Fluid container and electrochemical cell

Abstract

A fluid container (3) is provided with a first metal member (31), a second metal member (32), an adhesion section (34), a first interface (4), and a second interface (5). The first metal member (31) contains chromium. The second metal member (32) contains chromium. The adhesion section (34) is composed of an oxide containing chromium as the main component. The adhesion section (34) adheres the first metal member (31) and the second metal member (32). The first interface (4) is the interface between the first metal member (31) and the adhesion section (34). The second interface (5) is the interface between the second metal member (32) and the adhesion section (34). The first interface (4) has a first inclined section (41). The first inclined section (41) is inclined with respect to the surface direction 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. Due to thermal cycles associated with starting and stopping the electrochemical cell, a difference in thermal expansion occurs between the first metal member and the second metal member, generating shear stress at the interface between the first metal member and the adhesive. This can result in peeling at the interface between the first metal member and the adhesive.

[0006] An object of the present invention is to provide a fluid container and an electrochemical cell that can suppress peeling at the interface between the first metal member and the adhesive portion.

[0007] A fluid container according to a first aspect is a fluid container having an internal space through which a fluid flows. This fluid container comprises a first metal member, a second metal member, a bonding portion, a first interface, and a second interface. The first metal member contains chromium. The second metal member contains chromium. The bonding portion is made of an oxide whose main component is chromium. The bonding portion bonds the first metal member and the second metal member. The first interface is the interface between the first metal member and the bonding portion. The second interface is the interface between the second metal member and the bonding portion. The first interface has a first inclined portion. The first inclined portion is inclined with respect to the surface direction of the first metal member.

[0008] According to this configuration, the first interface between the first metal member and the adhesive portion has a first inclined portion that is inclined with respect to the surface direction of the first metal member. This allows a portion of the shear stress generated at the first interface to be converted from the surface direction to the thickness direction. As a result, peeling at the interface between the first metal member and the adhesive portion can be suppressed.

[0009] A fluid container according to a second aspect is the fluid container according to the first aspect, and is configured as follows: the adhesive portion extends in an annular shape so as to surround the internal space, and the first inclined portion extends along the adhesive portion.

[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 inclined portion inclines from the internal space toward the outer periphery of the fluid container.

[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 second interface has a second inclined portion that is inclined with respect to the surface direction of the second metal member.

[0012] A fluid container according to a fifth aspect is the fluid container according to the fourth aspect, and is configured as follows: the first inclined portion and the second inclined portion overlap each other when viewed in the thickness direction, and are inclined so as to approach each other from the internal space toward the outer periphery of the fluid container.

[0013] A fluid container according to a sixth aspect is the fluid container according to the fifth aspect, and is configured as follows: The first interface has a third inclined portion inclined with respect to the surface direction of the first metal member. The second interface has a fourth inclined portion inclined with respect to the surface direction of the second metal member. The third inclined portion is arranged on the outer peripheral edge side with respect to the first inclined portion. The fourth inclined portion is arranged on the outer peripheral edge side with respect to the second inclined portion. The third inclined portion and the fourth inclined portion overlap each other when viewed in the thickness direction, and are inclined so as to move away from each other from the internal space toward the outer peripheral edge.

[0014] A fluid container according to a seventh aspect is the fluid container according to the sixth aspect, configured as follows: the adhesive portion has a first tapered portion and a second tapered portion. The first tapered portion is defined by a first inclined portion and a second inclined portion. The second tapered portion is defined by a third inclined portion and a fourth inclined portion. The taper ratio of the first tapered portion is greater than the taper ratio of the second tapered portion.

[0015] A fluid container according to an eighth aspect is the fluid container according to the sixth aspect, further comprising a metal joint. The metal joint is integrally formed with the first metal member and the second metal member. The metal joint is made of a metal material. The adhesive portion has a first tapered portion and a second tapered portion. The first tapered portion is defined by a first inclined portion and a second inclined portion. The second tapered portion is defined by a third inclined portion and a fourth inclined portion. The metal joint is disposed between the first tapered portion and the second tapered portion.

[0016] A fluid container according to a ninth aspect is the fluid container according to any one of the first to eighth aspects, and is configured as follows: The adhesive portion has a space therein that extends in the surface direction of the first metal member.

[0017] A fluid container according to a tenth aspect is the fluid container according to any one of the first to ninth aspects, and is configured as follows: the adhesive portion is configured by a plurality of layers, and the number of layers of the adhesive portion varies in a direction from the internal space toward the outer periphery of the fluid container.

[0018] A fluid container according to an eleventh aspect is the fluid container according to any one of the first to tenth aspects, and is configured as follows: The number of layers of the adhesive portion decreases in a direction from the internal space toward the outer periphery of the fluid container.

[0019] A fluid container according to a twelfth aspect is the fluid container according to any one of the first to eleventh aspects, configured as follows: The adhesive portion is a seal for sealing the internal space.

[0020] An electrochemical cell according to a thirteenth aspect includes the fluid container according to any one of the first to twelfth aspects, and a cell main body disposed on the fluid container.

[0021] An electrochemical cell according to a fourteenth aspect is the electrochemical cell according to the thirteenth aspect, configured as follows: 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.

[0022] An electrochemical cell according to a fifteenth aspect is the electrochemical cell according to the thirteenth aspect, configured as follows: the second metal member has a plurality of communication holes that communicate with the internal space, and the cell main body is disposed on the second metal member so as to cover the plurality of communication holes.

[0023] According to the present invention, peeling at the interface between the first metal member and the adhesive portion can be suppressed.

[0024] Fig. 2 is a plan view of an electrolysis cell. Fig. 3 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 4 is an enlarged cross-sectional view of the periphery of a first adhesive portion. Fig. 5 is an enlarged cross-sectional view of the periphery of a first adhesive portion according to a modified example. Fig. 6 is an enlarged cross-sectional view of the periphery of a first adhesive portion according to a modified example. Fig. 7 is an enlarged cross-sectional view of the periphery of a first adhesive portion according to a modified example.

[0025] <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.

[0026] 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.

[0027] As shown in FIGS. 1 and 2, the electrolysis cell 100 includes a cell body 2 and a fluid container 3 .

[0028] <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).

[0029] 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.

[0030] <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.

[0031] 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.

[0032] Hydrogen electrode 21: H ２ O + 2e － →H ２ +O ２－ ... (1) The raw material gas is H ２ O plus CO ２In 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.

[0033] 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)

[0034] H generated at the hydrogen electrode 21 ２ The gas flows out from each of the communication holes 313 of the metal support 31 into the internal space 30 described below.

[0035] 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).

[0036] 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.

[0037] 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.

[0038] 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.

[0039] <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.

[0040] 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 .

[0041] 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.

[0042] 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.

[0043] 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.

[0044] <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.

[0045] The reaction prevention layer 23 is made of an oxide ion conductive material, such as GDC or SDC.

[0046] 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.

[0047] 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.

[0048] <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.

[0049] 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.

[0050] Oxygen electrode 24:2O ２－ →O ２ +4e － ...(5)

[0051] 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).

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 3, the fluid container 3 has a first interface 4 and a second interface 5. FIG. 3 is an enlarged cross-sectional view showing the details of the first adhesive portion 34 and its surroundings.

[0057] 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.

[0058] The metal support 31 has a plurality of communication holes 313 , a first main surface 311 and a second main surface 312 .

[0059] 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.

[0060] Each of the communication holes 313 can be formed by mechanical processing (for example, punching), laser processing, or chemical processing (for example, etching).

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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).

[0065] <Frame> The frame 32 is a spacer for forming the internal space 30. In this embodiment, the frame 32 is formed in an annular shape. 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 may be, for example, 0.1 mm or more and 2.0 mm or less.

[0066] 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.

[0067] 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.

[0068] <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.

[0069] 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.

[0070] 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.

[0071] <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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] <Second adhesive portion> The second adhesive portion 35 is disposed between the frame body 32 and the interconnector 33. The second adhesive portion 34 bonds the frame body 32 and the interconnector 33. In detail, the second adhesive portion 35 is joined to each of the frame body 32 and the interconnector 33.

[0083] 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.

[0084] 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.

[0085] 3 , the first interface 4 is an interface between the metal support 31 and the first adhesive portion 34. The first interface 4 has a first inclined portion 41 and a third inclined portion 42. The first inclined portion 41 and the third inclined portion 42 are inclined with respect to the surface direction of the metal support 31. The first interface 4 also has a first flat portion 43. The first flat portion 43 extends substantially parallel to the surface direction of the metal support 31. The surface direction of the metal support 31 is the direction in which a portion of the second main surface 312 of the metal support 31 excluding the surfaces constituting the first inclined portion 41 and the third inclined portion 42 extends, and is the XY surface direction.

[0086] The first inclined portion 41 and the third inclined portion 42 extend in an annular shape along the first adhesive portion 34. The first inclined portion 41 and the third inclined portion 42 may extend in an annular shape continuously or intermittently. The third inclined portion 42 is disposed closer to the outer periphery of the fluid container 3 (to the right in FIG. 3 ) than the first inclined portion 41. The first inclined portion 41 and the third inclined portion 42 are connected to each other.

[0087] The first inclined portion 41 and the third inclined portion 42 are inclined from the internal space 30 toward the outer peripheral edge of the fluid container 3. That is, the first inclined portion 41 and the third inclined portion 42 extend from the internal space 30 toward the outer peripheral edge of the fluid container 3 and are inclined toward the thickness direction (Z-axis direction).

[0088] Specifically, the first inclined portion 41 is inclined from the internal space 30 toward the outer peripheral edge of the fluid container 3 (toward the right in FIG. 3 ) so as to approach the frame 32. The third inclined portion 42 is inclined from the internal space 30 toward the outer peripheral edge of the fluid container 3 so as to move away from the frame 32. The first inclined portion 41 and the third inclined portion 42 are inclined in opposite directions from the internal space 30 toward the outer peripheral edge of the fluid container 3.

[0089] The first flat portion 43 is disposed closer to the internal space 30 than the first inclined portion 41. The first flat portion 43 is longer than the first inclined portion 41 in the direction from the internal space 30 toward the outer periphery of the fluid container 3. The first flat portion 43 may also be disposed closer to the outer periphery of the fluid container 3 than the third inclined portion 42.

[0090] The second interface 5 is an interface between the frame body 32 and the first adhesive portion 34. The second interface 5 has a second inclined portion 51 and a fourth inclined portion 52. The second inclined portion 51 and the fourth inclined portion 52 are inclined with respect to the surface direction of the frame body 32. The second interface 5 also has a second flat portion 53. The second flat portion 53 extends substantially parallel to the surface direction of the frame body 32. The surface direction of the frame body 32 is the direction in which the portion of the first main surface 321 of the frame body 32 excluding the surfaces constituting the second inclined portion 51 and the fourth inclined portion 52 extends, and is the XY surface direction. The surface direction of the frame body 32 is substantially parallel to the surface direction of the metal support body 31.

[0091] The second inclined portion 51 and the fourth inclined portion 52 extend in an annular shape along the first adhesive portion 34. The second inclined portion 51 and the fourth inclined portion 52 may extend in an annular shape continuously or intermittently. The fourth inclined portion 52 is disposed closer to the outer periphery of the fluid container 3 (to the right in FIG. 3 ) than the second inclined portion 51. The second inclined portion 51 and the fourth inclined portion 52 are connected to each other.

[0092] The second inclined portion 51 and the fourth inclined portion 52 are inclined from the internal space 30 toward the outer peripheral edge of the fluid container 3. That is, the second inclined portion 51 and the fourth inclined portion 52 extend from the internal space 30 toward the outer peripheral edge of the fluid container 3 and are inclined toward the thickness direction (Z-axis direction).

[0093] Specifically, the second inclined portion 51 is inclined from the internal space 30 toward the outer peripheral edge of the fluid container 3 (toward the right in FIG. 3 ) so as to approach the metal support 31. The fourth inclined portion 52 is inclined from the internal space 30 toward the outer peripheral edge of the fluid container 3 so as to move away from the metal support 31. The second inclined portion 51 and the fourth inclined portion 52 are inclined in opposite directions from the internal space 30 toward the outer peripheral edge of the fluid container 3.

[0094] The second flat portion 53 is disposed closer to the internal space 30 than the first inclined portion 41. The second flat portion 53 is longer than the first inclined portion 41 in the direction from the internal space 30 toward the outer periphery of the fluid container 3. The second flat portion 53 may also be disposed closer to the outer periphery of the fluid container 3 than the fourth inclined portion 52.

[0095] The first inclined portion 41 and the second inclined portion 51 overlap each other when viewed in the thickness direction (when viewed in the Z-axis direction). The first inclined portion 41 and the second inclined portion 51 are inclined so as to approach each other from the internal space 30 toward the outer periphery of the fluid container 3 (toward the right in FIG. 3 ).

[0096] The first adhesive portion 34 has a first tapered portion 341 defined by a first inclined portion 41 and a second inclined portion 51. The first tapered portion 341 has a thickness t that decreases from the internal space 30 toward the outer periphery of the fluid container 3. The maximum thickness t1 of the first tapered portion 341 is, for example, 1 μm or more and 100 μm or less, and the minimum thickness t2 is, for example, 0.1 μm or more and 10 μm or less. The thickness of the first adhesive portion 34 excluding the first tapered portion 341 and a second tapered portion 342 (described later) is substantially the same as the maximum thickness t1 of the first tapered portion 341. The thickness of the first adhesive portion 34 is the dimension between the first flat portion 43 and the second flat portion 53. Here, the thickness refers to the dimension in the direction (Z-axis direction) perpendicular to the surface direction (XY surface direction) of the metal support 31.

[0097] The taper ratio ((t4-t2) / L1) of the first taper portion 341 is, for example, 0.01 or more and 0.1 or less. Here, t4 refers to the thickness of the first taper portion 341 at point P1, which is a distance L1 away from the point where the first taper portion 341 has the minimum thickness t2 toward the internal space 30. The thickness of the first taper portion 341 is measured at three points within a range of ±10 μm from point P1 in the X-axis direction in FIG. 3, and the average of the measured values ​​is taken as thickness t4. Then, the thickness t4 is measured at each point P1 where L1 is 100 μm, 200 μm, 300 μm, 400 μm, and 500 μm, and the taper ratio is calculated. The first taper portion 341 is formed so that any of the calculated taper ratios falls within the above numerical range.

[0098] The third inclined portion 42 and the fourth inclined portion 52 overlap each other when viewed in the thickness direction (when viewed in the Z-axis direction). The third inclined portion 42 and the fourth inclined portion 52 are inclined so as to move away from each other from the internal space 30 toward the outer periphery of the fluid container 3 (toward the right in FIG. 3 ).

[0099] The first adhesive portion 34 has a second tapered portion 342 defined by a third inclined portion 42 and a fourth inclined portion 52. The second tapered portion 342 has a thickness t that increases from the internal space 30 toward the outer periphery of the fluid container 3. The second tapered portion 342 has a maximum thickness t3 that is, for example, 1.0 μm or more and 100 μm or less. The second tapered portion 342 is connected to the first tapered portion 341 at its thinnest portion, and therefore the second tapered portion 342 has a minimum thickness t2 that is the same as the minimum thickness t2 of the first tapered portion 341.

[0100] The taper ratio ((t5-t2) / L2) of the second taper portion 342 is, for example, 0.01 or more and 0.1 or less. Here, t5 refers to the thickness of the second taper portion 342 at point P2, which is a distance L2 away from the point where the second taper portion 342 has the minimum thickness t2 toward the internal space 30. The thickness of the second taper portion 342 is measured at three points within a range of ±10 μm from point P2 in the X-axis direction in FIG. 3, and the average of the measured values ​​is taken as thickness t5. Then, the thickness t5 is measured at each point P2 where L2 is 100 μm, 200 μm, 300 μm, 400 μm, and 500 μm, and the taper ratio is calculated. The second taper portion 342 is formed so that any of the calculated taper ratios falls within the above numerical range.

[0101] The taper ratio of the first tapered portion 341 can be made larger than the taper ratio of the second tapered portion 342. By making the taper ratio of the first tapered portion 341 larger than the taper ratio of the second tapered portion 342 in this way, the mechanical reliability of the first tapered portion 341 can be relatively improved.

[0102] <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 shape described above. Note that the shape described above 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.

[0103] 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 given the shape described above.

[0104] 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.

[0105] (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.

[0106] (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.

[0107] (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.

[0108] (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.

[0109] 4, the first tapered portion 341 and the second tapered portion 342 may be spaced apart from each other. In this case, the fluid container 3 further includes a metal joint 36. The metal joint 36 is disposed between the first tapered portion 341 and the second tapered portion 342.

[0110] The metal joint 36 is made of a metal material. The composition of the metal joint 36 may be the same as the composition of the metal support 31, the same as the composition of the frame 32, or a mixture of the metal support 31 and the frame 32. Furthermore, the composition of the metal joint 36 may be different from the composition of the metal support 31 and the frame 32.

[0111] The metal joint 36 is formed integrally with the metal support body 31 and the frame body 32. The metal joint 36 can be formed, for example, by welding the metal support body 31 and the frame body 32 together, or by brazing the metal support body 31 and the frame body 32 together. The metal joint 36 according to this embodiment is formed by lap-welding the metal support body 31 and the frame body 32 together.

[0112] The metal joint 36 is disposed between the first tapered portion 341 and the second tapered portion 342 and is therefore isolated from the internal space 30. Therefore, the metal joint 36 is not exposed to the internal space 30.

[0113] This allows the reducing gas (in this embodiment, H ２ ) can be prevented from coming into contact with the metal joint 36, thereby preventing the metal joint 36 from being deteriorated (e.g., embrittlement) by the reducing gas. Furthermore, in this embodiment, water vapor flowing through the internal space 30 can be prevented from coming into contact with the metal joint 36, thereby preventing corrosion of the metal joint 36 by water vapor.

[0114] Furthermore, since the metal joint 36 is disposed between the first tapered portion 341 and the second tapered portion 342, it is isolated from the space outside the fluid container 3. Therefore, the metal joint 36 is not exposed to the external space.

[0115] This prevents water vapor contained in the air in the external space from coming into contact with the metal joint 36, thereby further preventing the metal joint 36 from being corroded by water vapor.

[0116] 5, the first adhesive portion 34 may have a space 343 therein that extends in the surface direction of the metal support 31. By forming the space 343 in this manner, stress generated in the first adhesive portion 34 can be alleviated.

[0117] 6, the first adhesive portion 34 may be composed of multiple layers. For example, the first adhesive portion 34 may be composed of a first layer 344, a second layer 345, and a third layer 346.

[0118] The first layer 344 is disposed on the metal support 31. The first layer 344 is sandwiched between the metal support 31 and the second layer 345. The first layer 344 is made of, for example, Cr ２ O ３ It is composed of:

[0119] The second layer 345 is disposed between the first layer 344 and the frame 32. Because the first adhesive portion 34 has the third layer 346, the second layer 345 is sandwiched between the first layer 344 and the third layer 346. In addition, a portion of the second layer 345 is sandwiched between the metal support 31 and the frame 32.

[0120] The oxide constituting the second layer 345 is preferably different from the oxide constituting the first layer 344. This makes it possible to stop cracks that attempt to propagate in the Z-axis direction from the first layer 344 toward the second layer 345, or from the second layer 345 toward the first layer 344, at the interface between the first layer 344 and the second layer 345. For example, the second layer 345 is made of chromium manganese oxide.

[0121] The third layer 346 is disposed on the frame 32. The third layer 346 is sandwiched between the second layer 345 and the frame 32. The oxide constituting the third layer 346 is preferably different from the oxide constituting the second layer 345. This allows cracks that attempt to propagate in the Z-axis direction from the second layer 345 toward the third layer 346, or from the third layer 346 toward the second layer 345, to be stopped at the interface between the second layer 345 and the third layer 346. In this embodiment, the third layer 346 is made of Cr ２ O ３ It is composed of:

[0122] The oxide constituting the third layer 346 is preferably the same as the oxide constituting the first layer 344. This makes the first adhesive portion 34 have a symmetrical structure in the thickness direction parallel to the Z-axis direction, thereby improving the mechanical reliability of the first adhesive portion 34.

[0123] The number of layers of the first adhesive portion 34 varies in the direction from the internal space 30 toward the outer peripheral edge of the fluid container 3. The number of layers of the first adhesive portion 34 decreases in the direction from the internal space 30 toward the outer peripheral edge of the fluid container 3. Furthermore, the number of layers of the first adhesive portion 34 decreases and then increases in the direction from the internal space 30 toward the outer peripheral edge of the fluid container 3.

[0124] Specifically, the number of layers of the first adhesive portion 34 is 3 in the first region R1. Then, the number of layers of the first adhesive portion 34 is 1 in the second region R2, which is closer to the outer periphery of the fluid container 3 than the first region R1. Furthermore, the number of layers of the first adhesive portion 34 is 3 in the third region R3, which is closer to the outer periphery of the fluid container 3 than the second region R2. In this way, the number of layers of the first adhesive portion 34 decreases and then increases in the direction from the internal space 30 toward the outer periphery of the fluid container 3.

[0125] (g) In the above embodiment, the first adhesive portion 34 has the first tapered portion 341 and the second tapered portion 342, but the first adhesive portion 34 does not have to have the second tapered portion 342. That is, the first interface 4 does not have to have the third inclined portion 42. Furthermore, the second interface 5 does not have to have the fourth inclined portion 52.

[0126] (h) 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.

[0127] (i) 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.

[0128] 2: Cell main body 3: Fluid container 30: Internal space 31: Metal support 32: Frame 34: First adhesive portion 341: First tapered portion 342: Second tapered portion 343: Space portion 36: Metal joint portion 4: First interface 41: First inclined portion 42: Third inclined portion 5: Second interface 51: Second inclined portion 52: Fourth inclined portion 100: Electrolytic cell

Claims

1. A fluid container having an internal space through which a fluid flows, 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 the interface between the first metal member and the adhesive portion; and a second interface which is the interface between the second metal member and the adhesive portion, wherein the first interface has a first inclined portion which is inclined with respect to the surface direction of the first metal member.

2. The fluid container according to claim 1, wherein the adhesive portion extends in an annular shape so as to surround the internal space, and the first inclined portion extends along the adhesive portion.

3. A fluid container as described in claim 1, wherein the first inclined portion inclines from the internal space toward the outer periphery of the fluid container.

4. A fluid container as described in claim 1, wherein the second interface has a second inclined portion that is inclined with respect to a surface direction of the second metal member.

5. A fluid container as described in claim 4, wherein the first inclined portion and the second inclined portion overlap each other when viewed in the thickness direction and are inclined so as to approach each other from the internal space toward the outer peripheral edge of the fluid container.

6. A fluid container as described in claim 5, wherein the first interface has a third inclined portion inclined with respect to the surface direction of the first metal member, the second interface has a fourth inclined portion inclined with respect to the surface direction of the second metal member, the third inclined portion is disposed on the outer peripheral edge side with respect to the first inclined portion, the fourth inclined portion is disposed on the outer peripheral edge side with respect to the second inclined portion, and the third inclined portion and the fourth inclined portion overlap each other when viewed in the thickness direction and are inclined away from each other from the internal space toward the outer peripheral edge.

7. A fluid container as described in claim 6, wherein the adhesive portion has a first tapered portion defined by the first inclined portion and the second inclined portion, and a second tapered portion defined by the third inclined portion and the fourth inclined portion, and a taper ratio of the first tapered portion is greater than a taper ratio of the second tapered portion.

8. A fluid container as described in claim 6, further comprising a metal joint portion formed integrally with the first metal member and the second metal member and made of a metal material, the adhesive portion having a first tapered portion defined by the first inclined portion and the second inclined portion, and a second tapered portion defined by the third inclined portion and the fourth inclined portion, and the metal joint portion being disposed between the first tapered portion and the second tapered portion.

9. The fluid container according to claim 1, wherein the adhesive portion has a space therein extending in a surface direction of the first metal member.

10. A fluid container as described in claim 1, wherein the adhesive portion is composed of a plurality of layers, and the number of layers of the adhesive portion varies in a direction from the internal space toward an outer peripheral edge of the fluid container.

11. The fluid container according to claim 9, wherein the number of layers of the adhesive portion decreases in a direction from the internal space toward the outer periphery of the fluid container.

12. The fluid container according to claim 1, wherein the adhesive portion is a seal for sealing the internal space.

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

14. The electrochemical cell described in claim 13, wherein the first metal member has a plurality of communication holes that connect 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.

15. The electrochemical cell described in claim 13, wherein the second metal member has a plurality of communicating holes that connect to the internal space, and the cell main body is positioned on the second metal member so as to cover the plurality of communicating holes.

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