Chromium alloy container and metal support type electrochemical cell

Abstract

A chromium alloy container (3) is provided with: a metal support (10) configured from an alloy containing chromium; a frame (20) configured from an alloy containing chromium; and a first seal (40) interposed between the metal support (10) and the frame (20). The first seal (40) includes: an oxide adhesive layer (41) composed of a Cr oxide; and metal connection sections (42) that are embedded in the oxide adhesive layer (41) and that connect the metal support (10) and the frame (20).

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 the bonding strength between the alloy members for a long period of time. This is a problem common to chromium alloy containers in general, not limited to containers that house 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 the bondability between alloy members for a long period of time.

[0008] A chromium alloy container according to a first aspect of the present invention has an internal space. The chromium alloy container includes a first alloy member made of an alloy containing chromium, a second alloy member made of an alloy containing chromium, and an insert member interposed between the first alloy member and the second alloy member. The insert member has an oxide bonding layer made of an oxide mainly containing chromium, and a metal connecting member embedded in the oxide bonding layer to connect the first alloy member and the second alloy member.

[0009] A chromium alloy container according to a second aspect of the present invention is related to the first aspect, wherein the metal connecting portion contains, as a main component, the same element as a main component of at least one of the first alloy member and the second alloy member.

[0010] A chromium alloy container according to a third aspect of the present invention is the chromium alloy container according to the first or second aspect, wherein the metal connecting portion contains chromium.

[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 ratio of the minimum width of the metal connecting portion in the surface direction to the thickness of the oxide adhesive layer in the thickness direction is 0.3 or more.

[0012] A chromium alloy container according to a fifth aspect of the present invention is the chromium alloy container according to any one of the first to fourth aspects, wherein the ratio of the longest distance between the metal connecting portions in the surface direction to the thickness of the oxide adhesive layer in the thickness direction is 20 or less.

[0013] A chromium alloy container according to a sixth aspect of the present invention is the chromium alloy container according to any one of the first to fifth aspects, wherein the ratio of the thickness of the first alloy member or the second alloy member in the thickness direction to the minimum width of the metal connecting portion in the surface direction is 50 or more.

[0014] A chromium alloy container according to a seventh aspect of the present invention relates to any one of the first to sixth aspects, wherein the ratio of the thickness of the first alloy member or the second alloy member in the thickness direction to the minimum width of the metal connecting portion in the surface direction is 2000 or less.

[0015] A chromium alloy container according to an eighth aspect of the present invention is the chromium alloy container according to any one of the first to seventh aspects, wherein the chromium content of the metal elements in the oxide adhesion layer is 50 mol % or more.

[0016] A chromium alloy container according to a ninth aspect of the present invention is the chromium alloy container according to any one of the first to eighth aspects, wherein the oxide adhesion layer is made of at least one of chromium oxide and chromium manganese oxide.

[0017] A chromium alloy container according to a tenth aspect of the present invention is the chromium alloy container according to any one of the first to ninth aspects, wherein the oxide adhesion layer is crystalline.

[0018] A chromium alloy container according to an eleventh aspect of the present invention is the chromium alloy container according to the tenth aspect, wherein the oxide adhesion layer has a spinel or corundum type crystal structure.

[0019] A chromium alloy container according to a twelfth aspect of the present invention relates to any one of the first to eleventh aspects, wherein the insertion portion is a seal for sealing the internal space.

[0020] A thirteenth aspect of the present invention relates to any one of the first to twelfth aspects, and the second alloy member has an embossed portion that contacts the first alloy member. The insertion portion bonds the embossed portion to the first alloy member.

[0021] A metal-supported electrochemical cell according to a fourteenth aspect of the present invention comprises the chromium alloy container according to any one of the first to thirteenth 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.

[0022] According to the present invention, it is possible to provide a chromium alloy container and a metal-supported electrochemical cell that can maintain the bondability between alloy members for a long period of time.

[0023] 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.

[0024] 1. First embodiment

[0025] (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.

[0026] The electrolysis cell 1 is an example of a "metal-supported electrochemical cell" according to the present invention.

[0027] 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.

[0028] As shown in FIGS. 1 and 2, the electrolytic cell 1 includes a cell body 2 and a chromium alloy container 3 .

[0029] (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).

[0030] 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.

[0031] [Hydrogen Electrode 6 ] The hydrogen electrode 6 is disposed on the first main surface 12 of the metal support 10 .

[0032] 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).

[0033] The raw material gas is H ２When the raw material gas contains only O, the hydrogen electrode 6 converts H ２ Generate.

[0034] Hydrogen electrode 6: H ２ O + 2e － →H ２ +O ２－ ...(1)

[0035] 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.

[0036] 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)

[0037] 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.

[0038] 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).

[0039] 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.

[0040] 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.

[0041] 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.

[0042] [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.

[0043] 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 .

[0044] 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.

[0045] 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.

[0046] 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.

[0047] [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.

[0048] The reaction prevention layer 8 is made of an oxide ion conductive material, such as GDC or SDC.

[0049] 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.

[0050] 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.

[0051] [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.

[0052] 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.

[0053] Oxygen electrode 9:2O ２－ →O ２ +4e － ...(5)

[0054] 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).

[0055] 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.

[0056] 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.

[0057] (Chromium alloy vessel 3) The chromium alloy vessel 3 contains a raw material gas supplied to the hydrogen electrode 6 and a reducing gas (H ２ ) and has an internal space 3a through which the

[0058] 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.

[0059] In this embodiment, one of the metal support 10 and the frame body 20 is an example of a "first alloy member" according to the present invention, and the other is an example of a "second alloy member" according to the present invention. Also, in this embodiment, one of the frame body 20 and the interconnector 30 is an example of a "first alloy member" according to the present invention, and the other is an example of a "second alloy member" according to the present invention. Each of the first seal portion 40 and the second seal portion 50 is an example of an "insertion portion" according to the present invention.

[0060] [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.

[0061] 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.

[0062] 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 .

[0063] 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.

[0064] Each supply hole 11 can be formed by mechanical processing (for example, punching), laser processing, chemical processing (for example, etching), or the like.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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).

[0069] [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.

[0070] 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 .

[0071] 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.

[0072] 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.

[0073] [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.

[0074] In this embodiment, the interconnector 30 is formed in a plate shape. The interconnector 30 may be in a flat plate shape or a curved plate shape.

[0075] The interconnector 30 is joined to the frame 20 via the second seal portion 50 .

[0076] 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.

[0077] 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.

[0078] [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.

[0079] The first seal portion 40 is formed in an annular shape. The first seal portion 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 portion 40 will be described later.

[0080] [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.

[0081] The second seal portion 50 is formed in an annular shape. The second seal portion 50 seals the gap between the frame body 20 and the interconnector 30. 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 frame body 20 and the interconnector 30.

[0082] 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.

[0083] (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 first main surface 12 of the metal support body 10.

[0084] The first sealing portion 40 includes an oxide adhesive layer 41 and a metal connecting portion 42 .

[0085] [Oxide Adhesion Layer 41] The oxide adhesion layer 41 is disposed between the metal support 10 and the frame 20. The oxide adhesion layer 41 is sandwiched between the metal support 10 and the frame 20. The oxide adhesion layer 41 is formed in a ring shape so as to surround the internal space 3 a. The oxide adhesion layer 41 is exposed to the internal space 3 a.

[0086] The oxide adhesive layer 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 oxide adhesive layer 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 oxide adhesive layer 41, the effect on the composition of the oxide adhesive layer 41 is small, and therefore a decrease in the strength of the oxide adhesive layer 41 can be suppressed. Furthermore, since the metal support 10, the frame 20, and the oxide adhesive layer 41 all contain Cr, the mutual bonding strength can be improved. Therefore, the bonding strength 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 oxide adhesive layer 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 oxide adhesion layer 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 oxide adhesion layer 41.

[0089] The Cr oxide constituting the oxide adhesion layer 41 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 oxide adhesion layer 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 oxide adhesive layer 41 is preferably crystalline, which can prevent the oxide adhesive layer 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 oxide adhesive layer 41 preferably has a spinel or corundum crystal structure. These crystal structures have high symmetry, which can improve the thermal stress resistance of the oxide adhesive layer 41. Furthermore, Cr oxides having these crystal structures have good bonding properties at the interfaces with the metal support 10 and the frame 20, which are made of a Cr-containing alloy, and can therefore improve the bonding strength between the oxide adhesive layer 41 and the metal support 10 and the frame 20, respectively.

[0093] [Metal connecting portion 42] The metal connecting portion 42 is embedded in the oxide adhesive layer 41. The metal connecting portion 42 extends along a thickness direction perpendicular to the first main surface 12 of the metal support 10. The metal connecting portion 42 penetrates the oxide adhesive layer 41 in the thickness direction. When viewed three-dimensionally, the metal connecting portion 42 is columnar. The outer peripheral surface of the metal connecting portion 42 is surrounded by the oxide adhesive layer 41.

[0094] The metal connecting portion 42 connects the metal support 10 and the frame body 20. One end of the metal connecting portion 42 is connected to the metal support body 10, and the other end of the metal connecting portion 42 is connected to the frame body 20. The metal connecting portion 42 may be substantially integral with at least one of the metal support body 10 and the frame body 20.

[0095] By embedding the metal connecting portions 42 in the oxide adhesive layer 41, cracks that occur in the oxide adhesive layer 41 can be stopped at the metal connecting portions 42. Therefore, brittle fracture of the oxide adhesive layer 41 can be suppressed, and the bond between the metal support 10 and the frame body 20 can be maintained for a longer period of time.

[0096] Although three metal connecting portions 42 are shown in FIG. 3, the number of metal connecting portions 42 in one cross section is not particularly limited as long as it is one or more.

[0097] 3 shows, from the left, a metal connecting portion 42 with a barrel-shaped cross section, a metal connecting portion 42 with a tilted cross section, and a metal connecting portion 42 with a constricted cross section. When the cross section of the metal connecting portion 42 is constricted, the interfacial area between the metal connecting portion 42 and the metal support body 10 and the frame body 20 can be increased, thereby improving the interfacial strength between the two. When the cross section of the metal connecting portion 42 is barrel-shaped or tilted, the volume of the metal connecting portion 42 itself can be increased, thereby further improving the crack stopping effect.

[0098] 3, the cross-sectional shapes of the metal connecting portions 42 are different from one another, but the cross-sectional shapes of the metal connecting portions 42 may be the same. The cross-sectional shape of the metal connecting portions 42 may also be a shape other than the shape shown in FIG. 3. The cross-sectional shape of each metal connecting portion 42 is preferably set in consideration of the balance between improving the interfacial strength by increasing the interfacial area between the metal supporting body 10 and the metal connecting portion 42 and between the metal supporting body 10 and the frame body 20 and improving the crack stopping effect by increasing the volume of the metal connecting portion 42.

[0099] The metal connecting portion 42 is made of metal. It is preferable that the metal connecting portion 42 contains, as its main component, the same element as the main component of at least one of the metal support 10 and the frame body 20. This makes it possible to suppress changes in the composition of the metal connecting portion 42 due to elemental diffusion from the metal support 10 and the frame body 20. For example, the metal connecting portion 42 can contain Cr or Fe as its main component. Incidentally, "containing Cr or Fe as its main component" means that the metal connecting portion 42 exhibits the maximum content when subjected to elemental analysis.

[0100] Furthermore, the metal connecting portion 42 preferably contains Cr, which can improve the oxidation resistance of the metal connecting portion 42.

[0101] The ratio of the minimum width W1 of the metal connecting portion 42 in the surface direction to the thickness of the oxide adhesive layer 41 in the thickness direction is preferably 0.3 or more. This ensures the strength of the metal connecting portion 42, thereby preventing damage to the metal connecting portion 42 due to cracks. The surface direction is the direction perpendicular to the thickness direction.

[0102] The thickness of the adhesive layer 41 is the arithmetic average of the thicknesses of the oxide adhesive layer 41 at three locations that divide the oxide adhesive layer 41 into four equal parts in the surface direction. However, if the location where the thickness is to be measured overlaps with the metal connecting portion 42, the thickness of the oxide adhesive layer 41 may be measured at any location close to the metal connecting portion 42. The thickness of the adhesive layer 41 is not particularly limited, but may be, for example, 0.3 μm or more and 30 μm or less.

[0103] The minimum width W1 of the metal connecting portion 42 is the smallest measured value when the width of the metal connecting portion 42 in the surface direction is measured at 10 locations that divide the metal connecting portion 42 into 11 equal parts in the thickness direction. The value of the minimum width W1 of the metal connecting portion 42 is not particularly limited, but can be, for example, 0.05 μm or more and 5 μm or less.

[0104] When a plurality of metal connectors 42 are present, the ratio of the longest distance D1 between the metal connectors 42 in the surface direction to the thickness of the oxide adhesive layer 41 in the thickness direction is preferably 20 or less. This allows the plurality of metal connectors 42 to be arranged in a narrow range in the surface direction, thereby preventing long cracks from occurring in the oxide adhesive layer 41. As a result, peeling of the oxide adhesive layer 41 from the metal support 10 and the frame 20 due to long cracks can be prevented.

[0105] The maximum distance D1 between the metal connecting portions 42 is the maximum distance between two straight lines that are parallel to the thickness direction and inscribed in the outlines of the side surfaces of the two opposing metal connecting portions 42. The value of the maximum distance D1 is not particularly limited, but can be, for example, 1 μm or more and 100 μm or less.

[0106] The ratio of the thickness of the metal support 10 or the frame body 20 in the thickness direction to the minimum width W1 of the metal connecting portion 42 in the surface direction is preferably equal to or less than 2000. This prevents the metal support 10 or the frame body 20 from becoming excessively thick (i.e., the metal connecting portion 42 from becoming excessively thin), thereby ensuring the strength of the metal connecting portion 42.

[0107] The ratio of the thickness of the metal support body 10 or the frame body 20 in the thickness direction to the minimum width W1 of the metal connecting portion 42 in the surface direction is preferably equal to or greater than 50. This prevents the metal support body 10 or the frame body 20 from becoming excessively thin (i.e., the metal connecting portion 42 from becoming excessively thick), thereby increasing the rigidity of the first seal portion 40.

[0108] The metal connecting portion 42 is preferably located away from the internal space 3 a. Specifically, the metal connecting portion 42 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 reduction gas (H ２ ) can prevent the metal connecting portion 42 from becoming embrittled. The central portion in the surface direction is the portion located in the center when the oxide adhesive layer 41 is divided into three equal parts in the surface direction. The peripheral portion in the surface direction is the portion located on the external space 3b side of the central portion in the surface direction when the oxide adhesive layer 41 is divided into three equal parts in the surface direction.

[0109] The first seal portion 40 can be formed as follows. First, a paste containing Cr oxide and metal particles is applied to the surface of at least one of the metal support 10 and the frame 20. At this time, the amount of paste applied is adjusted so that the thickness of the applied paste is approximately the same as the average particle size of the metal particles. Next, the paste is fired to form the first seal portion 40. The metal particles are connected to the metal support 10 and the frame 20 as elements diffuse between them. The firing conditions can be set as appropriate, but can be, for example, 600°C to 1100°C and 0.5 hours to 24 hours.

[0110] 2. Second embodiment

[0111] 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.

[0112] 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 joint portion 60. These differences will be mainly described below.

[0113] In this embodiment, one of the metal support 10 and the interconnector 30 is an example of a "first alloy member" according to the present invention, and the other is an example of a "second alloy member" according to the present invention. In addition, the joint portion 60 is an example of an "insertion portion" according to the present invention.

[0114] 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.

[0115] 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 need to be fixed to the metal support 10.

[0116] 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.

[0117] The joint 60 joins the embossed portion 31 to the metal support 10. The joint 60 is arranged 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 joint 60 is preferably formed in a ring shape so as to surround the tip portion of the embossed portion 31. This can improve the bonding between the embossed portion 31 and the metal support 10.

[0118] Here, Fig. 5 is a partially enlarged view of Fig. 4. Fig. 5 shows a cross section of the joint 60. The cross section shown in Fig. 5 is perpendicular to the second main surface 13 of the metal support 10.

[0119] The joint 60 is disposed between the metal support 10 and the embossed portion 31. The joint 60 is sandwiched between the metal support 10 and the embossed portion 31. The joint 60 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.

[0120] In this embodiment, the bonding portion 60 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 bonding portion 60 is exposed to the internal space 3 a.

[0121] The joint 60 includes an oxide adhesion layer 43 and a metal interconnect 44 .

[0122] [Oxide Adhesion Layer 43] The oxide adhesion layer 43 is disposed between the metal support 10 and the embossed portion 31. The oxide adhesion layer 43 is sandwiched between the metal support 10 and the embossed portion 31. The oxide adhesion layer 43 is formed in a ring shape so as to surround the tip portion of the embossed portion 31. The oxide adhesion layer 43 is exposed to the internal space 3 a.

[0123] The oxide adhesive layer 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 oxide adhesive layer 43 during the manufacture or operation of the electrolysis cell 1. Furthermore, even if Cr diffuses from the metal support 10 and the embossed portion 31 to the oxide adhesive layer 43, the effect on the composition of the oxide adhesive layer 43 is small, and therefore a decrease in the strength of the oxide adhesive layer 43 can be suppressed. Furthermore, since the metal support 10, the embossed portion 31, and the oxide adhesive layer 43 all contain Cr, the mutual bonding strength can be improved. Therefore, the bonding strength between the metal support 10 and the embossed portion 31 can be maintained for a long period of time.

[0124] The Cr content of the metal elements in the Cr oxide constituting the oxide adhesion layer 43 is preferably 50 mol % or more, which significantly suppresses the diffusion of Cr contained in the metal support 10 and the embossed portion 31 into the oxide adhesion layer 43.

[0125] The Cr oxide constituting the oxide adhesion layer 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 oxide adhesion layer 43.

[0126] The Cr oxide constituting the oxide adhesive layer 43 is preferably crystalline, which can prevent the oxide adhesive layer 43 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.

[0127] The Cr oxide constituting the oxide adhesive layer 43 preferably has a spinel or corundum crystal structure. These crystal structures have high symmetry, which can improve the thermal stress resistance of the oxide adhesive layer 43. Furthermore, Cr oxides having these crystal structures have good bonding properties at the interfaces with the metal support 10 and the embossed portion 31, which are made of a Cr-containing alloy, and can therefore improve the bonding strength between the oxide adhesive layer 43 and each of the metal support 10 and the embossed portion 31.

[0128] [Metal connecting portion 44] The metal connecting portion 44 is embedded in the oxide adhesive layer 43. The metal connecting portion 44 extends along a thickness direction perpendicular to the first main surface 12 of the metal support 10. The metal connecting portion 44 penetrates the oxide adhesive layer 43 in the thickness direction. When viewed three-dimensionally, the metal connecting portion 44 is columnar. The side surfaces of the metal connecting portion 44 are surrounded by the oxide adhesive layer 43.

[0129] The metal connecting portion 44 connects the metal support 10 and the embossed portion 31. One end of the metal connecting portion 44 is connected to the metal support 10, and the other end of the metal connecting portion 44 is connected to the embossed portion 31. The metal connecting portion 44 may be substantially integral with at least one of the metal support 10 and the embossed portion 31.

[0130] By embedding the metal connecting portion 44 in the oxide adhesive layer 43, cracks that occur in the oxide adhesive layer 43 can be stopped at the metal connecting portion 44. Therefore, brittle fracture of the oxide adhesive layer 43 can be suppressed, and the bond between the metal support 10 and the embossed portion 31 can be maintained for a longer period of time.

[0131] Although two metal connecting portions 44 are shown in FIG. 5, the number of metal connecting portions 44 in one cross section is not particularly limited as long as it is one or more.

[0132] 5 shows, from the left, a metal connecting portion 44 with a constricted cross section and a metal connecting portion 44 with a linear cross section. Although the cross-sectional shapes of the metal connecting portions 44 are different from one another in FIG. 5, the cross-sectional shapes of the metal connecting portions 44 may be the same. Furthermore, the cross-sectional shapes of the metal connecting portions 44 may be shapes other than those shown in FIG. 5.

[0133] The metal connecting portion 44 is made of metal. It is preferable that the metal connecting portion 44 contains, as a main component, the same element as the main component of at least one of the metal support 10 and the embossed portion 31. This makes it possible to suppress changes in the composition of the metal connecting portion 44 due to element diffusion from the metal support 10 and the embossed portion 31. For example, the metal connecting portion 44 can contain Cr or Fe as a main component.

[0134] Furthermore, it is preferable that the metal connecting portion 44 contains Cr, which can improve the oxidation resistance of the metal connecting portion 44.

[0135] The ratio of the minimum width W2 of the metal connecting portion 44 in the surface direction to the thickness of the oxide adhesive layer 43 in the thickness direction is preferably 0.3 or more. This ensures the strength of the metal connecting portion 44, thereby preventing damage to the metal connecting portion 44 due to cracks. The surface direction is the direction perpendicular to the thickness direction.

[0136] The thickness of the adhesive layer 43 is the arithmetic average of the thicknesses of the oxide adhesive layer 43 at three locations that divide the oxide adhesive layer 43 into four equal parts in the surface direction. However, if the location where the thickness is to be measured overlaps with the metal connecting portion 44, the thickness of the oxide adhesive layer 43 may be measured at any location close to the metal connecting portion 44. The thickness of the adhesive layer 43 is not particularly limited, but may be, for example, 0.3 μm or more and 30 μm or less.

[0137] The minimum width W2 of the metal connecting portion 44 is the smallest measured value when the width of the metal connecting portion 44 in the surface direction is measured at 10 locations that divide the metal connecting portion 44 into 11 equal parts in the thickness direction. The value of the minimum width W2 of the metal connecting portion 44 is not particularly limited, but can be, for example, 0.05 μm or more and 5 μm or less.

[0138] When a plurality of metal connectors 44 are present, the ratio of the longest distance D2 between the metal connectors 44 in the surface direction to the thickness of the oxide adhesive layer 43 in the thickness direction is preferably 20 or less. This allows the plurality of metal connectors 44 to be arranged in a narrow range in the surface direction, thereby preventing long cracks from occurring in the oxide adhesive layer 43. As a result, peeling of the oxide adhesive layer 43 from the metal support 10 and the embossed portion 31 due to long cracks can be prevented.

[0139] The maximum distance D2 between the metal connecting portions 44 is the maximum distance between two straight lines that are parallel to the thickness direction and inscribed in the outlines of the side surfaces of the two opposing metal connecting portions 44. The value of the maximum distance D2 is not particularly limited, but can be, for example, 1 μm or more and 100 μm or less.

[0140] The ratio of the thickness of the metal support 10 or the embossed portion 31 in the thickness direction to the minimum width W2 of the metal connecting portion 44 in the surface direction is preferably equal to or less than 2000. This prevents the metal support 10 or the embossed portion 31 from becoming excessively thick (i.e., the metal connecting portion 44 from becoming excessively thin), thereby ensuring the strength of the metal connecting portion 44.

[0141] The ratio of the thickness of the metal support 10 or the embossed portion 31 in the thickness direction to the minimum width W2 of the metal connecting portion 44 in the surface direction is preferably equal to or greater than 50. This prevents the metal support 10 or the embossed portion 31 from becoming excessively thin (i.e., the metal connecting portion 44 from becoming excessively thick), thereby increasing the rigidity of the joint 60.

[0142] The metal connecting portion 44 is preferably located away from the internal space 3a. Specifically, the metal connecting portion 44 is preferably located at least one of the central portion in the surface direction and the inner peripheral portion in the surface direction. This allows the reduction gas (H ２ ) can prevent the metal connecting portion 44 from becoming embrittled. The central portion in the surface direction is the portion located in the center when the oxide adhesive layer 43 is divided into thirds in the surface direction. The inner peripheral portion in the surface direction is the portion located on the opposite side of the internal space 3 a from the central portion in the surface direction when the oxide adhesive layer 43 is divided into thirds in the surface direction.

[0143] The joint 60 can be formed as follows. First, a paste containing Cr oxide and metal particles is applied to the surface of at least one of the metal support 10 and the embossed portion 31. At this time, the amount of paste applied is adjusted so that the thickness of the applied paste is approximately the same as the average particle size of the metal particles. Next, the paste is fired to form the joint 60. The metal particles are connected to the metal support 10 and the embossed portion 31 as elements diffuse between them. The firing conditions can be set as appropriate, but can be, for example, 600°C to 1100°C and 0.5 hours to 24 hours.

[0144] (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.

[0145] [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.

[0146] [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.

[0147] [Modification 3] In the first and second embodiments, the oxide adhesion layer 41 has a single-layer structure, but is not limited to this. The oxide adhesion layer 41 may have a multi-layer structure of two or more layers, each layer being made of Cr oxides with a different composition.

[0148] [Modification 4] In the second embodiment, the oxide adhesion layer 43 has a single-layer structure, but is not limited to this. The oxide adhesion layer 43 may have a multi-layer structure of two or more layers each composed of Cr oxides with different compositions.

[0149] [Variation 5] In the first embodiment, the metal support body 10 and the frame body 20 may be partially welded or brazed to each other. In this case, the first seal portion 40 may be divided in the surface direction by welding or brazing the metal support body 10 and the frame body 20 to each other.

[0150] In the first embodiment, the frame body 20 and the interconnector 30 may be partially welded or brazed together. In this case, the second seal portion 50 may be divided in the planar direction by welding or brazing the frame body 20 and the interconnector 30 together.

[0151] In the second embodiment, the metal support 10 and the embossed portion 31 may be partially welded or brazed to each other. In this case, the joint 60 may be divided in the planar direction by the welding or brazing of the metal support 10 and the embossed portion 31.

[0152] [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.

[0153] [Modification 7] 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.

[0154] 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.

[0155] (Samples No. 1 to 5) Chromium alloy containers 3 (see FIG. 3) according to Samples No. 1 to 5 were fabricated as follows.

[0156] First, Cr was applied to the outer periphery of the second main surface 13 of the metal support 10. ２ O ３ A paste containing metal particles (specifically, SUS430 particles) was applied to the laminate, and then the frame 20 was placed on the paste to fabricate the laminate. At this time, the minimum width W1 of the metal connecting portion 42 was changed by changing the particle size of the metal particles.

[0157] Next, the laminate was subjected to a heat treatment (1000°C, 1 hour) to form the first seal portion 40 from the paste, which was composed of the oxide adhesive layer 41 and the metal connecting portion 42. In this way, the chromium alloy container 3 equipped with the first seal portion 40 was completed.

[0158] Next, the chromium alloy container 3 was subjected to a thermal cycle test in which the temperature was increased from room temperature to 800°C at a rate of 200°C / hr, and then decreased from 800°C to room temperature at a rate of 200°C / hr, repeated 10 times.

[0159] Next, the chromium alloy container 3 was cut along the thickness direction to expose a cross section of the first seal portion 40 along the thickness direction.

[0160] Next, as described in the above embodiment, the cross section of the first sealing portion 40 was observed with an SEM (5000x magnification) to measure the ratio of the minimum width W1 of the metal connecting portion 42 to the thickness of the oxide adhesive layer 41. The measurement results of this ratio are shown in Table 1.

[0161] Next, the cross section of the first seal portion 40 was observed with an SEM (5000x magnification) to check for the presence or absence of cracks at the joints between the metal support body 10 and the metal connecting portion 42 and between the frame body 20 and the metal connecting portion 42. The crack confirmation results are shown in Table 1.

[0162]

[0163] As shown in Table 1, in Samples No. 1 to 4 in which the ratio of the minimum width W1 of the metal connecting portion 42 to the thickness of the oxide adhesive layer 41 was 0.3 or more, it was possible to suppress the occurrence of cracks at the joints between the metal support 10 and the metal connecting portion 42 and between the metal support 10 and the frame 20 and between the metal connecting portion 42 and the frame 20. This shows that the strength of the metal connecting portion 42 can be ensured by setting the ratio of the minimum width W1 of the metal connecting portion 42 to the thickness of the oxide adhesive layer 41 to 0.3 or more.

[0164] Although not shown in Table 1, the same results as those of the first seal portion 40 were obtained for the second seal portion 50.

[0165] (Samples Nos. 6 to 10) Chromium alloy containers 3 (see FIG. 3) according to Samples Nos. 6 to 10 were fabricated as follows.

[0166] First, Cr was applied to the outer periphery of the second main surface 13 of the metal support 10. ２ O ３ A paste containing metal particles (specifically, SUS430 particles) was applied to the laminate, and then the frame 20 was placed on the paste to fabricate the laminate. At this time, the maximum distance D1 between the metal connecting portions 42 was changed by changing the amount of metal particles added.

[0167] Next, the laminate was subjected to a heat treatment (1000°C, 1 hour) to form the first seal portion 40 from the paste, which was composed of the oxide adhesive layer 41 and the metal connecting portion 42. In this way, the chromium alloy container 3 equipped with the first seal portion 40 was completed.

[0168] Next, the chromium alloy container 3 was subjected to a thermal cycle test in which the temperature was increased from room temperature to 800°C at a rate of 200°C / hr, and then decreased from 800°C to room temperature at a rate of 200°C / hr, repeated 10 times.

[0169] Next, the chromium alloy container 3 was cut along the thickness direction to expose a cross section of the first seal portion 40 along the thickness direction.

[0170] Next, as described in the above embodiment, the cross section of the first sealing portion 40 was observed with an SEM (5000x magnification) to measure the ratio of the longest distance D1 between the metal connecting portions 42 to the thickness of the oxide adhesive layer 41. The measurement results of this ratio are shown in Table 2.

[0171] Next, the cross section of the first sealing portion 40 was observed with an SEM (5000x magnification) to check whether the oxide adhesive layer 41 had locally peeled off from the metal support 10 and the frame 20 near the cracks that had occurred in the oxide adhesive layer 41. The peeling confirmation results are shown in Table 2.

[0172]

[0173] As shown in Table 2, in samples Nos. 6 to 9, in which the ratio of the longest distance D1 between the metal connectors 42 to the thickness of the oxide adhesive layer 41 was set to 20 or less, peeling of the oxide adhesive layer 41 was suppressed. This shows that by setting the ratio of the longest distance D1 between the metal connectors 42 to the thickness of the oxide adhesive layer 41 to 20 or less, local peeling due to cracks in the oxide adhesive layer 43 can be suppressed.

[0174] Although not shown in Table 2, the same results as those of the first seal portion 40 were obtained for the second seal portion 50.

[0175] (Samples Nos. 11 to 18) Chromium alloy containers 3 (see FIG. 3) according to Samples Nos. 11 to 18 were fabricated as follows.

[0176] First, Cr was applied to the outer periphery of the second main surface 13 of the metal support 10. ２ O ３ A paste containing metal particles (specifically, SUS430 particles) was applied to the laminate, and then the frame 20 was placed on the paste to fabricate the laminate. At this time, the minimum width W1 of the metal connecting portion 42 was changed by changing the particle size of the metal particles.

[0177] Next, the laminate was subjected to a heat treatment (1000°C, 1 hour) to form the first seal portion 40 from the paste, which was composed of the oxide adhesive layer 41 and the metal connecting portion 42. In this way, the chromium alloy container 3 equipped with the first seal portion 40 was completed.

[0178] Next, the chromium alloy container 3 was subjected to a thermal cycle test in which the temperature was increased from room temperature to 800°C at a rate of 200°C / hr, and then decreased from 800°C to room temperature at a rate of 200°C / hr, repeated 10 times.

[0179] Next, the chromium alloy container 3 was cut along the thickness direction to expose a cross section of the first seal portion 40 along the thickness direction.

[0180] Next, as explained in the above embodiment, the ratio of the thickness of the metal support 10 to the minimum width W1 of the metal connecting portion 42 was measured. Table 3 shows the measurement results of this ratio.

[0181] Next, the cross section of the first seal portion 40 was observed with an SEM (5000x magnification) to check for the presence or absence of cracks at the joints between the metal support 10 and the metal connecting portion 42 and between the metal support 10 and the frame 20, respectively. The crack confirmation results are shown in Table 3.

[0182] Next, a three-dimensional shape measuring device was used to measure the amount of deflection of the first seal portion 40. The measurement results of the amount of deflection are shown in Table 3.

[0183]

[0184] As shown in Table 3, in Samples Nos. 11 to 17, in which the ratio of the thickness of the metal support 10 to the minimum width W1 of the metal connecting portion 42 was set to 2000 or less, it was possible to suppress the occurrence of cracks at the joints between the metal support 10 and the metal connecting portion 42 and the frame body 20. This shows that the strength of the metal connecting portion 42 can be ensured by setting the ratio of the thickness of the metal support 10 to the minimum width W1 of the metal connecting portion 42 to 2000 or less.

[0185] Furthermore, as shown in Table 3, in samples Nos. 12 to 18, in which the ratio of the thickness of the metal support 10 to the minimum width W1 of the metal connecting portion 42 was set to 50 or more, it was possible to suppress the amount of deflection of the first seal portion 40. This shows that the rigidity of the first seal portion 40 can be increased by setting the ratio of the thickness of the metal support 10 to the minimum width W1 of the metal connecting portion 42 to 50 or more.

[0186] Although not shown in Table 3, the same results as those of the first seal portion 40 were obtained for the second seal portion 50.

[0187] REFERENCE SIGNS LIST 1, 1a Electrolytic cell 2 Cell 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, 43 Oxide adhesive layer 42, 44 Metal connecting portion 50 Second seal portion 60 Joint portion

Claims

1. A chromium alloy container having an internal space, comprising: a first alloy member made of an alloy containing chromium; a second alloy member made of an alloy containing chromium; and an insert portion interposed between the first alloy member and the second alloy member, the insert portion having an oxide bonding layer made of an oxide mainly composed of chromium; and a metal connecting portion embedded in the oxide bonding layer and connecting the first alloy member and the second alloy member.

2. The chromium alloy container according to claim 1, wherein the metal connecting portion contains, as a main component, the same element as a main component of at least one of the first alloy member and the second alloy member.

3. The chromium alloy container according to claim 1 or 2, wherein the metal connecting portion contains chromium.

4. The chromium alloy container according to claim 1, wherein the ratio of the minimum width of the metal connection portion in the surface direction to the thickness of the oxide adhesive layer in the thickness direction is 0.3 or more.

5. The chromium alloy container according to claim 1, wherein the ratio of the maximum distance between said metal connections in the surface direction to the thickness of said oxide adhesive layer in the thickness direction is 20 or less.

6. The chromium alloy container according to claim 1, wherein the ratio of the thickness of said first alloy member or said second alloy member in the thickness direction to the minimum width of said metal connecting portion in the surface direction is 50 or more.

7. The chromium alloy container according to claim 1, wherein the ratio of the thickness of said first alloy member or said second alloy member in the thickness direction to the minimum width of said metal connecting portion in the surface direction is 2000 or less.

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

9. The chromium alloy container according to claim 1, wherein the oxide adhesion layer is composed of at least one of chromium oxide and chromium manganese oxide.

10. The chromium alloy container of claim 1, wherein the oxide adhesion layer is crystalline.

11. The chromium alloy container according to claim 10, wherein the oxide adhesion layer has a spinel or corundum type crystal structure.

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

13. 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 insert portion bonds the embossed portion to the first alloy member.

14. 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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