Gas distribution container and metal-supported electrochemical cell

Abstract

A gas distribution container (3) comprises: a metal support body (10); an interconnector (20); a first gas flow path member (30) that is positioned in a gas distribution space (3a) between the metal support body (10) and the interconnector (20), and that forms a raw material gas flow path (32); and a first non-vitreous bonding part (C1) that is constituted by a non-vitreous material, and bonds the metal support body (10) and the first gas flow path member (30).

Description

Gas flow container and metal-supported electrochemical cell

[0001] The present invention relates to a gas flow container and a metal-supported electrochemical cell.

[0002] Patent Document 1 discloses a metal-supported fuel cell that includes a gas flow container and a cell body disposed on the gas flow container.

[0003] The gas flow container is composed of a metal support, an interconnector, and a spacer. The spacer is inserted between the metal support and the interconnector, thereby forming a gas flow space between the metal support and the interconnector. A gas flow path connected to the gas flow space is formed in the spacer. The metal support, the interconnector, and the spacer are joined to each other by welding.

[0004] JP 2017-508254 A

[0005] To increase the degree of freedom in designing the gas flow path, it is desirable to provide a gas flow path member separate from the spacer. However, if welding is used to join the gas flow path member, the gas flow path member will deform due to heat input during welding, making it impossible to form a gas flow path with a desired shape. Furthermore, if a vitreous joint is used to join the gas flow path member, the vitreous material softened during firing will protrude into the gas flow path, making it impossible to form a gas flow path with a desired shape.

[0006] An object of the present invention is to provide a gas flow container and a metal-supported electrochemical cell that are capable of forming a gas flow path of a desired shape.

[0007] A gas flow container according to a first aspect of the present invention includes a first metal member, a second metal member, a gas flow path member that is disposed in a gas flow space between the first metal member and the second metal member and that forms a gas flow path, and a non-vitreous joining portion that is made of a non-vitreous material and that joins the first metal member and the gas flow path member.

[0008] A gas flow container according to a second aspect of the present invention is related to the first aspect, wherein the non-vitreous bonding portion is made of an oxide containing chromium as a main component.

[0009] A gas flow container according to a third aspect of the present invention is related to the second aspect, wherein the non-vitreous joint has a first layer disposed on the first metal member and a second layer disposed between the first layer and the second metal member, and the oxide constituting the second layer is different from the oxide constituting the first layer.

[0010] A gas flow container according to a fourth aspect of the present invention is related to the third aspect, wherein the non-vitreous joining portion has a third layer sandwiched between the second layer and the second alloy member, and the oxide constituting the third layer is the same as the oxide constituting the first layer.

[0011] A gas flow container according to a fifth aspect of the present invention is related to any one of the first to fourth aspects, wherein the non-vitreous joint portion has metal particles at least partially embedded in the non-vitreous material.

[0012] A gas flow container according to a sixth aspect of the present invention is related to any one of the first to fifth aspects and includes a metal connecting portion surrounded by the non-vitreous joining portion and connecting the first metal member and the second metal member.

[0013] A gas flow container according to a seventh aspect of the present invention is the gas flow container according to any one of the first to sixth aspects, wherein the non-vitreous joint portion has an internal void.

[0014] A metal-supported electrochemical cell according to an eighth aspect of the present invention includes the gas flow container according to any one of the first to seventh aspects and a cell main body disposed on the first metal member or the second metal member. The metal member on which the cell main body is disposed, either the first metal member or the second metal member, has a plurality of communication holes that connect to the gas flow space. The cell main body covers the plurality of communication holes.

[0015] According to the present invention, it is possible to provide a gas flow container and a metal-supported electrochemical cell that are capable of forming a gas flow path of a desired shape.

[0016] FIG. 1 is a plan view of an electrolysis cell according to an embodiment. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is an exploded perspective view showing the configuration of a gas flow container according to an embodiment. FIG. 4 is a schematic view showing an example of a cross section of a first non-vitreous joint according to an embodiment. FIG. 5 is a schematic view showing an example of a cross section of a first non-vitreous joint according to an embodiment. FIG. 6 is a schematic view showing an example of a cross section of a first non-vitreous joint according to an embodiment. FIG. 7 is a schematic view showing an example of a cross section of a first non-vitreous joint according to an embodiment.

[0017] (Electrolytic cell 1) Fig. 1 is a plan view of an electrolytic cell 1 according to an embodiment. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1.

[0018] The electrolysis cell 1 is an example of a "metal-supported electrochemical cell" according to the present invention.

[0019] The electrolytic cell 1 is formed in a plate shape extending in the X-axis and Y-axis directions. In the present embodiment, the electrolytic cell 1 is formed in a substantially rectangular shape extending in the Y-axis direction when viewed in a plan view from the Z-axis direction perpendicular to the X-axis and Y-axis directions. However, the planar shape of the electrolytic cell 1 is not particularly limited, and may be a polygon other than a rectangle, an ellipse, a circle, or the like.

[0020] As shown in FIGS. 1 and 2, the electrolysis cell 1 includes a cell body 2 and a gas flow container 3 .

[0021] (Cell main body 2) The cell main body 2 is placed on the gas flow container 3. The cell main body 2 is supported by a metal support 10 (described later) in the gas flow container 3. The cell main body 2 has a hydrogen electrode layer 6 (cathode), an electrolyte layer 7, a reaction prevention layer 8, and an oxygen electrode layer 9 (anode).

[0022] The hydrogen electrode layer 6, electrolyte layer 7, reaction prevention layer 8, and oxygen electrode layer 9 are stacked in this order in the Z-axis direction from the gas flow container 3 side. The hydrogen electrode layer 6, electrolyte layer 7, and oxygen electrode layer 9 are essential components, while the reaction prevention layer 8 is optional.

[0023] [Hydrogen Electrode Layer 6 ] The hydrogen electrode layer 6 is disposed on the first main surface 12 of the metal support 10 .

[0024] The hydrogen electrode layer 6 is supplied with a source gas through each of the communication holes 11 of the metal support 10. The source gas contains at least H ２ Contains O.

[0025] The raw material gas is H ２ When only O is contained, the hydrogen electrode layer 6 converts H from the raw material gas according to the electrochemical reaction of water electrolysis shown in the following formula (1): ２ Generate.

[0026] Hydrogen electrode layer 6: H ２ O + 2e － →H ２ +O ２－ ... (1) The raw material gas is H ２ O plus CO ２ In this case, the hydrogen electrode layer 6 converts H from the source gas according to the co-electrolytic electrochemical reactions shown in the following formulas (2), (3), and (4). ２ , CO and O ２－ Generate.

[0027] Hydrogen electrode layer 6: CO ２ +H ２ O+4e － →CO+H ２ +20 ２－ ... (2) H ２ Electrochemical reaction of O: H ２ O + 2e － →H ２ +O ２－ ... (3) CO ２ Electrochemical reaction of: CO ２ +2e － →CO+O ２－ ...(4) The hydrogen electrode layer 6 contains a conductive material. As the conductive material, a metal material such as Ni (nickel) or Fe (iron), or a conductive ceramic material can be used. In the case of co-electrolysis, Ni is used as the catalyst for the generated H ２ and CO contained in the raw material gas ２ It also functions as a thermal catalyst, promoting the thermal reaction with HCl to maintain an appropriate gas composition for methanation and reverse water-gas shift reactions.

[0028] The hydrogen electrode layer 6 includes an oxide ion conductive material, such as YSZ, CSZ, ScSZ, GDC, SDC, and (La, Sr)(Cr, Mn)O. ３ , (La,Sr)TiO ３ , Sr ２ (Fe, Mo) ２ O ６ , (La, Sr)VO ３ , (La,Sr)FeO ３ , LDC, LSGM, and a mixed material of two or more of these can be used.

[0029] In this embodiment, the hydrogen electrode layer 6 has a single-layer structure made of a single composition, but may have a multi-layer structure made of different compositions.

[0030] The porosity of the hydrogen electrode layer 6 is not particularly limited, but may be, for example, 5% to 70%. The thickness of the hydrogen electrode layer 6 is not particularly limited, but may be, for example, 1 μm to 500 μm.

[0031] The method for forming the hydrogen electrode layer 6 is not particularly limited, and may be a firing method, a spray coating method (such as a thermal spraying method, an aerosol deposition method, an aerosol gas deposition method, a powder jet deposition method, a particle jet deposition method, or a cold spray method), a PVD method (such as a sputtering method or a pulsed laser deposition method), or a CVD method.

[0032] [Electrolyte Layer 7] The electrolyte layer 7 is disposed between the hydrogen electrode layer 6 and the oxygen electrode layer 9. In this embodiment, the reaction prevention layer 8 is disposed between the electrolyte layer 7 and the oxygen electrode layer 9, and therefore the electrolyte layer 7 is sandwiched between the hydrogen electrode layer 6 and the reaction prevention layer 8.

[0033] The electrolyte layer 7 covers the hydrogen electrode layer 6 and also covers the region of the first main surface 12 of the metal support 10 that is exposed from the hydrogen electrode layer 6 .

[0034] The electrolyte layer 7 absorbs the O generated in the hydrogen electrode layer 6. ２－The electrolyte layer 7 is made of a dense material having oxide ion conductivity. The electrolyte layer 7 can be made of, for example, YSZ (yttria-stabilized zirconia, e.g., 8YSZ), GDC (gadolinium-doped ceria), ScSZ (scandia-stabilized zirconia), SDC (samarium-doped ceria), or LSGM (lanthanum gallate).

[0035] The porosity of the electrolyte layer 7 is not particularly limited, but may be, for example, 0.1% to 7%. The thickness of the electrolyte layer 7 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0036] The method for forming the electrolyte layer 7 is not particularly limited, and may be a baking method, a spray coating method, a PVD method, a CVD method, or the like.

[0037] [Reaction prevention layer 8] The reaction prevention layer 8 is disposed between the electrolyte layer 7 and the oxygen electrode layer 9. The reaction prevention layer 8 is disposed on the opposite side of the electrolyte layer 7 from the hydrogen electrode layer 6. The reaction prevention layer 8 prevents the constituent elements of the electrolyte layer 7 from reacting with the constituent elements of the oxygen electrode layer 9 to form a layer with high electrical resistance.

[0038] The reaction prevention layer 8 is made of an oxide ion conductive material, such as GDC or SDC.

[0039] The porosity of the reaction prevention layer 8 is not particularly limited, but may be, for example, 0.1% to 50%. The thickness of the reaction prevention layer 8 is not particularly limited, but may be, for example, 1 μm to 50 μm.

[0040] The method for forming the reaction prevention layer 8 is not particularly limited, and may be a baking method, a spray coating method, a PVD method, a CVD method, or the like.

[0041] [Oxygen Electrode Layer 9] The oxygen electrode layer 9 is disposed on the opposite side of the electrolyte layer 7 from the hydrogen electrode layer 6. In this embodiment, the reaction prevention layer 8 is disposed between the electrolyte layer 7 and the oxygen electrode layer 9, and therefore the oxygen electrode layer 9 is connected to the reaction prevention layer 8. If the reaction prevention layer 8 is not disposed between the electrolyte layer 7 and the oxygen electrode layer 9, the oxygen electrode layer 9 is connected to the electrolyte layer 7.

[0042] The oxygen electrode layer 9 reacts with O transferred from the hydrogen electrode layer 6 through the electrolyte layer 7 in accordance with the chemical reaction of the following formula (5): ２－ From O ２ Generate.

[0043] Oxygen electrode layer 9: 2O ２－ →O ２ +4e － ...(5) The oxygen electrode layer 9 is a porous body having oxide ion conductivity and electrical conductivity. The oxygen electrode layer 9 is, for example, (La, Sr)(Co, Fe)O ３ , (La,Sr)FeO ３ , La(Ni,Fe)O ３ , (La,Sr)CoO ３ , and (Sm,Sr)CoO ３ and an oxide ion conductive material (such as GDC).

[0044] The porosity of the oxygen electrode layer 9 is not particularly limited, but may be, for example, 20% to 60%. The thickness of the oxygen electrode layer 9 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0045] The method for forming the oxygen electrode layer 9 is not particularly limited, and may be a firing method, a spray coating method, a PVD method, a CVD method, or the like.

[0046] (Gas Flow Container 3) The gas flow container 3 supports the cell main body 2. The gas flow container 3 is used for supplying and discharging gas to and from the hydrogen electrode layer 6. The gas flow container 3 supplies raw material gas to the hydrogen electrode layer 6. The gas flow container 3 is used for discharging H generated in the hydrogen electrode layer 6. ２ The remaining raw material gas (hereinafter collectively referred to as "exhaust gas") that has not been consumed in the hydrogen electrode layer 6 is discharged to the outside.

[0047] 3 is an exploded perspective view showing the configuration of the gas flow container 3. The configuration of the gas flow container 3 will be described below with reference to FIGS.

[0048] The gas flow container 3 includes a gas flow space 3a, a metal support 10, an interconnector 20, a first gas flow path member 30, and a second gas flow path member 40. In this embodiment, one of the metal support 10 and the frame 21 is an example of the "first metal member" according to the present invention, and the other is an example of the "second metal member" according to the present invention.

[0049] [Gas Distribution Space 3a] The gas distribution space 3a is a space between the metal support 10 and the interconnector 20. Gases supplied to and exhausted from the hydrogen electrode layer 6 flow through the gas distribution space 3a. A raw material gas is supplied to the gas distribution space 3a. H generated in the hydrogen electrode layer 6 ２ The remaining raw material gas that has not been consumed in the hydrogen electrode layer 6 is discharged from the gas flow space 3a.

[0050] [Metal Support 10] The metal support 10 supports the cell main body 2. In this embodiment, the metal support 10 is formed in a plate shape. The metal support 10 may be in a flat plate shape or a curved plate shape.

[0051] The metal support 10 is only required to be able to support the cell body 2, and its thickness is not particularly limited, but can be, for example, 0.1 mm or more and 2.0 mm or less.

[0052] The metal support 10 has a plurality of communication holes 11 , a first main surface 12 and a second main surface 13 .

[0053] Each communication hole 11 penetrates the metal support 10 from the first main surface 12 to the second main surface 13. Each communication hole 11 opens to the first main surface 12 and the second main surface 13. Each communication hole 11 is covered by the cell main body 2. Specifically, the opening of each communication hole 11 on the first main surface 12 side is covered by the hydrogen electrode layer 6. The opening of each communication hole 11 on the second main surface 13 side is connected to the gas flow space 3 a.

[0054] Each of the communication holes 11 can be formed by mechanical processing (for example, punching), laser processing, or chemical processing (for example, etching).

[0055] In this embodiment, each communication hole 11 is formed linearly along the Z-axis direction. However, each communication hole 11 may be inclined with respect to the Z-axis direction or may not be linear. Furthermore, the communication holes 11 may be connected to each other.

[0056] The first main surface 12 is provided on the opposite side to the second main surface 13. The cell body 2 is disposed on the first main surface 12. An interconnector 20 is joined to the second main surface 13.

[0057] The metal support 10 has raw material gas flow holes 15 and exhaust gas flow holes 16 .

[0058] The raw material gas circulation holes 15 penetrate the metal support 10 from the first main surface 12 to the second main surface 13. The raw material gas circulation holes 15 open to both the first main surface 12 and the second main surface 13. The opening of the raw material gas circulation hole 15 on the first main surface 12 side is connected to a raw material gas circulation hole 26 of an interconnector 20 of another electrolysis cell 1 (not shown). The opening of the raw material gas circulation hole 15 on the second main surface 13 side is connected to a raw material gas circulation hole 31 of a first gas flow path member 30 (described later).

[0059] The exhaust gas flow hole 16 penetrates the metal support 10 from the first main surface 12 to the second main surface 13. The exhaust gas flow hole 16 opens to both the first main surface 12 and the second main surface 13. The opening of the exhaust gas flow hole 16 on the first main surface 12 side is connected to an exhaust gas flow hole 27 of an interconnector 20 of another electrolysis cell 1 (not shown). The opening of the exhaust gas flow hole 16 on the second main surface 13 side is connected to an exhaust gas flow hole 41 of a second gas flow path member 40 (described later).

[0060] The metal support 10 is made of a metal material. For example, the metal support 10 can be made of an alloy material containing Cr (chromium). Examples of such metal materials include Fe—Cr alloy steel (stainless steel, etc.) and Ni—Cr alloy steel. The Cr content in the metal support 10 is not particularly limited, but can be set to 4 mass % or more and 30 mass % or less.

[0061] The metal support 10 may contain Ti (titanium) or Zr (zirconium). The Ti content in the metal support 10 is not particularly limited, but may be 0.01 mol % or more and 1.0 mol % or less. The Zr content in the metal support 10 is not particularly limited, but may be 0.01 mol % or more and 0.4 mol % or less. The metal support 10 may contain Ti in the form of TiO ２ (titania), or Zr may be contained as ZrO ２ It may be contained as (zirconia).

[0062] [Interconnector 20] The interconnector 20 is joined to the metal support 10. The interconnector 20 may be welded to the metal support 10 or brazed to the metal support 10. Alternatively, the interconnector 20 may be joined to the metal support 10 via a joint made of a non-glassy material described later.

[0063] The interconnector 20 is made of a metal material. For example, the interconnector 20 can be made of the above-mentioned alloy material. The material composition of the interconnector 20 may be the same as or different from the material composition of the metal support 10.

[0064] The interconnector 20 has a frame portion 21 and a plate-like portion 22. In this embodiment, the frame portion 21 and the plate-like portion 22 are separate members.

[0065] The frame portion 21 is formed in an annular shape. The frame portion 21 is disposed on the outer edge of the plate-like portion 22. The frame portion 21 functions as a spacer for forming the gas flow space 3 a. The thickness of the frame portion 21 is not particularly limited, but may be, for example, 0.1 mm or more and 2.0 mm or less.

[0066] The plate-shaped portion 22 is disposed on the opposite side of the metal support 10 with respect to the frame portion 21. The plate-shaped portion 22 is an electrical connection member for electrically connecting the electrolytic cell 1 to another electrolytic cell or an external power source. The plate-shaped portion 22 is formed in a plate shape. The plate-shaped portion 22 may be in the shape of a flat plate or a curved plate. The thickness of the plate-shaped portion 22 is not particularly limited, but may be, for example, 0.1 mm or more and 2.0 mm or less.

[0067] The plate-like portion 22 has a first main surface 23 and a second main surface 24. The first main surface 23 faces the second main surface 13 of the metal support 10. The second main surface 24 is provided on the opposite side of the first main surface 23.

[0068] The plate-like portion 22 has a raw material gas circulation hole 26 and an exhaust gas circulation hole 27 .

[0069] The raw material gas circulation holes 26 penetrate the plate-shaped portion 22 from the first main surface 23 to the second main surface 24. The opening of the raw material gas circulation hole 26 on the first main surface 23 side communicates with the raw material gas circulation hole 31 of the first gas flow path member 30 described below. The opening of the raw material gas circulation hole 26 on the second main surface 24 side communicates with the raw material gas circulation hole 15 of the metal support 10 of another electrolysis cell 1 (not shown).

[0070] The exhaust gas circulation hole 27 penetrates the plate-shaped portion 22 from the first main surface 23 to the second main surface 24. The exhaust gas circulation hole 27 opens to both the first main surface 23 and the second main surface 24. The opening of the exhaust gas circulation hole 27 on the first main surface 23 side communicates with an exhaust gas circulation hole 41 of a second gas flow path member 40, which will be described later. The opening of the exhaust gas circulation hole 27 on the second main surface 24 side communicates with an exhaust gas circulation hole 16 of a metal support 10 of another electrolysis cell 1, not shown.

[0071] [First gas flow path member 30 and second gas flow path member 40] The first gas flow path member 30 and the second gas flow path member 40 are each disposed in the gas flow space 3a. The first gas flow path member 30 and the second gas flow path member 40 are each members for forming a gas flow path. The first gas flow path member 30 and the second gas flow path member 40 are each sandwiched between the metal support 10 and the plate-like portion 22 of the interconnector 20. The first gas flow path member 30 and the second gas flow path member 40 are each separate members separated from the frame portion 21 of the interconnector 20.

[0072] The first gas flow path member 30 and the second gas flow path member 40 are each formed in a plate shape. In this embodiment, each of the first gas flow path member 30 and the second gas flow path member 40 is formed of a single plate-shaped member. However, each of the first gas flow path member 30 and the second gas flow path member 40 may be formed of two or more plate-shaped members. Furthermore, the shape and size of the plate-shaped members forming each of the first gas flow path member 30 and the second gas flow path member 40 can be changed as appropriate.

[0073] The first gas flow path member 30 forms a raw material gas flow path 32 between itself and the interconnector 20. The raw material gas flow path 32 is a gap between the first gas flow path member 30 and the frame 21 of the interconnector 20 in the planar direction. Because the first gas flow path member 30 is a member separate from the frame 21 of the interconnector 20, the design flexibility of the raw material gas flow path 32 can be increased. In this embodiment, the raw material gas flow path 32 is U-shaped in a planar view, but the shape, size, and position of the raw material gas flow path 32 can be changed as appropriate. A portion of the raw material gas flowing in from the raw material gas flow holes 26 of the interconnector 20 flows from the raw material gas flow path 32 to the gas flow space 3 a. The remainder of the raw material gas flowing in from the raw material gas flow holes 26 of the interconnector 20 flows to the raw material gas flow holes 15 of the metal support 10.

[0074] The second gas flow path member 40 forms an exhaust gas flow path 42 between itself and the interconnector 20. The exhaust gas flow path 42 is a gap in the planar direction between the second gas flow path member 40 and the frame portion 21 of the interconnector 20. Because the second gas flow path member 40 is a member separate from the frame portion 21 of the interconnector 20, the design freedom of the exhaust gas flow path 42 can be increased. In this embodiment, the exhaust gas flow path 42 is U-shaped in a planar view, but the shape, size, and position of the exhaust gas flow path 42 can be changed as appropriate. The exhaust gas flowing out from the exhaust gas flow path 42 flows into the exhaust gas flow holes 27 of the interconnector 20 together with the exhaust gas from the exhaust gas flow holes 16 of the metal support 10.

[0075] 2, the first gas flow path member 30 is joined to the metal support 10 via a first non-vitreous joint C1 and to the interconnector 20 via a second non-vitreous joint C2. The second gas flow path member 40 is joined to the metal support 10 via a third non-vitreous joint C3 and to the interconnector 20 via a fourth non-vitreous joint C4.

[0076] The first non-vitreous joint C1 joins the metal support 10 and the first gas flow path member 30. The second non-vitreous joint C2 joins the interconnector 20 and the first gas flow path member 30. The third non-vitreous joint C3 joins the metal support 10 and the first gas flow path member 30. The fourth non-vitreous joint C4 joins the interconnector 20 and the first gas flow path member 30.

[0077] Each of the first to fourth non-vitreous joints C1 to C4 is an example of a "non-vitreous joint" according to the present invention. In this embodiment, the first to fourth non-vitreous joints C1 to C4 have similar configurations. Therefore, the following description will discuss the preferred configuration of each non-vitreous joint C, using the first non-vitreous joint C1 as a representative example.

[0078] [First Non-vitreous Joint C1] (1) Constituent Material The first non-vitreous joint C1 is made of a non-vitreous material. The non-vitreous material means a material that does not substantially contain glass elements such as boron (element B) or silicon (element Si).

[0079] Because the first non-vitreous joint C1 is made of a non-vitreous material, deformation of the first gas flow path member 30 due to heat input can be suppressed compared to when the first gas flow path member 30 is welded to the metal support 10. Furthermore, because the first non-vitreous joint C1 is made of a non-vitreous material, protrusion of the first non-vitreous joint C1 into the source gas flow hole 31 and the source gas flow path 32 can be suppressed compared to when the first gas flow path member 30 is joined to the metal support 10 using a vitreous joint. Therefore, deformation of the source gas flow hole 31 and the source gas flow path 32 can be suppressed, and the source gas flow hole 31 and the source gas flow path 32 can be maintained in a desired shape.

[0080] Furthermore, since the first non-vitreous joint C1 is substantially free of vitreous matter, the chemical stability of the first non-vitreous joint C1 against reducing gases and water vapor can be improved, and thermal degradation of the first non-vitreous joint C1 can be suppressed compared to when the first non-vitreous joint C1 contains vitreous matter.

[0081] In this embodiment, being substantially free of glassy substances means that when the content of glassy substances such as boron and silicon is measured using an energy dispersive spectroscopy (EDS) device, the content of each element is below the detection limit or 1 mol% or less.

[0082] The first non-vitreous joint C1 is preferably made of an oxide primarily composed of chromium (Cr) (hereinafter referred to as "Cr oxide"). This prevents Cr from diffusing from the metal support 10 to the first non-vitreous joint C1 during the manufacture or operation of the electrolysis cell 1. Even if Cr diffuses from the metal support 10 to the first non-vitreous joint C1, the effect on the composition of the first non-vitreous joint C1 is minimal, preventing a decrease in the strength of the first non-vitreous joint C1. Furthermore, the Cr content of both the metal support 10 and the first non-vitreous joint C1 improves their bondability. Therefore, the bondability between the metal support 10 and the first gas flow path member 30 can be maintained over a long period of time.

[0083] In this embodiment, "Cr is the main component" means that, when the composition of the first non-vitreous joint C1 is analyzed by an energy dispersive spectroscopy (EDS) device, the Cr content is the highest among all metal elements. The Cr content in the first non-vitreous joint C1 is not particularly limited, but may be, for example, 20 mol % to 100 mol %.

[0084] The Cr content in the first non-vitreous bonding portion C1 is preferably 50 mol % or more, which significantly prevents Cr contained in the metal support 10 from diffusing into the first non-vitreous bonding portion C1.

[0085] The Cr oxide constituting the first non-vitreous joint C1 is preferably composed of at least one of chromium oxide and chromium-manganese oxide, which have the property of making Cr particularly difficult to diffuse, thereby improving the durability of the first non-vitreous joint C1.

[0086] Chromium oxides include Cr ２ O ３ Examples of chromium manganese oxide include MnCr ２ O ４ (Spinel), Mn １，５ Cr １，５ O ４ (Spinel), etc.

[0087] The Cr oxide constituting the first non-vitreous joint C1 is preferably crystalline, which can prevent the first non-vitreous joint C1 from being damaged due to a phase transition of the Cr oxide from amorphous to crystalline even when the electrolysis cell 1 is operated for a long period of time.

[0088] The Cr oxide constituting the first non-vitreous bonding portion C1 preferably has a spinel or corundum crystal structure, which has high symmetry and can improve the thermal stress resistance of the first non-vitreous bonding portion C1.

[0089] (2) Multilayer Structure Fig. 4 is a schematic diagram showing an example of a cross section of the first non-vitreous joint C1. Fig. 4 shows a cross section of the first non-vitreous joint C1 along the thickness direction. The thickness direction is the direction perpendicular to the first main surface 12 of the metal support 10.

[0090] As shown in Figure 4, the first non-vitreous joint C1 preferably has a multi-layer structure, which means a structure of two or more layers in which layers of different constituent materials are stacked adjacent to each other.

[0091] In the example shown in FIG. 4, the first non-vitreous bonding portion C1 has a three-layer structure made up of a first layer 1A, a second layer 2A, and a third layer 3A.

[0092] The first layer 1A is disposed on a metal support 10. The first layer 1A is sandwiched between the metal support 10 and a second layer 2A. In this embodiment, the first layer 1A is made of chromium oxide.

[0093] The second layer 2A is disposed between the first layer 1A and the first gas flow path member 30. The second layer 2A is sandwiched between the first layer 1A and the third layer 3A.

[0094] The oxide constituting the second layer 2A is preferably different from the oxide constituting the first layer 1A. This makes it possible to stop cracks that attempt to propagate from the first layer 1A toward the second layer 2A, or from the second layer 2A toward the first layer 1A, at the interface between the first layer 1A and the second layer 2A. In this embodiment, the second layer 2A is composed of chromium manganese oxide.

[0095] The third layer 3A is disposed on the first gas flow path member 30. The third layer 3A is sandwiched between the second layer 2A and the first gas flow path member 30. The oxide constituting the third layer 3A is preferably different from the oxide constituting the second layer 2A. This makes it possible to stop cracks that attempt to propagate from the second layer 2A toward the third layer 3A, or from the third layer 3A toward the second layer 2A, at the interface between the second layer 2A and the third layer 3A. In this embodiment, the third layer 3A is made of chromium oxide.

[0096] The oxide constituting the third layer 3A is preferably the same as the oxide constituting the first layer 1A, which makes the first non-vitreous bonding portion C1 symmetrical as a whole in the thickness direction, thereby improving the mechanical reliability of the first non-vitreous bonding portion C1.

[0097] The thickness of the first layer 1A is not particularly limited, but may be, for example, 0.1 μm or more and 100 μm or less. The thickness of the second layer 2A is not particularly limited, but may be, for example, 0.1 μm or more and 100 μm or less. The thickness of the third layer 3A is not particularly limited, but may be, for example, 0.1 μm or more and 100 μm or less. The thickness of the first layer 1A is obtained by arithmetically averaging thicknesses measured at three locations that divide the first layer 1A into four equal parts in the plane direction perpendicular to the thickness direction. The thicknesses of the second layer 2A and the third layer 3A are calculated in the same manner as the thickness of the first layer 1A.

[0098] The ratio of the thickness of the thickest layer to the thinnest layer among the first layer 1A, the second layer 2A, and the third layer 3A is preferably equal to or less than 5. By reducing the variation in thickness of each layer in this manner, the mechanical reliability of the first non-vitreous bonding portion C1 can be improved.

[0099] Although the above description has been given of the first non-vitreous joint C1 having a three-layer structure, the first non-vitreous joint C1 may also have a two-layer structure. For example, the first non-vitreous joint C1 may be composed of a first layer 1A and a second layer 2A, or may be composed of a second layer 2A and a third layer 3A. The first non-vitreous joint C1 may also have a multi-layer structure of four or more layers.

[0100] (3) Metal Particles Fig. 5 is a schematic diagram showing an example of a cross section of the first non-vitreous bonding portion C1. Fig. 5 shows a cross section along the thickness direction of the first non-vitreous bonding portion C1.

[0101] 5, the first non-vitreous joint C1 preferably contains metal particles 50 therein. This composites the non-vitreous material and the metal particles 50, improving the toughness of the first non-vitreous joint C1. This prevents the first non-vitreous joint C1 from fracturing brittlely, thereby maintaining the bond between the metal support 10 and the first gas flow path member 30 for a long period of time.

[0102] 5 shows four metal particles 50, the number of metal particles 50 in one cross section is not particularly limited as long as it is one or more. Furthermore, the metal particles 50 may be entirely embedded in the non-glassy material, or may be partially exposed from the non-glassy material.

[0103] The metal particles 50 preferably contain, as a main component, the same element as the main component of at least one of the metal support 10 and the first gas flow path member 30. This can prevent the composition of the first non-vitreous bonding portion C1 from changing due to elemental diffusion from the metal support 10 and the first gas flow path member 30. For example, the metal particles 50 can contain Cr or Fe as a main component. "Containing as a main component" means that the target element exhibits the highest content when elemental analysis of the metal particles 50 is performed.

[0104] The metal particles 50 preferably contain Cr, which can improve the oxidation resistance of the metal particles 50.

[0105] In the cross section of the first non-vitreous joint C1, the ratio of the area of ​​the metal particles 50 to the area of ​​the non-vitreous material is preferably 5% or more and 30% or less. By making the area ratio of the metal particles 50 5% or more, the effect of improving toughness due to the presence of the metal particles 50 can be further improved. Furthermore, by making the area ratio of the metal particles 50 30% or less, a decrease in rigidity of the first non-vitreous joint C1 due to the presence of an excess of metal particles 50 can be suppressed.

[0106] The area ratio of the metal particles 50 is calculated using the following method. First, a cross section of the first non-vitreous joint C1 along the thickness direction is exposed. Next, a backscattered electron image of the cross section of the first non-vitreous joint C1 is acquired at 10,000x magnification using an SEM device (FE-SEM JSM-7900F, manufactured by JEOL Ltd.). Next, using image analysis software Image-Pro manufactured by MEDIACYBERNETICS, the gray areas (corresponding to the non-vitreous material), the white areas (corresponding to the metal particles 50), and the black areas (corresponding to voids) in the backscattered electron image are identified. The area ratio of the metal particles 50 is then calculated by dividing the total area of ​​the metal particles 50 by the total area of ​​the solid phase in the first non-vitreous joint C1 (i.e., the total area excluding voids).

[0107] In the first non-vitreous bonding portion C1, the area ratio of the metal particles 50 at the end portion in the planar direction exposed to the gas flow space 3a is preferably smaller than the area ratio of the metal particles 50 at the center portion in the planar direction of the first non-vitreous bonding portion C1. This allows the reduction gas (H ２ ) can prevent the metal particles 50 from becoming embrittled. The in-plane central portion refers to a portion located at the center when the first non-vitreous bonding portion C1 is divided into three equal parts in the in-plane direction. The in-plane end portions of the first non-vitreous bonding portion C1 refer to portions located on both sides of the in-plane central portion when the first non-vitreous bonding portion C1 is divided into three equal parts in the in-plane direction.

[0108] In the cross section of the first non-vitreous joint C1, the average distance between the metal particles 50 is preferably equal to or less than the average thickness of the first non-vitreous joint C1, thereby further improving the toughness improvement effect of the presence of the metal particles 50. The thickness of the first non-vitreous joint C1 is the arithmetic mean of the thicknesses of the first non-vitreous joint C1 at three locations that divide the first non-vitreous joint C1 into four equal parts in the planar direction.

[0109] The cross-sectional shape of the metal particles 50 is not particularly limited and may be circular, elliptical, rectangular, polygonal, or the like. In the cross section of the first non-vitreous bonding portion C1, the metal particles 50 may extend along the thickness direction or the surface direction. Furthermore, the metal particles 50 may be inclined relative to both the thickness direction and the surface direction.

[0110] (4) Metallic Joint Portion Fig. 6 is a schematic diagram showing an example of a cross section of the first non-vitreous joint C1, taken along the thickness direction of the first non-vitreous joint C1.

[0111] As shown in FIG. 6, the gas flow vessel 3 preferably has a metallic connection 60 surrounded by a non-vitreous connection.

[0112] The metal connecting portion 60 extends along the thickness direction. When viewed three-dimensionally, the metal connecting portion 60 is columnar. The metal connecting portion 60 penetrates the first non-vitreous bonding portion C1 in the thickness direction. The lateral surface of the metal connecting portion 60 is surrounded by the first non-vitreous bonding portion C1.

[0113] The metal connecting part 60 connects the metal support 10 and the first gas flow path member 30. One end of the metal connecting part 60 is connected to the metal support 10, and the other end of the metal connecting part 60 is connected to the first gas flow path member 30. The metal connecting part 60 may be substantially integral with at least one of the metal support 10 and the first gas flow path member 30.

[0114] In this way, by embedding the metal connecting portion 60 in the first non-vitreous joint C1, the propagation of cracks that occur in the first non-vitreous joint C1 can be stopped at the metal connecting portion 60. This makes it possible to prevent the first non-vitreous joint C1 from undergoing brittle fracture, thereby maintaining the bondability between the metal support 10 and the first gas flow path member 30 for a long period of time.

[0115] Although three metal connecting portions 60 are shown in FIG. 6, the number of metal connecting portions 60 in one cross section is not particularly limited as long as it is one or more.

[0116] 6 shows, from the left, a metal connecting portion 60 with a barrel-shaped cross section, a metal connecting portion 60 with a tilted cross section, and a metal connecting portion 60 with a constricted cross section. When the cross section of the metal connecting portion 60 is constricted, the bonding area between the metal connecting portion 60 and the metal support 10 and the first gas flow path member 30 can be increased, thereby improving the interfacial strength between them. When the cross section of the metal connecting portion 60 is barrel-shaped or tilted, the volume of the metal connecting portion 60 itself can be increased, thereby further improving the crack stopping effect.

[0117] 6, the cross-sectional shapes of the metal connecting portions 60 are different from one another, but the cross-sectional shapes of the metal connecting portions 60 may be the same. Also, the cross-sectional shape of the metal connecting portions 60 may be a shape different from the shape shown in FIG. 6. The cross-sectional shape of each metal connecting portion 60 is preferably set in consideration of the balance between improving the interfacial strength by increasing the bonding area between the metal supporting body 10 and the first gas flow path member 30 and the metal connecting portion 60, and improving the crack stopping effect by increasing the volume of the metal connecting portion 60.

[0118] The metal connecting portion 60 is made of metal. It is preferable that the metal connecting portion 60 contains, as a main component, the same element as the main component of at least one of the metal support 10 and the first gas flow path member 30. This makes it possible to suppress changes in the composition of the metal connecting portion 60 due to elemental diffusion from the metal support 10 and the first gas flow path member 30. For example, the metal connecting portion 60 can contain Cr or Fe as a main component. "Containing as a main component" means that, when elemental analysis of the metal connecting portion 60 is performed, the target element exhibits the maximum content.

[0119] The metal connecting portion 60 preferably contains Cr, which can improve the oxidation resistance of the metal connecting portion 60 .

[0120] The ratio of the minimum width W1 of the metal connecting portion 60 in the planar direction to the thickness of the first non-vitreous joining portion C1 in the thickness direction is preferably 0.3 or more, which ensures the strength of the metal connecting portion 60 and prevents the metal connecting portion 60 from being damaged by cracks.

[0121] The thickness of the first non-vitreous joint C1 is the arithmetic mean of the thicknesses of the first non-vitreous joint C1 at three locations that divide the first non-vitreous joint C1 into four equal parts in the planar direction. However, if the location where the thickness is to be measured overlaps with the metal connector 60, the thickness of the first non-vitreous joint C1 may be measured at any location close to the metal connector 60. The thickness of the first non-vitreous joint C1 is not particularly limited, but may be, for example, 0.3 μm to 30 μm.

[0122] The minimum width W1 of the metal connecting portion 60 is the smallest measured value when the width of the metal connecting portion 60 in the surface direction is measured at 10 locations that divide the metal connecting portion 60 into 11 equal parts in the thickness direction. The value of the minimum width W1 of the metal connecting portion 60 is not particularly limited, but can be, for example, 0.05 μm or more and 5 μm or less.

[0123] When multiple metal connectors 60 are present, the ratio of the longest distance D1 between the metal connectors 60 in the planar direction to the thickness of the first non-vitreous joint C1 in the thickness direction is preferably 20 or less. This allows multiple metal connectors 60 to be arranged in a narrow range in the planar direction, thereby preventing long cracks from occurring in the first non-vitreous joint C1. As a result, separation of the first non-vitreous joint C1 from the metal support 10 and the first gas flow path member 30 due to long cracks can be prevented.

[0124] The longest distance D1 between the metal connecting portions 60 is the maximum distance between two straight lines parallel to the thickness direction that are inscribed in the outlines of the side surfaces of the two opposing metal connecting portions 60. The value of the longest distance D1 is not particularly limited, but can be, for example, 1 μm or more and 100 μm or less.

[0125] The ratio of the thickness of the metal support 10 or the first gas flow path member 30 in the thickness direction to the minimum width W1 of the metal connecting portion 60 in the surface direction is preferably equal to or less than 2000. This prevents the metal connecting portion 60 from becoming excessively thin, thereby ensuring the strength of the metal connecting portion 60.

[0126] The ratio of the thickness of the metal support 10 or the first gas flow path member 30 in the thickness direction to the minimum width W1 of the metal connecting portion 60 in the surface direction is preferably equal to or greater than 50. This prevents the metal connecting portion 60 from becoming excessively thick, thereby increasing the rigidity of the first non-vitreous joining portion C1.

[0127] The metal connecting portion 60 is preferably located away from the gas flow space 3a. Specifically, the metal connecting portion 60 is preferably located at least one of the central portion in the surface direction and the peripheral portion in the surface direction. This allows the reducing gas (H ２ ) can prevent the metal connecting portion 60 from becoming brittle. The central portion in the surface direction is the portion located in the center when the first non-vitreous joining portion C1 is divided into three equal parts in the surface direction. The peripheral portion in the surface direction is the portion located on both sides of the central portion in the surface direction when the first non-vitreous joining portion C1 is divided into three equal parts in the surface direction.

[0128] (5) Voids Fig. 7 is a schematic diagram showing an example of a cross section of the first non-vitreous joint C1, taken along the thickness direction of the first non-vitreous joint C1.

[0129] 7, the first non-vitreous joint C1 has an internal void 70. This allows the propagation of cracks that occur in the first non-vitreous joint C1 to be stopped at the void 70. This prevents the first non-vitreous joint C1 from undergoing brittle fracture, thereby maintaining the bond between the metal support 10 and the first gas flow path member 30 for a long period of time.

[0130] Although two voids 70 are shown in FIG. 7, the number of voids 70 in one cross section is not particularly limited, and may be one.

[0131] 7, the gap 70 is preferably spaced apart from the metal support 10 and the first gas flow path member 30. This prevents the bonding area between the metal support 10 and the first gas flow path member 30 and the first non-vitreous bonding portion C1 from decreasing, thereby ensuring the bondability between the metal support 10 and the first gas flow path member 30 and the first non-vitreous bonding portion C1.

[0132] The voids 70 may extend along the thickness direction. This allows cracks propagating along the surface direction to be stopped over a wide area by the voids 70. Extending along the thickness direction means that the height of the voids 70 in the thickness direction is greater than the width of the voids 70 in the surface direction.

[0133] The voids 70 may extend in the surface direction. This allows cracks propagating in the thickness direction to be stopped over a wide area by the voids 70. Extending in the surface direction means that the height of the voids 70 in the thickness direction is smaller than the width of the voids 70 in the surface direction.

[0134] The voids 70 may extend in directions inclined relative to both the thickness direction and the surface direction. This allows the voids 70 to stop both cracks propagating in the thickness direction and cracks propagating in the surface direction in a balanced manner. In this case, the height of the voids 70 in the thickness direction may be approximately the same as the width of the voids 70 in the surface direction.

[0135] The void 70 is preferably located in the thickness-wise central portion of the first non-vitreous joint C1. This reduces the difference in strength of the first non-vitreous joint C1 on both sides of the void 70 in the thickness direction, thereby preventing a decrease in the mechanical reliability of the first non-vitreous joint C1. It is more preferable that the void 70 is entirely located in the thickness-wise central portion of the first non-vitreous joint C1. The thickness-wise central portion refers to the portion located in the middle when the first non-vitreous joint C1 is divided into three equal parts in the thickness direction.

[0136] The height of the void 70 in the thickness direction is preferably ¾ or less of the thickness of the first non-vitreous joint C1, which prevents a decrease in the strength of the first non-vitreous joint C1 on both sides of the void 70 in the thickness direction, thereby preventing the first non-vitreous joint C1 from peeling off from the metal support 10 and the first gas flow path member 30.

[0137] The ratio of the thickness of at least one of the metal support 10 and the first gas flow path member 30 to the height of the void 70 in the thickness direction is preferably 20 or more and 500 or less. A thickness ratio of 20 or more can sufficiently exert the effect of stopping cracks in the void 70. Furthermore, a thickness ratio of 500 or less can suppress a decrease in the mechanical reliability (strength) of the first non-vitreous bonding part C1 due to the presence of the void 70.

[0138] In the cross section of the first non-vitreous joint C1, the ratio of the area of ​​the voids 70 to the area of ​​the first non-vitreous joint C1 is preferably 5% or more and 30% or less. An area ratio of 5% or more allows the voids 70 to fully exert the effect of stopping cracks. Furthermore, an area ratio of 30% or less prevents a decrease in the mechanical reliability (strength) of the first non-vitreous joint C1 due to the presence of the voids 70.

[0139] The area ratio is calculated by the following method. First, a cross section of the first non-vitreous joint C1 along the thickness direction is exposed. Next, a backscattered electron image of the cross section of the first non-vitreous joint C1 is acquired at 10,000x magnification using an SEM device (FE-SEM JSM-7900F, manufactured by JEOL Ltd.). Next, the black areas (corresponding to the voids 70) in the backscattered electron image are identified using image analysis software Image-Pro manufactured by MEDIACYBERNETICS. The area ratio is then calculated by dividing the total area of ​​the voids 70 by the total area of ​​the backscattered electron image of the first non-vitreous joint C1.

[0140] The area ratio at the end portion of the first non-vitreous joint C1 in the plane direction exposed to the gas flow space 3a is preferably smaller than the area ratio at the center portion in the plane direction. ２) can be prevented from entering the gap 70, thereby improving the sealing performance of the first non-vitreous joint C1. The surface-direction central portion of the first non-vitreous joint C1 is the portion located in the center when the first non-vitreous joint C1 is divided into three equal parts in the surface direction. The surface-direction end portions of the first non-vitreous joint C1 are the portions located on both sides of the surface-direction central portion.

[0141] (Modifications of the Embodiment) Although the embodiment of the present invention has been described above, the present invention is not limited to these, and various modifications are possible without departing from the spirit of the present invention.

[0142] [Variation 1] In the above embodiment, the first gas flow path member 30 is joined to the metal support 10 via the first non-vitreous joint C1 and is joined to the interconnector 20 via the second non-vitreous joint C2. However, the first gas flow path member 30 may be joined to only one of the metal support 10 and the interconnector 20. When the first gas flow path member 30 is joined only to the metal support 10, the gas flow container 3 does not include the second non-vitreous joint C2. When the first gas flow path member 30 is joined only to the interconnector 20, the gas flow container 3 does not include the first non-vitreous joint C1.

[0143] [Variation 2] In the above embodiment, the second gas flow path member 40 is joined to the metal support 10 via the third non-vitreous joint C3, and is joined to the interconnector 20 via the fourth non-vitreous joint C4. However, the second gas flow path member 40 may be joined to only one of the metal support 10 and the interconnector 20. When the second gas flow path member 40 is joined only to the metal support 10, the gas flow container 3 does not have the fourth non-vitreous joint C4. When the second gas flow path member 40 is joined only to the interconnector 20, the gas flow container 3 does not have the third non-vitreous joint C3.

[0144] [Variant 3] In the above embodiment, the first to fourth non-vitreous joints C1 to C4 have similar configurations. However, as long as they have in common the fact that they are made of non-vitreous materials, the configurations adopted for the above-mentioned constituent materials, multi-layer structure, metal particles 50, metal connecting portions 60, and voids 70 can be changed appropriately for each non-vitreous joint.

[0145] [Variation 4] In the above embodiment, the gas flow container 3 includes the first gas flow path member 30 and the second gas flow path member 40. However, the gas flow container 3 may include only one of the first gas flow path member 30 and the second gas flow path member 40.

[0146] [Modification 5] In the above embodiment, the frame portion 21 and the plate-like portion 22 that constitute the interconnector 20 are separate members, but the frame portion 21 and the plate-like portion 22 may be integral with each other.

[0147] [Variation 6] In the above embodiment, an electrolytic cell has been described as an example of an electrochemical cell, but the electrochemical cell is not limited to an electrolytic cell. An electrochemical cell is a general term for an element in which a pair of electrodes are arranged so that an electromotive force is generated from an overall oxidation-reduction reaction in order to convert electrical energy into chemical energy, and an element for converting chemical energy into electrical energy. Therefore, electrochemical cells include, for example, fuel cells that use oxide ions or protons as carriers.

[0148] REFERENCE SIGNS LIST 1 Electrolysis cell 2 Cell main body 3 Gas flow container 3a Gas flow space 6 Hydrogen electrode 7 Electrolyte 8 Reaction prevention layer 9 Oxygen electrode 10 Metal support 11 Communication hole 12 First main surface 13 Second main surface 20 Interconnector 21 Frame 22 Plate-shaped portion 30 First gas flow path member 31 Source gas flow hole 32 Source gas flow path 40 Second gas flow path member 41 Exhaust gas flow hole 42 Exhaust gas flow path C1 to C4 First to fourth non-vitreous joining portions 1A First layer 2A Second layer 3A Third layer 50 Metal particles 60 Metal connecting portion 70 Void

Claims

1. A gas flow-through container comprising: a first metal member; a second metal member; a gas flow path member disposed in a gas flow space between the first metal member and the second metal member for forming a gas flow path; and a non-glass joint portion made of a non-glass material for joining the first metal member and the gas flow path member.

2. The gas flow-through container according to claim 1, wherein the non-glass joint portion is made of an oxide mainly composed of chromium.

3. The gas flow-through container according to claim 2, wherein the non-glass joint portion has a first layer disposed on the first metal member and a second layer disposed between the first layer and the second metal member, and the oxide constituting the second layer is different from the oxide constituting the first layer.

4. The gas flow-through container according to claim 3, wherein the non-glass joint portion has a third layer sandwiched between the second layer and the second alloy member, and the oxide constituting the third layer is the same as the oxide constituting the first layer.

5. The gas flow-through container according to claim 1, wherein the non-glass joint portion has metal particles at least partially embedded in the non-glass material.

6. The gas flow-through container according to claim 1, comprising a metal connection portion surrounded by the non-glass joint portion for connecting the first metal member and the second metal member.

7. The gas flow-through container according to claim 1, wherein the non-glass joint portion has voids inside.

8. A metal-supported electrochemical cell comprising: the gas flow-through container according to claim 1; and a cell body portion disposed on the first metal member or the second metal member, wherein the metal member on which the cell body portion is disposed among the first metal member and the second metal member has a plurality of communication holes leading to the gas flow space, and the cell body portion covers the plurality of communication holes.

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