Electrochemical cell and electrochemical cell with separator
The electrochemical cell's innovative structure with a gas sealing layer and frame addresses low gas supply efficiency by preventing backflow, enhancing gas distribution and structural integrity.
Patent Information
- Application Number
- JP2024561413
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2022-11-30
- Filing Date
- 2023-11-21
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2043-11-21
AI Technical Summary
Existing electrochemical cells suffer from low gas supply efficiency due to gas flowing back into the first electrode layer, reducing the effectiveness of gas distribution.
The electrochemical cell design includes a current collecting layer, a gas sealing layer, and a frame that surround the lateral periphery, with specific porosity and thermal expansion coefficients to enhance gas sealing and support structure, preventing gas backflow and improving gas supply efficiency.
The design enhances gas supply efficiency by minimizing gas backflow and providing structural support, thereby improving the overall performance of the electrochemical cell.
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Figure 0007819362000003
Abstract
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.) that include an electrolyte layer disposed between a first electrode layer and a second electrode layer have been known (see, for example, Patent Document 1). The electrochemical cell divides the space on the first electrode layer side from the space on the second electrode layer side, and is joined to a metal separator that is electrically connected to the first electrode layer. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Patent Publication No. 2014-049322 Summary of the Invention [Problem to be solved by the invention]
[0004] In the electrochemical cell described in Patent Document 1, gas that flows into the first electrode layer from the space on the first electrode layer side returns to the hydrogen electrode side space from the side of the first electrode layer, resulting in low gas supply efficiency to the first electrode layer.
[0005] An object of the present invention is to provide an electrochemical cell and a separator-equipped electrochemical cell that can improve gas supply efficiency. [Means for solving the problem]
[0006] An electrochemical cell according to a first aspect of the present invention includes a current collecting layer, a gas sealing layer surrounding the lateral periphery of the current collecting layer, a frame surrounding the lateral periphery of the gas sealing 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.
[0007] An electrochemical cell according to a second aspect of the present invention is the electrochemical cell according to the first aspect, wherein the porosity of the gas sealing layer is 5% or less.
[0008] An electrochemical cell according to a third aspect of the present invention is related to the first or second aspect, wherein the gas sealing layer includes a first constituent element contained in the current collecting layer and a second constituent element contained in the frame.
[0009] An electrochemical cell according to a fourth aspect of the present invention is related to the third aspect, wherein the gas sealing layer contains a composite oxide containing a first constituent element and a second constituent element.
[0010] 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 thermal expansion coefficient of the gas sealing layer is between the thermal expansion coefficient of the current collecting layer and the thermal expansion coefficient of the frame.
[0011] An electrochemical cell according to a sixth aspect of the present invention is the electrochemical cell according to any one of the first to fifth aspects, wherein the frame has insulating properties.
[0012] 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.
[0013] 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.
[0014] 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]
[0015] According to the present invention, it is possible to provide an electrochemical cell and a separator-equipped electrochemical cell that can improve gas supply efficiency. [Brief explanation of the drawings]
[0016] [Figure 1] FIG. 1 is a cross-sectional view of a separator-equipped electrolysis cell according to the 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 Modification 2. [Figure 4] FIG. 4 is a cross-sectional view of a separator-equipped electrolysis cell according to Modification 2. DETAILED DESCRIPTION OF THE INVENTION
[0017] 1 is a cross-sectional view of a separator-equipped electrolytic cell 1 according to an embodiment. The separator-equipped electrolytic cell 1 is an example of the "separator-equipped electrochemical cell" according to the present invention.
[0018] 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.
[0019] (Electrolytic cell 10) As shown in FIG. 1 , the electrolysis cell 10 includes a hydrogen electrode current collecting layer 11, a gas sealing layer 12, a frame 13, a hydrogen electrode active layer 14, an electrolyte layer 15, a reaction prevention layer 16, and an oxygen electrode layer 17. 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 14 is an example of a "first electrode layer" according to the present invention. The oxygen electrode layer 17 is an example of a "second electrode layer" according to the present invention.
[0020] The hydrogen electrode current collecting layer 11, hydrogen electrode active layer 14, electrolyte layer 15, reaction prevention layer 16, and oxygen electrode layer 17 are stacked in this order in the Z-axis direction. The hydrogen electrode current collecting layer 11, frame 13, hydrogen electrode active layer 14, electrolyte layer 15, and oxygen electrode layer 17 are essential components, while the reaction prevention layer 16 is optional.
[0021] [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 with the gas sealing layer 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.
[0022] 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.
[0023] 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 14, in addition to the current collecting function.
[0024] 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 14 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).
[0025] 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.
[0026] 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.
[0027] The thickness of the hydrogen electrode current collecting layer 11 is not particularly limited and can be, for example, 150 μm or more and 1500 μm or less. In this embodiment, the hydrogen electrode current collecting layer 11 functions as a support for the electrolysis cell 10 together with the gas sealing layer 12 and the frame 13. 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 14, the electrolyte layer 15, the reaction prevention layer 16, and the oxygen electrode layer 17. 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.
[0028] The method for forming the hydrogen electrode current collecting layer 11 is not particularly limited, and tape casting, screen printing, casting, dry pressing, etc. may be used.
[0029] [Gas sealing layer 12] 2 is a perspective view of the gas sealing layer 12 surrounding the side periphery of the hydrogen electrode current collecting layer 11. The gas sealing layer 12 surrounds the side periphery of the hydrogen electrode current collecting layer 11. The side periphery of the hydrogen electrode current collecting layer 11 refers to the periphery of the side surface 11b. In this embodiment, the gas sealing layer 12 functions as a support for the electrolysis cell 10 together with the hydrogen electrode current collecting layer 11 and the frame 13.
[0030] The gas sealing layer 12 covers the side surface 11b of the hydrogen electrode current collecting layer 11. It is preferable that the gas sealing layer 12 covers the entire side surface 11b of the hydrogen electrode current collecting layer 11, but it is sufficient that the gas sealing layer 12 covers at least a part of the side surface 11b of the hydrogen electrode current collecting layer 11.
[0031] In this embodiment, the planar shape of the gas sealing layer 12 is rectangular, but it may be circular, elliptical, or polygonal with three or more sides, depending on the planar shape of the hydrogen electrode current collecting layer 11 .
[0032] The gas sealing layer 12 is a dense body with gas sealing properties. Therefore, the source gas that has flowed from the hydrogen electrode side space S1 into the hydrogen electrode current collecting layer 11 can be prevented 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 14. Furthermore, the bonding area between the gas sealing layer 12 and the hydrogen electrode current collecting layer 11 and the frame 13 can be increased, thereby improving the bonding between the gas sealing layer 12 and the hydrogen electrode current collecting layer 11 and the frame 13. From these viewpoints, the porosity of the gas sealing layer 12 is preferably 5% or less, and more preferably 2% or less.
[0033] The gas sealing layer 12 preferably contains the first constituent element contained in the hydrogen electrode current collecting layer 11 and the second constituent element contained in the frame 13. This can further improve the bonding between the gas sealing layer 12 and the hydrogen electrode current collecting layer 11 and between the gas sealing layer 12 and the frame 13.
[0034] In this case, the gas sealing layer 12 may contain a composite oxide containing the first and second constituent elements. When the gas sealing layer 12 contains such a composite oxide, the reaction progresses at the eutectic point during sintering, and a stronger interface is formed.
[0035] The coefficient of thermal expansion of the gas barrier layer 12 is preferably a value between the coefficient of thermal expansion of the hydrogen electrode current collector layer 11 and the coefficient of thermal expansion of the frame body 13. Thereby, during the operation of the electrolytic cell 10a, the thermal stress caused by the difference in the coefficient of thermal expansion between the hydrogen electrode current collector layer 11 and the frame body 13 can be relaxed in the gas barrier layer 12, so that the bonding properties between the gas barrier layer 12 and the hydrogen electrode current collector layer and the frame body 13 can be further improved.
[0036] The gas barrier layer 12 can be composed of, for example, nickel (Ni), nickel oxide (NiO), yttria (Y2O3), magnesia (MgO), iron oxide (Fe2O3), zirconia (ZrO2, including partially stabilized zirconia), alumina (Al2O3), calcia (CaO), silica (Si2O3), spinel (MgAl2O4, NiAl2O4), YAG (Y3Al )、YAM(Y4Al2O9), nickel oxide-magnesia solid solution (Mg x Ni (1-x) O[0<x<1]), and a mixed material combining two or more of these.
[0037] The method for forming the gas barrier layer 12 is not particularly limited, and tape forming, screen printing, casting molding, dry pressing method, etc. can be used.
[0038] [Frame body 13] As shown in FIG. 1, the frame body 13 is disposed on the metal separator 20. The frame body 13 is positioned with respect to the metal separator 20 by the sealing portion 30.
[0039] The frame body 13 is formed in a frame shape. As shown in FIGS. 1 and 2, the frame body 13 surrounds the side circumference of the gas barrier layer 12. In the present embodiment, the frame body 13 functions as a support for the electrolytic cell 10 together with the hydrogen electrode current collector layer 11 and the gas barrier layer 12.
[0040] In the present embodiment, the planar shape of the frame body 13 is rectangular, but it may be circular, elliptical, a polygon with three or more sides, etc. according to the planar shapes of the hydrogen electrode current collector layer 11 and the gas barrier layer 12.
[0041] The frame body 13 can be made of, for example, forsterite (Mg2SiO4), magnesium silicate (MgSiO3), zirconia (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) NiO[0 < x < 1]) and a mixed material combining two or more of these.
[0042] The frame body 13 preferably has electrical insulation. This can prevent a short circuit from occurring between the hydrogen electrode current collector layer 11 and the metal separator 20. Therefore, since there is no need to provide a short-circuit prevention function to the sealing portion 30 described later, the configuration of the sealing portion 30 can be simplified. Thus, the electrolytic cell 10 can be easily insulated from the metal separator 20. The electron conductivity of the frame body 13 only needs to be sufficiently low and is not particularly limited, but can be 0.1 S / m or less.
[0043] The porosity of the frame body 13 is not particularly limited, but can be, for example, 0.1% or more and 15% or less. The porosity of the frame body 13 is preferably 5% or less. This can impart gas sealing properties to the frame body 13 in addition to the gas sealing layer 12, and thus can further suppress the raw material gas flowing from the hydrogen electrode side space S1 into the hydrogen electrode current collector layer 11 from passing through the frame body 13 and returning to the hydrogen electrode side space S1.
[0044] The width of the frame body 13 in the X-axis direction is not particularly limited, but can be, for example, 0.5 mm or more and 10 mm or less.
[0045] The method for forming the frame body 13 is not particularly limited, and tape casting, screen printing, casting molding, dry pressing method, etc. can be used.
[0046] [Hydrogen electrode active layer 14] The hydrogen electrode active layer 14 functions as a cathode. The hydrogen electrode active layer 14 is disposed on the hydrogen electrode current collecting layer 11. The hydrogen electrode active layer 14 is covered with an electrolyte layer 15.
[0047] The source gas is supplied to the hydrogen electrode active layer 14 via the hydrogen electrode current collecting layer 11. In this embodiment, the source gas contains at least H2O.
[0048] When the raw material gas contains only H2O, the hydrogen electrode active layer 14 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 14: H2O+2e- → H2+O2- (1)
[0049] When the raw material gas contains CO in addition to H O, the hydrogen electrode active layer 14 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 14: 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)
[0050] The hydrogen electrode active layer 14 is a porous material with electronic conductivity. The hydrogen electrode active layer 14 may also have ionic conductivity. The hydrogen electrode active layer 14 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.
[0051] The porosity of the hydrogen electrode active layer 14 is not particularly limited, but may be, for example, 20% to 40%. The thickness of the hydrogen electrode active layer 14 is not particularly limited, but may be, for example, 5 μm to 10 μm.
[0052] The method for forming the hydrogen electrode active layer 14 is not particularly limited, and tape casting, screen printing, casting, dry pressing, etc. may be used.
[0053] [Electrolyte layer 15] The electrolyte layer 15 is disposed between the hydrogen electrode active layer 14 and the oxygen electrode layer 17. In this embodiment, the reaction prevention layer 16 is disposed between the electrolyte layer 15 and the oxygen electrode layer 17, so the electrolyte layer 15 is disposed between the hydrogen electrode active layer 14 and the reaction prevention layer 16 and is connected to both the hydrogen electrode active layer 14 and the reaction prevention layer 16.
[0054] The electrolyte layer 15 covers the hydrogen electrode active layer 14. As shown in Fig. 1, the electrolyte layer 15 preferably covers the entire surface of the hydrogen electrode active layer 14. The outer periphery of the electrolyte layer 15 is connected to the frame 13.
[0055] The electrolyte layer 15 absorbs the O generated in the hydrogen electrode active layer 14. 2- to the oxygen electrode layer 17. The electrolyte layer 15 is a dense body that has ionic conductivity but no electronic conductivity. The electrolyte layer 15 can be made of, for example, YSZ, GDC, ScSZ, SDC, or lanthanum gallate (LSGM).
[0056] The porosity of the electrolyte layer 15 is not particularly limited, but may be, for example, 0.1% to 7%. The thickness of the electrolyte layer 15 is not particularly limited, but may be, for example, 1 μm to 100 μm.
[0057] The method for forming the electrolyte layer 15 is not particularly limited, and tape casting, screen printing, slip casting, dry pressing, or the like can be used.
[0058] [Reaction prevention layer 16] The reaction prevention layer 16 is disposed between the electrolyte layer 15 and the oxygen electrode layer 17. The reaction prevention layer 16 is disposed on the opposite side of the electrolyte layer 15 from the hydrogen electrode active layer 14. The reaction prevention layer 16 prevents the constituent elements of the electrolyte layer 15 from reacting with the constituent elements of the oxygen electrode layer 17 to form a layer with high electrical resistance.
[0059] The reaction prevention layer 16 is made of an ion-conductive material, such as GDC or SDC.
[0060] The porosity of the reaction prevention layer 16 is not particularly limited, but may be, for example, 0.1% to 50%. The thickness of the reaction prevention layer 16 is not particularly limited, but may be, for example, 1 μm to 50 μm.
[0061] The method for forming the reaction prevention layer 16 is not particularly limited, and tape casting, screen printing, casting, dry pressing, etc. may be used.
[0062] [Oxygen electrode layer 17] The oxygen electrode layer 17 functions as an anode. The oxygen electrode layer 17 is disposed on the opposite side of the electrolyte layer 15 from the hydrogen electrode active layer 14. In this embodiment, the reaction prevention layer 16 is disposed between the electrolyte layer 15 and the oxygen electrode layer 17, and therefore the oxygen electrode layer 17 is connected to the reaction prevention layer 16. If the reaction prevention layer 16 is not disposed between the electrolyte layer 15 and the oxygen electrode layer 17, the oxygen electrode layer 17 is connected to the electrolyte layer 15.
[0063] The oxygen electrode layer 17 reacts with O 2 transferred from the hydrogen electrode active layer 14 through the electrolyte layer 15 in accordance with the chemical reaction of the following formula (5): 2- The O2 produced in the oxygen electrode layer 17 is released into the oxygen electrode side space S2. Oxygen electrode layer 17:2O 2- →O2+4e - ···(5)
[0064] The oxygen electrode layer 17 is a porous body having ionic and electronic conductivity and 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).
[0065] The porosity of the oxygen electrode layer 17 is not particularly limited, but may be, for example, 20% to 60%. The thickness of the oxygen electrode layer 17 is not particularly limited, but may be, for example, 1 μm to 100 μm.
[0066] The method for forming the oxygen electrode layer 17 is not particularly limited, and tape casting, screen printing, casting, dry pressing, etc. may be used.
[0067] (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.
[0068] 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.
[0069] 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).
[0070] 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.
[0071] (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.
[0072] The current collecting member 25 has electronic conductivity and air permeability. 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 13, but it does not have to be in contact with the frame 13.
[0073] (Sealing portion 30) The sealing portion 30 positions the frame 13 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 13 is breathable, the sealing portion 30 prevents gas from mixing through the frame 13 itself.
[0074] In this embodiment, the sealing portion 30 is connected to the frame 13 and the electrolyte layer 15 of the electrolysis cell 10, but if the frame 13 is not breathable, the sealing portion 30 does not need to be connected to the electrolyte layer 15.
[0075] 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, if the frame 13 can prevent short circuits between the hydrogen electrode current collecting layer 11 and the metal separator 20, the short circuit prevention function of the sealing portion 30 may be secondary.
[0076] The sealing portion 30 can be made of, for example, glass, glass ceramics (crystallized glass), a composite of glass and ceramics, or the like.
[0077] (Features) The electrolysis cell 10 includes a gas sealing layer 12 that surrounds the side periphery of the hydrogen electrode current collecting layer 11. 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 14.
[0078] Furthermore, the hydrogen electrode current collecting layer 11, the gas sealing layer 12, and the frame 13 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.
[0079] 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 gas sealing layer 12 and the frame 13, deformation of the hydrogen electrode current collecting layer 11 can be suppressed.
[0080] (Modification of the embodiment) 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.
[0081] [Variation 1] In the above embodiment, the gas sealing layer 12 surrounds only the side periphery of the hydrogen electrode current collecting layer 11 of the electrolysis cell 10, but this is not limiting. The gas sealing layer 12 may surround the side periphery of the hydrogen electrode active layer 14 or the side periphery of the electrolyte layer 15.
[0082] [Variation 2] In the above embodiment, the frame 13 is arranged on the metal separator 20, but as shown in Fig. 3, the frame 13 may be arranged on the sealing portion 30. Furthermore, if the frame 13 does not have air permeability, the sealing portion 30 may be connected to the frame 13 and not connected to the electrolyte layer 15, as shown in Fig. 4.
[0083] [Variation 3] In the above embodiment, the hydrogen electrode active layer 14 functions as a cathode and the oxygen electrode layer 17 functions as an anode. However, the hydrogen electrode active layer 14 may function as an anode and the oxygen electrode layer 17 may function as a cathode. In this case, the constituent materials of the hydrogen electrode active layer 14 and the oxygen electrode layer 17 are switched, and a source gas is passed over the outer surface of the hydrogen electrode active layer 14. 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 above embodiment.
[0084] [Variation 4] In the above embodiment, 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 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]
[0085] 1 Electrolytic cell with separator 10 Electrolysis Cell 11 Hydrogen electrode current collecting layer 12 Gas sealing layer 13 Frame 14 Hydrogen electrode active layer 15 Electrolyte layer 16 Reaction prevention layer 17 Oxygen polar 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 gas sealing layer surrounding the side periphery of the current collecting layer; a frame surrounding the side periphery of the gas sealing layer; 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; Equipped with the gas sealing layer covers the entire side surface of the current collecting layer, a thermal expansion coefficient of the gas sealing 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 gas sealing layer is 5% or less.
10. The electrochemical cell of claim 1.
3. The frame has insulating properties.
10. The electrochemical cell of claim 1.
4. The porosity of the frame is 15% or less.
10. The electrochemical cell of claim 1.
5. 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.
6. 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.
Citation Information
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