Electrochemical cell and electrochemical cell with separator

Abstract

According to the present invention, an electrolysis cell (10) comprises a hydrogen electrode collector layer (11), a frame body (12), a hydrogen electrode active layer (13), an electrolyte layer (14), a reaction prevention layer (15) and an oxygen electrode layer (16). The frame body (12) surrounds the lateral periphery of the hydrogen electrode collector layer (11). The frame body (12) has electronic insulation properties.

Description

[Technical Field]

[0001] The present invention relates to an electrochemical cell and an electrochemical cell with a separator. [Background technology]

[0002] Conventionally, electrochemical cells (electrolysis cells, fuel cells, etc.) have been known that include an electrolyte layer disposed between a first electrode layer and a second electrode layer. The electrochemical cell is joined to a metal separator that divides the space on the first electrode layer side from the space on the second electrode layer side and is electrically connected to the first electrode layer.

[0003] Patent Document 1 discloses that a joint and a sealing part are disposed between an electrolyte layer and a metal separator. The joint is made of a brazing material such as Ag brazing and joins the electrochemical cell to the metal separator. The sealing part is made of an insulating material such as crystallized glass and seals the space between the first electrode layer side and the second electrode layer side. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2014-049322 Summary of the Invention [Problem to be solved by the invention]

[0005] The sealing portion described in Patent Document 1 not only functions to seal the space between the first electrode layer side and the second electrode layer side, but also to prevent a short circuit from occurring between the first electrode layer and the metal separator. Therefore, to reliably prevent a short circuit between the first electrode layer and the metal separator, it is necessary to adjust the size and position of the sealing portion, which necessitates a complex structure.

[0006] An object of the present invention is to provide an electrochemical cell and an electrochemical cell with a separator that can easily insulate the electrochemical cell from a metal separator. [Means for solving the problem]

[0007] An electrochemical cell according to a first aspect of the present invention includes a current collecting layer, an electronically insulating frame surrounding the lateral periphery of the current collecting layer, a first electrode layer disposed on the current collecting layer, an electrolyte layer disposed on the first electrode layer, and a second electrode layer disposed on the opposite side of the electrolyte layer from the first electrode layer.

[0008] The electrochemical cell according to a second aspect of the present invention is the same as that according to the first aspect, and further comprises a bonding layer disposed between the current collecting layer and the frame, bonding the current collecting layer to the frame.

[0009] An electrochemical cell according to a third aspect of the present invention is related to the second aspect, wherein the bonding layer includes a first constituent element contained in the current collecting layer and a second constituent element contained in the frame.

[0010] An electrochemical cell according to a fourth aspect of the present invention is related to the third aspect, wherein the bonding layer includes a complex oxide containing a first constituent element and a second constituent element.

[0011] An electrochemical cell according to a fifth aspect of the present invention is the electrochemical cell according to any one of the second to fourth aspects, wherein the thermal expansion coefficient of the bonding layer is between the thermal expansion coefficient of the current collecting layer and the thermal expansion coefficient of the frame.

[0012] An electrochemical cell according to a sixth aspect of the present invention is the electrochemical cell according to any one of the second to fifth aspects, wherein the porosity of the bonding layer is 10% or less.

[0013] An electrochemical cell according to a seventh aspect of the present invention is the electrochemical cell according to any one of the first to sixth aspects, wherein the porosity of the frame is 15% or less.

[0014] An electrochemical cell according to an eighth aspect of the present invention relates to any one of the first to seventh aspects, wherein the thickness of the current collecting layer is greater than the thickness of each of the first electrode layer, the electrolyte layer, and the second electrode layer.

[0015] A separator-equipped electrochemical cell according to a ninth aspect of the present invention comprises an electrochemical cell according to any one of the first to eighth aspects, a metal separator electrically connected to the current collecting layer, and a sealing portion that seals the gap between the electrolyte layer and the metal separator. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide an electrochemical cell and an electrochemical cell with a separator, in which the electrochemical cell can be easily insulated from a metal separator. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view of a separator-equipped electrolysis cell according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of a frame according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view of a separator-equipped electrolysis cell according to a second embodiment. [Figure 4] FIG. 4 is a cross-sectional view of a separator-equipped electrolysis cell according to Modification 2. [Figure 5] FIG. 5 is a cross-sectional view of a separator-equipped electrolysis cell according to Modification 2. DETAILED DESCRIPTION OF THE INVENTION

[0018] 1. First embodiment 1 is a cross-sectional view of a separator-equipped electrolytic cell 1 according to the first embodiment. The separator-equipped electrolytic cell 1 is an example of the "separator-equipped electrochemical cell" according to the present invention.

[0019] The separator-equipped electrolytic cell 1 includes an electrolytic cell 10, a metal separator 20, a current collecting member 25, and a sealing portion 30. The electrolytic cell 10 is an example of an "electrochemical cell" according to the present invention. A cell stack (not shown) can be formed by stacking multiple separator-equipped electrolytic cells 1 in the Z-axis direction, which is perpendicular to the X-axis direction and the Y-axis direction.

[0020] (Electrolytic cell 10) As shown in FIG. 1 , the electrolysis cell 10 includes a hydrogen electrode current collecting layer 11, a frame 12, a hydrogen electrode active layer 13, an electrolyte layer 14, a reaction prevention layer 15, and an oxygen electrode layer 16. The hydrogen electrode current collecting layer 11 is an example of a "current collecting layer" according to the present invention. The hydrogen electrode active layer 13 is an example of a "first electrode layer" according to the present invention. The oxygen electrode layer 16 is an example of a "second electrode layer" according to the present invention.

[0021] The hydrogen electrode current collecting layer 11, hydrogen electrode active layer 13, electrolyte layer 14, reaction prevention layer 15, and oxygen electrode layer 16 are stacked in this order in the Z-axis direction. The hydrogen electrode current collecting layer 11, frame 12, hydrogen electrode active layer 13, electrolyte layer 14, and oxygen electrode layer 16 are essential components, while the reaction prevention layer 15 is optional.

[0022] [Hydrogen electrode current collecting layer 11] The hydrogen electrode current collecting layer 11 is formed in a plate shape. The hydrogen electrode current collecting layer 11 has a main surface 11a and a side surface 11b. The main surface 11a faces the metal separator 20. The side surface 11b is continuous with the main surface 11a. The side surface 11b is covered by a frame 12. In this embodiment, the side surface 11b is substantially perpendicular to the main surface 11a, but may be inclined inward or outward relative to the main surface 11a.

[0023] The hydrogen electrode current collecting layer 11 is electrically connected to the metal separator 20 via the current collecting member 25. Between the hydrogen electrode current collecting layer 11 and the metal separator 20, a hydrogen electrode side space S1 is formed.

[0024] The hydrogen electrode current collecting layer 11 has a gas diffusing function of diffusing the source gas supplied to the hydrogen electrode side space S1 toward the hydrogen electrode active layer 13 in addition to the current collecting function.

[0025] The hydrogen electrode current collecting layer 11 is an electron-conductive porous material. The hydrogen electrode current collecting layer 11 contains nickel (Ni). In the case of co-electrolysis, Ni functions as an electron conductor and also as a thermal catalyst that promotes the thermal reaction between H2 generated in the hydrogen electrode active layer 13 and CO2 contained in the feed gas, thereby maintaining an appropriate gas composition for methanation, Fischer-Tropsch (FT) synthesis, and the like. During operation of the electrolysis cell 10, the Ni contained in the hydrogen electrode current collecting layer 11 is essentially present in the form of metallic Ni, but may also exist in part in the form of nickel oxide (NiO).

[0026] The hydrogen electrode current collecting layer 11 contains a ceramic in addition to nickel (Ni). The ceramic may have ion conductivity. Examples of the ceramic that can be used include yttria (YO), magnesia (MgO), iron oxide (FeO), zirconia (including ZrO and partially stabilized zirconia), yttria-stabilized zirconia (YSZ), calcia-stabilized zirconia (CSZ), scandia-stabilized zirconia (ScSZ), gadolinium-doped ceria (GDC), samarium-doped ceria (SDC), and a mixed material of two or more of these.

[0027] The porosity of the hydrogen electrode current collecting layer 11 is not particularly limited, but can be, for example, 20% or more and 40% or less.

[0028] The thickness of the hydrogen electrode current collecting layer 11 is not particularly limited and can be, for example, 150 μm or more and 1000 μm or less. In this embodiment, the hydrogen electrode current collecting layer 11, together with the frame 12, functions as a support for the electrolysis cell 10. In the Z-axis direction, the thickness of the hydrogen electrode current collecting layer 11 may be greater than the thicknesses of the hydrogen electrode active layer 13, the electrolyte layer 14, the reaction prevention layer 15, and the oxygen electrode layer 16. The electrolysis cell 10 according to this embodiment is a so-called anode-supported cell. However, the electrolysis cell 10 may also be a so-called electrolyte-supported cell or a so-called cathode-supported cell.

[0029] The method for forming the hydrogen electrode current collector layer 11 is not particularly limited, and tape molding, screen printing, casting molding, dry pressing method, etc. can be used.

[0030] [Frame body 12] As shown in FIG. 1, the frame body 12 is disposed on the metal separator 20. The frame body 12 is positioned with respect to the metal separator 20 by the sealing portion 30.

[0031] FIG. 2 is a perspective view of the frame body 12 surrounding the side periphery of the hydrogen electrode current collector layer 11. The frame body 12 is formed in a frame shape. The frame body 12 surrounds the side periphery of the hydrogen electrode current collector layer 11. The side periphery of the hydrogen electrode current collector layer 11 means the periphery of the side surface 11b described later. In the present embodiment, the frame body 12 functions as a support of the electrolytic cell 10 together with the hydrogen electrode current collector layer 11. In the present embodiment, the frame body 12 covers the entire side surface 11b of the hydrogen electrode current collector layer 11.

[0032] In the present embodiment, the planar shape of the frame body 12 is rectangular, but it may be circular, elliptical, a polygon with three or more sides, etc. according to the planar shape of the hydrogen electrode current collector layer 11.

[0033] The frame body 12 has electronic insulation. The frame body 12 has a function of preventing a short circuit from occurring between the hydrogen electrode current collector layer 11 and the metal separator 20. The frame body 12 is composed of an electronic insulating material. Examples of the insulating material include forsterite (Mg2SiO4), magnesium silicate (MgSiO3), zirconia (ZrO2, including partially stabilized zirconia), magnesia (MgO), spinel (MgAl2O4, NiAl2O4), yttria-stabilized zirconia (YSZ), calcia-stabilized zirconia (CSZ), nickel (Ni), nickel oxide (NiO), alumina (Al2O3), nickel oxide-magnesia solid solution (Mg x Ni (1-x) O[0 < x < 1]) and a mixed material formed by combining two or more of these.

[0034] The electronic conductivity of the frame 12 is not particularly limited as long as it is sufficiently low, but it can be 0.1 S / m or less.

[0035] The porosity of the frame 12 is not particularly limited, but can be, for example, 0.1% to 15%. The porosity of the frame 12 is preferably 5% or less. This provides the frame 12 with gas sealing properties, thereby preventing the source gas that has flowed from the hydrogen electrode side space S1 into the hydrogen electrode current collecting layer 11 from passing through the frame 12 and returning to the hydrogen electrode side space S1. This improves the efficiency of gas supply from the hydrogen electrode current collecting layer 11 to the hydrogen electrode active layer 13.

[0036] The width of the frame 12 in the X-axis direction is not particularly limited, but can be, for example, 0.5 mm or more and 10 mm or less.

[0037] The method for forming the frame 12 is not particularly limited, and tape casting, screen printing, slip casting, dry pressing, etc. may be used.

[0038] [Hydrogen electrode active layer 13] The hydrogen electrode active layer 13 functions as a cathode. The hydrogen electrode active layer 13 is disposed on the hydrogen electrode current collecting layer 11. The hydrogen electrode active layer 13 is covered with an electrolyte layer 14.

[0039] The source gas is supplied to the hydrogen electrode active layer 13 via the hydrogen electrode current collecting layer 11. In this embodiment, the source gas contains at least H2O.

[0040] When the raw material gas contains only H2O, the hydrogen electrode active layer 13 generates H2 from the raw material gas in accordance with the electrochemical reaction of water electrolysis shown in the following formula (1). Hydrogen electrode active layer 13: H2O+2e- → H2+O2- (1)

[0041] When the raw material gas contains CO in addition to H O, the hydrogen electrode active layer 13 converts H, CO, and O from the raw material gas in accordance with the electrochemical reactions of co-electrolysis shown in the following formulas (2), (3), and (4): 2- Generate. ·Hydrogen electrode active layer 13: CO2+H2O+4e - →CO+H2+2O 2- ···(2) Electrochemical reaction of H2O: H2O + 2e - →H2+O 2- ···(3) Electrochemical reaction of CO2: CO2 + 2e - →CO+O 2- ···(4)

[0042] The hydrogen electrode active layer 13 is a porous material with electronic conductivity. The hydrogen electrode active layer 13 may also have ionic conductivity. The hydrogen electrode active layer 13 can be made of, for example, YSZ, CSZ, ScSZ, GDC, (SDC), (La,Sr)(Cr,Mn)O3, (La,Sr)TiO3, Sr2(Fe,Mo)2O6, (La,Sr)VO3, (La,Sr)FeO3, a mixed material of two or more of these, or a composite of one or more of these with NiO.

[0043] The porosity of the hydrogen electrode active layer 13 is not particularly limited, but may be, for example, 20% to 40%. The thickness of the hydrogen electrode active layer 13 is not particularly limited, but may be, for example, 5 μm to 50 μm.

[0044] The method for forming the hydrogen electrode active layer 13 is not particularly limited, and tape casting, screen printing, casting, dry pressing, etc. may be used.

[0045] [Electrolyte layer 14] The electrolyte layer 14 is disposed between the hydrogen electrode active layer 13 and the oxygen electrode layer 16. In this embodiment, the reaction prevention layer 15 is disposed between the electrolyte layer 14 and the oxygen electrode layer 16, so the electrolyte layer 14 is disposed between the hydrogen electrode active layer 13 and the reaction prevention layer 15 and is connected to both the hydrogen electrode active layer 13 and the reaction prevention layer 15.

[0046] The electrolyte layer 14 covers the hydrogen electrode active layer 13. As shown in Figure 1, the electrolyte layer 14 preferably covers the entire surface of the hydrogen electrode active layer 13. The outer periphery of the electrolyte layer 14 is connected to the frame 12.

[0047] The electrolyte layer 14 absorbs the O generated in the hydrogen electrode active layer 13. 2- to the oxygen electrode layer 16. The electrolyte layer 14 is a dense body that has ionic conductivity but not electronic conductivity. The electrolyte layer 14 can be made of, for example, YSZ, GDC, ScSZ, SDC, lanthanum gallate (LSGM), or the like.

[0048] The porosity of the electrolyte layer 14 is not particularly limited, but may be, for example, 0.1% to 7%. The thickness of the electrolyte layer 14 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0049] The method for forming the electrolyte layer 14 is not particularly limited, and tape casting, screen printing, slip casting, dry pressing, etc. may be used.

[0050] [Reaction prevention layer 15] The reaction prevention layer 15 is disposed between the electrolyte layer 14 and the oxygen electrode layer 16. The reaction prevention layer 15 is disposed on the opposite side of the electrolyte layer 14 from the hydrogen electrode active layer 13. The reaction prevention layer 15 prevents the constituent elements of the electrolyte layer 14 from reacting with the constituent elements of the oxygen electrode layer 16 to form a layer with high electrical resistance.

[0051] The reaction prevention layer 15 is made of an ion-conductive material, such as GDC or SDC.

[0052] The porosity of the reaction prevention layer 15 is not particularly limited, but may be, for example, 0.1% to 50%. The thickness of the reaction prevention layer 15 is not particularly limited, but may be, for example, 1 μm to 50 μm.

[0053] The method for forming the reaction prevention layer 15 is not particularly limited, and tape casting, screen printing, casting, dry pressing, etc. may be used.

[0054] [Oxygen electrode layer 16] The oxygen electrode layer 16 functions as an anode. The oxygen electrode layer 16 is disposed on the opposite side of the electrolyte layer 14 from the hydrogen electrode active layer 13. In this embodiment, the reaction prevention layer 15 is disposed between the electrolyte layer 14 and the oxygen electrode layer 16, and therefore the oxygen electrode layer 16 is connected to the reaction prevention layer 15. If the reaction prevention layer 15 is not disposed between the electrolyte layer 14 and the oxygen electrode layer 16, the oxygen electrode layer 16 is connected to the electrolyte layer 14.

[0055] The oxygen electrode layer 16 reacts with O 2 transferred from the hydrogen electrode active layer 13 through the electrolyte layer 14 in accordance with the chemical reaction of the following formula (5): 2- The O2 produced in the oxygen electrode layer 16 is released into the oxygen electrode side space S2. Oxygen electrode layer 16:2O 2- →O2+4e - ···(5)

[0056] The oxygen electrode layer 16 is a porous body having ionic and electronic conductivity. The oxygen electrode layer 16 can 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 ion-conducting material (such as GDC).

[0057] The porosity of the oxygen electrode layer 16 is not particularly limited, but may be, for example, 20% to 60%. The thickness of the oxygen electrode layer 16 is not particularly limited, but may be, for example, 1 μm to 100 μm.

[0058] The method for forming the oxygen electrode layer 16 is not particularly limited, and tape casting, screen printing, casting, dry pressing, etc. may be used.

[0059] (Metal separator 20) The metal separator 20 is electrically connected to the hydrogen electrode current collecting layer 11 via the current collecting member 25. The metal separator 20 has a connection portion 20a that contacts the current collecting member 25.

[0060] The metal separator 20 is made of a metal material having electron conductivity. The metal separator 20 can be made of, for example, an alloy material containing Cr (chromium). Examples of such alloy materials include Fe-Cr alloy steel (stainless steel, etc.) and Ni-Cr alloy steel. The Cr content of the metal separator 20 is not particularly limited, but can be set to 4% by mass or more and 30% by mass or less.

[0061] The metal separator 20 may contain Ti (titanium) or Zr (zirconium). The Ti content in the metal separator 20 is not particularly limited, but can be set to 0.01 mol% or more and 1.0 mol% or less. The Al content in the metal separator 20 is not particularly limited, but can be set to 0.01 mol% or more and 0.4 mol% or less. The metal separator 20 may contain Ti as TiO2 (titania) or Zr as ZrO2 (zirconia).

[0062] The metal separator 20 may have an oxide film on its surface, which is formed by oxidation of the constituent elements of the metal separator 20. 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 separator 20.

[0063] (current collecting member 25) The current collecting member 25 electrically connects the hydrogen electrode current collecting layer 11 and the metal separator 20. As shown in Figure 1, the current collecting member 25 is disposed in the hydrogen electrode side space S1 between the hydrogen electrode current collecting layer 11 and the metal separator 20. The current collecting member 25 contacts the main surface 11a of the hydrogen electrode current collecting layer 11 and the connection portion 20a of the metal separator 20.

[0064] The current collecting member 25 has electronic conductivity and breathability. For example, nickel, a nickel alloy, stainless steel, or the like can be used as the current collecting member 25. The size, shape, and position of the current collecting member 25 can be changed as appropriate. For example, in this embodiment, the current collecting member 25 is in contact with both the hydrogen electrode current collecting layer 11 and the frame 12, but it does not have to be in contact with the frame 12.

[0065] (Sealing portion 30) The sealing portion 30 positions the frame 12 relative to the metal separator 20. The sealing portion 30 is a dense body. The sealing portion 30 seals the gap between the electrolysis cell 10 and the metal separator 20. This prevents gas from mixing between the hydrogen electrode side space S1 and the oxygen electrode side space S2 through the gap between the electrolysis cell 10 and the metal separator 20. Furthermore, when the frame 12 is breathable, the sealing portion 30 prevents gas from mixing through the frame 12 itself.

[0066] In this embodiment, the sealing portion 30 is connected to the frame body 12 and the electrolyte layer 14 of the electrolysis cell 10, but if the frame body 12 is not breathable, the sealing portion 30 does not need to be connected to the electrolyte layer 14.

[0067] The sealing portion 30 preferably has electronic insulation properties, which can more reliably prevent short circuits from occurring between the hydrogen electrode current collecting layer 11 and the metal separator 20. However, as described above, since short circuits between the hydrogen electrode current collecting layer 11 and the metal separator 20 can be prevented by the frame 12, even if the sealing portion 30 has a short circuit prevention function, it may only be a secondary function.

[0068] The sealing portion 30 can be made of, for example, glass, glass ceramics (crystallized glass), a composite of glass and ceramics, or the like.

[0069] (Features) The electrolysis cell 10 includes a frame 12 that surrounds the lateral periphery of the hydrogen electrode current collecting layer 11. This prevents short circuits between the hydrogen electrode current collecting layer 11 and the metal separator 20. Therefore, the sealing unit 30 does not need to have a short circuit prevention function as long as it has a gas sealing function, which simplifies the configuration of the sealing unit 30. This allows the electrolysis cell 10 to be easily insulated from the metal separator 20.

[0070] Furthermore, the hydrogen electrode current collecting layer 11 and the frame 12 function as a support for the electrolytic cell 10, thereby improving the strength of the electrolytic cell 10. This can prevent the electrolytic cell 10 from being damaged by external forces applied when assembling the electrolytic cell 10 to the metal separator 20 or by thermal stresses that occur during operation of the electrolytic cell 10.

[0071] Furthermore, if Ni contained in the hydrogen electrode current collecting layer 11 aggregates during operation of the electrolysis cell 10, the hydrogen electrode current collecting layer 11 is likely to deform. However, because the hydrogen electrode current collecting layer 11 is surrounded by the frame 12, deformation of the hydrogen electrode current collecting layer 11 can be suppressed.

[0072] 2. Second embodiment 3 is a cross-sectional view of a separator-equipped electrolytic cell 1a according to a second embodiment. The separator-equipped electrolytic cell 1a according to this embodiment differs from the separator-equipped electrolytic cell 1 according to the first embodiment in that the electrolytic cell 10a has a bonding layer 17. This difference will be mainly described below.

[0073] The electrolysis cell 10a according to this embodiment has a bonding layer 17. The bonding layer 17 is disposed between the hydrogen electrode current collecting layer 11 and the frame 12. The bonding layer 17 is preferably disposed over the entire area between the hydrogen electrode current collecting layer 11 and the frame 12, but it is sufficient that the bonding layer 17 is disposed over at least a portion of the area between the hydrogen electrode current collecting layer 11 and the frame 12.

[0074] The bonding layer 17 bonds the hydrogen electrode current collecting layer 11 to the frame 12. This makes it possible to suppress expansion and contraction of the hydrogen electrode current collecting layer 11 that occurs in response to oxidation and reduction of the hydrogen electrode current collecting layer 11, thereby maintaining the bond between the hydrogen electrode current collecting layer 11 and the frame 12 for a long period of time.

[0075] The bonding layer 17 preferably contains the first constituent element contained in the hydrogen electrode current collecting layer 11 and the second constituent element contained in the frame 12. This can further improve the bondability between the bonding layer 17 and each of the hydrogen electrode current collecting layer 11 and the frame 12.

[0076] In this case, bonding layer 17 may contain a complex oxide containing a first constituent element and a second constituent element. When bonding layer 17 contains such a complex oxide, the reaction progresses at the eutectic point during sintering, and a stronger interface is formed.

[0077] The thermal expansion coefficient of the bonding layer 17 is preferably a value between the thermal expansion coefficient of the hydrogen electrode current collecting layer 11 and the thermal expansion coefficient of the frame 12. This allows the bonding layer 17 to relieve thermal stress caused by the difference in thermal expansion coefficient between the hydrogen electrode current collecting layer 11 and the frame 12 during operation of the electrolysis cell 10a, thereby further improving the bond between the bonding layer 17 and each of the hydrogen electrode current collecting layer 11 and the frame 12.

[0078] The bonding layer 17 is preferably a dense body with gas sealing properties. This prevents the source gas that has flowed from the hydrogen electrode side space S1 into the hydrogen electrode current collecting layer 11 from returning to the hydrogen electrode side space S1 from the side surface 11b of the hydrogen electrode current collecting layer 11. This improves the efficiency of gas supply from the hydrogen electrode current collecting layer 11 to the hydrogen electrode active layer 13. Furthermore, the bonding area between the bonding layer 17 and the hydrogen electrode current collecting layer 11 and the frame 12 can be increased, which further improves the bonding between the bonding layer 17 and the hydrogen electrode current collecting layer 11 and the frame 12. From these perspectives, the porosity of the bonding layer 17 is preferably 10% or less, and more preferably 5% or less.

[0079] The bonding layer 17 can be formed of, for example, nickel (Ni), nickel oxide (NiO), yttria (Y2O3), magnesia (MgO), iron oxide (Fe2O3), zirconia (including partially stabilized zirconia), alumina (Al2O3), calcia (CaO), silica (Si2O3), spinel (MgAl2O4, NiAl2O4), YAG (Y3Al5O 12 ), YAM (Y4Al2O9), a nickel oxide-magnesia solid solution (Mg x Ni (1-x) O[0<x<1]), and a mixed material formed by combining two or more of these materials.

[0080] The method for forming the bonding layer 17 is not particularly limited, and tape casting, screen printing, casting molding, dry pressing, or the like can be used.

[0081] In this embodiment as well, the frame 12 surrounds the side periphery of the hydrogen electrode current collector layer 11. The frame 12 surrounding the side periphery of the hydrogen electrode current collector layer 11 is a concept that includes not only the case where the frame 12 directly contacts the hydrogen electrode current collector layer 11 as in the first embodiment but also the case where the bonding layer 17 inserted between the frame 12 and the hydrogen electrode current collector layer 11 directly contacts the hydrogen electrode current collector layer 11 as in this embodiment.

[0082] (Modification of the embodiment) As described above, the embodiments of the present invention have been explained. However, 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 first and second embodiments described above, the frame 12 is configured to surround only the side periphery of the hydrogen electrode current collector layer 11 in the electrolytic cell 10. However, the present invention is not limited to this. The frame 12 may surround the side periphery of the hydrogen electrode active layer 13 or the side periphery of the electrolyte layer 14.

[0084] [Modification 2] In the first and second embodiments, the frame 12 is arranged on the metal separator 20, but as shown in Fig. 4, the frame 12 may be arranged on the sealing portion 30. Furthermore, if the frame 12 does not have air permeability, the sealing portion 30 may be connected to the frame 12 and not connected to the electrolyte layer 14, as shown in Fig. 5.

[0085] [Variation 3] In the first and second embodiments, the hydrogen electrode active layer 13 functions as a cathode and the oxygen electrode layer 16 functions as an anode. However, the hydrogen electrode active layer 13 may function as an anode and the oxygen electrode layer 16 may function as a cathode. In this case, the constituent materials of the hydrogen electrode active layer 13 and the oxygen electrode layer 16 are interchanged, and a source gas is passed over the outer surface of the hydrogen electrode active layer 13. The hydrogen electrode current collecting layer 11 functions as an oxygen electrode current collecting layer, and the configuration and function of the oxygen electrode current collecting layer are the same as those of the hydrogen electrode current collecting layer 11 described in the first embodiment.

[0086] [Variation 4] In the first and second embodiments, the electrolysis cell 10 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. [Explanation of symbols]

[0087] 1,1a Electrolytic cell with separator 10,10a electrolytic cell 11 Hydrogen electrode current collecting layer 12 Frame 13 Hydrogen electrode active layer 14 Electrolyte layer 15 Reaction prevention layer 16 Oxygen polar layer 17 Bonding layer 20 Metal separator 30 Sealing part

Claims

1. a porous current collecting layer formed in a plate shape and containing nickel and ceramic; a frame body that surrounds the side periphery of the current collecting layer and has electronic insulation properties; a first electrode layer disposed on the current collecting layer; an electrolyte layer disposed on the first electrode layer; a second electrode layer disposed on the opposite side of the first electrode layer with respect to the electrolyte layer; a bonding layer disposed between the current collecting layer and the frame body and bonding the current collecting layer to the frame body; Equipped with the bonding layer covers the entire side surface of the current collecting layer, a thermal expansion coefficient of the bonding layer is between a thermal expansion coefficient of the current collecting layer and a thermal expansion coefficient of the frame; Electrochemical cell.

2. The porosity of the bonding layer is 10% or less.

10. The electrochemical cell of claim 1.

3. The porosity of the frame is 15% or less.

10. The electrochemical cell of claim 1.

4. the thickness of the current collecting layer is greater than the thickness of each of the first electrode layer, the electrolyte layer, and the second electrode layer; 10. The electrochemical cell of claim 1.

5. The electrochemical cell of claim 1; a metal separator electrically connected to the current collecting layer; a sealing portion that seals a gap between the electrochemical cell and the metal separator; Equipped with Electrochemical cell with separator.

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