Electrochemical cell

Abstract

An electrolysis cell (1) comprises: a metal support (10); and a cell body (20). The cell body (20) has a hydrogen electrode layer (6) disposed on a first main surface (12) of the metal support (10). The metal support (10) comprises: a base material 50 having a first recess (14a); a Cr2O3 layer (51) that covers the surface (50S) of the base material (50); and a first MnCr composite oxide phase (52a) that is connected to the Cr2O3 layer (51). At least a portion of the first MnCr composite oxide phase (52a) is disposed in the first recess (14a).

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 is formed on the main surface of the metal support and includes a first electrode layer covering the plurality of through-holes, a second electrode layer, and an electrolyte layer disposed between the first and second electrode layers.

[0003] Here, Patent Document 1 states that Cr ２ O ３ and forming an oxide film containing conductive particles (for example, Ni particles) on the substrate surface of a metal support.

[0004] International Publication No. 2020 / 218431

[0005] However, in the metal support described in Patent Document 1, the oxide film is prone to peeling off from the substrate due to the difference in thermal expansion coefficient between the substrate and the oxide film. Therefore, there is a demand for preventing the oxide film from peeling off from the substrate while ensuring electrical connectivity between the substrate and the oxide film.

[0006] An object of the present invention is to provide an electrochemical cell that can suppress peeling of the oxide film while ensuring electrical connectivity between the substrate of the metal support and the oxide film.

[0007] An electrochemical cell according to a first aspect of the present invention comprises a metal support having a plurality of through holes formed in a main surface thereof, and a cell body portion disposed on the main surface. The cell body portion has a first electrode layer and a second electrode layer disposed on the main surface, and an electrolyte layer disposed between the first electrode layer and the second electrode layer. The metal support comprises a substrate having a recess formed on its surface, and a Cr layer covering the surface of the substrate. ２ O ３ layer, and the Cr ２ O ３ and a MnCr composite oxide phase connected to the layer, at least a portion of the MnCr composite oxide phase being disposed within the recess.

[0008] An electrochemical cell according to a second aspect of the present invention is related to the first aspect, wherein the recess is formed to be narrower at the opening on the side of the first electrode layer.

[0009] An electrochemical cell according to a third aspect of the present invention is related to the first or second aspect, wherein the width of the portion of the MnCr composite oxide phase protruding from the recess is equal to or smaller than the opening width of the recess.

[0010] An electrochemical cell according to a fourth aspect of the present invention is the electrochemical cell according to any one of the first to third aspects, wherein the Cr concentration in the MnCr composite oxide phase is ２ O ３ The Mn concentration in the MnCr composite oxide phase is higher as it approaches the Cr layer. ２ O ３ The closer to the layer, the smaller it is.

[0011] An electrochemical cell according to a fifth aspect of the present invention is the electrochemical cell according to any one of the first to fourth aspects, wherein the MnCr composite oxide phase comprises Cr embedded therein. ２ O ３ Contains particles.

[0012] An electrochemical cell according to a sixth aspect of the present invention is related to any one of the first to fifth aspects, wherein the MnCr composite oxide phase is in contact with the substrate.

[0013] According to the present invention, it is possible to provide an electrochemical cell that can suppress peeling of the oxide film while ensuring electrical connectivity between the substrate of the metal support and the oxide film.

[0014] Fig. 1 is a plan view of an electrolysis cell according to an embodiment, Fig. 2 is a cross-sectional view taken along line AA in Fig. 1, and Fig. 3 is a partially enlarged view of Fig. 2.

[0015] (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.

[0016] 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.

[0017] 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.

[0018] 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 .

[0019] [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.

[0020] 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.

[0021] 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 .

[0022] 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 both 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 the hydrogen electrode layer 6, which will be described later. The opening of each communication hole 11 on the second main surface 13 side is connected to a flow path 30a, which will be described later.

[0023] Each of the communication holes 11 can be formed by mechanical processing (for example, punching), laser processing, or chemical processing (for example, etching).

[0024] 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.

[0025] 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.

[0026] The metal support 10 is mainly made of a metal material. The detailed configuration of the metal support 10 will be described later. [Cell main body 20] The cell main body 20 is disposed on the metal support 10. The cell main body 20 is supported by the metal support 10. The cell main 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).

[0027] 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.

[0028] [Hydrogen Electrode Layer 6] The hydrogen electrode layer 6 is an example of a "first electrode layer" according to the present invention. The hydrogen electrode layer 6 is formed on the first main surface 12 of the metal support 10. The hydrogen electrode layer 6 is disposed between the metal support 10 and the electrolyte layer 7. A portion of the hydrogen electrode layer 6 may extend into each of the communicating holes 11 of the metal support 10.

[0029] The hydrogen electrode layer 6 is supplied with a source gas through each of the communication holes 11. The source gas contains at least H ２ Contains O.

[0030] 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 Hydrogen electrode layer 6: H ２ O + 2e － →H ２ +O ２－ ...(1)

[0031] 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 O２－ 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)

[0032] The hydrogen electrode layer 6 is a porous body having electrical conductivity. The hydrogen electrode layer 6 has gas diffusibility. A source gas is supplied to the hydrogen electrode layer 6 through each of the communication holes 11. The hydrogen electrode layer 6 discharges the product gas generated inside to each of the communication holes 11.

[0033] 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.

[0034] When the conductive material is a metal material, the conductive material exists in an oxide state (e.g., NiO) in an oxidizing atmosphere and in a metal 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.

[0035] The hydrogen electrode layer 6 contains an oxide ion conductive material. The oxide ion conductive material is an example of the "ion conductive material" according to the present invention. Examples of the oxide ion conductive material 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, LSGM, and a mixed material of two or more of these can be used.

[0036] 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.

[0037] The porosity of the hydrogen electrode layer 6 is not particularly limited, but may be, for example, 5% to 70%. The thickness of the hydrogen electrode layer 6 is not particularly limited, but may be, for example, 1 μm to 500 μm.

[0038] In this specification, the thickness direction refers to a direction perpendicular to the surface of the electrolyte layer 7 on the side of the hydrogen electrode layer 6. The thickness direction is specified using an approximate straight line that indicates the surface of the electrolyte layer 7 and is determined by the least squares method. The thickness direction may be substantially the same as the Z-axis direction.

[0039] 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.

[0040] [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.

[0041] The electrolyte layer 7 covers the hydrogen electrode layer 6 , and its outer edge is connected to the first main surface 12 of the metal support 10 .

[0042] 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).

[0043] 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.

[0044] 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.

[0045] [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.

[0046] The reaction prevention layer 8 is made of an oxide ion conductive material, such as GDC or SDC.

[0047] 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.

[0048] 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.

[0049] [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.

[0050] 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 Oxygen electrode layer 9: 2O ２－ →O ２ +4e － ...(5)

[0051] 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).

[0052] 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.

[0053] 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.

[0054] [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.

[0055] 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.

[0056] The flow path member 30 has a frame 31 and a separator 32. The frame 31 is an annular member that surrounds the side of the flow path 30a. The frame 31 is bonded to the second main surface 13 of the metal support 10. The separator 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 separator 32 is bonded to the frame 31.

[0057] In this embodiment, the frame 31 and the separator 32 are separate members, but the frame 31 and the separator 32 may be an integrated member.

[0058] (Detailed Structure of Metal Support 10) Fig. 3 is a partially enlarged view of Fig. 2. Fig. 3 shows a cross section of the metal support 10 and the hydrogen electrode layer 6.

[0059] As shown in FIG. 3, the metal support 10 is made of a substrate 50 and a Cr ２ O ３ 3, first to fourth MnCr composite oxide phases 52a to 52d are illustrated as the plurality of MnCr composite oxide phases 52. However, the metal support 10 is only required to have one or more MnCr composite oxide phases 52, and the number of MnCr composite oxide phases 52 is not particularly limited.

[0060] The substrate 50 is made of a metal material. For example, the substrate 50 is made of an alloy material containing Cr (chromium). Examples of the metal material include Fe—Cr alloy steel, Ni—Cr alloy steel, Fe—Cr—Mn alloy steel (stainless steel, etc.), and Ni—Cr—Mn alloy steel. The Cr content in the substrate 50 is not particularly limited, but can be set to 4% by mass or more and 30% by mass or less.

[0061] The substrate 50 has a surface 50S and a plurality of recesses 14 formed on the surface 50S. In Fig. 3, first to fourth recesses 14a to 14d are illustrated as the plurality of recesses 14. However, the metal support 10 only needs to have one or more recesses 14, and the number of recesses 14 is not particularly limited.

[0062] The first recess 14a is formed to be narrow at the opening on the side of the hydrogen electrode layer 6. The first recess 14a may be gradually narrowed toward the side of the hydrogen electrode layer 6. The second recess 14b has a similar configuration to the first recess 14a.

[0063] The third recess 14c is formed wider at the opening on the side of the hydrogen electrode layer 6. The third recess 14d may gradually widen toward the side of the hydrogen electrode layer 6. The fourth recess 14d has a similar configuration to the third recess 14d.

[0064] Cr ２ O ３ The layer 51 is disposed on the surface 50S of the substrate 50. ２ O ３ The layer 51 covers at least a portion of the surface 50S of the substrate 50. ２ O ３ The layer 51 may cover the entire surface 50S of the substrate 50. ２ O ３ The layer 51 may cover the inner surface of each of the communication holes 11 (see FIG. 2) described above.

[0065] Cr ２ O ３ The layer 51 is formed in a layered form. The layered form means that the layer is continuous without interruption while maintaining a thickness within a predetermined range. ２ O ３ The layer 51 is made of Cr ２ O ３ It is composed of:

[0066] As shown in FIG. ２ O ３ A part of the layer 51 is embedded in the first recess 14a and the third recess 14c. ２ O ３ The portion of the layer 51 that penetrates into the first recess 14a is connected to the first MnCr composite oxide phase 52a. ２O ３ The portion of the layer 51 that extends into the third recess 14c is connected to the third MnCr composite oxide phase 52c.

[0067] Cr ２ O ３ The thickness of the layer 51 is not particularly limited, but may be, for example, 1 μm or more and 10 μm or less. ２ O ３ The thickness of the layer 51 is calculated by the following method. ２ O ３ The cross section of the layer 51 is exposed. Next, a backscattered electron image of the cross section is obtained at 3000 magnifications using an SEM device (FE-SEM JSM-7900F, manufactured by JEOL Ltd.). Next, Cr ２ O ３ Cr at three points that divide the layer 51 into four equal parts ２ O ３ The thickness of the layer 51 is measured. ２ O ３ When the position where the thickness of the layer 51 is to be measured overlaps with the recess 14 of the metal support 10, the Cr ２ O ３ The thickness of the layer 51 is measured near the recess 14. The arithmetic mean of the three measurements is then calculated. ２ O ３ The thickness of the layer 51 is determined.

[0068] The first to fourth MnCr composite oxide phases 52a to 52d are separated from one another in the planar direction. That is, the first to fourth MnCr composite oxide phases 52a to 52d are formed in an island shape rather than a layer shape. The planar direction refers to a direction parallel to the surface 50S of the substrate 50. When specifying the planar direction, an approximate straight line representing the surface 50S obtained by the least squares method is used.

[0069] Each of the first to fourth MnCr composite oxide phases 52a to 52d is made of a composite oxide containing at least Mn (manganese) and Cr (chromium). ２ O ４ , Mn ２ CrO ４ , MnCrO ３Each of the first to fourth MnCr composite oxide phases 52a to 52d may be composed of secondary particles formed by aggregation of primary particles, or may be composed of higher order particles formed by aggregation of secondary particles.

[0070] At least a portion of the first MnCr composite oxide phase 52a is disposed in the first recess 14a. ２ O ３ Since the layer 51 is anchored to the substrate 50, the Cr ２ O ３ The layer 51 can be prevented from peeling off from the substrate 50. ２ O ３ Since there is room for direct contact between the layers 51, the Cr ２ O ３ The first MnCr composite oxide phase 52a has a lower electrical conductivity than the layer 51. ２ O ３ Therefore, the electrical connection between the layer 51 and the substrate 50 can be prevented from being impaired. ２ O ３ While ensuring electrical connectivity between the layer 51 and the substrate 50, ２ O ３ This can prevent the layer 51 from peeling off from the substrate 50 .

[0071] In addition, the substrate 50 and Cr ２ O ３ The first MnCr composite oxide phase 52a is disposed between the layers 51, and thus the substrate 50 and the Cr ２ O ３ Therefore, the difference in the thermal expansion coefficient between the substrate 50 and the Cr layer 51 can be reduced. ２ O ３ Since the thermal stress between the layers 51 can be suppressed, Cr ２ O ３ This can further prevent the layer 51 from peeling off from the substrate 50 .

[0072] The first MnCr composite oxide phase 52a is preferably in contact with the substrate 50. Specifically, the first MnCr composite oxide phase 52a is preferably in contact with the inner surface of the first recess 14a. This allows the substrate 50 and the Cr ２ O ３The difference in the thermal expansion coefficient of the layer 51 can be further alleviated. ２ O ３ This further prevents the layer 51 from peeling off from the substrate 50 .

[0073] The above effects can also be obtained by the second to fourth MnCr composite oxide phases 52b to 52d, respectively.

[0074] The first MnCr composite oxide phase 52a is entirely disposed within the first recess 14a. ２ O ３ The second MnCr composite oxide phase 52b is connected to the portion of the layer 51 that is in the first recess 14a. A portion of the second MnCr composite oxide phase 52b is disposed in the second recess 14b, and the remaining portion is Cr. ２ O ３ The portion of the second MnCr composite oxide phase 52b protruding from the second recess 14b is made of Cr. ２ O ３ It is connected to layer 51.

[0075] The third MnCr composite oxide phase 52c is entirely disposed within the third recess 14c. ２ O ３ The fourth MnCr composite oxide phase 52d is connected to the portion of the layer 51 that is in the third recess 14c. A part of the fourth MnCr composite oxide phase 52d is disposed in the fourth recess 14d, and the remaining part is Cr. ２ O ３ The portion of the fourth MnCr composite oxide phase 52d that protrudes from the fourth recess 14d is made of Cr. ２ O ３ It is connected to layer 51.

[0076] In the first recess 14a, a first MnCr composite oxide phase 52a embedded in the first recess 14a and Cr ２ O ３ The portion of the layer 51 that is inserted into the first recess 14a functions as an anchor portion. In the first recess 14a, the maximum width W1 of the anchor portion in the surface direction is larger than the opening width W2 of the first recess 14a in the surface direction. ２ O ３Since the layer 51 is firmly anchored to the substrate 50, the Cr ２ O ３ This can further prevent the layer 51 from peeling off from the substrate 50 .

[0077] In the second recesses 14b, the portions of the second MnCr composite oxide phase 52b that fill the second recesses 14b function as anchor portions. In the second recesses 14b, the maximum width W3 of the anchor portions in the surface direction is greater than the opening width W4 of the second recesses 14b in the surface direction. This allows the Cr ２ O ３ Since the layer 51 is firmly anchored to the substrate 50, the Cr ２ O ３ This can further prevent the layer 51 from peeling off from the substrate 50. In addition, the width of the portion of the second MnCr composite oxide phase 52b protruding from the second recess 14b is larger than the opening width W4 of the second recess 14b. ２ O ３ Peeling off from the layer 51 can be suppressed.

[0078] In the third recess 14c, a third MnCr composite oxide phase 52c embedded in the third recess 14c and Cr ２ O ３ The portion of the layer 51 that is inserted into the third recess 14c functions as an anchor portion.

[0079] In the fourth recess 14d, the portion of the fourth MnCr composite oxide phase 52d that fills the fourth recess 14d functions as an anchor portion. The width of the portion of the fourth MnCr composite oxide phase 52d that protrudes from the fourth recess 14d is equal to or less than the opening width W5 of the fourth recess 14d. This prevents the Cr from being removed from the substrate 50. ２ O ３ This can prevent the flow of current through the layer 51 from being obstructed by the portion of the fourth MnCr composite oxide phase 52d that protrudes from the fourth recess 14d.

[0080] In each of the first to fourth MnCr composite oxide phases 52a to 52d, the Cr concentration is Cr ２ O ３ The closer to the layer 51, the higher the Mn concentration. ２ O ３It is preferable that the closer to the layer 51, the smaller the Cr ２ O ３ Since the adhesion between the layer 51 and each of the first to fourth MnCr composite oxide phases 52a to 52d can be improved, each MnCr composite oxide phase 52 can be made of Cr. ２ O ３ It is possible to suppress separation from the layer 51 .

[0081] The Cr concentration and Mn concentration in the first to fourth MnCr composite oxide phases 52a to 52d are obtained by line analysis using an EPMA (Electron Probe Micro Analyzer) on a cross section of the metal support 10. EPMA is a concept that includes EDS (Energy Dispersive x-ray spectroscopy).

[0082] (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.

[0083] [Modification 1] In the above embodiment, Cr ２ O ３ The layer 51 is made of Cr ２ O ３ It was decided to be composed of Cr ２ O ３ For example, Cr may contain other compositions. ２ O ３ The layer 51 may have an MnCr composite oxide phase embedded therein.

[0084] [Modification 2] The MnCr composite oxide phase 52 has Cr embedded therein. ２ O ３The electrochemical cell 1 may contain particles. [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.

[0085] 1 Electrolytic cell 10 Metal support 50 Substrate 51 Cr ２ O ３ Layer 52 MnCr composite oxide phase 11 Through hole 12 First main surface 13 Second main surface 14 Recess 20 Cell main body 6 Hydrogen electrode layer 7 Electrolyte layer 8 Reaction prevention layer 9 Oxygen electrode layer 30 Flow path member 30a Flow path

Claims

1. A metal support having a plurality of through holes formed on a main surface thereof, and a cell body portion disposed on the main surface, wherein the cell body portion has a first electrode layer and a second electrode layer disposed on the main surface, and an electrolyte layer disposed between the first electrode layer and the second electrode layer, and the metal support comprises a base material having a recess formed on its surface, and a Cr layer covering the surface of the base material. ２ O ３ layer, and the Cr ２ O ３ an MnCr composite oxide phase connected to the layer, wherein at least a portion of the MnCr composite oxide phase is disposed within the recess.

2. The electrochemical cell according to claim 1, wherein the recess is formed narrower at the opening on the side of the first electrode layer.

3. The electrochemical cell according to claim 1 or 2, wherein the width of the portion of the MnCr composite oxide phase that protrudes from the recess is equal to or less than the opening width of the recess.

4. The Cr concentration in the MnCr composite oxide phase is ２ O ３ The Mn concentration in the MnCr composite oxide phase is higher as it approaches the Cr layer. ２ O ３ 3. The electrochemical cell of claim 1, wherein the thickness of the layer is smaller as the layer is closer to the layer.

5. The MnCr composite oxide phase has Cr embedded inside. ２ O ３ 3. An electrochemical cell according to claim 1 or 2, comprising particles.

6. The electrochemical cell according to claim 1 or 2, wherein the MnCr composite oxide phase is in contact with the substrate.

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