Electrochemical cell

Abstract

An electrolytic cell (1) comprising a metal support (10) and a cell body part (20). The cell body part (20) has a gas diffusion layer (5) disposed on a first main surface (12) of the metal support (10). In a plan view of the first main surface (12) of the metal support (10), at least a portion of the outer edge (5a) of the gas diffusion layer (5) has a wave shape in which crest parts (51) and trough parts (52) alternate in succession.

Description

electrochemical cell

[0001] The present invention relates to electrochemical cells.

[0002] Conventionally, electrochemical cells (electrolysis cells, fuel cells, etc.) have been known that include a cell body disposed on a metal support. The metal support has a plurality of through holes formed in a main surface. The cell body includes a first electrode layer and a second electrode layer formed on the main surface of the metal support, and an electrolyte layer disposed between the first and second electrode layers.

[0003] Here, Patent Document 1 describes that a conductive gas diffusion layer is interposed between the cell body and the metal support.

[0004] International Publication No. 2021 / 221052

[0005] However, in the electrochemical cell described in Patent Document 1, there is a risk that peeling of the gas diffusion layer may occur due to stress generated between the metal support and the gas diffusion layer due to the difference in thermal expansion coefficient between the metal support and the cell main body.

[0006] An object of the present invention is to provide an electrochemical cell capable of suppressing peeling of a gas diffusion layer.

[0007] An electrochemical cell according to a first aspect of the present invention includes a metal support having a plurality of through holes formed in a principal surface thereof, and a cell main body disposed on the principal surface. The cell main body includes a conductive gas diffusion layer disposed on the principal surface, a first electrode layer and a second electrode layer disposed on the gas diffusion layer, and an electrolyte layer disposed between the first and second electrode layers. In a plan view of the principal surface, at least a portion of the outer edge of the gas diffusion layer has a corrugated shape in which peaks and valleys alternate continuously.

[0008] An electrochemical cell according to a second aspect of the present invention is related to the above-mentioned first aspect, and in a planar view of the main surface, the peaks protrude in a curved shape away from the plurality of communicating holes, and in a planar view of the main surface, the valleys are recessed in a curved shape toward the plurality of communicating holes.

[0009] An electrochemical cell according to a third aspect of the present invention is related to the second aspect, and in a planar view of the main surface, the distance between the outermost communicating hole located at the outermost end in the surface direction among the plurality of communicating holes and the bottom point of the valley portion is shorter than the distance between the outermost communicating hole and the apex of the peak portion.

[0010] An electrochemical cell according to a fourth aspect of the present invention relates to the third aspect, and in a planar view of the main surface, the second perpendicular line intersects with an inner communicating hole among the plurality of communicating holes that is arranged one stage inward from the outermost communicating hole.

[0011] According to the present invention, it is possible to provide an electrochemical cell capable of suppressing peeling of the gas diffusion layer.

[0012] Fig. 1 is a plan view of an electrolytic cell according to an embodiment. Fig. 2 is a cross-sectional view taken along the line A-A in Fig. 1. Fig. 3 is a plan view showing an electrolytic cell according to an embodiment from which a hydrogen electrode layer, an electrolyte layer, a reaction prevention layer, and an oxygen electrode layer have been removed. Fig. 4 is a partially enlarged view of Fig. 3.

[0013] (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.

[0014] 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.

[0015] 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.

[0016] As shown in FIG. 2 , the electrolysis cell 1 includes a metal support 10 , a cell main body 20 , and a flow path member 30 .

[0017] [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.

[0018] 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.

[0019] As shown in FIG. 2 , the metal support 10 has a plurality of through holes 11 , a first main surface 12 and a second main surface 13 .

[0020] Each communication hole 11 penetrates the metal support 10 from the first main surface 12 to the second main surface 13. Each communication hole 11 opens to the first main surface 12 and the second main surface 13. In this embodiment, the opening of each communication hole 11 on the first main surface 12 side is covered by a gas diffusion layer 5 described later. The opening of each communication hole 11 on the second main surface 13 side is connected to a flow path 30a described later.

[0021] Each of the communication holes 11 can be formed by mechanical processing (for example, punching), laser processing, or chemical processing (for example, etching).

[0022] In this embodiment, each communication hole 11 is formed linearly along the Z-axis direction. However, each communication hole 11 may be inclined with respect to the Z-axis direction, or may not be linear. Furthermore, the communication holes 11 may be connected to each other.

[0023] The first main surface 12 is an example of a "main surface" according to the present invention. The first main surface 12 is provided on the opposite side of the second main surface 13. The cell main body 20 is disposed on the first main surface 12. The flow path member 30 is bonded to the second main surface 13.

[0024] 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.

[0025] 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 Al 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).

[0026] 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 chromium oxide film covers at least a portion of the surface of the metal support 10. The chromium oxide film may also cover at least a portion of the inner wall surface of each communicating hole 11.

[0027] [Cell Body 20] The cell body 20 is disposed on the metal support 10. The cell body 20 is supported by the metal support 10. The cell body 20 has a gas diffusion layer 5, a hydrogen electrode layer 6 (cathode), an electrolyte layer 7, a reaction prevention layer 8, and an oxygen electrode layer 9 (anode).

[0028] The gas diffusion layer 5, 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 gas diffusion layer 5, hydrogen electrode layer 6, electrolyte layer 7, and oxygen electrode layer 9 are essential components, while the reaction prevention layer 8 is optional.

[0029] [Gas Diffusion Layer 5] The gas diffusion layer 5 is formed on the first main surface 12 of the metal support 10. The gas diffusion layer 5 is interposed between the metal support 10 and the hydrogen electrode layer 6. In this embodiment, the gas diffusion layer 5 covers each of the communicating holes 11 of the metal support 10. A portion of the gas diffusion layer 5 may extend inside each of the communicating holes 11 of the metal support 10.

[0030] The gas diffusion layer 5 is a porous body having gas diffusibility and electrical conductivity. The gas diffusion layer 5 supplies the source gas supplied from each of the communication holes 11 to the hydrogen electrode layer 6, and also discharges the product gas generated in the hydrogen electrode layer 6 to each of the communication holes 11.

[0031] The gas diffusion layer 5 includes a conductive material, such as a metal material such as Ni (nickel) or Fe (iron), or a conductive ceramic material.

[0032] The gas diffusion layer 5 may include a substrate that supports a conductive material. The substrate may be insulating. Examples of the substrate include YSZ, CSZ, ScSZ, GDC, SDC, and (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 (lanthanum doped ceria), LSGM (lanthanum gallate), and a mixed material of two or more of these can be used.

[0033] The gas diffusion layer 5 may contain the metal element contained in the metal support 10. This is preferable because it improves the adhesion between the gas diffusion layer 5 and the metal support 10. Note that the above-mentioned conductive material is different from the metal element contained in the metal support 10. Therefore, the conductive material contained in the gas diffusion layer 5 does not need to be contained in the metal support 10.

[0034] The porosity of the gas diffusion layer 5 is not particularly limited, but can be, for example, 20% or more and 40% or less.

[0035] The porosity of the gas diffusion layer 5 is calculated by the following method. First, a cross section of the gas diffusion layer 5 along the Z-axis direction is exposed. Next, a backscattered electron image of the cross section of the gas diffusion layer 5 is obtained at 10,000x magnification using an SEM device (FE-SEM JSM-7900F, manufactured by JEOL Ltd.). Next, using image analysis software Image-Pro manufactured by MEDIACYBERNETICS, the areas displayed in black (corresponding to pores) in the backscattered electron image are identified. The porosity of the gas diffusion layer 5 is then calculated by dividing the total area of ​​the pores by the total area of ​​the backscattered electron image of the gas diffusion layer 5.

[0036] The thickness of the gas diffusion layer 5 is not particularly limited, but can be, for example, 1 μm or more and 50 μm or less. In this specification, the term "thickness" refers to the thickness in the thickness direction of the cell main body 20. The thickness direction is the direction perpendicular to the plane direction parallel to the first main surface 12 of the metal support 10. When specifying the thickness direction, an approximate straight line of the first main surface 12 obtained by the least squares method in a cross section of the metal support 10 along the Z-axis direction is used.

[0037] The method for forming the gas diffusion layer 5 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.

[0038] [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 formed on the gas diffusion layer 5. The hydrogen electrode layer 6 is disposed between the gas diffusion layer 5 and the electrolyte layer 7.

[0039] The source gas is supplied to the hydrogen electrode layer 6 through the gas diffusion layer 5 and the communication holes 11. The source gas contains at least H ２ Contains O.

[0040] 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.

[0041] Hydrogen electrode layer 6: H ２ O + 2e － →H ２ +O ２－ ...(1)

[0042] The raw material gas is H ２ O plus CO ２ In this case, the hydrogen electrode layer 6 converts H from the source gas according to the co-electrolytic electrochemical reactions shown in the following formulas (2), (3), and (4). ２ , CO and O ２－ Generate.

[0043] 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)

[0044] The hydrogen electrode layer 6 is a porous body having gas diffusibility and electrical conductivity. A source gas is supplied to the hydrogen electrode layer 6 from the gas diffusion layer 5. The product gas generated in the hydrogen electrode layer 6 is discharged to the gas diffusion layer 5 side.

[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 (e.g., NiO) in an oxidizing atmosphere and in a metallic state (e.g., Ni) in a reducing atmosphere. In this embodiment, it is assumed that the electrolysis cell 1 is exposed to 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 made of a single composition, but may have a multi-layer structure made of different compositions.

[0049] The porosity of the hydrogen electrode layer 6 is not particularly limited, but may be, for example, 20% to 40%. The porosity of the hydrogen electrode layer 6 is calculated by dividing the total area of ​​the pores by the total area of ​​the backscattered electron image of the hydrogen electrode layer 6, similar to the porosity of the gas diffusion layer 5 described above.

[0050] The thickness of the hydrogen electrode layer 6 is not particularly limited, but can be, for example, 1 μm or more and 500 μm or less.

[0051] The method for forming the hydrogen electrode layer 6 is not particularly limited, and may be a firing method, a spray coating method, a PVD method, a CVD method, or the like.

[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.

[0053] The electrolyte layer 7 covers the hydrogen electrode layer 6 and also covers the region of the first main surface 12 of the metal support 10 that is exposed from the gas diffusion layer 5 .

[0054] 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).

[0055] 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.

[0056] 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.

[0057] [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.

[0058] The reaction prevention layer 8 is made of an oxide ion conductive material, such as GDC or SDC.

[0059] 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.

[0060] 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.

[0061] [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 electrolyte layer 7 from the hydrogen electrode layer 6. 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 is connected to the electrolyte layer 7.

[0062] 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.

[0063] Oxygen electrode layer 9: 2O ２－ →O ２ +4e － ...(5)

[0064] 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).

[0065] 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.

[0066] 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.

[0067] [Flow Channel Member 30] The flow channel member 30 is bonded to the second main surface 13 of the metal support 10. A flow channel 30a is formed between the flow channel member 30 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 11 of the metal support 10.

[0068] The flow path member 30 can be made of, for example, an alloy material. The flow path member 30 may be made of the same material as the metal support 10. In this case, the flow path member 30 may be substantially integrated with the metal support 10.

[0069] The flow path member 30 has a frame 31 and an interconnector 32. The frame 31 is an annular member that surrounds the side of the flow path 30a. The frame 31 is joined to the second main surface 13 of the metal support 10. The interconnector 32 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 32 is joined to the frame 31.

[0070] In this embodiment, the frame body 31 and the interconnector 32 are separate members, but the frame body 31 and the interconnector 32 may be an integrated member.

[0071] (Planar Shape of Gas Diffusion Layer 5) Fig. 3 is a plan view of the electrolysis cell 1 showing the state in which the hydrogen electrode layer 6, the electrolyte layer 7, the reaction prevention layer 8, and the oxygen electrode layer 9 of the cell main body 20 have been removed. Fig. 4 is a partially enlarged view of Fig. 3.

[0072] 3 , in a plan view of the first main surface 12 of the cell body 20, the gas diffusion layer 5 covers the plurality of communication holes 11 of the metal support 10. In this embodiment, the planar shape of the gas diffusion layer 5 is rectangular overall, but is not limited to this. The planar shape of the gas diffusion layer 5 can be changed as appropriate taking into account the planar shape of the cell body 20 and the planar shape of the region in which the plurality of communication holes 11 are formed.

[0073] 4, the plurality of communicating holes 11 in the metal support 10 are arranged in a staggered pattern, which makes it possible to easily increase the density of the communicating holes 11. However, the arrangement of the communicating holes 11 can be changed as appropriate.

[0074] As shown in Figure 4, in a plan view of the first main surface 12, the outer edge 5a of the gas diffusion layer 5 has a corrugated shape in which peaks 51 and valleys 52 alternate continuously. This allows the stress acting on the outer edge 5a to be dispersed in the planar direction when stress occurs between the metal support 10 and the gas diffusion layer 5 due to a difference in the thermal expansion coefficients of the metal support 10 and the cell main body 20. Furthermore, the total length of the outer edge 5a can be increased compared to when the outer edge 5a has a linear shape. As a result, the stress acting on the outer edge 5a can be alleviated, thereby preventing the gas diffusion layer 5 from peeling off from the metal support 10.

[0075] In this embodiment, the entire outer edge 5a is corrugated as shown in Fig. 3, but it is sufficient that at least a portion of the outer edge 5a of the gas diffusion layer 5 is corrugated. Even in this case, the corrugated region of the outer edge 5a can prevent the gas diffusion layer 5 from peeling off from the metal support 10, as described above. Therefore, a portion of the outer edge 5a may be linear.

[0076] In this embodiment, as shown in FIG. 4 , the peaks 51 of the outer edge 5 a protrude in a curved shape away from the communicating holes 11, and the valleys 52 of the outer edge 5 a recess in a curved shape toward the communicating holes 11. That is, the outer edge 5 a has a curved wave shape. This allows the stress acting on the outer edge 5 a to be dispersed in the planar direction and the overall length of the outer edge 5 a to be longer than when the outer edge 5 a has a linear wave shape (serrated shape). As a result, the stress acting on the outer edge 5 a can be further alleviated, thereby further preventing the gas diffusion layer 5 from peeling off from the metal support 10.

[0077] Here, the metal support 10 is provided with a plurality of communication holes 11, and heat conduction within the surface of the metal support 10 is interrupted by each communication hole 11, making it easy for a temperature distribution to occur in the metal support 10. Furthermore, while heat is absorbed and generated from the cell main body 20 during operation of the electrolysis cell 1, heat is transferred to and from the cell main body 20 by heating or dissipating heat to and from the cell main body 20, making it easy for a temperature distribution to occur in the outer periphery of the cell main body 20. That is, in a plan view of the first main surface 12, a larger temperature distribution is likely to occur inside and outside the communication holes 11 arranged at the outermost periphery of the plurality of communication holes 11 in the metal support 10, resulting in a large difference in the amount of expansion and contraction due to thermal expansion. Therefore, the metal support 10 does not deform isotropically near the communication holes 11 arranged at the outermost periphery. Therefore, stress is likely to occur between the metal support 10 and the outer edge 5a of the gas diffusion layer 5 in a region close to the communication holes 11 arranged at the outermost periphery. The communication holes 11 arranged on the outermost periphery are the communication holes 11 that are located at the outermost ends in the planar direction (X-axis direction or Y-axis direction) among the plurality of communication holes 11 .

[0078] 4 , in the present embodiment, in a plan view of the first main surface 12, the positions of the communicating holes 11 arranged on the outermost periphery (hereinafter referred to as "outermost peripheral communicating holes 11a") coincide with the positions of the valley portions 52. Specifically, a first perpendicular line M1, which is perpendicular to a first tangent line L1 tangent to a valley bottom point 52b of the valley portion 52 and passes through the valley bottom point 52b, intersects with the outermost peripheral communicating hole 11a. Furthermore, a second perpendicular line M2, which is perpendicular to a second tangent line L2 tangent to the vertex 51a of the peak portion 51 and passes through the vertex 51a, does not intersect with the outermost peripheral communicating hole 11a.

[0079] This allows the outer edge 5a of the gas diffusion layer 5 to be closer to the outermost peripheral communicating holes 11a than when the positions of the outermost peripheral communicating holes 11a are aligned with the positions of the ridges 51. This further reduces the stress applied to the outer edge 5a due to deformation of the metal support 10 near the outermost peripheral communicating holes 11a. This further prevents the gas diffusion layer 5 from peeling off from the metal support 10.

[0080] 4, in the plan view of the first main surface 12, the positions of the communication holes 11 (hereinafter referred to as "inner communication holes 11b") arranged one stage inward from the outermost peripheral communication holes 11a coincide with the positions of the peaks 51. Specifically, a second perpendicular line M2 passing through the apexes 51a of the peaks 51 intersects with the inner communication holes 11b. Furthermore, a first perpendicular line M1 passing through the bottoms 52b of the valleys 52 does not intersect with the inner communication holes 11b.

[0081] The "inside" of the inner communicating hole 11b means the opposite side of the outer edge 5a with respect to the position of the outermost peripheral communicating hole 11a in the direction parallel to the second perpendicular line M2.

[0082] In a direction parallel to the first perpendicular line M1, a distance D1 between the outermost peripheral communicating hole 11a and the bottom point 52b of the valley portion 52 is shorter than a distance D2 between the outermost peripheral communicating hole 11a and the apex 51a of the peak portion 51. Distance D1 is the shortest distance between the outermost peripheral communicating hole 11a and the bottom point 52b in a direction parallel to the first perpendicular line M1. Distance D2 is the shortest distance between the outermost peripheral communicating hole 11a and the apex 51a in a direction parallel to the first perpendicular line M1.

[0083] In a direction parallel to the first perpendicular line M1, a distance D3 between the inner communicating hole 11b and the apex 51a of the peak 51 is longer than a distance D2 between the outermost communicating hole 11a and the apex 51a of the peak 51. Distance D3 is the shortest distance between the inner communicating hole 11b and the apex 51a in a direction parallel to the first perpendicular line M1.

[0084] The value of the distance D1 is not particularly limited, but may be, for example, 0.20 mm or more and 1.0 mm or less. The value of the distance D2 is not particularly limited, but may be, for example, 0.25 mm or more and 2.0 mm or less. The value of the distance D3 is not particularly limited, but may be, for example, 0.50 mm or more and 3.0 mm or less.

[0085] The value of the distance D4 between the vertices 51a in the direction parallel to the first tangent line L1 is not particularly limited, but can be, for example, 0.20 mm or more and 5.0 mm or less.

[0086] The value of the distance D5 between the valley bottom points 52b in the direction parallel to the first tangent line L1 is not particularly limited, but can be, for example, 0.20 mm or more and 5.0 mm or less.

[0087] (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.

[0088] [Variation 1] In the above embodiment, the openings of each communication hole 11 on the first main surface 12 side of the metal support 10 are covered by the gas diffusion layer 5, but this is not limited to this. The gas diffusion layer 5 does not have to cover the openings of each communication hole 11 on the first main surface 12 side. In this case, through holes communicating with each communication hole 11 are formed in the gas diffusion layer 5, allowing for more efficient supply and exhaust of gas via the through holes.

[0089] [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.

[0090] [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.

[0091] REFERENCE SIGNS LIST 1 electrolysis cell 10 metal support 11 communicating hole 12 first main surface 13 second main surface 20 cell body 5 gas diffusion layer 5a outer edge 51 peak 51a apex 52 valley 52b valley bottom 6 hydrogen electrode layer 7 electrolyte layer 8 reaction prevention layer 9 oxygen electrode layer 30 flow path member 30a flow path La first tangent Ma first perpendicular Lb second tangent Mb second perpendicular

Claims

1. a metal support having a plurality of communicating holes formed on a main surface thereof; A cell main body portion disposed on the main surface; Equipped with The cell body portion is a conductive gas diffusion layer disposed on the main surface; a first electrode layer disposed on the gas diffusion layer; A second electrode layer; an electrolyte layer disposed between the first electrode layer and the second electrode layer; having the plurality of communication holes are covered by the gas diffusion layer or the first electrode layer, When viewed from above on the main surface, at least a part of the outer edge of the gas diffusion layer has a corrugated shape in which peaks and valleys are alternately arranged. Electrochemical cell.

2. When viewed in a plan view of the main surface, the peak portion protrudes in a curved shape in a direction away from the plurality of communication holes, In a plan view of the main surface, the valley portion is recessed in a curved shape toward the plurality of communication holes.

10. The electrochemical cell of claim 1.

3. in a plan view of the main surface, a first perpendicular line that is perpendicular to a first tangent line that touches a valley bottom point of the valley portion and passes through the valley bottom point intersects with an outermost communicating hole that is located at an outermost end in a surface direction among the plurality of communicating holes, a second perpendicular line that is perpendicular to a second tangent line that touches the apex of the peak portion and passes through the apex does not intersect with the outermost peripheral communicating hole in a plan view of the main surface; 3. The electrochemical cell of claim 2.

4. When seen in a plan view of the main surface, the second perpendicular line intersects with an inner communication hole that is arranged one stage more inward than the outermost communication hole among the plurality of communication holes.

4. The electrochemical cell of claim 3.