Electrochemical cell

Abstract

An electrolytic cell (1) comprises a metal support (10), a cell body (20), and a seal part (30). The metal support (10) has a recess (13) formed in a first main surface (11) and a plurality of through holes (16) formed in the bottom surface (14) of the recess (13). The cell body (20) is positioned on the bottom surface of the recess (13). The seal part (30) has a first portion (31) that is joined to an inner surface (15) of the recess (13) and a side surface (23) of the cell body (20), and a second portion (32) that is positioned on the first section (31) and is joined to the first main surface (11) of the metal support (10) and the upper surface (21) of the cell body (20).

Description

electrochemical cell

[0001] The present invention relates to electrochemical cells.

[0002] Patent Document 1 discloses an electrochemical cell (electrolysis cell, fuel cell, etc.) that includes a metal support, a cell body portion disposed on the metal support, and a seal portion disposed between the metal support and the cell body portion.

[0003] The metal support has a recess formed in a main surface and a plurality of communication holes formed in a bottom surface of the recess. The cell body is disposed on the bottom surface of the recess. The seal is bonded to the main surface of the metal support and the upper surface of the cell body.

[0004] JP 2020-140924 A

[0005] However, in the electrochemical cell described in Patent Document 1, warping or deformation of the cell body causes cracks to form in the sealing portion.

[0006] An object of the present invention is to provide an electrochemical cell that can suppress the occurrence of cracks in the sealing portion.

[0007] An electrochemical cell according to a first aspect of the present invention comprises a metal support having a recess formed in a main surface and a plurality of communication holes formed in a bottom surface of the recess, a cell main body portion disposed on the bottom surface of the recess, and a seal portion disposed between the metal support and the cell main body portion. The seal portion has a first portion bonded to an inner surface of the recess and a side surface of the cell main body portion, and a second portion disposed on the first portion and bonded to the main surface of the metal support and an upper surface of the cell main body portion.

[0008] An electrochemical cell according to a second aspect of the present invention is related to the first aspect, wherein the first portion has coarse pores therein.

[0009] An electrochemical cell according to a third aspect of the present invention is related to the first or second aspect, wherein the second portion has an upper surface and a recess formed in the upper surface.

[0010] An electrochemical cell according to a fourth aspect of the present invention is related to any one of the first to third aspects, wherein the first portion has a lower surface facing the bottom surface of the recess, and the lower surface of the first portion is spaced apart from the bottom surface of the recess.

[0011] An electrochemical cell according to a fifth aspect of the present invention is related to the fourth aspect, wherein the cell main body has a lower surface facing the bottom surface of the recess, and the outer edge of the lower surface of the cell main body is spaced apart from the bottom surface of the recess.

[0012] An electrochemical cell according to a sixth aspect of the present invention is related to the fifth aspect, wherein the gap between the lower surface of the first portion and the bottom surface of the recess is connected to the gap between the lower surface of the cell main body portion and the bottom surface of the recess.

[0013] An electrochemical cell according to a seventh aspect of the present invention is the electrochemical cell according to any one of the first to sixth aspects, wherein the cell main body has an uneven surface on its side surface.

[0014] According to the present invention, it is possible to provide an electrochemical cell that can suppress the occurrence of cracks in the sealing portion.

[0015] FIG. 1 is a plan view of an electrolysis cell according to an embodiment. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 4 is a cross-sectional view illustrating the configuration of a side surface of a cell main body according to Modification 1. FIG. 5 is a cross-sectional view illustrating the configuration of a side surface of a cell main body according to Modification 1. FIG. 6 is a cross-sectional view illustrating the configuration of a side surface of a cell main body according to Modification 1.

[0016] (Electrolytic cell 1) Fig. 1 is a plan view of an electrolytic cell 1 according to an embodiment. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1.

[0017] The electrolytic cell 1 is an example of an "electrochemical cell" according to the present invention. The electrolytic cell 1 is a so-called metal-supported electrolytic cell.

[0018] The electrolytic cell 1 is formed in a plate shape extending in the X-axis and Y-axis directions. In the present embodiment, the electrolytic cell 1 is formed in a rectangular shape extending in the Y-axis direction when viewed in a plan view from the Z-axis direction perpendicular to the X-axis and Y-axis directions. However, the planar shape of the electrolytic cell 1 is not particularly limited, and may be a polygon other than a rectangle, an ellipse, a circle, or the like.

[0019] As shown in FIG. 2 , the electrolysis cell 1 includes a metal support 10 , a cell main body 20 , a seal portion 30 , and a flow path member 40 .

[0020] [Metal Support 10] The metal support 10 supports the cell main body 20. The metal support 10 is formed in a plate shape. The metal support 10 may be in the shape of a flat plate or a curved plate.

[0021] The metal support 10 is only required to be able to support the cell main body 20, and its thickness is not particularly limited, but can be, for example, 0.1 mm or more and 2.0 mm or less.

[0022] As shown in FIG. 2 , the metal support 10 has a first main surface 11 , a second main surface 12 , a recess 13 , a bottom surface 14 , an inner side surface 15 , and a plurality of communication holes 16 .

[0023] The first main surface 11 is an example of a "main surface" according to the present invention. The first main surface 11 is provided on the opposite side of the second main surface 12. The first main surface 11 is provided on the opposite side of the flow path member 40. A recess 13 is formed in the first main surface 11. The flow path member 40 is joined to the second main surface 12.

[0024] The recess 13 is formed in the first main surface 11. The recess 13 is a bottomed recess that opens to the first main surface 11. At least a portion of the cell main body 20 is housed in the recess 13.

[0025] The recess 13 has a bottom surface 14 and an inner side surface 15. The cell main body 20 is disposed on the bottom surface 14. The bottom surface 14 faces the lower surface 22 of the cell main body 20. At least a portion of the bottom surface 14 is joined to the lower surface 22 of the cell main body 20. The inner side surface 15 is formed in an annular shape. In this embodiment, the inner side surface 15 is formed in a rectangular annular shape. The inner side surface 15 is continuous with the first main surface 11 and the bottom surface 14. The inner side surface 15 faces at least a portion of the side surface 23 of the cell main body 20. The inner side surface 15 is spaced from the side surface 23 of the cell main body 20. A portion of the seal portion 30 is disposed in the gap between the inner side surface 15 and the side surface 23 of the cell main body 20. A portion of the seal portion 30 is joined to the inner side surface 15.

[0026] Each communication hole 16 penetrates the metal support 10 from the bottom surface 14 of the recess 13 to the second main surface 12. Each communication hole 16 opens to both the bottom surface 14 and the second main surface 12. In this embodiment, the opening of each communication hole 16 on the bottom surface 14 side is covered by the hydrogen electrode layer 6, which will be described later. The opening of each communication hole 16 on the second main surface 12 side is connected to a flow path 30a, which will be described later.

[0027] Each communication hole 16 can be formed by mechanical processing (for example, punching), laser processing, chemical processing (for example, etching), or the like. In this embodiment, each communication hole 16 is formed linearly along the Z-axis direction. However, each communication hole 16 may be inclined with respect to the Z-axis direction, or may not be linear. Furthermore, the communication holes 16 may be connected to each other.

[0028] The metal support 10 is made of a metal material. For example, the metal support 10 is made of an alloy material containing Cr (chromium). Examples of such metal materials include Fe—Cr alloy steel (stainless steel, etc.) and Ni—Cr alloy steel. The Cr content in the metal support 10 is not particularly limited, but can be set to 4% by mass or more and 30% by mass or less.

[0029] The metal support 10 may contain Ti (titanium) or Zr (zirconium). The Ti content in the metal support 10 is not particularly limited, but may be 0.01 mol % or more and 1.0 mol % or less. The Zr content in the metal support 10 is not particularly limited, but may be 0.01 mol % or more and 0.4 mol % or less. The metal support 10 may contain Ti in the form of TiO ２ (titania), or Zr may be contained as ZrO ２ It may be contained as (zirconia).

[0030] The metal support 10 may have an oxide film on its surface, which is formed by oxidation of the constituent elements of the metal support 10. A typical example of the oxide film is a chromium oxide film. The oxide film covers at least a portion of the surface of the metal support 10. The oxide film may also cover at least a portion of the inner wall surface of each communicating hole 16.

[0031] [Cell main body 20] The cell main body 20 is disposed on the bottom surface 14 of the recess 13 of the metal support 10. At least a portion of the cell main body 20 is housed within the recess 13. The entire cell main body 20 may be housed within the recess 13, or a portion of the cell main body 20 may protrude from the recess 13.

[0032] As shown in FIG. 2 , the cell body 20 has an upper surface 21 , a lower surface 22 , and a side surface 23 .

[0033] The upper surface 21 is provided on the opposite side of the metal support 10. The lower surface 22 faces the bottom surface 14 of the recess 13. At least a portion of the lower surface 22 is joined to the bottom surface 14 of the recess 13. As will be described later in this embodiment, the outer edge of the lower surface 22 is spaced apart from the bottom surface 14 of the recess 13.

[0034] The side surface 23 faces the inner surface 15 of the recess 13. The side surface 23 is spaced apart from the inner surface 15 of the recess 13. Although the side surface 23 is illustrated as being flat in FIG. 2 , the side surface 23 may be partially or entirely uneven. A part of the seal portion 30 is disposed in the gap between the side surface 23 and the inner surface 15 of the recess 13. The seal portion 30 is joined to the side surface 23.

[0035] As shown in FIG. 2, the cell body 20 has a hydrogen electrode layer 6 (cathode), an electrolyte layer 7, a reaction prevention layer 8, and an oxygen electrode layer 9 (anode).

[0036] The hydrogen electrode layer 6, electrolyte layer 7, reaction prevention layer 8, and oxygen electrode layer 9 are stacked in this order in the Z-axis direction from the metal support 10 side. The hydrogen electrode layer 6, electrolyte layer 7, and oxygen electrode layer 9 are essential components, while the reaction prevention layer 8 is optional.

[0037] [Hydrogen Electrode Layer 6] The hydrogen electrode layer 6 is an example of the "first electrode layer" according to the present invention. The hydrogen electrode layer 6 is disposed on the bottom surface 14 of the recess 13 of the metal support 10. A portion of the hydrogen electrode layer 6 may extend into each of the communicating holes 16 of the metal support 10.

[0038] The hydrogen electrode layer 6 is supplied with a source gas through each of the communication holes 16 of the metal support 10. The source gas contains at least H ２ Contains O.

[0039] The raw material gas is H ２ When only O is contained, the hydrogen electrode layer 6 converts H from the raw material gas according to the electrochemical reaction of water electrolysis shown in the following formula (1): ２ Generate.

[0040] Hydrogen electrode layer 6: H ２ O + 2e － →H ２ +O ２－ ...(1)

[0041] The raw material gas is H ２ O plus CO ２ In this case, the hydrogen electrode layer 6 converts the source 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.

[0042] Hydrogen electrode layer 6: CO ２ +H ２ O+4e － →CO+H ２ +20 ２－ ... (2) ・H ２ Electrochemical reaction of O: H ２ O + 2e － →H ２ +O ２－... (3) CO ２ Electrochemical reaction of: CO ２ +2e － →CO+O ２－ ...(4)

[0043] The product gas generated in the hydrogen electrode layer 6 is discharged to each of the communication holes 16 in the metal support 10 .

[0044] The hydrogen electrode layer 6 is a porous body having gas diffusibility and electrical conductivity.

[0045] The hydrogen electrode layer 6 contains a conductive material. As the conductive material, a metal material such as Ni (nickel) or Fe (iron), or a conductive ceramic material can be used. In the case of co-electrolysis, Ni is used as the catalyst for the generated H ２ and CO contained in the raw material gas ２ It also functions as a thermal catalyst, promoting the thermal reaction with HCl to maintain an appropriate gas composition for methanation and reverse water-gas shift reactions.

[0046] The conductive material exists in an oxide state (eg, NiO) in an oxidizing atmosphere and in a metallic state (eg, Ni) in a reducing atmosphere.

[0047] The hydrogen electrode layer 6 includes an oxide ion conductive material, such as YSZ, CSZ, ScSZ, GDC, SDC, or (La, Sr)(Cr, Mn)O. ３ , (La,Sr)TiO ３ , Sr ２ (Fe, Mo) ２ O ６ , (La, Sr)VO ３ , (La,Sr)FeO ３ , LDC, LSGM, and a mixed material of two or more of these can be used.

[0048] In this embodiment, the hydrogen electrode layer 6 has a single layer structure, but may have a multi-layer structure made up of different materials.

[0049] The porosity of the hydrogen electrode layer 6 is not particularly limited, but may be, for example, 20% to 40%. The thickness of the hydrogen electrode layer 6 is not particularly limited, but may be, for example, 1 μm to 500 μm.

[0050] In this specification, the term "thickness" refers to the size in the thickness direction. The thickness direction is the direction perpendicular to the plane direction parallel to the interface between the hydrogen electrode layer 6 and the electrolyte layer 7. The plane direction is the direction parallel to the approximation line of the interface obtained by the least squares method in the cross section of the hydrogen electrode layer 6 and the electrolyte layer 7. The thickness direction may coincide with the Z-axis direction shown in FIGS. 1 and 2 .

[0051] The method for forming the hydrogen electrode layer 6 is not particularly limited, and may be a firing method, a spray coating method (such as a thermal spraying method, an aerosol deposition method, an aerosol gas deposition method, a powder jet deposition method, a particle jet deposition method, or a cold spray method), a PVD method (such as a sputtering method or a pulsed laser deposition method), or a CVD method.

[0052] [Electrolyte Layer 7] The electrolyte layer 7 is disposed between the hydrogen electrode layer 6 and the oxygen electrode layer 9. In this embodiment, the reaction prevention layer 8 is disposed between the electrolyte layer 7 and the oxygen electrode layer 9, and therefore the electrolyte layer 7 is sandwiched between the hydrogen electrode layer 6 and the reaction prevention layer 8. The electrolyte layer 7 covers the hydrogen electrode layer 6.

[0053] The electrolyte layer 7 absorbs the O generated in the hydrogen electrode layer 6. ２－ The electrolyte layer 7 is made of a dense material having oxide ion conductivity. The electrolyte layer 7 can be made of, for example, YSZ (yttria-stabilized zirconia, e.g., 8YSZ), GDC (gadolinium-doped ceria), ScSZ (scandia-stabilized zirconia), SDC (samarium-doped ceria), or LSGM (lanthanum gallate).

[0054] The porosity of the electrolyte layer 7 is not particularly limited, but may be, for example, 0.1% to 7%. The thickness of the electrolyte layer 7 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0055] The method for forming the electrolyte layer 7 is not particularly limited, and may be a baking method, a spray coating method, a PVD method, a CVD method, or the like.

[0056] [Reaction prevention layer 8] The reaction prevention layer 8 is disposed between the electrolyte layer 7 and the oxygen electrode layer 9. The reaction prevention layer 8 is disposed on the opposite side of the electrolyte layer 7 from the hydrogen electrode layer 6. The reaction prevention layer 8 prevents the constituent elements of the electrolyte layer 7 from reacting with the constituent elements of the oxygen electrode layer 9 to form a layer with high electrical resistance.

[0057] The reaction prevention layer 8 is made of an oxide ion conductive material, such as GDC or SDC.

[0058] The porosity of the reaction prevention layer 8 is not particularly limited, but may be, for example, 0.1% to 50%. The thickness of the reaction prevention layer 8 is not particularly limited, but may be, for example, 1 μm to 50 μm.

[0059] The method for forming the reaction prevention layer 8 is not particularly limited, and may be a baking method, a spray coating method, a PVD method, a CVD method, or the like.

[0060] [Oxygen Electrode Layer 9] The oxygen electrode layer 9 is an example of a "second electrode layer" according to the present invention. The oxygen electrode layer 9 is disposed on the opposite side of the hydrogen electrode layer 6 with respect to the electrolyte layer 7. In this embodiment, the reaction prevention layer 8 is disposed between the electrolyte layer 7 and the oxygen electrode layer 9, and therefore the oxygen electrode layer 9 is connected to the reaction prevention layer 8. If the reaction prevention layer 8 is not disposed between the electrolyte layer 7 and the oxygen electrode layer 9, the oxygen electrode layer 9 would be connected to the electrolyte layer 7.

[0061] The oxygen electrode layer 9 reacts with O transferred from the hydrogen electrode layer 6 through the electrolyte layer 7 in accordance with the chemical reaction of the following formula (5): ２－ From O ２ Generate.

[0062] Oxygen electrode layer 9: 2O ２－ →O ２ +4e － ...(5)

[0063] The oxygen electrode layer 9 is a porous body having oxide ion conductivity and electrical conductivity. The oxygen electrode layer 9 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).

[0064] The porosity of the oxygen electrode layer 9 is not particularly limited, but may be, for example, 20% to 60%. The thickness of the oxygen electrode layer 9 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0065] The method for forming the oxygen electrode layer 9 is not particularly limited, and may be a firing method, a spray coating method, a PVD method, a CVD method, or the like.

[0066] [Sealing section 30] The sealing section 30 is disposed between the metal support 10 and the cell main body 20. The sealing section 30 seals the gap between the metal support 10 and the cell main body 20. The sealing section 30 prevents gas from directly passing between the space on the hydrogen electrode layer 6 side of the electrolyte layer 7 and the space on the oxygen electrode layer 9 side of the electrolyte layer 7.

[0067] The seal portion 30 surrounds the side periphery of the cell main body portion 20. The seal portion 30 is formed in an annular shape. In this embodiment, the seal portion 30 is formed in a rectangular annular shape.

[0068] The sealing portion 30 is made of a gas-impermeable dense material. The sealing portion 30 can be made of, for example, crystallized glass, amorphous glass, ceramic material, spinel oxide, brazing material, etc. Crystallized glass is glass in which the ratio of the "volume occupied by the crystalline phase" to the total volume (degree of crystallization) is 60% or more, and the ratio of the "volume occupied by the amorphous phase and impurities" to the total volume is less than 40%. Examples of such crystallized glass include SiO ２ -B ２ O ３ system, SiO ２ -CaO-based or SiO ２ As the ceramic material, for example, the materials listed as the constituent materials of the electrolyte layer 7 can be used.

[0069] The sealing part 30 may be conductive or insulating when it is separated from the oxygen electrode layer 9. When it is bonded to the oxygen electrode layer 9, the sealing part 30 must be insulating.

[0070] The detailed configuration of the seal portion 30 will be described later.

[0071] [Flow Channel Member 40] The flow channel member 40 is bonded to the second main surface 12 of the metal support 10. The flow channel member 40 forms a flow channel 30a between itself and the metal support 10. A source gas is supplied to the flow channel 30a. The source gas supplied to the flow channel 30a is supplied to the hydrogen electrode layer 6 of the cell main body 20 via each communication hole 16 of the metal support 10.

[0072] The flow path member 40 can be made of, for example, an alloy material. The flow path member 40 may be made of the same material as the metal support 10. In this case, the flow path member 40 may be substantially integrated with the metal support 10.

[0073] The flow path member 40 has a frame 41 and an interconnector 42. The frame 41 is an annular member that surrounds the side of the flow path 30a. The frame 41 is joined to the second main surface 12 of the metal support 10. The interconnector 42 is a plate-like member for electrically connecting an external power source or another electrolytic cell to the electrolytic cell 1 in series. The interconnector 42 is joined to the frame 41.

[0074] In this embodiment, the frame body 41 and the interconnector 42 are separate members, but the frame body 41 and the interconnector 42 may be integral with each other.

[0075] (Detailed Configuration of Sealing Portion 30) FIG. 3 is a partially enlarged view of FIG.

[0076] The seal portion 30 has a first portion 31 and a second portion 32 .

[0077] The first portion 31 is a portion of the seal portion 30 that is disposed within the recess 13 of the metal support 10. The first portion 31 is sandwiched between the inner surface 15 of the recess 13 and the side surface 23 of the cell main body 20. The first portion 31 is joined to the inner surface 15 of the recess 13 and the side surface 23 of the cell main body 20.

[0078] The second portion 32 is disposed on the first portion 31. The second portion 32 is a portion of the seal portion 30 that is disposed outside the recess 13 of the metal support 10. The second portion 32 protrudes from the recess 13 of the metal support 10. The second portion 32 is wider than the first portion 31 in the planar direction. The second portion 32 covers the first portion 31, a portion of the metal support 10, and a portion of the cell main body 20. The second portion 32 is bonded to the first main surface 11 of the metal support 10 and the upper surface 21 of the cell main body 20.

[0079] In this way, the first portion 31 is joined to the inner surface 15 of the recess 13 and the side surface 23 of the cell main body 20, and the second portion 32 is joined to the first main surface 11 of the metal support 10 and the upper surface 21 of the cell main body 20, thereby improving the strength of the seal portion 30. Therefore, even if the cell main body 20 warps or deforms, the occurrence of cracks in the seal portion 30 can be suppressed.

[0080] 3, the first portion 31 preferably has coarse pores 33 therein. This provides flexibility to the first portion 31, thereby further preventing cracks from occurring in the seal portion 30. Furthermore, even if a crack does occur in the seal portion 30, the coarse pores 33 can stop the crack from progressing.

[0081] The coarse pores 33 are preferably closed pores. In Fig. 3, the coarse pores 33 are separated from both the inner surface 15 of the recess 13 and the side surface 23 of the cell main body 20. However, the coarse pores 33 may be in contact with at least one of the inner surface 15 of the recess 13 and the side surface 23 of the cell main body 20.

[0082] The equivalent circle diameter of the coarse pores 33 is not particularly limited, but may be, for example, 5 μm to 500 μm. The equivalent circle diameter is the diameter of a circle having the same area as the coarse pores 33 in a cross section along the thickness direction of the seal portion 30.

[0083] 3, the second portion 32 has an upper surface 34 provided on the opposite side of the recess 13. It is preferable that a depression 35 is formed on the upper surface 34. The depression 35 is a recess formed on the upper surface 34. The formation of the depression 35 on the upper surface 34 can impart flexibility to the second portion 32, thereby further suppressing the occurrence of cracks in the seal portion 30.

[0084] 3, it is preferable that the contour of the recess 35 is curved as a whole in a cross section along the thickness direction of the seal portion 30. This can suppress the occurrence of cracks originating from the surface of the recess 35.

[0085] It is more preferable that at least a portion of the recess 35 overlaps with the first portion 31 in the thickness direction. This makes it possible to impart flexibility not only to the second portion 32 but also to the first portion 31, thereby further suppressing the occurrence of cracks in the seal portion 30.

[0086] The recesses 35 may be formed intermittently in a plan view of the upper surface 34, but are preferably formed continuously, and are particularly preferably formed in a ring shape as a whole.

[0087] 3, the first portion 31 has a lower surface 36 that faces the bottom surface 14 of the recess 13. The lower surface 36 is preferably spaced apart from the bottom surface 14 of the recess 13. This provides flexibility to the first portion 31, thereby further preventing cracks from occurring in the seal portion 30.

[0088] 3, the contour of the lower surface 36 is preferably curved overall in a cross section along the thickness direction of the seal portion 30. This can suppress the occurrence of cracks originating from the lower surface 36.

[0089] 3, it is more preferable that the lower surface 36 be curved convexly toward the second portion 32. This allows the bonding area between the metal support 10 and the first portion 31 and the cell main body 20 to be larger than when the lower surface 36 is curved convexly toward the side opposite the second portion 32.

[0090] 3, it is preferable that the outer edge of the lower surface 22 of the cell main body 20 is spaced apart from the bottom surface 14 of the recess 13. This allows the portion of the cell main body 20 that is not constrained by the metal support 10 to deform in the planar direction, thereby reducing the stress applied to the seal portion 30. As a result, the occurrence of cracks in the seal portion 30 can be further suppressed.

[0091] 3, it is preferable that the gap between the lower surface 36 of the first portion 31 and the bottom surface 14 of the recess 13 is connected to the gap between the lower surface 22 of the cell main body 20 and the bottom surface 14 of the recess 13. This can further increase the flexibility of the first portion 31 and further increase the deformability of the cell main body 20.

[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] [Modification 1] In the above embodiment, the side surface 23 of the cell main body 20 is flat, but this is not limited thereto. For example, as shown in Figures 4 to 6, the side surface 23 may have projections and recesses.

[0094] In Fig. 4, the dimensions of the electrolyte layer 7 and the reaction prevention layer 8 are smaller than the dimensions of the hydrogen electrode layer 6 in the planar direction, resulting in unevenness on the side surface 23. In Fig. 5, the dimensions of the electrolyte layer 7 and the reaction prevention layer 8 are larger than the dimensions of the hydrogen electrode layer 6 in the planar direction, resulting in unevenness on the side surface 23. In Fig. 6, protrusions are formed on the surface of the hydrogen electrode layer 6, resulting in unevenness on the side surface 23.

[0095] In this way, by forming the unevenness on the side surface 23, it is possible to further improve the bonding between the seal portion 30 and the cell main body portion 20 by utilizing the anchor effect.

[0096] [Modification 2] In the above embodiment, the hydrogen electrode layer 6 functions as a cathode and the oxygen electrode layer 9 functions as an anode, but the arrangement of the hydrogen electrode layer 6 and the oxygen electrode layer 9 may be reversed.

[0097] [Variation 3] In the above embodiment, the electrolysis cell 1 has been described as an example of an electrochemical cell, but the electrochemical cell is not limited to an electrolysis cell. An electrochemical cell is a general term for an element in which a pair of electrodes are arranged so that an electromotive force is generated from an overall oxidation-reduction reaction in order to convert electrical energy into chemical energy, and an element for converting chemical energy into electrical energy. Therefore, electrochemical cells include, for example, fuel cells that use oxide ions or protons as carriers.

[0098] REFERENCE SIGNS LIST 1 Electrolysis cell 10 Metal support 11 First main surface 12 Second main surface 13 Recess 14 Bottom surface of recess 15 Inner surface of recess 16 Communication hole 20 Cell main body 21 Upper surface 22 Lower surface 23 Side surface 6 Hydrogen electrode layer 7 Electrolyte layer 8 Reaction prevention layer 9 Oxygen electrode layer 30 Sealing portion 31 First portion 32 Second portion 33 Coarse pores 34 Upper surface 35 Recess 36 Lower surface 40 Flow path member 40a Flow path

Claims

1. An electrochemical cell comprising: a metal support having a recess formed on a main surface and a plurality of communication holes formed on a bottom surface of the recess; a cell body portion disposed on the bottom surface of the recess; and a seal portion disposed between the metal support and the cell body portion, wherein the seal portion has a first portion joined to an inner surface of the recess and a side surface of the cell body portion, and a second portion disposed on the first portion and joined to the main surface of the metal support and an upper surface of the cell body portion.

2. The electrochemical cell according to claim 1, wherein the first portion has large pores inside.

3. The electrochemical cell according to claim 1 or 2, wherein the second portion has an upper surface and a depression formed on the upper surface.

4. The electrochemical cell according to claim 1, wherein the first portion has a lower surface facing the bottom surface of the recess, and the lower surface of the first portion is spaced apart from the bottom surface of the recess.

5. The electrochemical cell according to claim 4, wherein the cell body portion has a lower surface facing the bottom surface of the recess, and an outer edge of the lower surface of the cell body portion is spaced apart from the bottom surface of the recess.

6. The electrochemical cell according to claim 5, wherein a gap between the lower surface of the first portion and the bottom surface of the recess is connected to a gap between the lower surface of the cell body portion and the bottom surface of the recess.

7. The electrochemical cell according to claim 1, wherein unevenness is formed on a side surface of the cell body portion.

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