Electrochemical cell, and electrochemical cell with separator

Abstract

This electrolysis cell (2) is provided with a cell body part (10) and an annular support frame (11). The cell body part (10) has a hydrogen electrode collector layer (12), a hydrogen electrode active layer (13) that is disposed on the hydrogen electrode collector layer (12), an electrolyte layer (14), and an oxygen electrode layer (16). The support frame (11) is connected to a metal separator (20). The support frame (11) surrounds the hydrogen electrode collector layer (12) of the cell body part (10). The support frame (11) contains zirconia and nickel oxide. The porosity of the support frame (11) after a reduction treatment at 750°C for 12 hours is 15% or less.

Description

Electrochemical cell and electrochemical cell with separator

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

[0002] Conventionally, solid electrolyte electrochemical cells have been known that include a cell body formed by an electrolyte layer disposed between a first electrode layer and a second electrode layer (see, for example, Patent Document 1). Examples of electrochemical cells include electrolysis cells and fuel cell cells. The fuel cell described in Patent Document 1 is a so-called electrode-supported cell, in which the first electrode layer is formed thicker than the electrolyte layer, and the electrolyte layer is connected to a separator.

[0003] JP 2016-58382 A

[0004] However, because the thermal expansion coefficients of the cell body and the metal separator are different, it is difficult to maintain a good connection between the cell body and the separator. This problem occurs regardless of whether the fuel cell is an electrode-supported cell, and also occurs in electrochemical cells other than fuel cells in general.

[0005] An object of the present invention is to provide an electrochemical cell and an electrochemical cell with a separator that can maintain good connection with a metal separator.

[0006] An electrochemical cell according to a first aspect of the present invention is an electrochemical cell connected to a metallic separator, and includes a cell body having a current collecting layer, a first electrode layer disposed on the current collecting layer, a second electrode layer, and an electrolyte layer disposed between the first and second electrode layers, and an annular support frame connected to the metallic separator and surrounding at least a portion of the cell body. The support frame contains zirconia and nickel oxide. The porosity of the support frame after reduction treatment at 750°C for 12 hours is 15% or less.

[0007] An electrochemical cell according to a second aspect of the present invention is the electrochemical cell according to the first aspect, wherein the strength of the support frame after the reduction treatment is 140 MPa or more.

[0008] An electrochemical cell according to a third aspect of the present invention is the electrochemical cell according to the first or second aspect, wherein the support frame further contains magnesium oxide.

[0009] An electrochemical cell according to a fourth aspect of the present invention is the electrochemical cell according to any one of the first to third aspects, wherein the support frame contains at least one of 3YSZ and 4YSZ as zirconia.

[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 difference in thermal expansion coefficient between the support frame and the metal separator after the reduction treatment is 2.5 ppm / K or less.

[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 support frame after the reduction treatment includes a plurality of pores, and an average equivalent circle diameter of the plurality of pores is 5 μm or less.

[0012] A separator-equipped electrochemical cell according to a seventh aspect of the present invention comprises any one of the first to sixth electrochemical cells and a metal separator connected to the support frame.

[0013] According to the present invention, it is possible to provide an electrochemical cell and an electrochemical cell with a separator that can maintain good connection with a metal separator.

[0014] Fig. 1 is a cross-sectional view of a separator-equipped electrolytic cell according to an embodiment. Fig. 2 is a cross-sectional view of a separator-equipped electrolytic cell according to Modification 2. Fig. 3 is a cross-sectional view of a separator-equipped electrolytic cell according to Modification 2.

[0015] 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 a "separator-equipped electrochemical cell" according to the present invention.

[0016] The separator-equipped electrolytic cell 1 includes an electrolytic cell 2, a metal separator 20, a current collecting member 25, and a joint 30. The electrolytic cell 2 is an example of an "electrochemical cell" according to the present invention. A cell stack (not shown) can be formed by stacking a plurality of separator-equipped electrolytic cells 1 in the Z-axis direction, which is perpendicular to the X-axis direction and the Y-axis direction.

[0017] (Electrolytic Cell 2 ) As shown in FIG. 1 , the electrolytic cell 2 is connected to a metal separator 20 via a joint 30 .

[0018] The electrolysis cell 2 includes a cell body 10 and a support frame 11 .

[0019] <Cell body 10> The cell body 10 is supported by a support frame 11. The cell body 10 is made of a ceramic material, as described below. The thermal expansion coefficient of the cell body 10 is smaller than the thermal expansion coefficient of the metal separator 20. The value of the thermal expansion coefficient of the cell body 10 is not particularly limited, but can be, for example, 10 ppm / K or more and 12 ppm / K or less.

[0020] The cell body 10 has a hydrogen electrode current collecting layer 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 12 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 12, the hydrogen electrode active layer 13, the electrolyte layer 14, the reaction prevention layer 15, and the oxygen electrode layer 16 are stacked in this order in the Z-axis direction. The hydrogen electrode current collecting layer 12, the hydrogen electrode active layer 13, the electrolyte layer 14, and the oxygen electrode layer 16 are essential components, while the reaction prevention layer 15 is optional.

[0022] [Hydrogen Electrode Current Collector Layer 12] The hydrogen electrode current collector layer 12 is formed in a plate shape and has a first main surface 12a, a second main surface 12b, and a side surface 12c.

[0023] The first main surface 12a is provided on the side opposite the hydrogen electrode active layer 13. The first main surface 12a is connected to the current collecting member 25. The second main surface 12b is provided on the hydrogen electrode active layer 13 side. The first main surface 12a is connected to the hydrogen electrode active layer 13. The side surface 12c is continuous with the first main surface 12a and the second main surface 12b. The side surface 12c is formed along the Z-axis direction. The Z-axis direction is the thickness direction of the hydrogen electrode current collecting layer 12. In this embodiment, the side surface 12c is surrounded by the support frame 11.

[0024] The hydrogen electrode current collecting layer 12 is electrically connected to the metal separator 20 via a current collecting member 25. A hydrogen electrode side space S1 is formed between the hydrogen electrode current collecting layer 12 and the metal separator 20.

[0025] The hydrogen electrode current collecting layer 12 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.

[0026] The hydrogen electrode current collecting layer 12 is an electron-conductive porous body. The hydrogen electrode current collecting layer 12 contains nickel (Ni). The Ni contained in the hydrogen electrode current collecting layer 12 is essentially present in the form of metallic Ni during operation of the electrolysis cell 2, but a portion of the Ni may also be present in the form of nickel oxide (NiO).

[0027] The hydrogen electrode current collecting layer 12 and the hydrogen electrode current collecting layer 11 contain ceramic in addition to nickel (Ni). The ceramic may have ion conductivity. For example, yttria (Y ２ O ３ ), magnesia (MgO), iron oxide (Fe ２ O ３ ), zirconia (ZrO ２ Examples of materials that can be used include yttria-stabilized zirconia (YSZ, partially stabilized zirconia), yttria-stabilized zirconia (YSZ), calcia-stabilized zirconia (CSZ), scandia-stabilized zirconia (ScSZ), gadolinium-doped ceria (GDC), samarium-doped ceria (SDC), and mixed materials of two or more of these.

[0028] The porosity of the hydrogen electrode current collecting layer 12 is not particularly limited, but can be, for example, 20% or more and 40% or less.

[0029] The thickness of the hydrogen electrode current collecting layer 12 is not particularly limited, but may be, for example, 150 μm to 1000 μm. The thickness of the hydrogen electrode current collecting layer 12 may be greater than the thickness of each of the hydrogen electrode active layer 13, the electrolyte layer 14, the reaction prevention layer 15, and the oxygen electrode layer 16.

[0030] The method for forming the hydrogen electrode current collecting layer 12 is not particularly limited, and tape casting, screen printing, casting, dry pressing, or the like can be used.

[0031] [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 12. The hydrogen electrode active layer 13 is covered with the electrolyte layer 14.

[0032] The source gas is supplied to the hydrogen electrode active layer 13 through the hydrogen electrode current collecting layer 12. In this embodiment, the source gas contains at least H ２ Contains O.

[0033] The raw material gas is H ２ When only O is contained, the hydrogen electrode active layer 14 converts H from the raw material gas according to the electrochemical reaction of water electrolysis shown in the following formula (1): ２ Generate.

[0034] Hydrogen electrode active layer 14: H2O+2e-→H2+O2- (1)

[0035] The raw material gas is H ２ O plus CO ２ In this case, the hydrogen electrode active layer 14 converts H from the source gas according to the co-electrolytic electrochemical reactions shown in the following formulas (2), (3), and (4). ２ , CO and O ２－ Generate.

[0036] Hydrogen electrode active layer 14: CO ２ +H ２ O+4e － →CO+H ２ +20 ２－ ... (2) ・H ２ Electrochemical reaction of O: H ２ O + 2e － →H ２ +O ２－ ... (3) CO ２ Electrochemical reaction of: CO ２ +2e － →CO+O ２－ ...(4)

[0037] The hydrogen electrode active layer 13 is a porous body having electron conductivity. The hydrogen electrode active layer 13 contains nickel (Ni). Ni functions as an electron conductor. In the case of co-electrolysis, Ni acts as an electron conductor. ２ and CO contained in the raw material gas ２It also functions as a thermal catalyst that promotes the thermal reaction with Ni and maintains an appropriate gas composition for methanation, reverse water gas shift reaction, etc. The Ni contained in the hydrogen electrode active layer 13 is basically present in the form of metal Ni during operation of the electrolysis cell 2, but a portion of it may also be present in the form of nickel oxide (NiO).

[0038] The hydrogen electrode active layer 13 may have ion conductivity. The hydrogen electrode active layer 13 may be made of, for example, YSZ, CSZ, ScSZ, GDC, (SDC), or (La, Sr) (Cr, Mn) O. ３ , (La,Sr)TiO ３ , Sr ２ (Fe, Mo) ２ O ６ , (La, Sr)VO ３ , (La,Sr)FeO ３ , a mixed material of two or more of these, or a composite of one or more of these with NiO.

[0039] 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.

[0040] 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.

[0041] [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.

[0042] The electrolyte layer 14 covers the hydrogen electrode active layer 13. As shown in Fig. 1, the electrolyte layer 14 preferably covers the entire surface of the hydrogen electrode active layer 13. In this embodiment, the outer periphery of the electrolyte layer 14 is disposed on the support frame 11.

[0043] The electrolyte layer 14 absorbs the O generated in the hydrogen electrode active layer 13.２－ The electrolyte layer 14 has a function of transmitting the oxygen 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.

[0044] 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.

[0045] The method for forming the electrolyte layer 14 is not particularly limited, and tape casting, screen printing, casting, dry pressing, or the like can be used.

[0046] [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.

[0047] The reaction prevention layer 15 is made of an ion-conductive material, such as GDC or SDC.

[0048] 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.

[0049] 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.

[0050] [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 disposed on 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 disposed on the electrolyte layer 14.

[0051] The oxygen electrode layer 16 reacts with O 2 transferred from the hydrogen electrode active layer 13 via the electrolyte layer 14 in accordance with the chemical reaction of the following formula (5): ２－ From O ２ The O generated in the oxygen electrode layer 16 ２ is released into the oxygen electrode side space S2.

[0052] Oxygen electrode layer 16:2O ２－ →O ２ +4e － ...(5)

[0053] The oxygen electrode layer 16 is a porous material having ionic and electronic conductivity. The oxygen electrode layer 16 is made of, for example, (La, Sr)(Co, Fe)O ３ , (La,Sr)FeO ３ , La(Ni,Fe)O ３ , (La,Sr)CoO ３ , and (Sm,Sr)CoO ３ The conductive layer 10 may be made of a composite material of one or more of the above and an ion-conducting material (such as GDC).

[0054] 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.

[0055] The method for forming the oxygen electrode layer 16 is not particularly limited, and tape casting, screen printing, casting, dry pressing, or the like can be used.

[0056] <Support frame 11> The support frame 11 supports the cell main body 10. The support frame 11 is disposed between the cell main body 10 and the metal separator 20. In this embodiment, the support frame 11 is connected to the metal separator 20 via a joint 30.

[0057] The support frame 11 is an annular member that surrounds at least a portion of the cell body 10. In this embodiment, the support frame 11 surrounds the hydrogen electrode current collecting layer 12 of the cell body 10. When viewed in a plan view from the Z-axis direction, the planar shape of the support frame 11 is not particularly limited, and various shapes such as a rectangular ring, a circular ring, or an elliptical ring can be adopted.

[0058] The support frame 11 is made of zirconia (ZrO ２ ) and nickel oxide (NiO). ２ By including NiO having a higher thermal expansion coefficient, the thermal expansion coefficient of the support frame 11 can be adjusted to a value between the thermal expansion coefficient of the cell main body 10 and the thermal expansion coefficient of the metal separator 20. Therefore, a good connection between the cell main body 10 and the metal separator 20 can be maintained. Specifically, in this embodiment, the thermal stress generated in the joint 30 interposed between the support frame 11 and the metal separator 20 can be reduced, thereby suppressing the occurrence of cracks or peeling in the joint 30.

[0059] Furthermore, the porosity of the support frame after the reduction treatment is 15% or less. This allows the denseness of the support frame 11 to be maintained after the reduction treatment, and therefore the occurrence of gas leakage through the support frame 11 can be suppressed. In this specification, the reduction treatment refers to a process performed in a reducing atmosphere at 750°C (for example, a humidified 100% H ２ This means a treatment in which the support frame 11 is left standing in a gas atmosphere for 12 hours.

[0060] The porosity of the support frame after the reduction treatment can be adjusted by controlling the amount of NiO before the reduction treatment.

[0061] The porosity of the support frame after reduction treatment is calculated by the following method. First, a cross section along the thickness direction of the support frame 11 after reduction treatment is exposed. Next, a backscattered electron image of the cross section of the support frame 11 is acquired at 10,000x magnification using an SEM device (FE-SEM JSM-7900F, manufactured by JEOL Ltd.). Next, the areas displayed in black in the backscattered electron image (corresponding to pores) are identified using image analysis software HALCON manufactured by MVTec. The porosity of the support frame 11 is then calculated by dividing the total area of ​​the pores by the total area of ​​the backscattered electron image of the support frame 11.

[0062] The porosity of the support frame before the reduction treatment is not particularly limited, but can be, for example, 10% or less.

[0063] ZrO in the support frame 11 after reduction treatment ２ The content of NiO in the support frame 11 after the reduction treatment is not particularly limited, but can be set to 40 mol % or more and 95 mol % or less. The content of NiO in the support frame 11 after the reduction treatment is not particularly limited, but can be set to 5 mol % or more and 60 mol % or less.

[0064] It is preferable that the support frame 11 after the reduction treatment has electronic insulation properties, which can prevent short circuits from occurring between the cell body 10 and the metal separator 20.

[0065] The strength of the support frame 11 after the reduction treatment is preferably 140 MPa or more. This can prevent the support frame 11 from being damaged by stress applied when a plurality of separator-equipped electrolysis cells 1 are stacked. The strength of the support frame 11 after the reduction treatment can be adjusted by controlling the Ni proportion in the support 11 and the particle size after firing.

[0066] The support frame 11 preferably further contains magnesium oxide (MgO). In a high-temperature environment, MgO reacts with ZrO ２ Compared to Mg, it is more easily dissolved in NiO, making it difficult to reduce. ｘ Ni （１－ｘ） As a result, the denseness of the support frame 11 can be maintained during operation of the electrolysis cell 2, and gas leakage through the support frame 11 can be suppressed for a long period of time.

[0067] The support frame 11 is made of ZrO ２ It is preferable that the support frame 11 contains YSZ as the sintered body. This can further improve the strength of the support frame 11 after the reduction treatment. ２ It is particularly preferable that the support frame 11 contains at least one of 3YSZ (3 mol % yttria-stabilized zirconia) and 4YSZ (4 mol % yttria-stabilized zirconia) as the yttria-stabilized zirconia. This makes it possible to ensure the strength of the support frame 11.

[0068] The thermal expansion coefficient of the support frame 11 after the reduction treatment is greater than that of the cell main body 10 and less than that of the metal separator 20. The value of the thermal expansion coefficient of the support frame 11 is not particularly limited, but can be, for example, 11 ppm / K or more and 12.5 ppm / K or less. The thermal expansion coefficient of the support frame 11 can be adjusted by controlling the amount of Ni contained in the support 11.

[0069] The difference in thermal expansion coefficient between the support frame 11 and the metal separator 20 after the reduction treatment is preferably 2.5 ppm / K or less. The difference in thermal expansion coefficient is more preferably 1.3 ppm / K or less, and even more preferably 0.7 ppm / K or less. This makes it possible to suppress the occurrence of thermal stress between the support frame 11 and the metal separator 20, thereby maintaining a better connection between the cell main body 10 and the metal separator 20.

[0070] The support frame 11 after the reduction treatment may contain a plurality of pores therein. In this case, the average equivalent circle diameter of the plurality of pores is preferably 5 μm or less. This makes it possible to prevent gas leakage through the support frame 11.

[0071] The average equivalent circular diameter of the plurality of pores is obtained by arithmetically averaging the equivalent circular diameters of pores having an equivalent circular diameter of 0.1 μm or more identified on the backscattered electron image used to calculate the porosity. The equivalent circular diameter of a pore means the diameter of a circle having the same area as the pore.

[0072] The method for forming the support frame 11 is not particularly limited, and tape casting, screen printing, slip casting, dry pressing, or the like can be used.

[0073] (Metallic separator 20) The metallic separator 20 is connected to the support frame 11 of the electrolytic cell 2 via a joint 30. The metallic separator 20 is electrically connected to the cell body 10 of the electrolytic cell 2 (specifically, the hydrogen electrode current collecting layer 12) via a current collecting member 25. The metallic separator 20 has a connecting portion 20a that contacts the current collecting member 25.

[0074] The metal separator 20 is made of a metal material as described below. The thermal expansion coefficient of the metal separator 20 is greater than the thermal expansion coefficient of the cell main body 10. The value of the thermal expansion coefficient of the metal separator 20 is not particularly limited, but can be, for example, 11.5 ppm / K or more and 13.5 ppm / K or less.

[0075] The metal separator 20 is made of a metal material having electronic 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 in the metal separator 20 is not particularly limited, but can be set to 4% by mass or more and 30% by mass or less.

[0076] 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 TiO ２ (titania), or Zr may be contained as ZrO ２ It may be contained as (zirconia).

[0077] 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.

[0078] (Current collecting member 25) The current collecting member 25 electrically connects the hydrogen electrode current collecting layer 12 and the metal separator 20. As shown in Fig. 1 , the current collecting member 25 is disposed in the hydrogen electrode side space S1 between the hydrogen electrode current collecting layer 12 and the metal separator 20. The current collecting member 25 contacts the first main surface 12a of the hydrogen electrode current collecting layer 12 and the connection portion 20a of the metal separator 20.

[0079] 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 12 and the support frame 11, but it does not have to be in contact with the support frame 11.

[0080] (Joint 30) The joint 30 positions the support frame 11 relative to the metal separator 20. The joint 30 is a dense body. The joint 30 seals the gap between the electrolysis cell 2 and the metal separator 20. This prevents gas leakage through the gap between the electrolysis cell 2 and the metal separator 20.

[0081] The joint 30 preferably has electronic insulation properties, which can prevent short circuits from occurring between the cell body 10 and the metal separator 20.

[0082] The joint 30 can be made of, for example, glass, glass ceramics (crystallized glass), a composite of glass and ceramics, or the like.

[0083] (Modifications of the Embodiment) Although the embodiment of the present invention has been described above, the present invention is not limited to these, and various modifications are possible without departing from the spirit of the present invention.

[0084] [Variation 1] In the above embodiment, the electrolytic cell is a so-called cathode-supported cell, but it may also be a so-called electrolyte-supported cell or a so-called anode-supported cell. If the electrolytic cell is an electrolyte-supported cell, the support frame 11 surrounds the electrolyte layer 14. If the electrolytic cell is an anode-supported cell, the support frame 11 surrounds the oxygen electrode layer 16.

[0085] [Variation 2] In the above embodiment, the support frame 11 is connected to the metal separator 20 via the joint 30, but the support frame 11 may be in contact with the metal separator 20. For example, as shown in Fig. 2, the support frame 11 may be placed directly on the metal separator 20 and fixed to the metal separator 20 by a sealing portion 31 that surrounds the outer periphery of the support frame 11. Alternatively, as shown in Fig. 3, the support frame 11 may be directly bonded to the metal separator 20 by performing a heat treatment while the support frame 11 is placed directly on the metal separator 20.

[0086] [Variation 3] In the above embodiment, 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 12 functions as an oxygen electrode current collecting layer, but the configuration and function of the oxygen electrode current collecting layer are the same as those of the hydrogen electrode current collecting layer 12 described in the above embodiment.

[0087] [Variation 4] In the above embodiment, the electrolysis cell 2 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.

[0088] REFERENCE SIGNS LIST 1 Electrolytic cell with separator 2 Electrolytic cell 10 Cell body 11 Support frame 12 Hydrogen electrode current collecting layer 13 Hydrogen electrode active layer 14 Electrolyte layer 15 Reaction prevention layer 16 Oxygen electrode layer 20 Metal separator 30 Joint

Claims

1. An electrochemical cell connected to a metal separator, A cell body having a current collector layer, a first electrode layer disposed on the current collector layer, a second electrode layer, and an electrolyte layer disposed between the first electrode layer and the second electrode layer, An annular support frame connected to the metal separator and surrounding at least a portion of the cell body, A current collector member is disposed between the metal separator and the current collector layer, Equipped with, The support frame comprises zirconia and nickel oxide. The porosity of the support frame after reduction treatment at 750°C for 12 hours is 15% or less. Electrochemical cell.

2. An electrochemical cell connected to a metal separator, A cell body having a current collector layer, a first electrode layer disposed on the current collector layer, a second electrode layer, and an electrolyte layer disposed between the first electrode layer and the second electrode layer, An annular support frame connected to the metal separator and surrounding at least a portion of the cell body, Equipped with, The support frame comprises zirconia and nickel oxide. The porosity of the support frame after reduction treatment at 750°C for 12 hours is 15% or less. The current collector layer is filled inside the support frame. Electrochemical cell.

3. The strength of the support frame after the reduction treatment is 140 MPa or more. The electrochemical cell according to claim 1 or 2.

4. The support frame further comprises magnesium oxide. The electrochemical cell according to claim 1 or 2.

5. The support frame includes at least one of 3YSZ and 4YSZ as zirconia. The electrochemical cell according to claim 1 or 2.

6. The difference in thermal expansion coefficients between the support frame and the metal separator after the reduction treatment is 2.5 ppm / K or less. The electrochemical cell according to claim 1 or 2.

7. The support frame after the reduction treatment includes a plurality of pores, The average equivalent diameter of the multiple pores is 5 μm or less. The electrochemical cell according to claim 1 or 2.

8. An electrochemical cell according to claim 1 or 2, A metal separator connected to the aforementioned support frame, Equipped with, Electrochemical cell with separator.