Fluid container and electrochemical cell

Abstract

A fluid container (3) comprises a first metal member (31), a second metal member (32), a bonding part (34), a first interface (4), and a second interface (5). The first and second metal members (31, 32) contain chromium. The bonding part (34) is composed of an oxide containing chromium as a main component. The bonding part (34) bonds the first metal member (31) and the second metal member (32). The first interface (4) is an interface between the first metal member (31) and the bonding part (34). The second interface (5) is an interface between the second metal member (32) and the bonding part (34). The first interface (4) has a first wavy part (41). The first wavy part (41) exhibits repeated amplitudes in the thickness direction. The first wavy part (41) extends along the outer peripheral edge part of the first metal member (31).

Description

Fluid container and electrochemical cell

[0001] The present invention relates to a fluid container and an electrochemical cell.

[0002] Electrochemical cells such as electrolysis cells and fuel cells have a fluid container for supplying fluid to the cell body. For example, the fluid container disclosed in Patent Document 1 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] JP 2015-156352 A

[0005] In the fluid container described above, the first metal member and the second metal member are bonded together by an adhesive. In this fluid container, due to thermal cycles associated with starting and stopping the electrochemical cell, a difference in thermal expansion between the first metal member and the second metal member occurs, which may cause a load to concentrate on the adhesive, potentially resulting in damage to the adhesive.

[0006] An object of the present invention is to provide a fluid container and an electrochemical cell that can suppress breakage of adhesive joints.

[0007] The fluid container according to the first aspect comprises a first metal member, a second metal member, an adhesive portion, a first interface, and a second interface. The first metal member contains chromium. The second metal member contains chromium. The adhesive portion is made of an oxide primarily composed of chromium. The adhesive portion bonds the first metal member and the second metal member. The first interface is the interface between the first metal member and the adhesive portion. The second interface is the interface between the second metal member and the adhesive portion. The first interface has a first wavy portion. The first wavy portion has repeated amplitudes in the thickness direction. The first wavy portion extends along the outer peripheral edge of the first metal member.

[0008] According to this configuration, the first wavy portion at the first interface of the adhesive portion disperses stress generated in the adhesive portion, thereby suppressing damage to the adhesive portion.

[0009] A fluid container according to a second aspect is the fluid container according to the first aspect, and is configured as follows: the second interface has a second wavy portion, the second wavy portion has a repeating amplitude in the thickness direction, and the second wavy portion extends along the outer peripheral edge portion of the second metal member.

[0010] A fluid container according to a third aspect is the fluid container according to the first or second aspect, and is configured as follows: The first wavy portion has a larger fluctuation amount at its outer circumferential edge than at its inner circumferential edge.

[0011] A fluid container according to a fourth aspect is the fluid container according to any one of the first to third aspects, and is configured as follows: The first adhesive portion has a void portion.

[0012] A fluid container according to a fifth aspect is the fluid container according to any one of the first to fourth aspects, and is configured as follows: The first wavy portion has a fluctuation amount of 1 μm or more and 50 μm or less.

[0013] A fluid container according to a sixth aspect is the fluid container according to the second aspect, wherein the first wavy portion has a fluctuation of 1 μm or more and 50 μm or less, and the second wavy portion has a fluctuation of 1 μm or more and 50 μm or less.

[0014] A seventh aspect of the present invention is the fluid container according to any one of the first to sixth aspects, further comprising an internal space through which the fluid flows. The adhesive portion extends in an annular shape so as to surround the internal space.

[0015] A fluid container according to an eighth aspect is the fluid container according to any one of the first to seventh aspects, further comprising an internal space through which the fluid flows. The adhesive portion is a seal for sealing the internal space.

[0016] An electrochemical cell according to a ninth aspect includes the fluid container according to any one of the first to eighth aspects, and a cell main body disposed on the fluid container.

[0017] An electrochemical cell according to a tenth aspect is the electrochemical cell according to the ninth aspect, and is configured as follows: the fluid container has an internal space through which a fluid flows, the first metal member has a plurality of communication holes that communicate with the internal space, and the cell main body is disposed on the first metal member so as to cover the plurality of communication holes.

[0018] An electrochemical cell according to an eleventh aspect is the electrochemical cell according to the ninth aspect, and is configured as follows: the fluid container has an internal space through which a fluid flows, the second metal member has a plurality of communication holes that connect to the internal space, and the cell main body is disposed on the second metal member so as to cover the plurality of communication holes.

[0019] According to the present invention, damage to the adhesive joint can be suppressed.

[0020] A plan view of an electrolysis cell. A cross-sectional view of II-II in FIG. 1. A cross-sectional view taken along line III-III in FIG. 1. A plan view of a fluid container. A diagram showing an example of a captured image. An enlarged cross-sectional view of a first adhesive portion according to a modified example. An enlarged cross-sectional view of a first adhesive portion according to a modified example.

[0021] <Electrolytic Cell> Fig. 1 is a plan view of an electrolytic cell 100. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1.

[0022] 1 , the electrolytic cell 100 (an example of an electrochemical cell) is formed in the shape of a plate extending in the X-axis and Y-axis directions. In the present embodiment, the electrolytic cell 100 is formed in a rectangular shape extending in the Y-axis direction when viewed in a plan view along the Z-axis direction, which is perpendicular to the X-axis and Y-axis directions. However, the planar shape of the electrolytic cell 100 is not particularly limited, and may be a polygon other than a rectangle, an ellipse, a circle, or the like.

[0023] As shown in FIGS. 1 and 2, the electrolysis cell 100 includes a cell body 2 and a fluid container 3 .

[0024] <Cell Main Body> The cell main body 2 is placed on the fluid container 3. The cell main body 2 is supported by a metal support 31 (described later) of the fluid container 3. The cell main body 2 is placed on the metal support 31 so as to cover a plurality of communication holes 313 (described later). The cell main body 2 has a hydrogen electrode 21 (cathode), an electrolyte 22, a reaction prevention layer 23, and an oxygen electrode 24 (anode).

[0025] The hydrogen electrode 21, the electrolyte 22, the reaction prevention layer 23, and the oxygen electrode 24 are stacked in this order in the Z-axis direction from the fluid container 3 side. The hydrogen electrode 21, the electrolyte 22, and the oxygen electrode 24 are essential components, while the reaction prevention layer 23 is an optional component.

[0026] <Hydrogen Electrode> The hydrogen electrode 21 is disposed on the first main surface 311 of the metal support 31. A source gas is supplied to the hydrogen electrode 21 through each of the communication holes 313 of the metal support 31. The source gas contains at least water vapor (H ２ The hydrogen electrode 21 contains H ２ Generate.

[0027] The raw material gas is H ２ When the raw material gas contains only O, the hydrogen electrode 21 converts H into H according to the electrochemical reaction of water electrolysis shown in the following formula (1): ２ Generate.

[0028] Hydrogen electrode 21: H ２ O + 2e － →H ２ +O ２－ ... (1) The raw material gas is H ２ O plus CO ２ In this case, the hydrogen electrode 21 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.

[0029] Hydrogen electrode 21: 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)

[0030] H generated at the hydrogen electrode 21 ２The gas flows out from each of the communication holes 313 of the metal support 31 into the internal space 30 described below.

[0031] The hydrogen electrode 21 is a porous body having electron conductivity. The hydrogen electrode 21 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 21 is basically present in the form of metallic Ni during operation of the electrolysis cell 100, but a portion of it may also be present in the form of nickel oxide (NiO).

[0032] The hydrogen electrode 21 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.

[0033] The thickness of the hydrogen electrode 21 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 21 is not particularly limited, but may be, for example, 12×10 ―６ / ℃ or more 20 x 10 －６ / °C or less.

[0034] The method for forming the hydrogen electrode 21 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.

[0035] <Electrolyte> The electrolyte 22 is formed on the hydrogen electrode 21. The electrolyte 22 is disposed between the hydrogen electrode 21 and the oxygen electrode 24. In this embodiment, the electrolyte 22 is sandwiched between the hydrogen electrode 21 and the reaction prevention layer 23 and connected to both of them.

[0036] The electrolyte 22 covers the hydrogen electrode 21 and also covers the region of the first main surface 311 of the metal support 31 that is exposed from the hydrogen electrode 21 .

[0037] The electrolyte 22 is a dense body having oxide ion conductivity. ２－ The electrolyte 22 is made of an oxide ion conductive material, such as YSZ, GDC, ScSZ, SDC, or LSGM (lanthanum gallate), with YSZ being particularly suitable.

[0038] The thickness of the electrolyte 22 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 22 is not particularly limited, but may be, for example, 10×10 ―６ / ℃ or more 12 x 10 ―６ / °C or less.

[0039] The method for forming the electrolyte 22 is not particularly limited, and a baking method, a spray coating method, a PVD method, a CVD method, or the like can be used.

[0040] <Reaction prevention layer> The reaction prevention layer 23 is disposed between the electrolyte 22 and the oxygen electrode 24. The reaction prevention layer 23 is disposed on the opposite side of the electrolyte 22 from the hydrogen electrode 21. The reaction prevention layer 23 prevents the constituent elements of the electrolyte 22 from reacting with the constituent elements of the oxygen electrode 24 to form a layer with high electrical resistance.

[0041] The reaction prevention layer 23 is made of an oxide ion conductive material, such as GDC or SDC.

[0042] The porosity of the reaction prevention layer 23 is not particularly limited, but may be, for example, 0.1% to 50%. The thickness of the reaction prevention layer 23 is not particularly limited, but may be, for example, 1 μm to 50 μm.

[0043] The method for forming the reaction prevention layer 23 is not particularly limited, and may be a baking method, a spray coating method, a PVD method, a CVD method, or the like.

[0044] <Oxygen electrode> The oxygen electrode 24 is disposed on the opposite side of the electrolyte 22 from the hydrogen electrode 21. In this embodiment, the reaction prevention layer 23 is disposed between the electrolyte 22 and the oxygen electrode 24, and therefore the oxygen electrode 24 is connected to the reaction prevention layer 23. If the reaction prevention layer 23 is not disposed between the electrolyte 22 and the oxygen electrode 24, the oxygen electrode 24 is connected to the electrolyte 22.

[0045] The oxygen electrode 24 converts O 2 transferred from the hydrogen electrode 21 through the electrolyte 22 in accordance with the chemical reaction of the following formula (5): ２－ From O ２ Generate.

[0046] Oxygen electrode 24:2O ２－ →O ２ +4e － ...(5)

[0047] The oxygen electrode 24 is a porous body having oxide ion conductivity and electron conductivity. The oxygen electrode 24 is made of, 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).

[0048] The porosity of the oxygen electrode 24 is not particularly limited, but may be, for example, 20% to 60%. The thickness of the oxygen electrode 24 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0049] The method for forming the oxygen electrode 24 is not particularly limited, and may be a baking method, a spray coating method, a PVD method, a CVD method, or the like.

[0050] 2, the fluid container 3 has an internal space 30. The internal space 30 contains a raw material gas supplied to the hydrogen electrode 21 and a reducing gas (in this embodiment, H ２ The raw material gas and the reducing gas are examples of the fluid of the present invention.

[0051] The fluid container 3 includes a metal support 31 (an example of a first metal member), a frame 32 (an example of a second metal member), an interconnector 33, a first adhesive portion 34 (an example of an adhesive portion), and a second adhesive portion 35. The internal space 30 is a space surrounded by the metal support 31, the frame 32, the interconnector 33, the first adhesive portion 34, and the second adhesive portion 35.

[0052] 3, the fluid container 3 has a first interface 4 and a second interface 5. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1, and is an enlarged cross-sectional view centering on the first adhesive portion 34.

[0053] 2 , the metal support 31 supports the cell main body 2. In the present embodiment, the metal support 31 is formed in a plate shape. The metal support 31 only needs to be able to support the cell main body 2, and the thickness of the metal support 31 is not particularly limited, but may be, for example, 0.1 mm or more and 2.0 mm or less.

[0054] The metal support 31 has a plurality of communication holes 313 , a first main surface 311 and a second main surface 312 .

[0055] Each communication hole 313 penetrates the metal support 31 from the first main surface 311 to the second main surface 312. Each communication hole 313 opens to the first main surface 311 and the second main surface 312. Each communication hole 313 is covered by the cell main body 2. Specifically, the opening of each communication hole 313 on the first main surface 311 side is covered by the hydrogen electrode 21. The opening of each communication hole 313 on the second main surface 312 side is connected to the internal space 30.

[0056] Each of the communication holes 313 can be formed by mechanical processing (for example, punching), laser processing, or chemical processing (for example, etching).

[0057] In this embodiment, each communication hole 313 is formed linearly along the Z-axis direction. However, each communication hole 313 may be inclined with respect to the Z-axis direction, or may not be linear. Furthermore, the communication holes 313 may be connected to each other.

[0058] The first main surface 311 is provided on the opposite side to the second main surface 312. The cell main body 2 is disposed on the first main surface 311. The frame 32 is joined to the second main surface 312 via a first adhesive portion 34.

[0059] The metal support 31 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 31 is not particularly limited, but can be set to 4% by mass or more and 30% by mass or less.

[0060] The metal support 31 may contain Ti (titanium) or Zr (zirconium). The Ti content in the metal support 31 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 31 is not particularly limited, but may be 0.01 mol % or more and 0.4 mol % or less. The metal support 31 may contain Ti in the form of TiO ２ (titania), or Zr may be contained as ZrO ２ It may be contained as (zirconia).

[0061] <Frame> The frame 32 is a spacer for forming the internal space 30. The frame 32 is formed in a ring shape when viewed from above (when viewed in the Z-axis direction). The frame 32 is joined to the metal support 31 via a first adhesive portion 34, and is joined to the interconnector 33 via a second adhesive portion 35. The thickness of the frame 32 is not particularly limited, but can be, for example, 0.1 mm or more and 2.0 mm or less.

[0062] The frame body 32 has a first main surface 321 and a second main surface 322. The first main surface 321 of the frame body 32 is a surface facing the metal support body 31. The second main surface 322 of the frame body 32 is a surface facing the interconnector 33.

[0063] The frame 32 is made of an alloy containing Cr. Examples of such alloys include Fe—Cr alloy steel and Ni—Cr alloy steel. The Cr content of the frame 32 is not particularly limited, but can be set to 4 mass % or more and 30 mass % or less. The composition of the frame 32 may be the same as or different from that of the metal support 31.

[0064] <Interconnector> The interconnector 33 is disposed on the opposite side of the frame 32 from the metal support 31. The interconnector 33 is a member for electrically connecting the electrolytic cell 100 to an external power source or another electrolytic cell.

[0065] The interconnector 33 is formed in a plate shape. The interconnector 33 is joined to the frame body 32 via the second adhesive portion 35. The thickness of the interconnector 33 is not particularly limited, but can be, for example, 0.1 mm or more and 2.0 mm or less.

[0066] The interconnector 33 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 33 is not particularly limited, but can be set to 4 mass % or more and 30 mass % or less. The composition of the interconnector 33 may be the same as or different from that of the metal support 31. The composition of the interconnector 33 may be the same as or different from that of the frame 32.

[0067] <First adhesive portion> The first adhesive portion 34 is disposed between the metal support body 31 and the frame body 32. The first adhesive portion 34 bonds the metal support body 31 and the frame body 32. In detail, the first adhesive portion 34 is bonded to each of the metal support body 31 and the frame body 32.

[0068] The first adhesive portion 34 seals the gap between the metal support 31 and the frame 32. This prevents the source gas supplied to the hydrogen electrode 21 and the reducing gas generated in the hydrogen electrode 21 from leaking to the outside through the gap between the metal support 31 and the frame 32.

[0069] The first adhesive portion 34 is disposed between the metal support 31 and the frame 32. The first adhesive portion 34 is sandwiched between the metal support 31 and the frame 32. The first adhesive portion 34 extends in an annular shape so as to surround the internal space 30. The first adhesive portion 34 functions as a seal for sealing the internal space 30. In other words, the first adhesive portion 34 extends continuously in an annular shape.

[0070] The first adhesive portion 34 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 31 and the frame 32 to the first adhesive portion 34 during the manufacture or operation of the electrolysis cell 100. Furthermore, even if Cr diffuses from the metal support 31 and the frame 32 to the first adhesive portion 34, the effect on the composition of the first adhesive portion 34 is small, and therefore a decrease in the strength of the first adhesive portion 34 can be suppressed. Furthermore, since the metal support 31, the frame 32, and the first adhesive portion 34 all contain Cr, the mutual adhesion can be improved. Therefore, the adhesion between the metal support 31 and the frame 32 can be maintained for a long period of time.

[0071] In this embodiment, "mainly composed of Cr" means that the Cr content is the highest among the metal elements when the composition of the Cr oxide constituting the first adhesive portion 34 is analyzed with an energy dispersive spectroscopy (EDS) device. The Cr content in the Cr oxide is not particularly limited, but can be, for example, 20 mol % to 100 mol % of the metal elements.

[0072] The Cr content of the metal elements in the Cr oxide constituting the first adhesive portion 34 is preferably 50 mol % or more, which significantly suppresses the Cr contained in the metal support 31 and the frame 32 from diffusing into the first adhesive portion 34.

[0073] The Cr oxide constituting the first adhesive portion 34 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 34.

[0074] 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.

[0075] The Cr oxide constituting the first adhesive portion 34 is preferably crystalline, which can prevent the first adhesive portion 34 from being damaged due to a phase transition of the Cr oxide from amorphous to crystalline even when the electrolysis cell 100 is operated for a long period of time.

[0076] The Cr oxide constituting the first adhesive portion 34 preferably has a spinel or corundum crystal structure. These crystal structures have high symmetry, and therefore can improve the thermal stress resistance of the first adhesive portion 34.

[0077] The first adhesive portion 34 can be formed by applying a paste containing Cr oxide to the surface of at least one of the metal support 31 and the frame 32, and then performing a heat treatment while the metal support 31 and the frame 32 are in close contact with each other. The conditions for the heat treatment can be set as appropriate, but can be, for example, 600° C. or higher and 1100° C. or lower, and 0.5 hours or higher and 24 hours or lower.

[0078] <Second adhesive portion> The second adhesive portion 35 is disposed between the frame body 32 and the interconnector 33. The second adhesive portion 35 bonds the frame body 32 and the interconnector 33. In detail, the second adhesive portion 35 is bonded to each of the frame body 32 and the interconnector 33.

[0079] The second adhesive portion 35 seals the gap between the frame 32 and the interconnector 33. This prevents the raw material gas supplied to the hydrogen electrode 21 and the reducing gas generated in the hydrogen electrode 21 from leaking to the outside through the gap between the frame 32 and the interconnector 33.

[0080] The configuration of the second adhesive portion 35 is substantially the same as the configuration of the first adhesive portion 34 described above, and therefore, in this embodiment, a description of the configuration of the second adhesive portion 35 will be omitted.

[0081] <First and Second Interfaces> As shown in Fig. 3 , the first interface 4 is the interface between the metal support 31 and the first adhesive portion 34. The first interface 4 has a first wavy portion 41. The first wavy portion 41 is configured to have repeated amplitudes in the thickness direction (Z-axis direction). That is, the first wavy portion 41 is configured with convex portions protruding toward the metal support 31 side (upper side in Fig. 3 ) and concave portions recessed toward the first adhesive portion 34 side (lower side in Fig. 3 ). The convex portions and concave portions constituting the first wavy portion 41 are arranged alternately along the outer periphery of the metal support 31.

[0082] The second interface 5 is the interface between the frame body 32 and the first adhesive portion 34. The second interface 5 has a second wavy portion 51. The second wavy portion 51 is configured to have repeated amplitudes in the thickness direction (Z-axis direction). That is, the second wavy portion 51 is configured with convex portions protruding toward the first adhesive portion 34 (upper side in FIG. 3 ) and concave portions recessed toward the frame body 32 (lower side in FIG. 3 ). The convex portions and concave portions that make up the second wavy portion 51 are arranged alternately along the outer circumferential edge of the frame body 32.

[0083] Fig. 4 is a plan view of the fluid container 3. As shown in Fig. 4, the first adhesive portion 34 has at least one straight line portion in a plan view (viewed in the Z-axis direction). That is, the first interface 4 and the second interface 5 each have at least one straight line portion in a plan view. In this embodiment, the first interface 4 and the second interface 5 each have four straight line portions. In detail, the first interface 4 and the second interface 5 each have a pair of straight line portions extending in the X-axis direction and a pair of straight line portions extending in the Y-axis direction. The first interface 4 and the second interface 5 each extend in a rectangular shape in a plan view.

[0084] The first wavy portions 41 constitute each straight portion. That is, each straight portion is constituted by four first wavy portions 41. That is, the first wavy portions 41 are formed around the entire circumference of the first interface 4.

[0085] As shown in FIG. 3 , the variation V1 of at least one of the first wavy portions 41 can be 1 μm or more and 50 μm or less. The variation V1 of each first wavy portion 41 can be measured as follows: First, a cut surface is created along the extension direction of the first wavy portion 41 to be measured. This cut surface is created at the center of the width direction of the first wavy portion 41. The width direction of the first wavy portion 41 is a direction perpendicular to the extension direction of the first wavy portion 41. For example, the width direction of a first wavy portion 41 extending in the X-axis direction is the Y-axis direction, and the width direction of a first wavy portion 41 extending in the Y-axis direction is the X-axis direction.

[0086] The cut surface is then photographed using an electron microscope (SEM) at a magnification of 1,000 to 10,000 times. This photographed image preferably includes the entire first wavy portion 41. If the entire first wavy portion 41 cannot fit in a single photographed image, multiple photographed images are created so that the entire first wavy portion 41 is photographed.

[0087] Then, as a pre-processing step for the measurement, a moving average line of the first wavy portion 41 is created. Specifically, the coordinates in the height direction (Z-axis direction) of the first interface 4 are measured at 10 μm intervals along the direction in which the first wavy portion 41 extends, and the average value of 10 adjacent points is taken as the height at the center (the middle between the fifth and sixth points). By performing this operation while shifting each point, a moving average line of the first wavy portion 41 is created, as shown in FIG. 3 .

[0088] Based on the moving average line of the first wavy portion 41 created as described above, the difference between the apex of each adjacent concave portion and the apex of each adjacent convex portion can be measured by image analysis as the fluctuation amount V1 of the first wavy portion 41, and the average value of the measured fluctuation amounts V1 can be used as the fluctuation amount V1 of the first wavy portion 41. In this embodiment, since there are four first wavy portions 41, four fluctuation amounts V1 can be calculated.

[0089] The amount of fluctuation of the first wavy portion 41 at the outer peripheral edge is greater than the amount of fluctuation at the inner peripheral edge. When measuring the amount of fluctuation of the first wavy portion 41 at the outer peripheral edge, the cut surface is prepared closer to the outer peripheral edge than the center in the width direction of the first wavy portion 41. When measuring the amount of fluctuation of the first wavy portion 41 at the inner peripheral edge, the cut surface is prepared closer to the inner peripheral edge than the center in the width direction of the first wavy portion 41.

[0090] The ratio (L1 / L0) of the actual length (L1) of each first wavy portion 41 to the distance (L0) between both ends of each first wavy portion 41 can be, for example, 1.01 or greater and 3.00 or less. The ratio (L1 / L0) of each first wavy portion 41 can be measured based on the moving average line of the first wavy portion 41 described above. That is, the distance between both ends of each first wavy portion 41 and the actual length are measured in the captured image, and the ratio is calculated based on the measured values.

[0091] The second wavy portions 51 constitute each straight portion. That is, each straight portion is constituted by four second wavy portions 51. That is, the second wavy portions 51 are formed around the entire circumference of the second interface 5.

[0092] The fluctuation amount V2 of at least one of the second wavy portions 51 can be set to 1 μm or more and 50 μm or less. The fluctuation amount V2 of each second wavy portion 51 can be calculated based on the captured image described above in a manner similar to the fluctuation amount V1 of the first wavy portion 41. That is, a moving average line of the second wavy portion 51 is created, and the difference between the apex of adjacent concave portions and the apex of adjacent convex portions on the moving average line of the second wavy portion 51 is measured as the fluctuation amount V2 of the second wavy portion 51. The average value of the measured fluctuation amounts V2 can be used as the fluctuation amount V2 of the second wavy portion 51. In this embodiment, since there are four second wavy portions 51, four fluctuation amounts V2 can be calculated.

[0093] The amount of fluctuation of the second wavy portion 51 at the outer peripheral edge is greater than the amount of fluctuation at the inner peripheral edge. When measuring the amount of fluctuation of the second wavy portion 51 at the outer peripheral edge, the cut surface is prepared closer to the outer peripheral edge than the center in the width direction of the second wavy portion 51. When measuring the amount of fluctuation of the second wavy portion 51 at the inner peripheral edge, the cut surface is prepared closer to the inner peripheral edge than the center in the width direction of the second wavy portion 51.

[0094] The ratio (L2 / L0) of the actual length (L2) of each second wavy portion 51 to the distance (L0) between both ends of each second wavy portion 51 can be, for example, 1.01 to 3.00. The ratio (L2 / L0) of each second wavy portion 51 can be measured based on the moving average of the second wavy portion 51 described above.

[0095] The thickness t1 of the first adhesive portion 34 is not particularly limited, but is, for example, 1 μm or more and 100 μm or less. The thickness t1 of the first adhesive portion 34 is the distance between the first interface 4 and the second interface 5. The thickness t1 of the first adhesive portion 34 can be measured based on the moving average lines of the first wavy portion 41 and the second wavy portion 51 described above. Specifically, as shown in FIG. 5 , the thickness t1 of the first adhesive portion 34 is measured at each of eight equal points obtained by dividing the moving average lines of the first wavy portion 41 and the second wavy portion 51 in the extension direction of the first adhesive portion 34, and the average value of these measurements can be used as the thickness of the first adhesive portion 34. The ratio (t2 / t1) of the thickness t2 of the metal support 31 to the thickness t1 of the first adhesive portion 34 can be, for example, 500 or less.

[0096] <Manufacturing Method> A method for manufacturing the first interface 4, the second interface 5, and the first adhesive portion 34 will be described below. First, the metal support 31 is subjected to a bending process such as press working, so that the region of the second main surface 312 of the metal support 31 that is bonded to the first adhesive portion 34, i.e., the region that constitutes the first interface 4, is formed into the above-described wave shape. Note that the above-described shape can also be formed by reducing the thickness of the second main surface 312 of the metal support 31 by cutting, etching, laser ablation, or the like.

[0097] Similarly, by performing a bending process such as press working on the frame body 32, the area of ​​the first main surface 321 of the frame body 32 that is adhered to the first adhesive portion 34, i.e., the area that constitutes the second interface 5, is made into the wave shape described above.

[0098] The first adhesive portion 34 can be formed by applying a paste containing a crystalline metal oxide to the surface of at least one of the metal support 31 and the frame 32, and then performing a heat treatment while the metal support 31 and the frame 32 are in close contact with each other. The conditions for the heat treatment can be set as appropriate, but can be, for example, 600° C. or higher and 1100° C. or lower, and 0.5 hours or higher and 24 hours or lower.

[0099] (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.

[0100] (a) In the first and second embodiments, the frame 32 and the interconnector 33 are separate members, but the frame 32 and the interconnector 33 may be an integrated member. In this case, the fluid container 3 does not include the second adhesive portion 35.

[0101] (b) In the first and second embodiments, the metal support 31 and the frame 32 are separate members, but the metal support 31 and the frame 32 may be an integral member. In this case, the fluid container 3 does not include the first adhesive portion 34.

[0102] (c) In the above embodiment, the metal support 31 is given as an example of the first metal member and the frame 32 is given as an example of the second metal member, but the configuration of the fluid container 3 is not limited to this. For example, the frame 32 may be an example of the first metal member and the metal support 31 may be an example of the second metal member.

[0103] (d) In the above embodiment, the first wavy portion 41 is formed around the entire circumference of the first interface 4, but the configuration of the first interface 4 is not limited to this. For example, only one of the four straight line portions of the first interface 4 may be formed by the first wavy portion 41, and the remaining straight line portions may be flat rather than wavy. In particular, the first wavy portion 41 may be formed in a portion of the four straight line portions where stress is likely to occur. Furthermore, the first wavy portion 41 does not need to constitute the entire straight line portion, but may constitute only a portion of the straight line portion. The same applies to the second interface 5.

[0104] (e) The second interface 5 does not have to have the second wavy portion 51. That is, as shown in FIG. 6 , only the first interface 4 may have the first wavy portion 41.

[0105] (f) As shown in Fig. 7, the first adhesive portion 34 may have a void portion 341 therein. In this case, the void portion 341 is not formed over the entire width direction (X direction in Fig. 7).

[0106] (g) In the above embodiment, an electrolytic cell has been described as an example of an electrochemical cell, but electrochemical cells are not limited to electrolytic cells. An electrochemical cell is a general term that refers to 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 also include, for example, fuel cells that use oxide ions or protons as carriers.

[0107] (h) In the above embodiment, the fluid container according to the present invention is applied to an electrochemical cell, but the fluid container can be used for various purposes. For example, the fluid container can be applied to a methanation reactor that synthesizes methane from hydrogen and carbon dioxide.

[0108] Examples of the present invention will be described below, but the present invention is not limited to the examples described below.

[0109] Twenty-one electrolysis cells 100 as shown in Fig. 2 were fabricated. Specifically, NiO-GDC (porosity: 35%, thickness: 25 µm, thermal expansion coefficient: 12.7 ppm / K) was used as the hydrogen electrode 21, YSZ (porosity: 0.6%, thickness: 8 µm, thermal expansion coefficient: 10.0 ppm / K) was used as the electrolyte 22, GDC (porosity: 25%, thickness: 8 µm, thermal expansion coefficient: 12.3 ppm / K) was used as the reaction prevention layer 23, and LSCF (porosity: 45%, thickness: 30 µm, thermal expansion coefficient: 15.0 ppm / K) was used as the oxygen electrode 24. The outer dimensions of the cell main body 2 were 130 mm square. Crofer 22 APU (external dimensions: 150 mm square, thickness: 200 μm, thermal expansion coefficient: 12.7 ppm / K) was used for the metal support plate 31, frame 32, and interconnector 33. The internal dimensions of the frame 32 were 130 mm square. The material of the first adhesive portion 34 and the second adhesive portion 35 was chromium oxide.

[0110] The electrolytic cells 100 were fabricated so that the amounts of fluctuation of the first wavy portion 41 and the second wavy portion 51 of the first adhesive portion 34 were different. The amounts of fluctuation of the first wavy portion 41 and the second wavy portion 51 are as shown in Table 1. In electrolytic cells 100 Nos. 1 and 2, the second interface 5 did not have the second wavy portion 51. In electrolytic cell 100 No. 21, the first interface 4 did not have the first wavy portion 41, and the second interface 5 also did not have the second wavy portion 51. All conditions except for the amounts of fluctuation were the same for each electrolytic cell 100.

[0111] <Evaluation Method> A thermal cycle test was performed on each electrolytic cell 100 to examine whether peeling and cracking occurred in the first adhesive portion 34. Specifically, each electrolytic cell 100 was placed in an electric furnace and subjected to 10 cycles of temperature increase and decrease from room temperature to 800°C at a temperature increase and decrease rate of 200°C / hr, and then removed from the electric furnace to examine whether peeling and cracking occurred in the first adhesive portion 34. The presence or absence of peeling was determined by visual inspection. The presence or absence of cracking was also determined by SEM observation at 5000x magnification. These results are shown in Table 1.

[0112]

[0113] <Evaluation Results> As shown in Table 1, it was found that by having a wavy portion in at least one of the first interface 4 and the second interface 5, peeling can be prevented or only partial peeling can be suppressed in the first adhesive region 34. It was also found that by having a wavy portion in at least one of the first interface 4 and the second interface 5, and by setting the amount of fluctuation of the wavy portion to 1 to 50 μm, peeling can be prevented in the first adhesive region 34. It was also found that by having the first wavy portion 41 in the first interface 4 and the second wavy portion 52 in the second interface 5, and by setting the amount of fluctuation of each wavy portion to 1 to 50 μm, peeling can be prevented in the first adhesive region 34 and the occurrence of microcracks can be prevented.

[0114] 2: Cell main body 3: Fluid container 30: Internal space 31: Metal support 32: Frame 34: First adhesive portion 4: First interface 41: First wavy portion 5: Second interface 51: Second wavy portion 100: Electrolytic cell

Claims

1. A fluid container comprising: a first metal member containing chromium; a second metal member containing chromium; an adhesive portion composed of an oxide mainly composed of chromium and bonding the first metal member and the second metal member; a first interface which is an interface between the first metal member and the adhesive portion; and a second interface which is an interface between the second metal member and the adhesive portion, wherein the first interface has a first wavy portion which repeats oscillations in the thickness direction and extends along the outer circumferential edge portion of the first metal member.

2. A fluid container as described in claim 1, wherein the second interface has a second wavy portion that repeats amplitudes in the thickness direction and extends along the outer circumferential edge of the second metal member.

3. The fluid container according to claim 1, wherein the first wavy portion has a greater amount of variation at its outer circumferential edge than at its inner circumferential edge.

4. The fluid container according to claim 1, wherein the first adhesive portion has a void portion.

5. The fluid container according to claim 1, wherein the first wavy portion has a fluctuation of 1 μm or more and 50 μm or less.

6. A fluid container according to claim 2, wherein the first wavy portion has a fluctuation amount of 1 μm or more and 50 μm or less, and the second wavy portion has a fluctuation amount of 1 μm or more and 50 μm or less.

7. The fluid container according to claim 1, further comprising an internal space through which a fluid flows, and the adhesive portion extends in an annular shape so as to surround the internal space.

8. The fluid container according to claim 1, further comprising an internal space through which a fluid flows, and the adhesive portion is a seal for sealing the internal space.

9. An electrochemical cell comprising: a fluid container according to claim 1; and a cell body portion disposed on the fluid container.

10. The electrochemical cell described in claim 9, wherein the fluid container has an internal space through which a fluid flows, the first metal member has a plurality of communication holes leading to the internal space, and the cell main body is positioned on the first metal member so as to cover the plurality of communication holes.

11. The electrochemical cell described in claim 9, wherein the fluid container has an internal space through which a fluid flows, the second metal member has a plurality of communication holes leading to the internal space, and the cell main body is positioned on the second metal member so as to cover the plurality of communication holes.

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