Electrochemical Cell

Abstract

An electrolysis cell (100) comprises a metal support (10) and a cell body portion (20). The cell body portion (20) is supported by the metal support (10). The cell body portion (20) has a hydrogen electrode layer (1), an electrolyte layer (3), and an oxide electrode layer (5). The hydrogen electrode layer (1) has a contact surface (S3) contacting the electrolyte layer (3). In a cross section along the thickness direction of the hydrogen electrode layer (1), the contact surface (S3) is curved to protrude toward the electrolyte layer (3).

Description

electrochemical cell

[0001] The present invention relates to electrochemical cells.

[0002] Electrochemical cells (electrolysis cells, fuel cells, etc.) having a structure in which a cell body is supported by a metal support have been known. For example, an electrochemical cell described in Patent Document 1 includes a cell body in which a first electrode layer, an electrolyte layer, and a second electrode layer are stacked in this order on a main surface of a metal support. The metal support is made of a metal material such as stainless steel.

[0003] JP 2020-155337 A

[0004] Since the heat resistance of the metal support is low, it is difficult to form the first electrode layer on the main surface of the metal support at high temperatures, and therefore there is a limit to how much strength the porous microstructure of the first electrode layer can be improved.

[0005] Therefore, there is a risk that the first electrode layer may be damaged (cracked or peeled off) by a compressive force applied from the electrolyte layer side, which is a dense body disposed on the first electrode layer.

[0006] An object of the present invention is to provide an electrochemical cell capable of suppressing damage to the first electrode layer.

[0007] An electrochemical cell according to a first aspect of the present invention includes a metal support and a cell body. The metal support has a first main surface, a second main surface, and a plurality of supply holes. The cell body is supported by the metal support and includes a first electrode layer, a second electrode layer, and an electrolyte layer disposed between the first and second electrode layers. The first electrode layer has a contact surface that contacts the electrolyte layer. In a cross section along the thickness direction of the first electrode layer, the contact surface is curved in a convex shape toward the electrolyte layer.

[0008] An electrochemical cell according to a second aspect of the present invention is the electrochemical cell according to the first aspect, wherein in the cross section, the apex of the contact surface is located at the center in the planar direction of the first electrode layer.

[0009] An electrochemical cell according to a third aspect of the present invention is the electrochemical cell according to the first or second aspect, wherein the metal support has a recess formed in the first main surface, and at least a portion of the first electrode layer is disposed within the recess.

[0010] An electrochemical cell according to a fourth aspect of the present invention is the electrochemical cell according to the third aspect, wherein in a cross section along the thickness direction of the metal support, the boundary between the side peripheral surface and the bottom surface of the recess is rounded.

[0011] An electrochemical cell according to a fifth aspect of the present invention is related to the third or fourth aspect, and the cell main body has a catalyst layer disposed in at least one of the plurality of supply holes and continuous with the first electrode layer.

[0012] According to the present invention, it is possible to provide an electrochemical cell that can suppress damage to the first electrode layer.

[0013] Fig. 1 is a plan view of an electrolytic cell according to an embodiment. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. Fig. 3 is a cross-sectional view of an electrolytic cell according to Modification 1. Fig. 4 is a cross-sectional view of an electrolytic cell according to Modification 2.

[0014] (Electrolytic cell 100) Fig. 1 is a plan view of an electrolytic cell 100 according to an embodiment. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. The electrolytic cell 100 is a so-called metal-supported electrolytic cell. The electrolytic cell 100 is an example of the "electrochemical cell" according to the present invention.

[0015] The electrolytic cell 100 is formed in a plate shape 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 in plan view, but 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.

[0016] As shown in FIG. 2 , the electrolysis cell 100 includes a metal support 10 , a cell 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 a flat plate shape or a curved plate shape. The metal support 10 may have any thickness as long as it can maintain the strength of the electrolysis cell 100, and the thickness is not particularly limited, but may be, for example, 0.1 mm or more and 2.0 mm or less.

[0018] As shown in FIG. 2 , the metal support 10 has a first main surface 11 , a second main surface 12 , a recess 13 , and a plurality of supply holes 14 .

[0019] The first main surface 11 is a main surface on the cell main body 20 side. The first main surface 11 is formed in a flat shape. The cell main body 20 is joined to the first main surface 11. A recess 13 is formed in the first main surface 11. Therefore, the first main surface 11 is formed in a ring shape in a plan view.

[0020] The second main surface 12 is a main surface opposite to the cell main body 20, and is provided on the opposite side to the first main surface 11. The second main surface 12 is formed in a flat shape. A flow path member 30 is joined to the second main surface 12.

[0021] The recess 13 is formed in the first main surface 11. The recess 13 opens to the first main surface 11. The recess 13 is a so-called bottomed recess. The hydrogen electrode layer 1, which will be described later, is disposed in the recess 13. The recess 13 has a bottom surface S1 and a peripheral side surface S2.

[0022] The bottom surface S1 is in contact with the hydrogen electrode layer 1. The bottom surface S1 covers the metal support 10 side of the hydrogen electrode layer 1. The bottom surface S1 is disposed between the first main surface 11 and the second main surface 12 in the Z-axis direction. The Z-axis direction is perpendicular to both the X-axis direction and the Y-axis direction, and is an example of the "thickness direction" according to the present invention. In this embodiment, the bottom surface S1 is formed to be flat.

[0023] The side peripheral surface S2 is continuous with the outer edge of the bottom surface S1 and the inner edge of the first main surface 11. The side peripheral surface S2 is formed in an annular shape. The side peripheral surface S2 is in contact with the hydrogen electrode layer 1. The side peripheral surface S2 covers the side periphery of the hydrogen electrode layer 1.

[0024] As shown in Figure 2, in a cross section along the thickness direction of the metal support 10, the boundary 13a between the bottom surface S1 and the peripheral side surface S2 is rounded. Therefore, the peripheral side surface S2 is smoothly connected to the bottom surface S1. There is no bending point between the bottom surface S1 and the peripheral side surface S2. A bending point refers to a point where two straight lines intersect. Although the boundary between the bottom surface S1 and the peripheral side surface S2 is not clear, the region parallel to the first main surface 11 may be considered to be the bottom surface S1, and the region other than the bottom surface S1 may be considered to be the peripheral side surface S2.

[0025] 2, the side peripheral surface S2 is curved in a convex shape outward in the surface direction. The curved shape means that the surface is curved in an arch shape and has no bending points. The surface direction is a direction perpendicular to the Z-axis direction (thickness direction). The outward surface direction means a direction away from the center of the metal support 10 in the surface direction.

[0026] The depth of the recess 13 in the Z-axis direction is not particularly limited, but can be set to 1% or more and 50% or less of the thickness of the metal support 10 in the Z-axis direction.

[0027] The plurality of supply holes 14 communicate with the second main surface 12 and the bottom surface S1 of the recess 13. Each supply hole 14 penetrates the metal support 10 from the second main surface 12 to the bottom surface S1. Each supply hole 14 opens to both the second main surface 12 and the bottom surface S1. The opening of the supply hole 14 on the bottom surface S1 side is covered by the hydrogen electrode layer 1. That is, each supply hole 14 is formed in a region of the bottom surface S1 to which the hydrogen electrode layer 1 is bonded. The opening of the supply hole 14 on the side opposite the bottom surface S1 communicates with a flow path 30a formed between the metal support 10 and the flow path member 30. A catalyst layer 2, which will be described later, is disposed in each supply hole 14.

[0028] Each supply hole 14 can be formed by mechanical processing (e.g., punching), laser processing, chemical processing (e.g., etching), or the like. In this embodiment, each supply hole 14 is formed linearly along the Z-axis direction, but it does not have to be along the Z-axis direction, and it does not have to be linear. For example, when the metal support 10 is made of porous metal, each supply hole 14 may be a three-dimensional network of open pores formed in the porous metal.

[0029] 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.

[0030] 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).

[0031] 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 circumferential surface of each supply hole 14.

[0032] (Cell main body 20) The cell main body 20 has a hydrogen electrode layer 1 (cathode), multiple catalyst layers 2, an electrolyte layer 3, a reaction prevention layer 4, and an oxygen electrode layer 5 (anode). The hydrogen electrode layer 1, the electrolyte layer 3, the reaction prevention layer 4, and the oxygen electrode layer 5 are stacked in this order from the metal support 10 side in the Z-axis direction, which is perpendicular to the X-axis direction and the Y-axis direction.

[0033] The hydrogen electrode layer 1 is an example of a "first electrode layer" according to the present invention. The oxygen electrode layer 5 is an example of a "second electrode layer" according to the present invention. The hydrogen electrode layer 1, electrolyte layer 3, and oxygen electrode layer 5 are essential components, while the catalyst layer 2 and reaction-preventing layer 4 are optional components.

[0034] [Hydrogen Electrode Layer 1] The hydrogen electrode layer 1 is disposed on the metal support 10. In this embodiment, the hydrogen electrode layer 1 is disposed in the recess 13 of the metal support 10. As a result, the hydrogen electrode layer 1 is held in the recess 13 of the metal support 10.

[0035] The hydrogen electrode layer 1 has a contact surface S3 that is in contact with the electrolyte layer 3. The contact surface S3 is covered by the electrolyte layer 3.

[0036] Here, the contact surface S3 is curved in a convex shape toward the electrolyte layer 3. That is, the contact surface S3 is curved in an arch shape toward the electrolyte layer 3, and there is no bending point on the electrolyte layer 3 side. In this way, the contact surface S3 is curved in an arch shape, which can improve the resistance of the hydrogen electrode layer 1 to the compressive force applied from the electrolyte layer 3 side.

[0037] The hydrogen electrode layer 1 is formed in the Z-axis direction such that its central portion in the plane extends into the electrolyte layer 3 from both end portions in the plane direction. The vertex S4 of the contact surface S3 in the Z-axis direction is located at the central portion of the hydrogen electrode layer 1 in the plane direction. The vertex S4 is the position on the uniformly curved contact surface S3 that extends furthest toward the electrolyte layer 3. The central portion of the hydrogen electrode layer 1 in the plane direction is the portion that is located at the center when the hydrogen electrode layer 1 is divided into thirds in the plane direction. The end portions of the hydrogen electrode layer 1 in the plane direction are the portions that are located on both sides of the central portion when the hydrogen electrode layer 1 is divided into thirds in the plane direction.

[0038] In this embodiment, the hydrogen electrode layer 1 fills the recess 13. That is, the entire hydrogen electrode layer 1 is disposed within the recess 13. Therefore, as shown in FIG. 2 , the hydrogen electrode layer 1 is formed so as to follow the contour of the recess 13.

[0039] The hydrogen electrode layer 1 contacts the bottom surface S1 and the side peripheral surface S2 of the recess 13. Therefore, the bottom surface S1 and the side peripheral surface S2 of the recess 13 are the interfaces between the hydrogen electrode layer 1 and the metal support 10.

[0040] The hydrogen electrode layer 1 covers each supply hole 14 formed in the bottom surface S1 of the recess 13. A source gas is supplied to the hydrogen electrode layer 1 from the flow path 30a through each supply hole 14. The source gas contains at least H ２ Contains O.

[0041] The raw material gas is H ２ When only O is contained, the hydrogen electrode layer 1 converts the raw material gas into H according to the electrochemical reaction of water electrolysis shown in the following formula (1): ２ Hydrogen electrode layer 1: H ２ O + 2e － →H ２ +O ２－ ...(1)

[0042] The raw material gas is H２ O plus CO ２ In this case, the hydrogen electrode layer 1 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－ Hydrogen electrode layer 1: 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 hydrogen electrode layer 1 is made of a porous material having electron conductivity. The hydrogen electrode layer 1 may have oxide ion conductivity. For example, the hydrogen electrode layer 1 may be made of 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 ３ , (La,Sr)TiO ３ , Sr ２ (Fe, Mo) ２ O ６ , (La, Sr)VO ３ , (La,Sr)FeO ３ , a mixed material of two or more of these, or a composite of one or more of these with NiO.

[0044] The porosity of the hydrogen electrode layer 1 is not particularly limited, but may be, for example, 5% to 70%. The thickness of the hydrogen electrode layer 1 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0045] The method for forming the hydrogen electrode layer 1 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.

[0046] [Catalyst Layer 2] Each of the plurality of catalyst layers 2 is disposed in a corresponding supply hole 14 and is continuous with the hydrogen electrode layer 1. Each catalyst layer 2 is engaged with the opening of the corresponding supply hole 14 on the bottom surface S1 side in the planar direction.

[0047] Each catalyst layer 2 is a porous body containing a catalyst. Nickel (Ni), iron (Fe), cobalt (Co), a noble metal, or the like can be used as the catalyst. When Ni is used as the catalyst, Ni functions as an electron conductor and also functions as a catalyst for the H generated in the hydrogen electrode layer 1. ２ and CO contained in the raw material gas ２ Ni is preferably present in the form of metal Ni during operation of the electrolytic cell 100, but may also exist partially in the form of NiO.

[0048] Each catalyst layer 2 may contain an oxide ion conductive material. As the oxide ion conductive material, the oxide ion conductive materials listed as the oxide ion conductive materials for the hydrogen electrode layer 1 can be used.

[0049] The porosity of each catalyst layer 2 is not particularly limited, but may be, for example, 5% to 70%. The depth of each catalyst layer 2 in the Z-axis direction is not particularly limited, but may be 10% to 100% of the length of each supply hole 14 in the Z-axis direction.

[0050] The method for forming each catalyst layer 2 is not particularly limited, and may be a calcination method, a spray coating method, a PVD method, a CVD method, or the like.

[0051] [Electrolyte Layer 3] The electrolyte layer 3 is disposed between the hydrogen electrode layer 1 and the oxygen electrode layer 5. In this embodiment, the reaction prevention layer 4 is disposed between the electrolyte layer 3 and the oxygen electrode layer 5, and therefore the electrolyte layer 3 is disposed between the hydrogen electrode layer 1 and the reaction prevention layer 4 and is connected to both the hydrogen electrode layer 1 and the reaction prevention layer 4.

[0052] The electrolyte layer 3 covers the contact surface S3 of the hydrogen electrode layer 1. In this embodiment, the hydrogen electrode layer 1 is filled in the recess 13 of the metal support 10, and therefore the electrolyte layer 3 is disposed outside the recess 13.

[0053] The outer edge of the electrolyte layer 3 is connected to the first main surface 11 of the metal support 10. In this embodiment, a part of the first main surface 11 is exposed from the electrolyte layer 3, but the entire first main surface 11 may be covered by the electrolyte layer 3.

[0054] The electrolyte layer 3 is formed by dissolving the O generated in the hydrogen electrode layer 1. ２－ The electrolyte layer 3 is made of a dense material having oxide ion conductivity. The electrolyte layer 3 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 3 is not particularly limited, but may be, for example, 0.1% to 7%. The thickness of the electrolyte layer 3 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0056] The method for forming the electrolyte layer 3 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 4] The reaction prevention layer 4 is disposed between the electrolyte layer 3 and the oxygen electrode layer 5. The reaction prevention layer 4 is disposed on the opposite side of the electrolyte layer 3 from the hydrogen electrode layer 1. The reaction prevention layer 4 prevents the constituent elements of the electrolyte layer 3 from reacting with the constituent elements of the oxygen electrode layer 5 to form a layer with high electrical resistance.

[0058] The reaction prevention layer 4 is made of an oxide ion conductive material, such as GDC or SDC.

[0059] The porosity of the reaction prevention layer 4 is not particularly limited, but may be, for example, 0.1% to 50%. The thickness of the reaction prevention layer 4 is not particularly limited, but may be, for example, 1 μm to 50 μm.

[0060] The method for forming the reaction prevention layer 4 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 5] The oxygen electrode layer 5 is disposed on the opposite side of the hydrogen electrode layer 1 with respect to the electrolyte layer 3. In this embodiment, the reaction prevention layer 4 is disposed between the electrolyte layer 3 and the oxygen electrode layer 5, and therefore the oxygen electrode layer 5 is connected to the reaction prevention layer 4. If the reaction prevention layer 4 is not disposed between the electrolyte layer 3 and the oxygen electrode layer 5, the oxygen electrode layer 5 is connected to the electrolyte layer 3.

[0062] The oxygen electrode layer 5 reacts with O 2 transferred from the hydrogen electrode layer 1 through the electrolyte layer 3 in accordance with the chemical reaction of the following formula (5): ２－ From O ２ Generate.

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

[0064] The oxygen electrode layer 5 is made of a porous material having oxide ion conductivity and electron conductivity, such as (La, Sr)(Co, Fe)O. ３ , (La,Sr)FeO ３ , La(Ni,Fe)O ３ , (La,Sr)CoO ３ , and (Sm,Sr)CoO ３ The insulating layer 10 may be made of a composite material of one or more of the above and an oxide ion conductive material (such as GDC).

[0065] The porosity of the oxygen electrode layer 5 is not particularly limited, but may be, for example, 20% to 60%. The thickness of the oxygen electrode layer 5 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0066] The method for forming the oxygen electrode layer 5 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 12 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 sequentially supplied to the catalyst layer 2 and the hydrogen electrode layer 1 of the cell main body 20 via each supply hole 14 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 integral 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 plate member that surrounds the side periphery of the flow path 30a. The frame 31 is joined to the second main surface 12 of the metal support 10. The interconnector 32 is a plate member for electrically connecting an external power source or another electrolytic cell to the electrolytic cell 100 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] (Features)

[0072] (1) The metal support 10 made of a metal material has low heat resistance, and it is difficult to form the hydrogen electrode layer 1 at high temperatures. Therefore, there is a limit to how much strength the porous microstructure of the hydrogen electrode layer 1 can be improved.

[0073] Therefore, in this embodiment, the contact surface S3 of the hydrogen electrode layer 1 is curved in a convex shape toward the electrolyte layer 3. This improves the resistance of the hydrogen electrode layer 1 to compressive forces applied from the electrolyte layer 3. Therefore, even if compressive forces are applied to the hydrogen electrode layer 1 from the electrolyte layer 3 due to sudden pressure changes during operation, damage (cracks and peeling) to the hydrogen electrode layer 1 can be suppressed.

[0074] (2) The apex S4 of the contact surface S3 is located at the center of the surface of the hydrogen electrode layer 1. Therefore, the compressive force applied from the electrolyte layer 3 side can be balanced, which further reduces damage to the hydrogen electrode layer 1.

[0075] (3) The hydrogen electrode layer 1 is disposed in a recess 13 formed in the first main surface 11 of the metal support 10. This allows the hydrogen electrode layer 1 to be held in the recess 13, reducing deformation of the hydrogen electrode layer 1 even when an external force is applied to the hydrogen electrode layer 1 in the surface direction. Furthermore, the contact area between the hydrogen electrode layer 1 and the metal support 10 can be increased compared to when the hydrogen electrode layer 1 is disposed on the first main surface 11. This further reduces damage to the hydrogen electrode layer 1.

[0076] Furthermore, since the deformation of the hydrogen electrode layer 1 can be reduced, the thickness of the hydrogen electrode layer 1 can be increased accordingly, thereby improving the gas diffusivity in the surface direction within the hydrogen electrode layer 1. As a result, the electrode resistance of the hydrogen electrode layer 1 can be reduced.

[0077] (4) In a cross section along the thickness direction of the metal support 10, the boundary 13a between the side peripheral surface S2 and the bottom surface S1 is rounded. Therefore, no corners are formed in the hydrogen electrode layer 1, and chipping of the hydrogen electrode layer 1 can be suppressed.

[0078] (5) The cell main body 20 has a catalyst layer 2 disposed in each supply hole 14 and continuous with the hydrogen electrode layer 1. This allows the anchoring effect of the catalyst layer 2 on the metal support 10 to further reduce deformation of the hydrogen electrode layer 1 in the planar direction.

[0079] (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.

[0080] [Variation 1] In the above embodiment, the entire hydrogen electrode layer 1 is disposed within the recess 13 of the metal support 10, but this is not limiting. For example, as shown in Fig. 3, only a portion of the hydrogen electrode layer 1 may be disposed within the recess 13. Alternatively, if the metal support 10 does not have a recess 13 and the first main surface 11 of the metal support 10 is formed flat, the hydrogen electrode layer 1 may be disposed on the first main surface 11 of the metal support 10.

[0081] [Variation 2] In the above embodiment, the electrolyte layer 3 is arranged outside the recess 13. However, as shown in FIG. 4 , if the thickness of the hydrogen electrode layer 1 is smaller than the depth of the recess 13, the electrolyte layer 3 may be arranged inside the recess 13.

[0082] [Modification 3] In the above embodiment, the boundary 13a between the side peripheral surface S2 and the bottom surface S1 has an R-shape, but this is not limited thereto. The side peripheral surface S2 may be arranged so as to be curved relative to the bottom surface S1.

[0083] [Modification 4] In the above embodiment, the cell body 20 has the catalyst layer 2, but it does not have to have the catalyst layer 2.

[0084] [Modification 5] In the above embodiment, the catalyst layer 2 is disposed in each of the plurality of supply holes 14, but this is not limiting. It is sufficient that the catalyst layer 2 is disposed in at least one of the plurality of supply holes 14.

[0085] In the above embodiment, the hydrogen electrode layer 1 functions as a cathode and the oxygen electrode layer 5 functions as an anode, but the hydrogen electrode layer 1 may function as an anode and the oxygen electrode layer 5 may function as a cathode. In this case, the constituent materials of the hydrogen electrode layer 1 and the oxygen electrode layer 5 are interchanged, and a source gas is passed over the outer surface of the hydrogen electrode layer 1.

[0086] [Variation 7] In the above embodiment, the electrolysis cell 100 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.

[0087] [Variation 8] In the above embodiment, the contact surface S3 is curved convexly toward the electrolyte layer 3, as described with reference to Fig. 2 , which shows a cross section of the hydrogen electrode layer 1 along the thickness direction. While the configuration shown in Fig. 2 is preferably observed in all cross sections of the hydrogen electrode layer 1, it is sufficient if it is observed in at least one cross section of the hydrogen electrode layer 1. This is because if the configuration shown in Fig. 2 is observed in even one cross section, the resistance of the hydrogen electrode layer 1 to the compressive force applied from the electrolyte layer 3 can be improved at least in that location.

[0088] REFERENCE SIGNS LIST 100 Electrolysis cell 10 Metal support 11 First main surface 12 Second main surface 13 Recess S1 Bottom surface S2 Side peripheral surface 13a Boundary portion 14 Supply hole 20 Cell main body 1 Hydrogen electrode layer S3 Contact surface S4 Apex 2 Catalyst layer 3 Electrolyte layer 4 Reaction prevention layer 5 Oxygen electrode layer 30 Flow path member 30a Flow path

Claims

1. An electrochemical cell comprising: a metal support having a first main surface, a second main surface, and a plurality of supply holes; and a cell body supported by the metal support and having a first electrode layer, a second electrode layer, and an electrolyte layer disposed between the first electrode layer and the second electrode layer, wherein the first electrode layer has a contact surface that contacts the electrolyte layer, and in a cross section taken along the thickness direction of the first electrode layer, the contact surface is curved in a convex shape toward the electrolyte layer.

2. The electrochemical cell according to claim 1, wherein, in the cross section, the apex of the contact surface is located at the center of the first electrode layer in the surface direction.

3. The electrochemical cell according to claim 1 or 2, wherein the metal support has a recess formed in the first main surface, and at least a portion of the first electrode layer is disposed within the recess.

4. The electrochemical cell according to claim 3, wherein in a cross section along the thickness direction of the metal support, the boundary between the side peripheral surface and the bottom surface of the recess is rounded.

5. An electrochemical cell according to claim 3 or 4, wherein the cell body has a catalyst layer disposed in at least one of the plurality of supply holes and continuous with the first electrode layer.

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