JP7668972B2 - Electrochemical Cell - Google Patents

Description

The present invention relates to an electrochemical cell.

Patent Document 1 discloses a metal-supported electrochemical cell (electrolysis cell, fuel cell, etc.) that includes a metal plate having a plurality of communication holes formed therein, a cell body supported by the metal plate, and a flow path member that forms a gas flow path between the metal plate. The cell body has a first electrode layer and a second electrode layer formed on the metal plate, and an electrolyte layer disposed between the first electrode layer and the second electrode layer.

JP 2020-155337 A

In the electrochemical cell described in Patent Document 1, the only route through which current flows is between the first electrode layer and the metal plate, so current tends to concentrate in the area of the first electrode layer that contacts the metal plate, causing degradation of that area to progress locally.

The object of the present invention is to provide an electrochemical cell capable of suppressing localized deterioration of the first electrode layer.

The electrochemical cell according to the first aspect of the present invention comprises a metal plate, a cell body, a current collector, a conductive flow path member, and an electrical connection member. The metal plate has a first main surface, a second main surface, and a plurality of communication holes communicating with the first main surface and the second main surface. The cell body has a first electrode layer formed on the first main surface of the metal plate, a second electrode layer, and an electrolyte layer disposed between the first electrode layer and the second electrode layer. The current collector is disposed in the plurality of communication holes and has a plurality of first portions connected to the first electrode layer. The flow path member is joined to the second main surface and forms a gas flow path between the metal plate. The electrical connection member is disposed in the gas flow path and electrically connects at least one of the flow path member and the metal plate to the current collector.

The electrochemical cell according to the second aspect of the present invention relates to the above-mentioned first aspect, and the electrical resistance of a first current route flowing between the first electrode layer and the flow path member via a current collecting portion and an electrical connection member is smaller than the electrical resistance of a second current route flowing between the first electrode layer and the flow path member via a metal plate.

The electrochemical cell according to the third aspect of the present invention relates to the second aspect described above, and the electrical connection member is metal-metal connected to each of the current collecting portion and the flow path member, and the metal plate has a base material and an oxide coating covering the surface of the base material.

The electrochemical cell according to a fourth aspect of the present invention relates to any one of the first to third aspects, and the current collecting portion is formed in a layer on the second main surface of the metal plate and has a second portion connected to a plurality of first portions.

The present invention provides an electrochemical cell capable of suppressing localized deterioration of the first electrode layer.

FIG. 1 is a cross-sectional view of an electrolysis cell according to an embodiment. FIG. 2 is a partially enlarged view of FIG. FIG. 11 is a schematic diagram of a current collecting portion according to Modification 3. FIG. 11 is a schematic diagram of a current collecting portion according to Modification 3. FIG. 11 is a schematic diagram of a current collecting portion according to Modification 3. FIG. 11 is a schematic diagram of a current collecting portion according to Modification 3. FIG. 13 is a schematic diagram of an electrical connection member according to a fourth modified example. FIG. 13 is a schematic diagram of an electrical connection member according to a fourth modified example.

An electrolytic cell according to an embodiment will be described with reference to the drawings. The electrolytic cell is an example of an electrochemical cell. In this embodiment, a ceramic solid oxide electrolytic cell (SOEC) will be described as an example of an electrolytic cell. In the following description, the solid oxide electrolytic cell will be abbreviated as "electrolytic cell."

Figure 1 is a cross-sectional view of an electrolysis cell 1 according to an embodiment. Figure 2 is an enlarged partial view of Figure 1.

As shown in FIG. 1, the cell 1 comprises a metal plate 10, a cell main body 20, a current collecting portion 30, a flow path member 40 and an electrical connection member 50.

(Metal plate 10)
The metal plate 10 supports the cell main body 20. In this embodiment, the metal plate 10 is formed in a plate shape. The metal plate 10 may be flat or curved. The metal plate 10 may have any thickness as long as it can maintain the strength of the cell 1, and the thickness is not particularly limited, but may be, for example, 0.1 mm or more and 2.0 mm or less.

As shown in FIG. 1, the metal plate 10 has a first main surface 11, a second main surface 12, and a plurality of communication holes 13. A cell main body 20 is disposed on the first main surface 11 of the metal plate 10. The second main surface 12 of the metal plate 10 is provided on the opposite side to the first main surface 11. A second portion 32 of the current collecting section 30, which will be described later, is disposed on the second main surface 12 of the metal plate 10. In addition, a flow path member 40 is joined to the second main surface 12 of the metal plate 10. In this embodiment, the metal plate 10 and the flow path member 40 are joined by a joint 60, as shown in FIG. 2.

A plurality of communication holes 13 are formed in a region corresponding to the hydrogen electrode layer 21 described later. Each communication hole 13 communicates with the first main surface 11 and the second main surface 12. A first portion 31 of the current collector 30 described later is disposed within each communication hole 13. In this embodiment, the first portion 31 fills the communication hole 13. Each communication hole 13 opens to the first main surface 11 and the second main surface 12, respectively. The opening of each communication hole 13 on the first main surface 11 side is covered by the hydrogen electrode layer 21. The opening of each communication hole 13 on the second main surface 12 side is covered by the second portion 32 of the current collector 30.

The area of the communication hole 13 in plan view can be, for example, 0.00005 ^mm2 or more and 1 ^mm2 or less. When the shape of the communication hole 13 in plan view is substantially circular, the diameter of the communication hole 13 can be, for example, 10 μm or more and 1000 μm or less. The shape of the communication hole 13 in plan view may be rectangular.

The through holes 13 can be formed by mechanical processing (e.g., punching), laser processing, or chemical processing (e.g., etching). In addition, since the through holes 13 do not have to be formed along the thickness direction of the metal plate 10, the metal plate 10 may be made of a porous metal having mesh-like pores.

As shown in Figure 2, the metal plate 10 in this embodiment is composed of a substrate 14 and an oxide coating 15.

The substrate 14 is made of a metal material. The substrate 14 is made of, for example, 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 plate 10 is not particularly limited, but can be 4% by mass or more and 30% by mass or less.

The substrate 14 may contain Ti (titanium) and Zr (zirconium). The Ti content in the substrate 14 is not particularly limited, but may be 0.01 mol% or more and 1.0 mol% or less. The Zr content in the substrate 14 is not particularly limited, but may be 0.01 mol% or more and 0.4 mol% or less. The substrate 14 may contain Ti as _TiO2 (titania) and may contain Zr as _ZrO2 (zirconia).

The oxide film 15 covers at least a portion of the surface of the substrate 14. In this embodiment, as shown in Fig. 2, the oxide film 15 covers the surface of the substrate 14 except for the area where the joint 60 is joined. Therefore, the oxide film 15 is interposed between the substrate 14 and the hydrogen electrode layer 21 described below, and between the substrate 14 and the current collector 30.

The oxide film 15 may be composed of an oxide of a constituent element of the substrate 14. For example, when the substrate 14 is composed of an alloy material containing Cr, the oxide film 15 may contain chromium oxide as a main component. "Containing chromium oxide as a main component" means that chromium oxide accounts for 70% by weight or more of the oxide film 15.

The thickness of the oxide film 15 is not particularly limited, but can be, for example, 0.1 μm or more and 20 μm or less.

The oxide film 15 can be formed by applying a material paste to the surface of the substrate 14, but it can also be formed by leaving the substrate 14 in air and allowing it to oxidize.

(Cell body 20)
1, the cell body 20 is disposed on the first main surface 11 of the metal plate 10. The cell body 20 has a hydrogen electrode layer 21 (cathode), an electrolyte layer 22, a reaction prevention layer 23, and an oxygen electrode layer 24 (anode). The hydrogen electrode layer 21 is an example of a "first electrode layer" according to the present invention, and the oxygen electrode layer 24 is an example of a "second electrode layer" according to the present invention.

The hydrogen electrode layer 21, electrolyte layer 22, reaction prevention layer 23 and oxygen electrode layer 24 are laminated in this order from the metal plate 10 side. However, the cell main body 20 does not have to have the reaction prevention layer 23.

[Hydrogen electrode layer 21]
1, the hydrogen electrode layer 21 is formed on the first main surface 11 of the metal plate 10. The hydrogen electrode layer 21 is provided so as to cover the region of the first main surface 11 in which the plurality of communication holes 13 are provided.

A source gas is supplied to the hydrogen electrode layer 21 through each of the communication holes 13 of the metal plate 10. In this embodiment, the source gas contains at least _H2O .

When the source gas contains only H ₂ O, the hydrogen electrode layer 21 produces H ₂ from the source gas in accordance with the electrochemical reaction of water electrolysis shown in the following formula (1).

Hydrogen electrode layer 21: H2O+2e-→H2+O2-... (1)

When the source gas contains CO ₂ in addition to H ₂ O, the hydrogen electrode layer 21 produces H ₂ , CO, and O ²⁻ from the source gas in accordance with the co-electrochemical reactions shown in the following formulas (2), (3), and (4).

・Hydrogen electrode layer 21: CO ₂ +H ₂ O+4e ^- →CO+H ₂ +2O ² -...(2)
Electrochemical reaction of H ₂ O: H ₂ O + 2e ⁻ → H ₂ + O ²⁻ (3)
Electrochemical reaction of _CO2 : _CO2 + ^2e- → CO + O2 ^-... (4)

The hydrogen electrode layer 21 is made of a conductive porous material. The hydrogen electrode layer 21 may have oxide ion conductivity. The hydrogen electrode layer 21 may be made of, for example, 8 mol % yttria-stabilized zirconia (8YSZ), 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 material of one or more of these and NiO.

The porosity of the hydrogen electrode layer 21 is not particularly limited, but may be, for example, 5% to 70%. The thickness of the hydrogen electrode layer 21 is not particularly limited, but may be, for example, 1 μm to 100 μm.

The method for forming the hydrogen electrode layer 21 is not particularly limited, and may be a firing method, a spray coating method (thermal spraying method, aerosol deposition method, aerosol gas deposition method, powder jet deposition method, particle jet deposition method, cold spray method, etc.), a PVD method (sputtering method, pulsed laser deposition method, etc.), a CVD method, etc.

[Electrolyte layer 22]
1 , the electrolyte layer 22 is disposed between the hydrogen electrode layer 21 and the oxygen electrode layer 24. In this embodiment, since the cell body 20 has the reaction prevention layer 23, the electrolyte layer 22 is interposed between the hydrogen electrode layer 21 and the reaction prevention layer 23.

The electrolyte layer 22 is disposed so as to cover the entire hydrogen electrode layer 21. The outer periphery of the electrolyte layer 22 is bonded to the first main surface 11 of the metal plate 10. This ensures airtightness between the hydrogen electrode layer 21 and the oxygen electrode layer 24, eliminating the need for a separate seal between the metal plate 10 and the electrolyte layer 22.

The electrolyte layer 22 transfers O ^2- generated in the hydrogen electrode layer 21 to the oxygen electrode layer 24. The electrolyte layer 22 is a dense body having oxide ion conductivity. Examples of oxide ion conductive materials include YSZ (yttria stabilized zirconia, for example, 8YSZ), GDC (gadolinium doped ceria), ScSZ (scandia stabilized zirconia), SDC (samarium doped ceria), LSGM (lanthanum gallate), and composite materials thereof.

The porosity of the electrolyte layer 22 is not particularly limited, but may be, for example, 0.1% to 7%. The thickness of the electrolyte layer 22 is not particularly limited, but may be, for example, 1 μm to 100 μm.

The method for forming the electrolyte layer 22 is not particularly limited, and for example, a firing method, a spray coating method, a PVD method, a CVD method, etc. can be used.

[Reaction prevention layer 23]
1, the reaction prevention layer 23 is disposed on the electrolyte layer 22. The reaction prevention layer 23 is interposed between the electrolyte layer 22 and the oxygen electrode layer 24. The reaction prevention layer 23 prevents the constituent material of the oxygen electrode layer 24 from reacting with the constituent material of the electrolyte layer 22 to form a reaction layer having a high electrical resistance.

The reaction prevention layer 23 is made of a material having oxide ion conductivity. The reaction prevention layer 23 can be made of a ceria-based material such as GDC or SDC.

The porosity of the reaction prevention layer 23 is not particularly limited, but can be, for example, 0% to 50%. The thickness of the reaction prevention layer 23 is not particularly limited, but can be, for example, 3 μm to 50 μm.

The method for forming the reaction prevention layer 23 is not particularly limited, and for example, a firing method, a spray coating method, a PVD method, a CVD method, etc. can be used.

[Oxygen electrode layer 24]
1 , the oxygen electrode layer 24 is disposed on the opposite side of the hydrogen electrode layer 21 with respect to the electrolyte layer 22. In this embodiment, since the reaction prevention layer 23 is disposed between the electrolyte layer 22 and the oxygen electrode layer 24, the oxygen electrode layer 24 is connected to the reaction prevention layer 23. If the reaction prevention layer 23 is not disposed between the electrolyte layer 22 and the oxygen electrode layer 24, the oxygen electrode layer 24 is connected to the electrolyte layer 22.

The oxygen electrode layer 24 produces O ₂ from O ²⁻ transferred from the hydrogen electrode layer 21 via the electrolyte layer 22 in accordance with the chemical reaction of the following formula (5).

Oxygen electrode layer 24: 2O ²⁻ →O ₂ +4e ⁻ (5)

The oxygen electrode layer 24 is made of a porous material having oxide ion conductivity and electrical conductivity, and may be made of a composite material of _one or more of (La,Sr)(Co,Fe)O3, (La,Sr) _FeO3 , La(Ni,Fe) _O3 , (La,Sr) _CoO3 , and (Sm,Sr) _CoO3 and an oxide ion conductive material (such as GDC).

The porosity of the oxygen electrode layer 24 is not particularly limited, but may be, for example, 20% to 60%. The thickness of the oxygen electrode layer 24 is not particularly limited, but may be, for example, 1 μm to 100 μm.

The method for forming the oxygen electrode layer 24 is not particularly limited, and a firing method, a spray coating method, a PVD method, a CVD method, etc. can be used.

(Current collecting portion 30)
1, the current collecting portion 30 is disposed on the opposite side of the hydrogen electrode layer 21 from the electrolyte layer 22. The current collecting portion 30 is connected to the hydrogen electrode layer 21.

The current collecting section 30 can be made of a conductive metal material, a conductive ceramic material, a composite material of a conductive metal material and a conductive ceramic material, or a composite material of a non-conductive ceramic material and a conductive metal material. Examples of conductive metal materials include Fe, Ni, Cu, Au, and Pt. Examples of conductive ceramic materials include (La, Sr) MnO ₃ , La (Cr, Ca) O ₃ , and (La, Sr) TiO ₃ . Examples of non-conductive ceramic materials include ZrO ₂ , CeO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , and Mg ₂ SiO _x .

The current collecting section 30 may be made of the same material as the hydrogen electrode layer 21. In this case, the current collecting section 30 may be substantially integral with the hydrogen electrode layer 21.

The porosity of the current collecting portion 30 is not particularly limited, but can be, for example, 30% or more and 70% or less.

As shown in FIG. 1, the collector portion 30 has a plurality of first portions 31 and second portions 32.

Each first portion 31 is disposed within each communication hole 13 of the metal plate 10. However, each first portion 31 may contain voids, cracks, etc. therein. Each first portion 31 is connected to the hydrogen electrode layer 21.

The diameter of the first portion 31 is substantially the same as the diameter of the communicating hole 13. In the thickness direction of the metal plate 10, the height of the first portion 31 is substantially the same as the length of the communicating hole 13.

The second portion 32 is formed in a layer on the second main surface 12 of the metal plate 10. The second portion 32 is provided so as to cover an area of the second main surface 12 in which the multiple communication holes 13 are provided. The second portion 32 is connected to each of the first portions 31. The second portion 32 is formed integrally with each of the first portions 31.

The thickness of the second portion 32 is not particularly limited, but can be, for example, 1 μm or more and 100 μm or less.

The first portion 31 can be formed by injecting a material paste containing the constituent material of the current collecting portion 30 into each of the communicating holes 13 of the metal plate 10 and then firing the material paste. The second portion 32 can be formed by applying the material paste to the second main surface 12 of the metal plate 10 and then firing the material paste. The first portion 31 and the second portion 32 may be formed by firing simultaneously. The method of forming the first portion 31 and the second portion 32 is not limited to the firing method, and for example, a vapor phase growth method such as a thermal spray method, an AD (Aerosol Deposition) method, and a sputtering method can be used.

[Flow path member 40]
The flow path member 40 is joined to the second main surface 12 of the metal plate 10. The flow path member 40 is formed in a tray shape that opens on the metal plate 10 side. The opening of the flow path member 40 is covered by the metal plate 10. As a result, a gas flow path 41 is formed between the flow path member 40 and the metal plate 10. In this embodiment, a raw material gas is supplied to the gas flow path 41.

As shown in FIG. 1, the flow path member 40 has a frame body 42 and an interconnector 43.

The frame body 42 is joined to the second main surface 12 of the metal plate 10 via a joint 60. The joint 60 is formed by welding or brazing the base material 14 of the metal plate 10 and the base material 44 of the frame body 42. The frame body 42 is an annular member that surrounds the gas flow path 41. The frame body 42 is arranged to surround the periphery of the current collecting section 30.

As shown in FIG. 2, the frame body 42 according to this embodiment is composed of a substrate 44 and an oxide film 45. The substrate 44 is composed of a metal material. The configuration of the substrate 44 is similar to that of the substrate 14 of the metal plate 10 described above. The oxide film 45 covers at least a portion of the surface of the substrate 44. In this embodiment, as shown in FIG. 2, the oxide film 45 covers the surface of the substrate 44 except for the area where the joint 60 and the joint 70 described below are joined. The configuration of the oxide film 45 is similar to that of the oxide film 15 of the metal plate 10 described above.

The interconnector 43 is a plate-like member for electrically connecting the electrolytic cell 1 in series with an external power source or another electrolytic cell. The interconnector 43 is joined to the frame 42 via a joint 70. The joint 70 is formed by welding or brazing the base material 44 of the frame 42 and the base material 46 of the interconnector 43. The interconnector 43 faces the current collecting section 30 across the gas flow path 41.

2, the interconnector 43 of this embodiment is composed of a substrate 46 and an oxide film 47. The substrate 46 is composed of a metal material. The configuration of the substrate 46 is similar to that of the substrate 14 of the metal plate 10 described above. The oxide film 47 covers at least a portion of the surface of the substrate 46. In this embodiment, as shown in FIG. 2, the oxide film 47 covers the surface of the substrate 46 excluding the area where the joint 70 is joined and the connection area 46a where the electrical connection member 50 is connected. The configuration of the oxide film 47 is similar to that of the oxide film 15 of the metal plate 10 described above.

In this embodiment, the frame body 42 and the interconnector 43 are separate components, but the frame body 42 and the interconnector 43 may also be an integrated component.

(Electrical connection member 50)
As shown in Fig. 1, the electrical connection member 50 is disposed in the gas flow path 41. The electrical connection member 50 electrically connects the current collecting unit 30 and the flow path member 40. More specifically, as shown in Fig. 2, the electrical connection member 50 electrically connects the second portion 32 of the current collecting unit 30 and the substrate 46 of the interconnector 43 of the flow path member 40.

It is preferable that the electrical connection member 50 has breathability so as not to impede the flow of the raw material gas flowing through the gas flow path 41. The breathability of the electrical connection member 50 can be obtained, for example, by making the electrical connection member 50 itself a porous body, or by making the electrical connection member 50 out of a mesh material woven in a net shape.

The electrical connection member 50 is made of a metal material that is conductive and does not form an oxide film on its surface. Examples of such metal materials include Ni, Fe, Cu, Au, and Pt.

In this embodiment, the electrical connection member 50 is connected to the second portion 32 of the current collecting portion 30 by metal-metal connection. The metal-metal connection means that the two members are electrically connected only through metal elements. The metal-metal connection between the current collecting portion 30 and the electrical connection member 50 includes a form in which the metal element contained in the second portion 32 and the metal element contained in the electrical connection member 50 are directly contacted with each other to form a direct electrical connection, and a form in which the metal element contained in the second portion 32 and the metal element contained in the electrical connection member 50 are indirectly electrically connected through the metal element contained in the conductive bonding material. The direct electrical connection can be formed by directly contacting the electrical connection member 50 with the second portion 32. The indirect electrical connection can be formed by bonding the electrical connection member 50 to the second portion 32 using a conductive bonding material. As the conductive bonding material, a metal paste containing a metal element can be used.

In this embodiment, the electrical connection member 50 is connected to the interconnector 43 of the flow path member 40 by metal-metal connection. The metal-metal connection between the flow path member 40 and the electrical connection member 50 includes a form in which the metal element contained in the base material 46 and the metal element contained in the electrical connection member 50 are directly contacted with each other to form a direct electrical connection, and a form in which the metal element contained in the base material 46 and the metal element contained in the electrical connection member 50 are indirectly electrically connected through the metal element contained in the conductive bonding material. A direct electrical connection can be formed by directly contacting the electrical connection member 50 with the base material 46, or by welding them together. An indirect electrical connection can be formed by joining the electrical connection member 50 to the base material 46 using a conductive bonding material, or by brazing. As the conductive bonding material, a metal paste or brazing material containing a metal element can be used.

(Current route)
In the electrolysis cell 1 according to this embodiment, as shown in FIG. 2, there are two routes for a current flowing between the hydrogen electrode layer 21 and the flow path member 40: a first current route R1 and a second current route R2.

The first current route R1 is a route from the hydrogen electrode layer 21 to the flow path member 40 via the current collecting part 30 and the electrical connection member 50. Specifically, the first current route R1 is a route in which current flows in the order of the hydrogen electrode layer 21 → current collecting part 30 → electrical connection member 50 → interconnector 43. The first current route R1 is a route in which current does not flow directly from the hydrogen electrode layer 21 to the metal plate 10, and is a route that does not exist in conventional metal-supported electrolytic cells (see, for example, JP 2020-155337 A).

The second current route R2 is a route from the hydrogen electrode layer 21 to the flow path member 40 without passing through the current collector 30 and the electrical connection member 50. Specifically, the second current route R2 is a route in which current flows in the order of the hydrogen electrode layer 21 → metal plate 10 → joint 60 → frame 42 → joint 70 → interconnector 43. The second current route R2 is a route in which current flows directly from the hydrogen electrode layer 21 to the metal plate 10, and is a route that exists in conventional metal-supported electrolytic cells.

In this way, the existence of the first current route R1 through which current flows from the hydrogen electrode layer 21 to the current collector 30 and the second current route R2 through which current flows from the hydrogen electrode layer 21 to the metal plate 10 allows current to flow using the entire hydrogen electrode layer 21. This prevents current from concentrating on the second current route R2, thereby preventing localized deterioration of the area of the hydrogen electrode layer 21 that contacts the metal plate 10.

In addition, since the oxide film 15 is interposed between the substrate 14 of the metal plate 10 and the hydrogen electrode layer 21, the oxide film 15 would heat up due to the current flowing through the second current route R2, but as described above, the current can be prevented from concentrating on the second current route R2, and therefore the heat generation of the oxide film 15 can be prevented. This prevents interdiffusion of elements between the hydrogen electrode layer 21 and the metal plate 10, and further prevents localized deterioration of the region of the hydrogen electrode layer 21 that contacts the metal plate 10. In addition, since the current flowing through the first current route R1 does not pass through the oxide film 15, problems caused by heat generation by the oxide film 15 do not occur.

Here, as described above, the electrical connection member 50 is connected metal-metal to each of the current collector 30 and the flow path member 40, so that the electrical resistance of the first current route R1 is kept small. On the other hand, the oxide film 15 is interposed between the base material 14 of the metal plate 10 and the hydrogen electrode layer 21, so that the electrical resistance of the second current route R2 is large. Therefore, the electrical resistance of the first current route R1 is smaller than the electrical resistance of the second current route R2. Therefore, the current flows from the hydrogen electrode layer 21 to the flow path member 40 through the first current route R1 as the main route and the second current route R2 as the sub-route. Therefore, the heat generation of the oxide film 15 can be further suppressed, so that the mutual diffusion of elements between the hydrogen electrode layer 21 and the metal plate 10 can be further suppressed. As a result, the local deterioration of the area of the hydrogen electrode layer 21 that contacts the metal plate 10 can be further suppressed.

(Modification)
Although the embodiments of the present invention have 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.

[Modification 1]
In the above embodiment, the hydrogen electrode layer 21 functions as a cathode and the oxygen electrode layer 24 functions as an anode, but the hydrogen electrode layer 21 may function as an anode and the oxygen electrode layer 24 may function as a cathode. Specifically, the positions of the hydrogen electrode layer 21, the reaction prevention layer 23, and the oxygen electrode layer 24 are interchanged, and a source gas is caused to flow over the outer surface of the hydrogen electrode layer 21. In this case, the oxygen electrode layer 2 serves as the first electrode layer according to the present invention, and the hydrogen electrode layer 21 serves as the second electrode layer according to the present invention.

[Modification 2]
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 the electrolysis cell. The 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 to convert electrical energy into chemical energy, and an element for converting chemical energy into electrical energy. Therefore, the electrochemical cell may be a solid oxide fuel cell (SOFC) using oxide ions or protons as carriers. In this case, the fuel electrode (anode) is the first electrode layer according to the present invention, and the air electrode (cathode) is the second electrode layer according to the present invention.

[Modification 3]
In the above embodiment, the current collecting part 30 has a plurality of first portions 31 and a layer-like second portion 32, but as shown in Fig. 3, the current collecting part 30 does not have to have the second portion 32. In this case, the electrical connection member 50 is connected to the first portion 31 of the current collecting part 30 by metal-metal connection.

In addition, when the current collecting portion 30 does not have the second portion 32, as shown in FIG. 4, the first portion 31 may protrude into the gas flow path 41 from the opening on the second main surface 12 side of the communication hole 13.

Furthermore, when the current collecting section 30 does not have the second portion 32, the first portion 31 does not have to fill the entire communication hole 13. For example, as shown in FIG. 5, the first portion 31 does not have to reach the opening of the communication hole 13 on the second main surface 12 side. Alternatively, as shown in FIG. 6, the first portion 31 may be arranged in a layer on at least a portion of the inner circumferential surface of the communication hole 13.

[Modification 4]
In the above embodiment, the electrical connection member 50 is connected to the interconnector 43 of the flow path member 40, but this is not limited thereto.

For example, as shown in Figure 7, the electrical connection member 50 may be connected to the frame 42 of the flow path member 40. In this case, the first current route R1 is a route through which current flows in the order of the hydrogen electrode layer 21 → current collecting section 30 → electrical connection member 50 → frame 42 → joint 70 → interconnector 43. It is preferable that the electrical connection member 50 is connected metal-metal to the frame 42 of the flow path member 40. Note that the electrical connection member 50 may be connected to both the frame 42 and the interconnector 43 of the flow path member 40.

8, the electrical connection member 50 may be connected to the metal plate 10. In this case, the first current route R1 is a route through which current flows in the order of the hydrogen electrode layer 21 → current collecting portion 30 → electrical connection member 50 → metal plate 10 → joint 60 → frame 42 → joint 70 → interconnector 43. It is preferable that the electrical connection member 50 is connected to the metal plate 10 by metal-metal connection. The electrical connection member 50 may be connected to both the flow path member 40 and the metal plate 10. It is sufficient that the electrical connection member 50 is connected to at least one of the flow path member 40 and the metal plate 10.

Reference Signs List 1 Electrolysis cell 10 Metal plate 11 First main surface 12 Second main surface 13 Through hole 14 Substrate 15 Oxide film 20 Cell body 21 Hydrogen electrode layer 22 Electrolyte layer 23 Reaction prevention layer 24 Oxygen electrode layer 30 Current collector 31 First portion 32 Second portion 40 Flow path member 41 Gas flow path 42 Frame 43 Interconnector 50 Electrical connection member

Claims (3)

A metal plate having a first main surface, a second main surface, and a plurality of communication holes communicating with the first main surface and the second main surface;
a cell body portion including a first electrode layer formed on the first main surface of the metal plate, a second electrode layer, and an electrolyte layer disposed between the first electrode layer and the second electrode layer;
a current collecting portion having a plurality of first portions disposed in the plurality of communication holes and connected to the first electrode layer;
a conductive flow path member joined to the second main surface of the metal plate and forming a gas flow path between the metal plate and the conductive flow path member;
an electrical connection member disposed in the gas flow path and electrically connecting at least one of the flow path member and the metal plate to the current collecting portion;
Equipped with
an electrical resistance of a first current route through which a current flows between the first electrode layer and the flow path member by sequentially passing through the current collecting portion and the electrical connection member, or by sequentially passing through the current collecting portion, the electrical connection member, and the metal plate, is smaller than an electrical resistance of a second current route through which a current flows between the first electrode layer and the flow path member only by passing through the metal plate;
Electrochemical cell. A metal plate having a first main surface, a second main surface, and a plurality of communication holes communicating with the first main surface and the second main surface;
a cell body portion including a first electrode layer formed on the first main surface of the metal plate, a second electrode layer, and an electrolyte layer disposed between the first electrode layer and the second electrode layer;
a current collecting portion having a plurality of first portions disposed in the plurality of communication holes and connected to the first electrode layer;
a conductive flow path member joined to the second main surface of the metal plate and forming a gas flow path between the metal plate and the conductive flow path member;
an electrical connection member disposed in the gas flow path and electrically connecting at least one of the flow path member and the metal plate to the current collecting portion;
Equipped with
the electrical connection member is connected to the current collecting portion and the flow path member by metal-metal connection,
The flow path member has a base material and an oxide film covering a surface of the base material,
The metal plate has a substrate and an oxide film covering a surface of the substrate.
Electrochemical cell. the current collecting portion is formed in a layer shape on the second main surface of the metal plate and has a second portion connected to the plurality of first portions;
3. An electrochemical cell according to claim 1 or 2.

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