Chromium alloy container and metal-supported electrochemical cell

Abstract

A chromium alloy container (3) comprises: a metal support body (10) formed from an alloy containing chromium; a frame body (20) formed from an alloy containing chromium; and a first bonding part (41) that bonds the metal support body (10) and the frame body (20). The first bonding part (41) is formed from an oxide containing chromium as a main component.

Description

Chromium alloy container and metal-supported electrochemical cell

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

[0002] Patent Document 1 discloses a chromium alloy container for housing a fuel cell, which includes a first interconnector, a second interconnector, a separator, an anode frame, and a glass seal.

[0003] The first interconnector is connected to the cathode of the fuel cell. The second interconnector is connected to the anode current collecting layer of the fuel cell. The separator is connected to the solid electrolyte of the fuel cell and separates the fuel gas and oxidant gas flow paths. The anode frame is disposed between the separator and the second interconnector. A glass seal bonds the first interconnector and the separator.

[0004] The first interconnector, the second interconnector, the separator, and the fuel electrode frame are each made of a chromium alloy (for example, SUS430, SUS444, etc.) The glass seal is made of a glass material.

[0005] JP 2015-156352 A

[0006] In the chromium alloy container described in Patent Document 1, the chromium contained in the first interconnector and the separator diffuses into the glass seal, causing a change in the composition of the glass seal and a decrease in its strength. As a result, the glass seal is deformed or cracked, making it impossible to maintain adhesion between the alloy members for a long period of time. This is a problem common to chromium alloy containers in general, not just containers for accommodating fuel cells.

[0007] An object of the present invention is to provide a chromium alloy container and a metal-supported electrochemical cell that can maintain adhesion between alloy members for a long period of time.

[0008] A chromium alloy container according to a first aspect of the present invention comprises a first alloy member made of an alloy containing chromium, a second alloy member made of an alloy containing chromium, and an adhesive joint for bonding the first alloy member and the second alloy member, the adhesive joint being made of an oxide containing chromium as a main component.

[0009] A chromium alloy container according to a second aspect of the present invention is the chromium alloy container according to the first aspect, wherein the chromium content in the metal elements in the oxide is 50 mol % or more.

[0010] A chromium alloy container according to a third aspect of the present invention is related to the first or second aspect, wherein the oxide is composed of at least one of chromium oxide and chromium manganese oxide.

[0011] A chromium alloy container according to a fourth aspect of the present invention is the chromium alloy container according to any one of the first to third aspects, wherein the oxide is crystalline.

[0012] A chromium alloy container according to a fifth aspect of the present invention is related to the fourth aspect, wherein the oxide has a spinel-type or corundum-type crystal structure.

[0013] A sixth aspect of the present invention relates to the chromium alloy container according to any one of the first to fifth aspects, wherein the adhesive portion has a first layer disposed on the first alloy member and a second layer disposed between the first layer and the second alloy member, and an oxide constituting the second oxide layer is different from an oxide constituting the first oxide layer.

[0014] A seventh aspect of the present invention relates to the sixth aspect of the chromium alloy container, and the adhesive portion has a third layer sandwiched between the second layer and the second alloy member. The oxide constituting the third layer is the same as the oxide constituting the first layer.

[0015] The chromium alloy container according to an eighth aspect of the present invention is the chromium alloy container according to the seventh aspect, wherein the thickness ratio of the thickest layer to the thinnest layer among the first layer, the second layer, and the third layer is 5 or less.

[0016] A ninth aspect of the present invention relates to the chromium alloy container according to any one of the sixth to eighth aspects, wherein the contact region of the surface of the first alloy member that contacts the adhesive portion includes a first region that contacts the first layer and a second region that contacts the second layer, and the second region is connected to the first region.

[0017] A chromium alloy container according to a tenth aspect of the present invention is the ninth aspect, wherein the adhesive portion is embedded in a bottomed recess formed between the first alloy member and the second alloy member, and the number of layers of the adhesive portion exposed from an opening of the bottomed recess is greater than the number of layers of the adhesive portion disposed in the deepest part of the bottomed recess.

[0018] A chromium alloy container according to an eleventh aspect of the present invention relates to any one of the first to tenth aspects, wherein the adhesive portion is a seal for sealing the internal space.

[0019] A chromium alloy container according to a twelfth aspect of the present invention is the chromium alloy container according to any one of the first to tenth aspects, wherein the second alloy member has an embossed portion abutting the first alloy member, and the adhesive portion bonds the embossed portion to the first alloy member.

[0020] A metal-supported electrochemical cell according to a thirteenth aspect of the present invention comprises the chromium alloy container according to any one of the first to twelfth aspects and a cell main body disposed on the chromium alloy container. The first alloy member has a plurality of communication holes communicating with the internal space. The cell main body is disposed on the first alloy member so as to cover the plurality of communication holes.

[0021] According to the present invention, it is possible to provide a chromium alloy container and a metal-supported electrochemical cell that can maintain the adhesion between alloy members for a long period of time.

[0022] Fig. 1 is a plan view of an electrolytic cell according to a first embodiment. Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1. Fig. 3 is a partially enlarged view of Fig. 2. Fig. 4 is a cross-sectional view of an electrolytic cell according to a second embodiment. Fig. 5 is a partially enlarged view of Fig. 4.

[0023] 1. First embodiment

[0024] (Electrolytic cell 1) Fig. 1 is a plan view of the electrolytic cell 1 according to the first embodiment. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1.

[0025] The electrolysis cell 1 is an example of a "metal-supported electrochemical cell" according to the present invention.

[0026] 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 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.

[0027] As shown in FIGS. 1 and 2, the electrolytic cell 1 includes a cell body 2 and a chromium alloy container 3 .

[0028] (Cell body 2) The cell body 2 is placed on the chromium alloy container 3. The cell body 2 is supported by a metal support 10 (described later) of the chromium alloy container 3. The cell body 2 has a hydrogen electrode 6 (cathode), an electrolyte 7, a reaction prevention layer 8, and an oxygen electrode 9 (anode).

[0029] The hydrogen electrode 6, electrolyte 7, reaction prevention layer 8, and oxygen electrode 9 are stacked in this order in the Z-axis direction from the chromium alloy container 3 side. The hydrogen electrode 6, electrolyte 7, and oxygen electrode 9 are essential components, while the reaction prevention layer 8 is optional.

[0030] [Hydrogen Electrode 6 ] The hydrogen electrode 6 is disposed on the first main surface 12 of the metal support 10 .

[0031] The hydrogen electrode 6 is supplied with a source gas from each supply hole 11 of the metal support 10. The source gas contains at least water vapor (H ２ O).

[0032] The raw material gas is H ２ When the raw material gas contains only O, the hydrogen electrode 6 converts H ２ Generate.

[0033] Hydrogen electrode 6: H ２ O + 2e － →H ２ +O ２－...(1)

[0034] The raw material gas is H ２ O plus CO ２ In this case, the hydrogen electrode 6 converts the raw material gas into H according to the electrochemical reactions of co-electrolysis shown in the following formulas (2), (3), and (4). ２ , CO and O ２－ Generate.

[0035] Hydrogen electrode 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)

[0036] H generated at the hydrogen electrode 6 ２ The gas flows out from each supply hole 11 of the metal support 10 into an internal space 3 a described later.

[0037] The hydrogen electrode 6 is a porous body having electron conductivity. The hydrogen electrode 6 contains nickel (Ni). In the case of co-electrolysis, Ni functions as an electron conductor and also functions as a conductor for the generated H ２ and CO contained in the raw material gas ２ It also functions as a thermal catalyst that promotes the thermal reaction with HCl and maintains an appropriate gas composition for methanation, Fischer-Tropsch (FT) synthesis, etc. The Ni contained in the hydrogen electrode 6 is basically present in the form of metallic Ni during operation of the electrolysis cell 1, but a portion of it may also be present in the form of nickel oxide (NiO).

[0038] The hydrogen electrode 6 may contain an ion-conductive material, such as yttria-stabilized zirconia (YSZ), calcia-stabilized zirconia (CSZ), scandia-stabilized zirconia (ScSZ), gadolinium-doped ceria (GDC), samarium-doped ceria (SDC), (La, Sr)(Cr, Mn)O, or the like. ３ , (La,Sr)TiO ３ , Sr ２ (Fe, Mo) ２ O ６ , (La, Sr)VO ３ , (La,Sr)FeO ３ and mixed materials of two or more of these.

[0039] The thickness of the hydrogen electrode 6 is not particularly limited, but may be, for example, 1 μm or more and 100 μm or less. The thermal expansion coefficient of the hydrogen electrode 6 is not particularly limited, but may be, for example, 12×10 ―６ / ℃ or more 20 x 10 －６ / °C or less.

[0040] The method for forming the hydrogen electrode 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.

[0041] [Electrolyte 7] The electrolyte 7 is formed on the hydrogen electrode 6. The electrolyte 7 is disposed between the hydrogen electrode 6 and the oxygen electrode 9. In this embodiment, the electrolyte 7 is sandwiched between the hydrogen electrode 6 and the reaction prevention layer 8 and connected to both of them.

[0042] The electrolyte 7 covers the hydrogen electrode 6 and also covers the region of the first main surface 12 of the metal support 10 that is exposed from the hydrogen electrode 6 .

[0043] The electrolyte 7 is a dense body having oxide ion conductivity. ２－The electrolyte 7 is made of an oxide ion conductive material, such as YSZ, GDC, ScSZ, SDC, or LSGM (lanthanum gallate), with YSZ being particularly suitable.

[0044] The thickness of the electrolyte 7 is not particularly limited, but may be, for example, 1 μm or more and 100 μm or less. The thermal expansion coefficient of the electrolyte 7 is not particularly limited, but may be, for example, 10×10 ―６ / ℃ or more 12 x 10 ―６ / °C or less.

[0045] The method for forming the electrolyte 7 is not particularly limited, and may be a baking method, a spray coating method, a PVD method, a CVD method, or the like.

[0046] [Reaction prevention layer 8] The reaction prevention layer 8 is disposed between the electrolyte 7 and the oxygen electrode 9. The reaction prevention layer 8 is disposed on the opposite side of the electrolyte 7 from the hydrogen electrode 6. The reaction prevention layer 8 prevents the constituent elements of the electrolyte 7 from reacting with the constituent elements of the oxygen electrode 9 to form a layer with high electrical resistance.

[0047] The reaction prevention layer 8 is made of an oxide ion conductive material, such as GDC or SDC.

[0048] 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.

[0049] 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.

[0050] [Oxygen Electrode 9] The oxygen electrode 9 is disposed on the opposite side of the hydrogen electrode 6 with respect to the electrolyte 7. In this embodiment, the reaction prevention layer 8 is disposed between the electrolyte 7 and the oxygen electrode 9, and therefore the oxygen electrode 9 is connected to the reaction prevention layer 8. If the reaction prevention layer 8 is not disposed between the electrolyte 7 and the oxygen electrode 9, the oxygen electrode 9 is connected to the electrolyte 7.

[0051] The oxygen electrode 9 converts O 2 transferred from the hydrogen electrode 6 through the electrolyte 7 according to the chemical reaction of the following formula (5): ２－ From O ２ Generate.

[0052] Oxygen electrode 9:2O ２－ →O ２ +4e － ...(5)

[0053] The oxygen electrode 9 is a porous body having oxide ion conductivity and electron conductivity. The oxygen electrode 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).

[0054] The porosity of the oxygen electrode 9 is not particularly limited, but may be, for example, 20% to 60%. The thickness of the oxygen electrode 9 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0055] The method for forming the oxygen electrode 9 is not particularly limited, and may be a baking method, a spray coating method, a PVD method, a CVD method, or the like.

[0056] (Chromium alloy vessel 3) The chromium alloy vessel 3 contains a raw material gas supplied to the hydrogen electrode 6 and a reducing gas (in this embodiment, H ２ ) and has an internal space 3a through which the

[0057] In this embodiment, the chromium alloy container 3 includes a metal support 10, a frame 20, an interconnector 30, a first seal portion 40, and a second seal portion 50. The internal space 3a is a space surrounded by the metal support 10, the frame 20, the interconnector 30, the first seal portion 40, and the second seal portion 50.

[0058] In this embodiment, one of the metal support 10 and the frame 20 is an example of the "first alloy member" according to the present invention, and the other is an example of the "second alloy member" according to the present invention. Also, in this embodiment, one of the frame 20 and the interconnector 30 is an example of the "first alloy member" according to the present invention, and the other is an example of the "second alloy member" according to the present invention.

[0059] [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.

[0060] 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.

[0061] As shown in FIG. 2 , the metal support 10 has a plurality of supply holes 11 , a first main surface 12 and a second main surface 13 .

[0062] Each supply hole 11 penetrates the metal support 10 from the first main surface 12 to the second main surface 13. Each supply hole 11 opens to the first main surface 12 and the second main surface 13. Each supply hole 11 is covered by the cell main body 2. Specifically, the opening of each supply hole 11 on the first main surface 12 side is covered by the hydrogen electrode 6. The opening of each supply hole 11 on the second main surface 13 side is connected to the internal space 3 a.

[0063] Each supply hole 11 can be formed by mechanical processing (for example, punching), laser processing, chemical processing (for example, etching), or the like.

[0064] In this embodiment, each supply hole 11 is formed linearly along the Z-axis direction. However, each supply hole 11 may be inclined with respect to the Z-axis direction or may not be linear. Furthermore, the supply holes 11 may be connected to each other.

[0065] The first main surface 12 is provided on the opposite side to the second main surface 13. The cell main body 2 is disposed on the first main surface 12. The frame 20 is joined to the second main surface 13 via a first seal portion 40.

[0066] The metal support 10 is made of an alloy containing chromium (Cr). Examples of such alloys 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% by mass or more and 30% by mass or less.

[0067] 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).

[0068] [Frame 20] The frame 20 is a spacer for forming the internal space 3a. In this embodiment, the frame 20 is formed in an annular shape.

[0069] The frame 20 is joined to the metal support 10 via the first seal portion 40 , and is joined to the interconnector 30 via the second seal portion 50 .

[0070] The thickness of the frame body 20 is not particularly limited, but can be, for example, 0.1 mm or more and 2.0 mm or less.

[0071] The frame 20 is made of an alloy containing Cr. Examples of such alloys include Fe—Cr alloy steel and Ni—Cr alloy steel. The Cr content in the frame 20 is not particularly limited, but can be set to 4 mass % or more and 30 mass % or less. The composition of the frame 20 may be the same as or different from that of the metal support 10.

[0072] [Interconnector 30] The interconnector 30 is disposed on the opposite side of the metal support 10 with respect to the frame 20. The interconnector 30 is a member for electrically connecting the electrolytic cell 1 to an external power source or another electrolytic cell.

[0073] In this embodiment, the interconnector 30 is formed in a plate shape. The interconnector 30 may be in the shape of a flat plate or a curved plate.

[0074] The interconnector 30 is joined to the frame 20 via the second seal portion 50 .

[0075] The thickness of the interconnector 30 is not particularly limited, but can be, for example, 0.1 mm or more and 2.0 mm or less.

[0076] The interconnector 30 is made of an alloy containing Cr. Examples of such alloys include Fe—Cr alloy steel and Ni—Cr alloy steel. The Cr content in the interconnector 30 is not particularly limited, but can be set to 4 mass % or more and 30 mass % or less. The composition of the interconnector 30 may be the same as or different from that of the metal support 10. The composition of the interconnector 30 may be the same as or different from that of the frame 20.

[0077] [First Seal Portion 40] The first seal portion 40 is disposed between the metal support body 10 and the frame body 20. The first seal portion 40 is joined to both the metal support body 10 and the frame body 20.

[0078] The first seal 40 seals the gap between the metal support 10 and the frame 20. This prevents the source gas supplied to the hydrogen electrode 6 and the reducing gas generated in the hydrogen electrode 6 from leaking to the outside through the gap between the metal support 10 and the frame 20. The detailed configuration of the first seal 40 will be described later.

[0079] [Second seal portion 50] The second seal portion 50 is disposed between the frame body 20 and the interconnector 30. The second seal portion 50 is joined to both the frame body 20 and the interconnector 30.

[0080] The second seal portion 50 seals the gap between the frame body 20 and the interconnector 30. This prevents the raw material gas supplied to the hydrogen electrode 6 and the reducing gas generated in the hydrogen electrode 6 from leaking to the outside through the gap between the frame body 20 and the interconnector 30.

[0081] The configuration of the second seal portion 50 is the same as the configuration of the first seal portion 40, which will be described next, and therefore, in this embodiment, a description of the configuration of the second seal portion 50 will be omitted.

[0082] (Detailed Configuration of First Seal Portion 40) Fig. 3 is a partially enlarged view of Fig. 2. Fig. 3 shows a cross section of the first seal portion 40. The cross section shown in Fig. 3 is perpendicular to the second main surface 13 of the metal support body 10.

[0083] The first seal portion 40 has a first adhesive portion 41 and a second adhesive portion 42. Each of the first adhesive portion 41 and the second adhesive portion 42 is an example of the "adhesive portion" according to the present invention.

[0084] [First adhesive portion 41] The first adhesive portion 41 is disposed between the metal support 10 and the frame body 20. The first adhesive portion 41 is sandwiched between the metal support body 10 and the frame body 20. The first adhesive portion 41 is formed in a ring shape so as to surround the internal space 3 a. The first adhesive portion 41 functions as a seal for sealing the internal space 3 a.

[0085] In this embodiment, the first adhesive portion 41 is embedded in a bottomed recess 60 formed between the metal support 10 and the frame 20. The cross section of the bottomed recess 60 is wedge-shaped. The bottomed recess 60 has a deepest portion 60a and an opening 60b. The opening 60b opens toward the internal space 3a. The first adhesive portion 41 is exposed to the internal space 3a.

[0086] The first adhesive portion 41 is composed of an oxide containing Cr as a main component (hereinafter, abbreviated as "Cr oxide"). This makes it possible to suppress the diffusion of Cr from the metal support 10 and the frame 20 to the first adhesive portion 41 during the manufacture or operation of the electrolysis cell 1. Furthermore, even if Cr diffuses from the metal support 10 and the frame 20 to the first adhesive portion 41, the effect on the composition of the first adhesive portion 41 is small, and therefore a decrease in the strength of the first adhesive portion 41 can also be suppressed. Furthermore, since the metal support 10, the frame 20, and the first adhesive portion 41 all contain Cr, the mutual adhesion can be improved. Therefore, the adhesion between the metal support 10 and the frame 20 can be maintained for a long period of time.

[0087] In this embodiment, "mainly composed of Cr" means that, when the composition of the Cr oxide constituting the first adhesive portion 41 is analyzed by an energy dispersive spectroscopy (EDS) device, the Cr content is the highest among the metal elements in the Cr oxide. The Cr content is not particularly limited, but can be, for example, 20 mol % or more and 100 mol % or less.

[0088] The Cr content of the metal elements in the Cr oxide constituting the first adhesive portion 41 is preferably 50 mol % or more, which significantly suppresses the diffusion of Cr contained in the metal support 10 and the frame 20 into the first adhesive portion 41.

[0089] The Cr oxide constituting the first adhesive portion 41 is preferably composed of at least one of chromium oxide and chromium manganese oxide, which have the property of making it particularly difficult for Cr to diffuse, thereby improving the durability of the first adhesive portion 41.

[0090] 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.

[0091] The Cr oxide constituting the first adhesive portion 41 is preferably crystalline, which can prevent the first adhesive portion 41 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.

[0092] The Cr oxide constituting the first adhesive portion 41 preferably has a spinel or corundum crystal structure. These crystal structures have high symmetry, and therefore can improve the thermal stress resistance of the first adhesive portion 41.

[0093] As shown in FIG. 3, the first adhesive portion 41 according to this embodiment is made up of a first layer 1A, a second layer 2A, and a third layer 3A.

[0094] The first layer 1A is disposed on the metal support 10. The first layer 1A is sandwiched between the metal support 10 and the second layer 2A. In this embodiment, the first layer 1A is made of Cr ２ O ３ It is composed of:

[0095] The second layer 2A is disposed between the first layer 1A and the frame 20. In this embodiment, since the first adhesive portion 41 has the third layer 3A, the second layer 2A is sandwiched between the first layer 1A and the third layer 3A. A portion of the second layer 2A fills the deepest portion 60a of the bottomed recess 60. The portion of the second layer 2A that fills the deepest portion 60a is sandwiched between the metal support 10 and the frame 20.

[0096] 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 in the Z-axis direction 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 made of chromium manganese oxide.

[0097] The third layer 3A is disposed on the frame 20. The third layer 3A is sandwiched between the second layer 2A and the frame 20. The oxide constituting the third layer 3A is preferably different from the oxide constituting the second layer 2A. This allows cracks that attempt to propagate in the Z-axis direction from the second layer 2A toward the third layer 3A, or from the third layer 3A toward the second layer 2A, to be stopped at the interface between the second layer 2A and the third layer 3A. In this embodiment, the third layer 3A is made of Cr ２ O ３ It is composed of:

[0098] The oxide constituting the third layer 3A is preferably the same as the oxide constituting the first layer 1A, which makes the first adhesive portion 41 have a symmetrical structure in the thickness direction parallel to the Z-axis direction, thereby improving the mechanical reliability of the first adhesive portion 41.

[0099] 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 a plane direction perpendicular to the Z-axis direction. The thicknesses of the second layer 2A and the third layer 3A are also obtained in the same manner as the thickness of the first layer 1A.

[0100] It is preferable that the thickness ratio of the thickest layer to the thinnest layer among the first layer 1A, the second layer 2A, and the third layer 3A is equal to or less than 5. By reducing the variation in thickness of each layer in this manner, the mechanical reliability of the first adhesive portion 41 can be improved.

[0101] 3 , the metal support 10 has a contact region 10S that contacts the first adhesive portion 41. In this embodiment, the contact region 10S is a part of the second main surface 13. The contact region 10S preferably includes a first region S1 that contacts the first layer 1A and a second region S2 that is connected to the first region S1 at a connection point P1 and contacts the second layer 2A. This makes it possible to stop a crack that propagates inward between the first layer 1A and the second layer 2A (i.e., toward the side away from the internal space 3a) at the connection point P1.

[0102] 3, the frame 20 has a contact region 20S that contacts the first adhesive portion 41. The contact region 20S preferably includes a third region S3 that contacts the third layer 3A, and a fourth region S4 that connects to the third region S3 at the connection point P2 and contacts the second layer 2A. This makes it possible to stop a crack that propagates inward between the second layer 2A and the third layer 3A at the connection point P2.

[0103] 3, the number of layers of the first adhesive portion 41 exposed from the opening 60b of the bottomed recess 60 is preferably greater than the number of layers of the first adhesive portion 41 arranged in the deepest portion 60a of the bottomed recess 60. This results in a smaller number of interfaces between each layer on the deepest portion 60a side than on the opening 60b side. This prevents cracks that attempt to propagate inward along the interfaces between each layer from reaching the deepest portion 60a. In this embodiment, the number of layers of the first adhesive portion 41 exposed from the opening 60b is "3," and the number of layers of the first adhesive portion 41 arranged in the deepest portion 60a is "1."

[0104] The first adhesive portion 41 can be formed by applying a paste containing Cr oxide to the surface of at least one of the metal support 10 and the frame 20, and then performing a heat treatment while the metal support 10 and the frame 20 are in close contact with each other. The conditions for the heat treatment can be set as appropriate, but can be, for example, 600° C. or higher and 1100° C. or lower, and 0.5 hours or higher and 24 hours or lower.

[0105] [Second adhesive portion 42] The second adhesive portion 42 is disposed between the metal support 10 and the frame body 20. The second adhesive portion 42 is sandwiched between the metal support body 10 and the frame body 20. The second adhesive portion 42 is disposed on the opposite side of the internal space 3a from the first adhesive portion 41. The second adhesive portion 42 is formed in a ring shape so as to surround the first adhesive portion 41. The second adhesive portion 42 functions as a seal for sealing the internal space 3a.

[0106] The second adhesive portion 42 is spaced apart from the first adhesive portion 41 in the surface direction. The metal support 10 and the frame body 20 are in close contact with or integrated with each other between the first adhesive portion 41 and the second adhesive portion 42. To improve the electrical connectivity between the metal support body 10 and the frame body 20, it is preferable that they are integrated by welding or brazing.

[0107] In this embodiment, the second adhesive portion 42 is embedded in a bottomed recess 70 formed between the metal support 10 and the frame body 20. The cross section of the bottomed recess 70 is wedge-shaped. The bottomed recess 70 has a deepest portion 70a and an opening 70b. The opening 70b opens toward the external space 3b. The second adhesive portion 42 is exposed to the external space 3b.

[0108] The second adhesive portion 42 is composed of Cr oxide. This makes it possible to suppress the diffusion of Cr from the metal support 10 and the frame 20 to the second adhesive portion 42 during the manufacture or operation of the electrolysis cell 1. Furthermore, even if Cr diffuses from the metal support 10 and the frame 20 to the second adhesive portion 42, the effect on the composition of the second adhesive portion 42 is small, and therefore a decrease in the strength of the second adhesive portion 42 can be suppressed. Furthermore, since the metal support 10, the frame 20, and the second adhesive portion 42 all contain Cr, the mutual adhesion can be improved. Therefore, the adhesion between the metal support 10 and the frame 20 can be maintained for a long period of time.

[0109] The Cr content of the metal elements in the Cr oxide constituting the second adhesive portion 42 can be, for example, 20 mol % or more and 100 mol % or less. The Cr content is preferably 50 mol % or more. This significantly prevents the Cr contained in the metal support 10 and the frame 20 from diffusing into the second adhesive portion 42.

[0110] The Cr oxide constituting the second adhesive portion 42 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, and therefore can improve the durability of the second adhesive portion 42.

[0111] The Cr oxide constituting the second adhesive portion 42 is preferably crystalline, which can prevent the second adhesive portion 42 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.

[0112] The Cr oxide constituting the second adhesive portion 42 preferably has a spinel or corundum crystal structure. These crystal structures have high symmetry, and therefore can improve the thermal stress resistance of the second adhesive portion 42.

[0113] As shown in FIG. 3, the second adhesive portion 42 according to this embodiment is made up of a first layer 1B, a second layer 2B, and a third layer 3B.

[0114] The first layer 1B is disposed on the metal support 10. The first layer 1B is sandwiched between the metal support 10 and the second layer 2B. In this embodiment, the first layer 1B is made of Cr. ２ O ３ It is composed of:

[0115] The second layer 2B is disposed between the first layer 1B and the frame 20. In this embodiment, since the second adhesive portion 42 has the third layer 3B, the second layer 2B is sandwiched between the first layer 1B and the third layer 3B. Furthermore, a portion of the second layer 2B fills the deepest portion 70a of the bottomed recess 70. The portion of the second layer 2B that fills the deepest portion 70a is sandwiched between the metal support 10 and the frame 20.

[0116] The oxide constituting the second layer 2B is preferably different from the oxide constituting the first layer 1B. This allows cracks that attempt to propagate in the Z-axis direction from the first layer 1B toward the second layer 2B, or from the second layer 2B toward the first layer 1B, to be stopped at the interface between the first layer 1B and the second layer 2B. In this embodiment, the second layer 2B is composed of chromium manganese oxide.

[0117] The third layer 3B is disposed on the frame 20. The third layer 3B is sandwiched between the second layer 2B and the frame 20. The oxide constituting the third layer 3B is preferably different from the oxide constituting the second layer 2B. This makes it possible to stop cracks that attempt to propagate in the Z-axis direction from the second layer 2B toward the third layer 3B, or from the third layer 3B toward the second layer 2B, at the interface between the second layer 2B and the third layer 3B. In this embodiment, the third layer 3B is made of Cr ２ O ３ It is composed of:

[0118] The oxide constituting the third layer 3B is preferably the same as the oxide constituting the first layer 1B, which makes the second adhesive portion 42 have a symmetrical structure in the thickness direction parallel to the Z-axis direction, thereby improving the mechanical reliability of the second adhesive portion 42.

[0119] The thickness of the first layer 1B 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 2B 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 3B 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 1B is obtained by arithmetically averaging thicknesses measured at three locations that divide the first layer 1B into four equal parts in a plane direction perpendicular to the Z-axis direction. The thicknesses of the second layer 2B and the third layer 3B are also obtained in the same manner as the thickness of the first layer 1B.

[0120] It is preferable that the thickness ratio of the thickest layer to the thinnest layer among the first layer 1B, the second layer 2B, and the third layer 3B be equal to or less than 5. By reducing the variation in thickness of each layer in this manner, the mechanical reliability of the second adhesive portion 42 can be improved.

[0121] 3 , the metal support 10 has a contact region 10T that contacts the second adhesive portion 42. In the present embodiment, the contact region 10T is a part of the second main surface 13. The contact region 10T preferably includes a first region T1 that contacts the first layer 1B and a second region T2 that is connected to the first region T1 at a connection point Q1 and that contacts the second layer 2B. This makes it possible to stop a crack that propagates inward between the first layer 1B and the second layer 2B (i.e., toward the side away from the external space 3b) at the connection point Q1.

[0122] 3, the frame 20 has a contact region 20T that contacts the second adhesive portion 42. The contact region 20T preferably includes a third region T3 that contacts the third layer 3B and a fourth region T4 that connects to the third region T3 at the connection point Q2 and contacts the second layer 2B. This makes it possible to stop a crack that propagates inward between the second layer 2B and the third layer 3B at the connection point Q2.

[0123] 3, the number of layers of the second adhesive portion 42 exposed from the opening 70b of the bottomed recess 70 is preferably greater than the number of layers of the second adhesive portion 42 disposed in the deepest portion 70a of the bottomed recess 70. This results in a smaller number of interfaces between each layer on the deepest portion 70a side than on the opening 70b side. This prevents cracks that attempt to propagate inward along the interfaces between each layer from reaching the deepest portion 70a. In this embodiment, the number of layers of the second adhesive portion 42 exposed from the opening 70b is "3," and the number of layers of the second adhesive portion 42 disposed in the deepest portion 70a is "1."

[0124] The second adhesive portion 42 can be formed by applying a paste containing Cr oxide to the surface of at least one of the metal support 10 and the frame 20, and then performing a heat treatment while the metal support 10 and the frame 20 are in close contact with each other. The conditions for the heat treatment can be set appropriately, and can be, for example, 600°C or higher and 1100°C or lower, and 0.5 hours or higher and 24 hours or lower. The second adhesive portion 42 may be formed simultaneously with the first adhesive portion 41.

[0125] 2. Second embodiment

[0126] 4 is a cross-sectional view of an electrolytic cell 1a according to a second embodiment. The electrolytic cell 1a is an example of a "metal-supported electrochemical cell" according to the present invention.

[0127] The electrolytic cell 1a according to the second embodiment differs from the electrolytic cell 1 according to the first embodiment in that the interconnector 30 has an embossed portion 31 and a debossed portion 32, and that the chromium alloy container 3 has a third adhesive portion 43. These differences will be mainly described below.

[0128] In this embodiment, one of the metal support 10 and the interconnector 30 is an example of the "first alloy member" according to the present invention, and the other is an example of the "second alloy member" according to the present invention. In addition, the third adhesive portion 43 is an example of the "adhesive portion" according to the present invention.

[0129] As shown in Fig. 4, the interconnector 30 has a plurality of embossed portions 31 and a plurality of debossed portions 32. Although two embossed portions 31 and three debossed portions 32 are shown in Fig. 4, the numbers of the embossed portions 31 and the debossed portions 32 can be changed as appropriate.

[0130] The embossed portion 31 abuts against the second main surface 13 of the metal support 10. This allows the metal support 10 to be supported by the interconnector 30, thereby suppressing deflection of the metal support 10. Note that the embossed portion 31 only needs to abut against the metal support 10, and does not have to be joined to the metal support 10.

[0131] The debossed portion 32 protrudes toward the side opposite to the metal support 10. The debossed portion 32 abuts against an external power source or another electrolysis cell.

[0132] The third adhesive portion 43 adheres the embossed portion 31 to the metal support 10. The third adhesive portion 43 is disposed around the tip portion of the embossed portion 31. The tip portion of the embossed portion 31 refers to the portion of the embossed portion 31 that abuts against the metal support 10. The third adhesive portion 43 is preferably formed in a ring shape so as to surround the tip portion of the embossed portion 31. This can improve the adhesion between the embossed portion 31 and the metal support 10.

[0133] Here, Fig. 5 is a partially enlarged view of Fig. 4. Fig. 5 shows a cross section of the third adhesive portion 43. The cross section shown in Fig. 5 is perpendicular to the second main surface 13 of the metal support 10.

[0134] The third adhesive portion 43 is disposed between the metal support 10 and the embossed portion 31. The third adhesive portion 43 is sandwiched between the metal support 10 and the embossed portion 31. The third adhesive portion 43 is disposed on the metal support 10, and is formed in a ring shape so as to surround the tip portion of the embossed portion 31.

[0135] In this embodiment, the third adhesive portion 43 is embedded in a bottomed recess 80 formed between the metal support 10 and the embossed portion 31. The cross section of the bottomed recess 80 is wedge-shaped. The bottomed recess 80 has a deepest portion 80a and an opening 80b. The opening 80b opens toward the internal space 3a. The third adhesive portion 43 is exposed to the internal space 3a.

[0136] The third adhesive portion 43 is composed of Cr oxide. This makes it possible to suppress the diffusion of Cr from the metal support 10 and the embossed portion 31 to the third adhesive portion 43 during the manufacture or operation of the electrolysis cell 1a. Furthermore, even if Cr diffuses from the metal support 10 and the embossed portion 31 to the third adhesive portion 43, the effect on the composition of the third adhesive portion 43 is small, and therefore a decrease in the strength of the third adhesive portion 43 can also be suppressed. Furthermore, since the metal support 10, the embossed portion 31, and the third adhesive portion 43 all contain Cr, the mutual adhesion can be improved. Therefore, the adhesion between the metal support 10 and the embossed portion 31 can be maintained for a long period of time.

[0137] The Cr content of the metal elements in the Cr oxide constituting the third adhesive portion 43 can be, for example, 20 mol % or more and 100 mol % or less. The Cr content is preferably 50 mol % or more. This significantly prevents the Cr contained in the metal support 10 and the embossed portion 31 from diffusing into the third adhesive portion 43.

[0138] The Cr oxide constituting the third adhesive portion 43 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, and therefore can improve the durability of the third adhesive portion 43.

[0139] The Cr oxide constituting the third adhesive portion 43 is preferably crystalline, which can prevent the third adhesive portion 43 from being damaged due to a phase transition of the Cr oxide from amorphous to crystalline even when the electrolysis cell 1a is operated for a long period of time.

[0140] The Cr oxide constituting the third adhesive portion 43 preferably has a spinel or corundum crystal structure, which has high symmetry and can improve the thermal stress resistance of the third adhesive portion 43.

[0141] As shown in FIG. 5, the third adhesive portion 43 according to this embodiment is made up of a first layer 1C, a second layer 2C, and a third layer 3C.

[0142] The first layer 1C is disposed on the metal support 10. The first layer 1C is sandwiched between the metal support 10 and the second layer 2C. In this embodiment, the first layer 1C is made of Cr ２ O ３ It is composed of:

[0143] The second layer 2C is disposed between the first layer 1C and the embossed portion 31. In this embodiment, since the third adhesive portion 43 includes the third layer 3C, the second layer 2C is sandwiched between the first layer 1C and the third layer 3C. A portion of the second layer 2C fills the deepest portion 80a of the bottomed recess 80. The portion of the second layer 2C that fills the deepest portion 80a is sandwiched between the metal support 10 and the embossed portion 31.

[0144] The oxide constituting the second layer 2C is preferably different from the oxide constituting the first layer 1C. This makes it possible to stop cracks that attempt to propagate in the Z-axis direction from the first layer 1C toward the second layer 2C or from the second layer 2C toward the first layer 1C at the interface between the first layer 1C and the second layer 2C. In this embodiment, the second layer 2C is made of chromium manganese oxide.

[0145] The third layer 3C is disposed on the embossed portion 31. The third layer 3C is sandwiched between the second layer 2C and the embossed portion 31. The oxide constituting the third layer 3C is preferably different from the oxide constituting the second layer 2C. This allows cracks that attempt to propagate in the Z-axis direction from the second layer 2C toward the third layer 3C, or from the third layer 3C toward the second layer 2C, to be stopped at the interface between the second layer 2C and the third layer 3C. In this embodiment, the third layer 3C is made of Cr ２ O ３ It is composed of:

[0146] The oxide constituting the third layer 3C is preferably the same as the oxide constituting the first layer 1C, which makes the third adhesive portion 43 have a symmetrical structure in the thickness direction parallel to the Z-axis direction, thereby improving the mechanical reliability of the third adhesive portion 43.

[0147] The thickness of the first layer 1C 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 2C 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 3C 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 1C is obtained by arithmetically averaging thicknesses measured at three locations that divide the first layer 1C into four equal parts in a plane direction perpendicular to the Z-axis direction. The thicknesses of the second layer 2C and the third layer 3C are also obtained in the same manner as the thickness of the first layer 1C.

[0148] It is preferable that the thickness ratio of the thickest layer to the thinnest layer among the first layer 1C, the second layer 2C, and the third layer 3C is equal to or less than 5. By reducing the variation in thickness of each layer in this manner, the mechanical reliability of the third adhesive portion 43 can be improved.

[0149] 5 , the metal support 10 has a contact region 10W that contacts the third adhesive portion 43. In this embodiment, the contact region 10W is a part of the second main surface 13. The contact region 10W preferably includes a first region W1 that contacts the first layer 1C and a second region W2 that is connected to the first region W1 at a connection point R1 and contacts the second layer 2C. This makes it possible to stop a crack that propagates inward between the first layer 1C and the second layer 2C (i.e., toward the side away from the internal space 3a) at the connection point R1.

[0150] 5, the embossed portion 31 has a contact region 31W that contacts the third adhesive portion 43. The contact region 31W preferably includes a third region W3 that contacts the third layer 3C and a fourth region W4 that connects to the third region W3 at the connection point R2 and contacts the second layer 2C. This makes it possible to stop a crack that propagates inward between the second layer 2C and the third layer 3C at the connection point R2.

[0151] 5, the number of layers of the third adhesive portion 43 exposed from the opening 80b of the bottomed recess 80 is preferably greater than the number of layers of the third adhesive portion 43 arranged in the deepest portion 80a of the bottomed recess 80. This results in a smaller number of interfaces between each layer on the deepest portion 80a side than on the opening 80b side. This prevents cracks that attempt to propagate inward along the interfaces between each layer from reaching the deepest portion 80a. In this embodiment, the number of layers of the third adhesive portion 43 exposed from the opening 80b is "3," and the number of layers of the third adhesive portion 43 arranged in the deepest portion 80a is "1."

[0152] The third adhesive portion 43 can be formed by applying a paste containing Cr oxide to the surface of at least one of the metal support 10 and the embossed portion 31, and then performing a heat treatment while the metal support 10 and the embossed portion 31 are in close contact with each other. The conditions for the heat treatment can be set appropriately, and can be, for example, 800°C or higher and 1100°C or lower, and 0.5 hours or higher and 24 hours or lower. The third adhesive portion 43 may be formed simultaneously with the first and second adhesive portions 41, 42.

[0153] (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.

[0154] [Modification 1] In the first and second embodiments, the frame 20 and the interconnector 30 are separate members, but the frame 20 and the interconnector 30 may be an integrated member. In this case, the chromium alloy container 3 does not include the second seal portion 50.

[0155] [Modification 2] In the first and second embodiments, the metal support 10 and the frame 20 are separate members, but the metal support 10 and the frame 20 may be an integrated member. In this case, the chromium alloy container 3 does not include the first seal portion 40.

[0156] [Variation 3] In the first and second embodiments, the first adhesive portion 41 is configured by the first layer 1A, the second layer 2A, and the third layer 3A, but is not limited to this. The first adhesive portion 41 may have a single-layer structure or a multi-layer structure of two or four or more layers. When the first adhesive portion 41 has a multi-layer structure, it is sufficient that at least one layer is configured by Cr oxide.

[0157] [Modification 4] In the first and second embodiments, the second adhesive portion 42 is configured by the first layer 1B, the second layer 2B, and the third layer 3B, but is not limited to this. The second adhesive portion 42 may have a single-layer structure or a multi-layer structure of two or four or more layers. When the second adhesive portion 42 has a multi-layer structure, it is sufficient that at least one layer is configured by Cr oxide.

[0158] [Variation 5] In the second embodiment, the third adhesive portion 43 is configured by the first layer 1C, the second layer 2C, and the third layer 3C, but is not limited to this. The third adhesive portion 43 may have a single-layer structure or a multi-layer structure of two or four or more layers. When the third adhesive portion 43 has a multi-layer structure, it is sufficient that at least one layer is configured by Cr oxide.

[0159] [Variation 6] In the above first and second embodiments, the first seal portion 40 has the first adhesive portion 41 and the second adhesive portion 42, but it may have only one of the first adhesive portion 41 and the second adhesive portion 42.

[0160] Furthermore, although the second seal portion 50 has the same configuration as the first seal portion 40, it may have a different configuration from the first seal portion 40. The second seal portion 50 may have only one of the first adhesive portion 41 and the second adhesive portion 42.

[0161] [Variation 7] In the first and second embodiments, the metal support 10 and the frame body 20 are in close contact with or integrated with each other between the first adhesive portion 41 and the second adhesive portion 42, but this is not limiting. The metal support body 10 and the frame body 20 do not have to be in close contact with or integrated with each other.

[0162] [Variation 8] 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.

[0163] [Modification 9] In the above embodiment, the chromium alloy container according to the present invention is applied to an electrochemical cell, but the chromium alloy container can be used for various purposes. For example, the chromium alloy container can be used in a methanation reactor that synthesizes methane from hydrogen and carbon dioxide.

[0164] Examples of the chromium alloy container according to the present invention will be described below, but the present invention is not limited to the examples described below.

[0165] (Samples No. 1 to 7) Chromium alloy containers according to Samples No. 1 to 7 were fabricated as follows.

[0166] First, Cr is applied to the outer periphery of the second main surface 13 of the metal support 10. ２ O ３ and Mn ３ O ４ After applying a paste containing at least one of the above, the frame 20 was placed on the paste to prepare a laminate. ２ O ３ and Mn ３ O ４ By changing the amount of each compound added, the Cr content in the metal elements in the Cr oxide constituting the adhesive joint was changed, as shown in Table 1.

[0167] Next, the laminate was subjected to a heat treatment (1000°C, 1 hour) to form an adhesive portion made of Cr oxide from the paste, which adhered the metal support 10 and the frame 20. This completed a chromium alloy container with a single-layer adhesive portion. Note that in this example, the metal support 10 and the frame 20 were not welded or brazed.

[0168] Next, the composition of the Cr oxide constituting the bonded joint was analyzed using an EDS device to measure the Cr content among the metal elements in the Cr oxide. The Cr content at this time is shown in Table 1 as the "Cr content before heat endurance test."

[0169] Next, a heat endurance test was carried out by subjecting the chromium alloy container to a heat treatment (800° C., 1000 hours).

[0170] Next, the composition of the Cr oxide constituting the bonded joint was analyzed using an EDS device to measure the Cr content of the metal elements in the Cr oxide again. The Cr content at this time is shown in Table 1 as the "Cr content after the thermal durability test."

[0171]

[0172] As shown in Table 1, in Samples Nos. 3 to 6, in which the Cr content of the metal elements in the Cr oxide constituting the adhesive joint was set to 50 mol % or more, the amount of change in the Cr content before and after the heat endurance test was significantly reduced. This shows that by setting the Cr content of the metal elements in the Cr oxide constituting the adhesive joint to 50 mol % or more, it is possible to significantly suppress the diffusion of Cr contained in the metal support 10 and the frame 20 into the adhesive joint.

[0173] (Samples Nos. 8 to 14) Chromium alloy containers 3 (see FIG. 3) according to Samples Nos. 8 to 14 were fabricated as follows.

[0174] First, Cr was applied to the outer periphery of the second main surface 13 of the metal support 10. ２ O ３ paste containing MnCr ２ O ４ paste containing Cr ２ O ３ A laminate was fabricated by sequentially applying pastes containing the above ingredients and then placing a frame 20 on the pastes. In this case, by changing the amount of each paste applied, the thickness ratio of each of the first to third layers 1A to 3A and the first to third layers 1B to 3B was changed as shown in Table 2.

[0175] Next, the metal support body 10 and the frame body 20 were lap-welded to be integrated with each other between the first adhesive portion 41 and the second adhesive portion 42 .

[0176] Next, the laminate was subjected to a heat treatment (1000°C, 1 hour) to form the first and second adhesive portions 41, 42 made of Cr oxide from the paste, which bond the metal support 10 and the frame 20. In this way, the chromium alloy container 3 having the first and second adhesive portions 41, 42 with a three-layer structure was completed.

[0177] Next, a heat endurance test was carried out by subjecting the chromium alloy container 3 to a heat treatment (800° C., 1000 hours).

[0178] Next, the chromium alloy container 3 was cut along the thickness direction to expose a cross section of the first adhesive portion 41 along the thickness direction.

[0179] Next, the thickness of each of the first to third layers 1A to 3A was measured in the cross section of the first adhesive portion 41 using the method described in the above embodiment, and the thickness ratio of the thickest layer to the thinnest layer was calculated based on each measured thickness. The calculated thickness ratios are shown in Table 2.

[0180] Next, the cross section of the first adhesive portion 41 was observed with an SEM to check for the presence or absence of cracks inside the first adhesive portion 41. Table 2 shows the results of the crack detection.

[0181]

[0182] As shown in Table 2, no cracks occurred even after the heat endurance test in Samples No. 8 to 12, in which the thickness ratio of the thickest layer to the thinnest layer among the first to third layers 1A to 3A was set to 5 or less. This shows that the mechanical reliability of the first adhesive portion 41 can be improved by setting the thickness ratio of the thickest layer to the thinnest layer among the first to third layers 1A to 3A to 5 or less.

[0183] Although not shown in Table 2, the same results as those of the first adhesive portion 41 were obtained in the second adhesive portion 42.

[0184] REFERENCE SIGNS LIST 1, 1a Electrolytic cell 2 Cell main body 3 Chromium alloy container 3a Internal space 6 Hydrogen electrode 7 Electrolyte 8 Reaction prevention layer 9 Oxygen electrode 10 Metal support 11 Supply hole 12 First main surface 13 Second main surface 20 Frame 30 Interconnector 31 Embossed portion 40 First seal portion 41 First adhesive portion 42 Second adhesive portion 43 Third adhesive portion 1A, 1B, 1C First layer 2A, 2B, 2C Second layer 3A, 3B, 3C Third layer 50 Second seal portion

Claims

1. A chromium alloy container comprising: a first alloy member made of an alloy containing chromium; a second alloy member made of an alloy containing chromium; and an adhesive portion for bonding the first alloy member and the second alloy member, wherein the adhesive portion is made of an oxide mainly composed of chromium.

2. The chromium alloy container according to claim 1, wherein the chromium content in the metal elements in the oxide is 50 mol % or more.

3. The chromium alloy container according to claim 1 or 2, wherein the oxide is at least one of chromium oxide and chromium manganese oxide.

4. The chromium alloy container according to claim 1, wherein the oxide is crystalline.

5. The chromium alloy container according to claim 4, wherein the oxide has a spinel or corundum type crystal structure.

6. The chromium alloy container according to claim 1, wherein the adhesive portion has a first layer disposed on the first alloy member and a second layer disposed between the first layer and the second alloy member, and an oxide constituting the second oxide layer is different from an oxide constituting the first oxide layer.

7. The chromium alloy container according to claim 6, wherein the adhesive 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.

8. The chromium alloy container according to claim 7, wherein the ratio of the thickness of the thickest layer to the thinnest layer among the first layer, the second layer and the third layer is 5 or less.

9. A chromium alloy container according to any one of claims 6 to 8, wherein a contact area of ​​the surface of the first alloy component that contacts the adhesive portion includes a first area that contacts the first layer and a second area that contacts the second layer, and the second area is connected to the first area.

10. The chromium alloy container according to claim 9, wherein the adhesive portion is embedded in a bottomed recess formed between the first alloy member and the second alloy member, and the number of layers of the adhesive portion exposed from an opening of the bottomed recess is greater than the number of layers of the adhesive portion disposed in the deepest portion of the bottomed recess.

11. The chromium alloy container according to claim 1, wherein the adhesive portion is a seal for sealing the internal space.

12. The chromium alloy container according to claim 1, wherein the second alloy member has an embossed portion that abuts against the first alloy member, and the adhesive portion adheres the embossed portion to the first alloy member.

13. A metal-supported electrochemical cell comprising: a chromium alloy container as described in claim 1; and a cell body portion arranged on the chromium alloy container, wherein the first alloy member has a plurality of communicating holes leading to the internal space, and the cell body portion is arranged on the first alloy member so as to cover the plurality of communicating holes.

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