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. The first bonding part (41) has a void (41a) therein.

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 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 adhesion 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 a bonding portion bonding the first alloy member and the second alloy member. The bonding portion is made of an oxide containing chromium as a main component. The bonding portion has an internal void.

[0009] A chromium alloy container according to a second aspect of the present invention is related to the first aspect, and the gap is spaced apart from each 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 gap extends along the thickness direction of the adhesive portion.

[0011] A chromium alloy container according to a fourth aspect of the present invention is related to any one of the first to third aspects, wherein the gap extends along a surface direction perpendicular to a thickness direction of the adhesive portion.

[0012] A chromium alloy container according to a fifth aspect of the present invention is related to any one of the first to third aspects, wherein the gap extends along a direction inclined with respect to both the thickness direction of the adhesive portion and a plane direction perpendicular to the thickness direction.

[0013] A chromium alloy container according to a sixth aspect of the present invention relates to any one of the first to third aspects, wherein the gap is located at the center of the adhesive portion in the thickness direction.

[0014] A chromium alloy container according to a seventh aspect of the present invention is the chromium alloy container according to any one of the first to sixth aspects, wherein the thickness of the gap in the thickness direction of the adhesive portion is ¾ or less of the thickness of the adhesive portion.

[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 a ratio of a thickness of at least one of the first alloy member and the second alloy member to a thickness of the gap in a thickness direction of the adhesive portion is 20 or more and 500 or less.

[0016] A ninth aspect of the present invention is the chromium alloy container according to any one of the first to eighth aspects, wherein in a cross section of the adhesive joint, the ratio of the area of ​​the void to the area of ​​the adhesive joint is 5% or more and 30% or less.

[0017] A chromium alloy container according to a tenth aspect of the present invention is related to any one of the first to ninth aspects, wherein the adhesive portion has metal particles at least partly embedded in the oxide.

[0018] A chromium alloy container according to an eleventh aspect of the present invention is related to any one of the first to tenth aspects, wherein the chromium content in the metal elements in the oxide is 50 mol % or more.

[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 oxide is composed of at least one of chromium oxide and chromium manganese oxide.

[0020] A chromium alloy container according to a thirteenth aspect of the present invention is the chromium alloy container according to any one of the first to twelfth aspects, wherein the oxide is crystalline.

[0021] A chromium alloy container according to a fourteenth aspect of the present invention is related to the thirteenth aspect, wherein the oxide has a spinel-type or corundum-type crystal structure.

[0022] A chromium alloy container according to a fifteenth aspect of the present invention relates to any one of the first to fourteenth aspects, wherein the adhesive portion is a seal for sealing the internal space.

[0023] A chromium alloy container according to a sixteenth aspect of the present invention is the chromium alloy container according to any one of the first to fourteenth aspects, wherein the second alloy member has an embossed portion abutting against the first alloy member, and the adhesive portion bonds the embossed portion to the first alloy member.

[0024] A metal-supported electrochemical cell according to a seventeenth aspect of the present invention comprises the chromium alloy container according to any one of the first to sixteenth 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.

[0025] 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.

[0026] 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.

[0027] 1. First embodiment

[0028] (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.

[0029] The electrolysis cell 1 is an example of a "metal-supported electrochemical cell" according to the present invention.

[0030] 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.

[0031] As shown in FIGS. 1 and 2, the electrolytic cell 1 includes a cell body 2 and a chromium alloy container 3 .

[0032] (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).

[0033] 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.

[0034] [Hydrogen Electrode 6 ] The hydrogen electrode 6 is disposed on the first main surface 12 of the metal support 10 .

[0035] 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).

[0036] The raw material gas is H ２ When the raw material gas contains only O, the hydrogen electrode 6 converts H ２ Generate.

[0037] Hydrogen electrode 6: H ２ O + 2e － →H ２ +O ２－ ...(1)

[0038] 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.

[0039] 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)

[0040] H generated at the hydrogen electrode 6 ２The gas flows out from each supply hole 11 of the metal support 10 into an internal space 3 a described later.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] 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.

[0045] [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.

[0046] 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 .

[0047] 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.

[0048] 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.

[0049] 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.

[0050] [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.

[0051] The reaction prevention layer 8 is made of an oxide ion conductive material, such as GDC or SDC.

[0052] 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.

[0053] 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.

[0054] [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.

[0055] 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.

[0056] Oxygen electrode 9:2O ２－ →O ２ +4e － ...(5)

[0057] 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).

[0058] 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.

[0059] 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.

[0060] (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

[0061] 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.

[0062] 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.

[0063] [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.

[0064] 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.

[0065] 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 .

[0066] 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.

[0067] Each supply hole 11 can be formed by mechanical processing (for example, punching), laser processing, chemical processing (for example, etching), or the like.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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).

[0072] [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.

[0073] 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 .

[0074] 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.

[0075] 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.

[0076] [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.

[0077] 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.

[0078] The interconnector 30 is joined to the frame 20 via the second seal portion 50 .

[0079] 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.

[0080] 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.

[0081] [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.

[0082] 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.

[0083] [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.

[0084] The second seal portion 50 seals the gap between the frame 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 20 and the interconnector 30.

[0085] 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.

[0086] (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.

[0087] 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.

[0088] [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.

[0089] 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.

[0090] 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.

[0091] In this embodiment, "mainly composed of Cr" means that, when the composition of the Cr oxide constituting the first adhesive portion 41 is analyzed with 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.

[0092] 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.

[0093] 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 Cr particularly difficult to diffuse, and therefore can improve the durability of the first adhesive portion 41.

[0094] 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.

[0095] 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.

[0096] The Cr oxide constituting the first adhesive portion 41 preferably has a spinel or corundum crystal structure. These crystal structures have high symmetry, which can improve the thermal stress resistance of the first adhesive portion 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 first adhesive portion 41 and each of the metal support 10 and the frame 20.

[0097] 3, the first adhesive portion 41 has a void 41a therein. This allows cracks that occur in the first adhesive portion 41 to be stopped at the void 41a. Therefore, brittle fracture of the first adhesive portion 41 can be suppressed, and the adhesion between the metal support 10 and the frame 20 can be maintained for a long period of time.

[0098] In this embodiment, the first adhesive portion 41 has two voids 41a, but the number of voids 41a in one cross section is not particularly limited, and may be one or three or more.

[0099] 3, the gap 41a is preferably spaced apart from the metal support 10 and the frame 20. This increases the adhesion area between the first adhesive portion 41 and the metal support 10 and between the first adhesive portion 41 and the frame 20, and improves the adhesion between the first adhesive portion 41 and the metal support 10 and between the first adhesive portion 41 and the frame 20.

[0100] The voids 41a may extend along a thickness direction parallel to the Z-axis direction. This allows the voids 41a to stop cracks extending along a surface direction perpendicular to the thickness direction over a wide area. The thickness direction is the direction perpendicular to the first main surface 12 of the metal support 10. Extending along the thickness direction means that the thickness of the voids 41a in the thickness direction is greater than the width of the voids 41a in the surface direction.

[0101] The voids 41 a may extend along a surface direction perpendicular to the Z-axis direction. This allows the voids 41 a to stop cracks extending along the thickness direction over a wide area. Note that extending along the surface direction means that the thickness of the voids 41 a in the thickness direction is smaller than the width of the voids 41 a in the surface direction.

[0102] The voids 41 a may extend in directions inclined relative to both the thickness direction and the surface direction. This allows the voids 41 a to stop cracks extending in the thickness direction and cracks extending in the surface direction in a balanced manner. In this case, the thickness of the voids 41 a in the thickness direction may be approximately the same as the width of the voids 41 a in the surface direction.

[0103] The void 41a is preferably located in the center in the thickness direction of the first adhesive portion 41. This reduces the difference in strength of the first adhesive portion 41 on the metal support 10 side and the frame 20 side of the void 41a, thereby preventing a decrease in the mechanical reliability of the first adhesive portion 41. It is more preferable that the void 41a is entirely contained in the center in the thickness direction of the first adhesive portion 41. Note that the center in the thickness direction refers to a portion located in the center when the first adhesive portion 41 is divided into three equal parts on an imaginary line that is parallel to the thickness direction and passes through the void 41a.

[0104] The thickness of the void 41a is preferably ¾ or less of the thickness of the first adhesive portion 41. This makes it possible to prevent a decrease in the strength of the first adhesive portion 41 on the metal support 10 side and the frame 20 side of the void 41a, and therefore to prevent the first adhesive portion 41 from peeling off from the metal support 10 and the frame 20. The thickness of the first adhesive portion 41 is the sum of the shortest distance between the void 41a and the metal support 10 in the thickness direction, the shortest distance of the void 41a in the thickness direction, and the thickness of the void 41a in the thickness direction.

[0105] The ratio of the thickness of at least one of the metal support 10 and the frame 20 to the thickness of the voids 41a is preferably 20 or more and 500 or less. A thickness ratio of 20 or more can sufficiently exert the effect of stopping cracks in the voids 41a. Furthermore, a thickness ratio of 500 or less can suppress a decrease in the mechanical reliability (strength) of the first adhesive portion 41 due to the presence of the voids 41a.

[0106] In the cross section of the first adhesive portion 41, the ratio of the area of ​​the voids 41a to the area of ​​the first adhesive portion 41 is preferably 5% or more and 30% or less. When the area ratio is 5% or more, the voids 41a can sufficiently exert the effect of stopping cracks. Furthermore, when the area ratio is 30% or less, a decrease in the mechanical reliability (strength) of the first adhesive portion 41 due to the presence of the voids 41a can be suppressed.

[0107] The area ratio is calculated by the following method. First, a cross section of the first adhesive portion 41 along the Z-axis direction is exposed. Next, a backscattered electron image of the cross section of the first adhesive portion 41 is obtained at 10,000x magnification using an SEM device (FE-SEM JSM-7900F, manufactured by JEOL Ltd.). Next, the image analysis software Image-Pro manufactured by MEDIACYBERNETICS is used to identify the portions displayed in black in the backscattered electron image (corresponding to the voids 41a). Then, the area ratio is calculated by dividing the total area of ​​the backscattered electron images of the first adhesive portion 41 by the total area of ​​the backscattered electron images of the first adhesive portion 41.

[0108] The area ratio at the end portion in the planar direction of the first adhesive portion 41 exposed to the internal space 3 a is preferably smaller than the area ratio at the center portion in the planar direction. ２ ) from entering the gap 41a, thereby further improving the sealing performance of the first adhesive portion 41. The central portion of the first adhesive portion 41 in the surface direction is a portion that is located in the center when the first adhesive portion 41 is divided into three equal parts on an imaginary line that is parallel to the surface direction and passes through the gap 41a. The end portion of the first adhesive portion 41 in the surface direction is a portion that is located on the imaginary line on the side of the central portion in the surface direction that is closer to the internal space 3a.

[0109] 3, the first adhesive portion 41 preferably has metal particles 41b at least partly embedded in Cr oxide, thereby forming a composite of the Cr oxide and the metal particles 41b, thereby improving the toughness of the first adhesive portion 41.

[0110] The metal particles 41b may be entirely embedded in the Cr oxide, or may be partially exposed inside the voids 41a. The metal particles 41b preferably contain the same element as the main component of at least one of the metal support 10 and the frame 20. This can prevent the composition of the first adhesive portion 41 from changing due to elemental diffusion from the metal support 10 and the frame 20. For example, the metal particles 41b may contain Cr or Fe as a main component. Incidentally, "containing Cr or Fe as a main component" means that the metal particles 41b exhibit the maximum content when subjected to elemental analysis.

[0111] The first adhesive portion 41 can be formed by applying a paste containing Cr oxide and a pore-forming material 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, 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. Note that when the first adhesive portion 41 contains metal particles 41b, the metal particles can be appropriately contained in the paste.

[0112] [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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] The Cr oxide constituting the second adhesive portion 42 preferably has a spinel or corundum crystal structure, which can improve the thermal stress resistance of the second adhesive portion 42 and can also improve the bonding strength between the second adhesive portion 42 and the metal support 10 and between the second adhesive portion 42 and the frame 20.

[0120] 3, the second adhesive portion 42 has a void 42a therein. This allows cracks that occur in the second adhesive portion 42 to be stopped at the void 42a. This prevents the second adhesive portion 42 from undergoing brittle fracture, thereby enabling the adhesion between the metal support 10 and the frame 20 to be maintained for a long period of time.

[0121] In this embodiment, the second adhesive portion 42 has one gap 42a, but the number of gaps 42a in one cross section is not particularly limited, and may be two or more.

[0122] 3, the gap 42a is preferably spaced apart from both the metal support 10 and the frame 20. This improves the adhesiveness between the second adhesive portion 42 and both the metal support 10 and the frame 20.

[0123] The voids 42a may extend in the thickness direction parallel to the Z-axis direction, thereby allowing cracks extending in the surface direction to be stopped over a wide area by the voids 42a.

[0124] The voids 42a may extend along a surface direction perpendicular to the Z-axis direction, thereby allowing cracks extending along the thickness direction to be stopped over a wide area by the voids 42a.

[0125] The voids 42 a may extend in directions inclined with respect to both the thickness direction and the surface direction, thereby allowing the voids 42 a to stop cracks extending in the thickness direction and cracks extending in the surface direction in a balanced manner.

[0126] The void 42a is preferably located in the center in the thickness direction of the second adhesive portion 42. This reduces the difference in strength of the second adhesive portion 42 on the metal support 10 side and the frame 20 side of the void 42a, thereby preventing a decrease in the mechanical reliability of the second adhesive portion 42. It is more preferable that the void 42a is entirely contained in the center in the thickness direction of the second adhesive portion 42.

[0127] The thickness of the gap 42a is preferably ¾ or less of the thickness of the second adhesive portion 42. This makes it possible to prevent the second adhesive portion 42 from peeling off from the metal support 10 and the frame 20, respectively.

[0128] The ratio of the thickness of the voids 42 a to the thickness of at least one of the metal support 10 and the frame 20 is preferably equal to or greater than 20 and equal to or less than 500. This makes it possible to fully exert the effect of stopping cracks caused by the voids 42 a and to suppress a decrease in the mechanical reliability of the second adhesive portion 42.

[0129] In the cross section of the second adhesive portion 42, the ratio of the area of ​​the voids 42a to the area of ​​the second adhesive portion 42 is preferably 5% or more and 30% or less. This makes it possible to fully exert the effect of stopping cracks caused by the voids 42a and to suppress a decrease in the mechanical reliability of the second adhesive portion 42.

[0130] The area ratio at the end portion in the planar direction of the second adhesive portion 42 exposed to the external space 3 b is preferably smaller than the area ratio at the center portion in the planar direction. ２ ) from entering the gap 42a, thereby further improving the sealing performance of the second adhesive portion 42. The center portion of the second adhesive portion 42 in the surface direction is a portion that is located in the center when the second adhesive portion 42 is divided into three equal parts on an imaginary line that is parallel to the surface direction and passes through the gap 42a. The end portion of the second adhesive portion 42 in the surface direction is a portion that is located on the imaginary line on the side of the center portion in the surface direction that faces the external space 3b.

[0131] 3, the second adhesive portion 42 preferably has metal particles 42b at least partly embedded in Cr oxide, which can improve the toughness of the second adhesive portion 42.

[0132] The metal particles 42b may be entirely embedded in the Cr oxide, or may be partially exposed in the voids 42a. The metal particles 42b preferably contain, as a main component, a metal element contained in at least one of the metal support 10 and the frame 20. This makes it possible to suppress changes in the composition of the second adhesive portion 42 due to element diffusion from the metal support 10 and the frame 20. The metal particles 42b may contain, for example, Fe, Cr, or the like as a main component.

[0133] The second adhesive portion 42 can be formed by applying a paste containing Cr oxide and a pore-forming material 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 heat treatment conditions 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. Note that when the second adhesive portion 42 contains metal particles 42b, the metal particles can be appropriately contained in the paste. Furthermore, the second adhesive portion 42 may be formed simultaneously with the first adhesive portion 41.

[0134] 2. Second embodiment

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] The Cr oxide constituting the third adhesive portion 43 preferably has a spinel or corundum crystal structure, which can improve the thermal stress resistance of the third adhesive portion 43 and can also improve the bonding strength between the third adhesive portion 43 and the metal support 10 and between the third adhesive portion 43 and the interconnector 30.

[0150] 5, the third adhesive portion 43 has a void 43a therein. This makes it possible to stop cracks occurring in the third adhesive portion 43 at the void 43a. Therefore, brittle fracture of the third adhesive portion 43 can be suppressed, and the adhesion between the metal support 10 and the interconnector 30 can be maintained for a long period of time.

[0151] In this embodiment, the third adhesive portion 43 has one gap 43a, but the number of gaps 43a in one cross section is not particularly limited, and may be two or more.

[0152] 5, the gap 43a is preferably spaced apart from both the metal support 10 and the interconnector 30. This makes it possible to improve the adhesiveness between the third adhesive portion 43 and both the metal support 10 and the interconnector 30.

[0153] The voids 43a may extend in the thickness direction parallel to the Z-axis direction, thereby allowing cracks extending in the surface direction to be stopped over a wide area by the voids 43a.

[0154] The voids 43a may extend along a surface direction perpendicular to the Z-axis direction, thereby allowing cracks extending along the thickness direction to be stopped over a wide area by the voids 43a.

[0155] The voids 43 a may extend in directions inclined with respect to both the thickness direction and the surface direction, thereby enabling the voids 43 a to stop cracks extending in the thickness direction and cracks extending in the surface direction in a balanced manner.

[0156] The void 43a is preferably located in the center in the thickness direction of the third adhesive portion 43. This reduces the difference in strength of the third adhesive portion 43 on the metal support 10 side and the interconnector 30 side of the void 43a, thereby preventing a decrease in the mechanical reliability of the third adhesive portion 43. It is more preferable that the void 43a is entirely contained in the center in the thickness direction of the third adhesive portion 43.

[0157] The thickness of the gap 43a is preferably ¾ or less of the thickness of the third adhesive portion 43. This can prevent the third adhesive portion 43 from peeling off from the metal support 10 and the interconnector 30, respectively.

[0158] The ratio of the thickness of the voids 43 a to the thickness of at least one of the metal support 10 and the interconnector 30 is preferably equal to or greater than 20 and equal to or less than 500. This makes it possible to fully exert the effect of stopping cracks caused by the voids 43 a and to suppress a decrease in the mechanical reliability of the third adhesive portion 43.

[0159] In the cross section of the third adhesive portion 43, the ratio of the area of ​​the voids 43a to the area of ​​the third adhesive portion 43 is preferably 5% or more and 30% or less. This makes it possible to fully exert the effect of stopping cracks caused by the voids 43a and to suppress a decrease in the mechanical reliability of the third adhesive portion 43.

[0160] The area ratio at the end portion in the planar direction of the third adhesive portion 43 exposed to the internal space 3 a is preferably smaller than the area ratio at the center portion in the planar direction. ２ ) can be prevented from entering the gap 43a, so that the sealing property of the third adhesive portion 43 can be further improved.

[0161] 5, the third adhesive portion 43 preferably has metal particles 43b at least partly embedded in Cr oxide, which can improve the toughness of the third adhesive portion 43.

[0162] The metal particles 43b may be entirely embedded in the Cr oxide, or may be partially exposed in the voids 43a. The metal particles 43b preferably contain, as a main component, a metal element contained in at least one of the metal support 10 and the interconnector 30. This makes it possible to suppress changes in the composition of the third adhesive portion 43 due to element diffusion from the metal support 10 and the interconnector 30. The metal particles 43b may contain, for example, Fe, Cr, or the like as a main component.

[0163] The third adhesive portion 43 can be formed by applying a paste containing Cr oxide and a pore-forming material 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 heat treatment conditions 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. Note that when the third adhesive portion 43 contains metal particles 43b, the paste may contain the metal particles as appropriate. The third adhesive portion 43 may also be formed simultaneously with the first and second adhesive portions 41 and 42.

[0164] (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.

[0165] [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.

[0166] [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.

[0167] [Modification 3] In the first and second embodiments, the first adhesive portion 41 has a single-layer structure, but is not limited to this. The first adhesive portion 41 may have a multi-layer structure of two or more layers each made of Cr oxides with different compositions.

[0168] [Modification 4] In the first and second embodiments, the second adhesive portion 42 has a single-layer structure, but is not limited to this. The second adhesive portion 42 may have a multi-layer structure of two or more layers each made of Cr oxides with different compositions.

[0169] [Modification 5] In the second embodiment, the third adhesive portion 43 has a single-layer structure, but is not limited to this. The third adhesive portion 43 may have a multi-layer structure including two or more layers each made of Cr oxides with different compositions.

[0170] [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.

[0171] 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.

[0172] [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.

[0173] [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.

[0174] [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.

[0175] 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.

[0176] (Samples Nos. 1 to 7) Chromium alloy containers 3 (see FIG. 3) according to Samples Nos. 1 to 7 were fabricated as follows.

[0177] 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 a pore-forming material (specifically, PMMA particles) was applied to the laminate, and then the frame 20 was placed on the paste to fabricate the laminate. At this time, the ratio of the thickness of the voids 41 a to the thickness of the first adhesive portion 41 was changed by changing the amount of paste applied and the particle size of the pore-forming material, as shown in Table 1.

[0178] 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 .

[0179] Next, the laminate was subjected to a heat treatment (1000°C, 1 hour) to form a first adhesive portion 41 having a void 41a therein and a second adhesive portion 42 having a void 42a therein from the paste. In this way, the chromium alloy container 3 having the first and second adhesive portions 41 and 42 was completed.

[0180] Next, a heat endurance test was carried out by subjecting the chromium alloy container 3 to a heat treatment (800° C., 1000 hours).

[0181] 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.

[0182] Next, as described in the above embodiment, the ratio of the thickness of the gap 41a to the thickness of the first adhesive portion 41 was measured in the cross section of the first adhesive portion 41. The measured thickness ratios are shown in Table 1.

[0183] Next, the cross section of the first adhesive portion 41 was observed with an SEM (5000x magnification) to check whether the first adhesive portion 41 had peeled off from the metal support 10 and the frame 20 in the vicinity of the void 41a of the first adhesive portion 41. The peeling confirmation results are shown in Table 1.

[0184]

[0185] As shown in Table 1, in Samples No. 1 to 5 in which the ratio of the thickness of the void 41a to the thickness of the first adhesive portion 41 was set to 3 / 4 or less, peeling of the first adhesive portion 41 from the metal support 10 and the frame 20 after the heat endurance test was suppressed. This shows that by setting the ratio of the thickness of the void 41a to the thickness of the first adhesive portion 41 to 3 / 4 or less, it is possible to suppress a decrease in strength of the first adhesive portion 41 on both the metal support 10 side and the frame 20 side of the void 41a.

[0186] Although not shown in Table 1, the same results as those of the first adhesive portion 41 were obtained in the second adhesive portion 42.

[0187] (Samples Nos. 8 to 18) Chromium alloy containers 3 (see FIG. 3) according to Samples Nos. 8 to 18 were fabricated as follows.

[0188] 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 a pore-forming material (specifically, PMMA particles) was applied to the laminate, and then the frame 20 was placed on the paste to fabricate the laminate. In this case, the particle size of the pore-forming material was changed to change the ratio of the thickness of the metal support 10 to the thickness of the voids 41a, as shown in Table 2.

[0189] 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 .

[0190] Next, the laminate was subjected to a heat treatment (1000°C, 1 hour) to form a first adhesive portion 41 having a void 41a therein and a second adhesive portion 42 having a void 42a therein from the paste. In this way, the chromium alloy container 3 having the first and second adhesive portions 41 and 42 was completed.

[0191] Next, a heat endurance test was carried out by subjecting the chromium alloy container 3 to a heat treatment (800° C., 1000 hours).

[0192] 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.

[0193] Next, as described in the above embodiment, the ratio of the thickness of the metal support 10 to the thickness of the gap 41a was measured. The measured thickness ratios are shown in Table 2.

[0194] Next, the cross section of the first adhesive portion 41 was observed with an SEM (5000x magnification) to measure the length of the largest crack that occurred inside the first adhesive portion 41. The largest crack is the crack with the longest linear distance between both ends among all cracks observed in the five fields of view. The length of the largest crack (linear distance between both ends) is shown in Table 2.

[0195]

[0196] As shown in Table 2, the maximum crack length was significantly reduced in Samples No. 8 to 14, in which the ratio of the thickness of the metal support 10 to the thickness of the void 41a was set to be 20 or more and 500 or less. This shows that by setting the ratio of the thickness of the metal support 10 to the thickness of the void 41a to be 20 or more and 500 or less, it is possible to sufficiently exert the effect of stopping cracks in the void 41a while suppressing a decrease in the strength of the first adhesive portion 41.

[0197] 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.

[0198] (Samples Nos. 19 to 27) Chromium alloy containers 3 (see FIG. 3) according to Samples Nos. 19 to 27 were fabricated as follows.

[0199] 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 the pore-forming material (specifically, PMMA particles) was applied to the laminate, and then the frame 20 was placed on the paste to fabricate the laminate. At this time, the ratio of the area of ​​the voids 41 a to the area of ​​the first adhesive portion 41 was changed by changing the amount of the pore-forming material added and the particle size, as shown in Table 3.

[0200] 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 .

[0201] Next, the laminate was subjected to a heat treatment (1000°C, 1 hour) to form a first adhesive portion 41 having a void 41a therein and a second adhesive portion 42 having a void 42a therein from the paste. In this way, the chromium alloy container 3 having the first and second adhesive portions 41 and 42 was completed.

[0202] Next, a heat endurance test was carried out by subjecting the chromium alloy container 3 to a heat treatment (800° C., 1000 hours).

[0203] 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.

[0204] Next, as described in the above embodiment, the ratio of the area of ​​the void 41a to the area of ​​the first adhesive portion 41 was calculated. The calculated area ratios are shown in Table 3.

[0205] Next, the cross section of the first adhesive portion 41 was observed with an SEM (5000x magnification) to measure the length of the largest crack that occurred inside the first adhesive portion 41. The largest crack was the crack with the longest linear distance between both ends among all cracks observed in the five fields of view. If the entire crack could not fit within the observation field of view, the crack length was measured by stitching together multiple images acquired while sliding the field of view as appropriate. The length of the largest crack (linear distance between both ends) is shown in Table 3.

[0206]

[0207] As shown in Table 3, the maximum crack length was significantly reduced in Samples Nos. 19 to 23, in which the ratio of the area of ​​the voids 41a to the area of ​​the first adhesive portion 41 was 5% or more and 30% or less. This shows that by setting the ratio of the area of ​​the voids 41a to the area of ​​the first adhesive portion 41 to 5% or more and 30% or less, it is possible to sufficiently exert the effect of stopping cracks at the voids 41a while suppressing a decrease in the strength of the first adhesive portion 41.

[0208] 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.

[0209] (Samples Nos. 28 to 34) Chromium alloy containers according to Samples Nos. 28 to 34 were prepared as follows.

[0210] 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 A paste containing at least one of the above and a pore-forming material (specifically, PMMA particles) was applied, and then the frame 20 was placed on the paste to fabricate a laminate. ２ O ３ and Mn ３ O ４By changing the amount of each material added, the Cr content in the metal elements in the Cr oxide constituting the adhesive joint was changed as shown in Table 1. However, the amount and particle size of the pore-forming material were the same in all samples.

[0211] Next, the laminate was subjected to a heat treatment (1000°C, 1 hour) to form a first adhesive portion 41 having a void 41a therein and a second adhesive portion 42 having a void 42a therein from the paste. This completed a chromium alloy container having the first and second adhesive portions 41, 42. In this example, the metal support 10 and the frame 20 were not welded or brazed.

[0212] 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 4 as the "Cr content before heat endurance test."

[0213] Next, a heat endurance test was carried out by subjecting the chromium alloy container to a heat treatment (800° C., 1000 hours).

[0214] 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 4 as the "Cr content after the thermal durability test."

[0215]

[0216] As shown in Table 4, in Samples Nos. 30 to 33, 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 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.

[0217] 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 First adhesive portion 42 Second adhesive portion 43 Third adhesive portion 41a, 42a, 43a Voids 41b, 42b, 43b Metal particles

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 adhesive portion that bonds the first alloy member and the second alloy member, wherein the adhesive portion is made of an oxide mainly composed of chromium, and the adhesive portion has an internal void.

2. The chromium alloy container according to claim 1, wherein the void is spaced from each of the first alloy member and the second alloy member.

3. The chromium alloy container according to claim 1 or 2, wherein the gap extends along the thickness direction of the adhesive portion.

4. The chromium alloy container according to claim 1 or 2, wherein the gap extends along a surface direction perpendicular to the thickness direction of the adhesive portion.

5. The chromium alloy container according to claim 1 or 2, wherein the gap extends along a direction inclined with respect to both the thickness direction of the adhesive portion and a surface direction perpendicular to the thickness direction.

6. The chromium alloy container according to claim 1, wherein the gap is located at the center of the adhesive portion in the thickness direction.

7. The chromium alloy container according to claim 1, wherein the thickness of the gap in the thickness direction of the adhesive portion is 3 / 4 or less of the thickness of the adhesive portion.

8. The chromium alloy container according to claim 1, wherein the ratio of the thickness of at least one of the first alloy member and the second alloy member to the thickness of the gap in the thickness direction of the adhesive portion is 20 or more and 500 or less.

9. The chromium alloy container according to claim 1, wherein in a cross section of the adhesive joint, the ratio of the area of ​​the void to the area of ​​the adhesive joint is 5% or more and 30% or less.

10. The chromium alloy container of claim 1, wherein the bond includes metal particles at least partially embedded in the oxide.

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

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

13. The chromium alloy container of claim 1, wherein the oxide is crystalline.

14. The chromium alloy container according to claim 13, wherein the oxide has a spinel or corundum type crystal structure.

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

16. 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.

17. 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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