separator fixed to the cell and extending outwards from the outer circumference of the cell, The interconnector in contact with the aforementioned air electrode, An electrically insulating frame disposed between the first separator and the interconnect in the thickness direction, The interconnect comprises the first separator, the frame, and a gas passage extending in the thickness direction of the interconnect, The passage is a stack that connects to the space between the first separator and the interconnector, The space includes an insulator disposed between the passage and the cell, The space in which the insulator is arranged includes a gas passage through which the gas passes between the passage and the cell. The gas passage portion is a stack provided on the insulator.

5. A cell containing an electrolyte that separates the fuel electrode and the air electrode in the thickness direction, A first separator fixed to the cell and extending outwards from the outer circumference of the cell, The interconnector in contact with the aforementioned air electrode, A second separator is fixed to the interconnect and extends outwards from the outer circumference of the interconnect, An electrically insulating frame disposed between the first separator and the second separator in the thickness direction, The first separator, the frame, and the gas passage extending in the thickness direction of the second separator are provided, The passage is a stack that connects to the space between the first separator and the second separator, The space includes an insulator disposed between the passage and the cell, The space in which the insulator is arranged includes a gas passage through which the gas passes between the passage and the cell. The insulator is a stack that is continuous around the entire circumference of the cell.

6. A cell containing an electrolyte that separates the fuel electrode and the air electrode in the thickness direction, A first separator fixed to the cell and extending outwards from the outer circumference of the cell, The interconnector in contact with the aforementioned air electrode, An electrically insulating frame disposed between the first separator and the interconnect in the thickness direction, The interconnect comprises the first separator, the frame, and a gas passage extending in the thickness direction of the interconnect, The passage is a stack that connects to the space between the first separator and the interconnector, The space includes an insulator disposed between the passage and the cell, The space in which the insulator is arranged includes a gas passage through which the gas passes between the passage and the cell. The insulator is a stack that is continuous around the entire circumference of the cell.

7. The stack according to any one of claims 3 to 6, wherein the bending modulus of the insulator is smaller than the bending modulus of the frame.

8. The stack according to claim 7, wherein the material of the insulator is ceramic felt.

9. The stack according to any one of claims 1 to 6, wherein the gas passage portion includes a groove provided in the insulator.

10. The first separator and the second separator include stress buffer portions that are curved in the same direction in the thickness direction within the space, The stack according to any one of claims 1, 3, or 5, wherein the insulator is disposed in the stress buffer portion.

11. The stack according to any one of claims 1 to 4, wherein the insulator is continuous around the entire circumference of the cell.

12. The stack according to any one of claims 1 to 6, wherein the cell has the function of electrolyzing fuel gas.

13. The stack according to claim 12, A vaporizer that generates water vapor, which is the fuel gas, A heat exchanger that performs heat exchange with the gas supplied to the stack, A heater for heating the aforementioned stack, A hot module comprising the stack, the vaporizer, the heat exchanger, and the heater, and an insulating material in which these are arranged.

14. A hydrogen production apparatus comprising the hot module described in claim 13.