Fluid container and electrochemical cell

Abstract

A fluid container (3) comprises a first metal member (31), a second metal member (32), and an adhesive part (34). The first and second metal members (31, 32) contain chromium. The adhesive part (34) is composed of an oxide containing chromium as a main component. The adhesive part (34) adheres the first metal member (31) to the second metal member (32). The adhesive part (34) includes a base section (341) and protruding sections (342). The protruding sections (342) protrude in the thickness direction from the base part (341).

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 joint, and there is a risk that a crack will occur in the adhesive joint, and the crack will propagate, causing the adhesive joint to break.

[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 includes a first metal member, a second metal member, and an adhesive portion. The first metal member and the second metal member contain chromium. The adhesive portion is made of an oxide containing chromium as a main component. The adhesive portion bonds the first metal member and the second metal member. The adhesive portion has a base portion and a protrusion portion. The protrusion portion protrudes from the base portion in the thickness direction.

[0008] With this configuration, the adhesive bond is sandwiched between the first metal member and the second metal member, and a local compressive stress acts on the area where the convex portion of the adhesive bond is formed. As a result, even if a crack occurs in the adhesive bond, the crack can be prevented from progressing in the area where the local compressive stress acts, and thus damage to the adhesive bond can be prevented.

[0009] The fluid container according to the second aspect is the fluid container according to the first aspect, and is configured as follows: The protrusion is configured from a material different from that of the base.

[0010] The fluid container according to the third aspect is the fluid container according to the first aspect, and is configured as follows: The protrusion is made of the same material as the base.

[0011] A fluid container according to a fourth aspect is the fluid container according to any one of the first to third aspects, further comprising an internal space through which a fluid flows. The adhesive portion extends annularly to surround the internal space. The adhesive portion has a plurality of protrusions. The protrusions are arranged along the outer periphery of the first metal member.

[0012] A fluid container according to a fifth aspect is the fluid container according to any one of the first to fourth aspects, further comprising an internal space through which a fluid flows. The adhesive portion has a plurality of protrusions arranged from the internal space toward the outer peripheral edge of the first metal member.

[0013] A fluid container according to a sixth aspect is the fluid container according to any one of the first to fifth aspects, and is configured as follows: the ratio (t2 / t1) of the thickness (t2) of the thickest part of the adhesive portion to the thickness (t1) of the thinnest part of the adhesive portion is 1.2 or more.

[0014] A seventh aspect of the present invention relates to the fluid container of any one of the first to sixth aspects, and further includes an internal space through which a fluid flows. The adhesive joint has a thick portion that is thicker than the average thickness of the adhesive joint. In a direction from the internal space toward the outer peripheral edge of the first metal member, the ratio (L / L0) of the length (L) of the thick portion to the length (L0) of the adhesive joint is 0.4 or less.

[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] 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 focusing on a first adhesive portion; Fig. 5 is a plan view of a fluid container; Fig. 6 is a view showing an example of a photographed image; Fig. 7 is an enlarged cross-sectional view focusing on 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] 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.

[0053] The metal support 31 has a plurality of communication holes 313 , a first main surface 311 and a second main surface 312 .

[0054] 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.

[0055] Each of the communication holes 313 can be formed by mechanical processing (for example, punching), laser processing, or chemical processing (for example, etching).

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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).

[0060] <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.

[0061] 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.

[0062] 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.

[0063] <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.

[0064] 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.

[0065] 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.

[0066] <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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 3 is an enlarged cross-sectional view focusing on the first adhesive portion 34. As shown in FIG.

[0078] 4 is a plan view of the fluid container 3. As shown in FIG. 4, the first adhesive portion 34 has four straight line portions in a plan view (viewed in the Z-axis direction). That is, the base portion 341 has four straight line portions in a plan view. Specifically, the base portion 341 has 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 base portion 341 extends in a rectangular shape in a plan view. That is, the base portion 341 extends in a continuous ring shape so as to surround the internal space 30.

[0079] As shown in FIG. 3 , each protrusion 342 is configured to protrude from the base portion 341 in the thickness direction (Z-axis direction) of the first adhesive portion 34. Specifically, the multiple protrusions 342 include multiple first protrusions 342a and multiple second protrusions 342b. Each first protrusion 342a protrudes from the base portion 341 toward the metal support 31 (upper side in FIG. 3 ). Each second protrusion 342b protrudes from the base portion 341 toward the frame 32 (lower side in FIG. 3 ). The first protrusions 342a and the second protrusions 342b may or may not overlap in a plan view.

[0080] The protrusions 342 are arranged along the outer periphery of the metal support 31. That is, the protrusions 342 are arranged along the direction in which the first adhesive portions 34 extend. Therefore, the protrusions 342 are arranged in a ring shape in a plan view. The protrusions 342 are also arranged from the internal space 30 toward the outer periphery of the metal support 31.

[0081] The ratio (t2 / t1) of the thickness (t2) of the thickest portion of the first adhesive portion 34 to the thickness (t1) of the thinnest portion of the first adhesive portion 34 is preferably 1.2 or greater. The thickness (t1) of the thinnest portion and the thickness (t2) of the thickest portion of the first adhesive portion 34 are measured based on multiple captured images. Specifically, the first adhesive portion 34 is cut along a direction from the internal space 30 toward the outer peripheral edge of the metal support 31 to create a cut surface of the first adhesive portion 34 as shown in FIG. 3 . Multiple images of this cut surface are then taken at 1000x magnification using a scanning electron microscope (SEM). The thickness of the thinnest portion of the first adhesive portion 34 in each captured image is measured as the thickness t1 of the thinnest portion. Similarly, the thickness of the thickest portion of the first adhesive portion 34 in each captured image is measured as the thickness t2 of the thickest portion. Then, for each captured image, a ratio (t2 / t1) of the thickness (t2) of the thickest part of the first adhesive portion 34 to the thickness (t1) of the thinnest part of the first adhesive portion 34 is calculated. It is preferable that this ratio (t2 / t1) is 1.2 or more for each captured image, but it is sufficient that the ratio (t2 / t1) is 1.2 or more for at least any of the captured images.

[0082] The average thickness t0 of the first adhesive portion 34 is not particularly limited, but is, for example, 1 μm or more and 100 μm or less. The average thickness t0 of the first adhesive portion 34 can be measured based on each of the captured images described above. Specifically, as shown in FIG. 5 , each captured image is divided into eight equal parts in the direction from the internal space 30 toward the outer peripheral edge of the metal support 31, and the thickness t of the first adhesive portion 34 is measured at each of the eight equal parts, and the average value of these measured values ​​can be defined as the average thickness of the first adhesive portion 34. In other words, the average value of all the measured values ​​measured in each captured image is defined as the average thickness t0 of the first adhesive portion 34. The ratio (t3 / t0) of the thickness t3 of the metal support 31 to the thickness t0 of the first adhesive portion 34 can be, for example, 500 or less.

[0083] As shown in FIG. 3 , in the direction from the internal space 30 toward the outer peripheral edge of the metal support 31, the ratio (L / L0) of the length (L) of the thick portion of the first adhesive portion 34 to the length L0 of the first adhesive portion 34 can be 0.4 or less. Here, the thick portion of the first adhesive portion 34 is a portion that is thicker than the average thickness t0 of the first adhesive portion 34. For example, when the first adhesive portion 34 has a shape as shown in FIG. 3 , the portion where each convex portion 342 is formed is a thick portion, and the first adhesive portion 34 has multiple thick portions. When multiple thick portions are formed in this way, the length L of the thick portion is the sum of the lengths of the respective thick portions. For example, when the first adhesive portion 34 has a shape as shown in FIG. 3 , the length L of the thick portion is the sum of L1, L2, and L3.

[0084] The first adhesive portion 34 is thicker in the region where the convex portion 342 is formed. Here, the convex portion 342 is a portion that is 20% or more thicker than the average thickness t0 of the first adhesive portion 34.

[0085] The base portion 341 and the protruding portion 342 are made of the material described above as the material for making up the first adhesive portion 34. The protruding portion 342 can be made of a material different from that of the base portion 341. For example, if the base portion 341 is made of chromium oxide, the protruding portion 342 is made of chromium manganese oxide. Note that the protruding portion 342 may be made of the same material as the base portion 341.

[0086] 2 , 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.

[0087] 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.

[0088] 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.

[0089] <Manufacturing Method> A method for manufacturing the first adhesive portion 34 will be described below. First, the metal support 31 is pressed to form a recess in a region of the second main surface 312 of the metal support 31 that is to be bonded to the first adhesive portion 34. Note that the recess may also be formed in the second main surface 312 of the metal support 31 by cutting, etching, laser ablation, or the like.

[0090] Similarly, by pressing the frame body 32, a recess is formed in the region of the first main surface 321 of the frame body 32 that is to be bonded to the first adhesive portion 34.

[0091] 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.

[0092] (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.

[0093] (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.

[0094] (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.

[0095] (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.

[0096] (d) In the above embodiment, the multiple protrusions 342 are formed around the entire circumference of the first adhesive portion 34, but the configuration of the first adhesive portion 34 is not limited to this. For example, the multiple protrusions 342 may be formed on only one of the four straight line portions of the first adhesive portion 34. In particular, the multiple protrusions 342 may be formed in a portion of the four straight line portions where cracks are likely to occur. Furthermore, the multiple protrusions 342 do not need to be formed on the entire straight line portion, but may be formed on only a portion of the straight line portion.

[0097] (e) In the above embodiment, the plurality of protrusions 342 include a first protrusion 342a and a second protrusion 342b, but the configuration of the protrusions 342 is not limited to this. For example, as shown in FIG. 6 , the plurality of protrusions 342 may include only a first protrusion 342a. Alternatively, the plurality of protrusions 342 may include only a second protrusion 342b. Furthermore, in the above embodiment, the first adhesive portion 34 includes a plurality of protrusions 342, but may include only a single protrusion 342.

[0098] (f) In the above embodiment, an electrolytic cell has been described as an example of an electrochemical cell, but the electrochemical cell is not limited to an electrolytic cell. An electrochemical cell is a general term 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.

[0099] (f) 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.

[0100] 2: Cell main body 3: Fluid container 30: Internal space 31: Metal support 313: Communication hole 32: Frame 34: First adhesive portion 341: Base portion 342: Protrusion 100: Electrolytic cell

Claims

1. A fluid container comprising: a first metal member containing chromium; a second metal member containing chromium; and an adhesive portion composed of an oxide primarily composed of chromium, which bonds the first metal member and the second metal member, wherein the adhesive portion has a base portion and a convex portion protruding from the base portion in the thickness direction.

2. The fluid container according to claim 1, wherein the protrusion is made of a material different from that of the base.

3. The fluid container according to claim 1, wherein the protrusion is made of the same material as the base.

4. A fluid container as described in claim 1, further comprising an internal space through which a fluid flows, the adhesive portion extending in an annular shape so as to surround the internal space, the adhesive portion having a plurality of the protrusions, and each of the protrusions being arranged along the outer circumferential edge of the first metal member.

5. A fluid container as described in claim 1, further comprising an internal space through which a fluid flows, the adhesive portion having a plurality of said protrusions, each of said protrusions being arranged from said internal space toward the outer peripheral edge portion of said first metal member.

6. The fluid container according to claim 1, wherein a ratio (t2 / t1) of a thickness (t2) of the thickest part of the adhesive portion to a thickness (t1) of the thinnest part of the adhesive portion is 1.2 or more.

7. A fluid container as described in claim 1, further comprising an internal space through which a fluid flows, the adhesive portion having a thick portion that is thicker than its average thickness, and in a direction from the internal space toward the outer peripheral edge portion of the first metal member, a ratio (L / L0) of a length (L) of the thick portion to a length (L0) of the adhesive portion is 0.4 or less.

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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