Electrochemical cell

Abstract

This electrolysis cell (10) is provided with: a support substrate (12) that has a first through hole (40a); and a hydrogen electrode collector layer (13) that has a first embedded part (70a) which is embedded in the first through hole (40a). A first layered part (80) includes a first gap (81) that is in contact with a first surface (T1) of the support substrate (12), the first surface being on the hydrogen electrode active layer (14) side. The first embedded part (70a) includes a first gap (71a) that is in contact with the inner peripheral surface (T1) of the first through hole (40a). The first gap (71a) extends along the thickness direction of the support substrate (12).

Description

electrochemical cell

[0001] The present invention relates to electrochemical cells.

[0002] Patent Document 1 discloses an anode-supported fuel cell comprising a support substrate having a through-hole, an anode embedded in the through-hole, an electrolyte layer disposed on the support substrate, and a cathode disposed on the electrolyte layer.

[0003] JP 2013-201061 A

[0004] In the fuel cell described in Patent Document 1, when operation is stopped, the Ni contained in the anode is oxidized to NiO, resulting in volume expansion. However, because the anode is constrained by the support substrate, stress concentrates between the anode and the support substrate, causing a problem of cracks in the anode. This problem is not limited to fuel cells, but occurs in all electrochemical cells, including electrolysis cells.

[0005] An object of the present invention is to provide an electrochemical cell that can suppress the occurrence of cracks in the anode.

[0006] An electrochemical cell according to a first aspect of the present invention includes a support substrate having a through hole, a current collecting layer having a buried portion buried in the through hole, a first electrode layer and a second electrode layer disposed on the current collecting layer, and an electrolyte layer disposed between the first electrode layer and the second electrode layer. The buried portion includes a void in contact with an inner circumferential surface of the through hole. The void extends along the thickness direction of the support substrate.

[0007] An electrochemical cell according to a second aspect of the present invention is the electrochemical cell according to the first aspect, wherein in a cross section perpendicular to the thickness direction, the void is formed in a ring shape along an inner circumferential surface of the through hole.

[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, in a cross section perpendicular to the thickness direction, the width of the voids is wider toward a supply side or an exhaust side of a raw material gas supplied to the current collecting layer.

[0009] According to the present invention, it is possible to provide an electrochemical cell that can suppress the occurrence of cracks in the anode.

[0010] Fig. 1 is a cross-sectional view of an electrolysis cell device according to an embodiment, Fig. 2 is a partially enlarged view of Fig. 1, and Fig. 3 is a cross-sectional view taken along line AA of Fig. 2.

[0011] (Electrolytic Cell Apparatus 1) FIG. 1 is a cross-sectional view showing the configuration of an electrolytic cell apparatus 1 according to an embodiment.

[0012] The electrolytic cell apparatus 1 includes an electrolytic cell 10, a separator 20, a current collecting member 25, and a sealing unit 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 a plurality of electrolytic cell apparatuses 1 in the Z-axis direction, which is perpendicular to the X-axis direction and the Y-axis direction.

[0013] 1 , the electrolytic cell 10 includes a support substrate 12, a hydrogen electrode current collecting layer 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 13, the hydrogen electrode active layer 14, the electrolyte layer 15, the reaction prevention layer 16, and the oxygen electrode layer 17 are stacked in this order in the Z-axis direction.

[0014] The hydrogen electrode current collecting layer 13 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.

[0015] The support substrate 12, the hydrogen electrode current collecting layer 13, the hydrogen electrode active layer 14, the electrolyte layer 15, and the oxygen electrode layer 17 are essential components, while the reaction prevention layer 16 is an optional component.

[0016] [Support Substrate 12] The support substrate 12 functions as a support for the electrolysis cell 10 together with the hydrogen electrode current collecting layer 13. The support substrate 12 has a plurality of through holes 40, beam portions 50, and a frame portion 60.

[0017] Each through hole 40 penetrates the support substrate 12. Each through hole 40 extends along the thickness direction (Z-axis direction) of the support substrate 12. Each through hole 40 is formed inside the beam portion 50 or between the beam portion 50 and the frame portion 60. At least a portion of the hydrogen electrode current collecting layer 13 is embedded in each through hole 40.

[0018] The beam portion 50 is disposed inside the frame portion 60. The beam portion 50 may be substantially integral with the frame portion 60.

[0019] The beam portion 50 is composed of a plurality of beam members 51. Each beam member 51 is formed in a rod shape. The end of each beam member 51 is connected to the inner peripheral surface of the frame portion 60. In this embodiment, the plurality of beam members 51 are connected to each other in a lattice pattern, but the number and positions of the beam members 51 can be changed as appropriate.

[0020] The beam portion 50 is made of, for example, forsterite (Mg ２ SiO ４ ), magnesium silicate (MgSiO ３ ), zirconia (ZrO ２ , including partially stabilized zirconia), magnesia (MgO), spinel (MgAl ２ O ４ , NiAl ２ O ４ ), yttria stabilized zirconia (YSZ), calcia stabilized zirconia (CSZ), nickel (Ni), nickel oxide (NiO), alumina (Al ２ O ３ ), nickel oxide-magnesia solid solution (Mg ｘ Ni （１－ｘ） 0[0<x<1]) and a mixed material that combines two or more of these.

[0021] The porosity of the beam portion 50 is not particularly limited, but may be, for example, 0.1% to 15%. The porosity of the beam portion 50 may be lower than the porosity of the hydrogen electrode current collecting layer 13. The porosity of the beam portion 50 is preferably 5% or less. This allows the rigidity of the beam portion 50 to be improved.

[0022] The electron conductivity of the beam portion 50 may be lower than that of the hydrogen electrode current collecting layer 13. The beam portion 50 may have electronic insulation. The electron conductivity of the beam portion 50 is not particularly limited, but may be, for example, 10 －１ It is possible to make it S / m or less.

[0023] The method for forming the beam portion 50 is not particularly limited, and may be an extrusion molding method, a tape casting method, a print lamination method, a casting method, a dry press method, or the like.

[0024] The frame 60 is formed in an annular shape. The frame 60 surrounds the beams 50 and the hydrogen electrode current collecting layer 13. In this embodiment, the frame 60 is disposed on the separator 20. The frame 60 is positioned by the sealing portion 30.

[0025] The frame 60 is made of, for example, forsterite (Mg ２ SiO ４ ), magnesium silicate (MgSiO ３ ), zirconia (ZrO ２ , including partially stabilized zirconia), magnesia (MgO), spinel (MgAl ２ O ４ , NiAl ２ O ４ ), yttria stabilized zirconia (YSZ), calcia stabilized zirconia (CSZ), nickel (Ni), nickel oxide (NiO), alumina (Al ２ O ３ ), nickel oxide-magnesia solid solution (Mg ｘ Ni （１－ｘ） 0[0<x<1]), and a mixed material that combines two or more of these. The frame portion 60 may be made of the same material as the beam portion 50. In this case, the frame portion 60 may be substantially integral with the beam portion 50. The frame portion 60 may be made of a material different from that of the beam portion 50.

[0026] The porosity of the frame 60 can be, for example, 0.1% or more and 15% or less. The porosity of the frame 60 may be lower than the porosity of the hydrogen electrode current collecting layer 13. The porosity of the frame 60 is preferably 5% or less. This provides the frame 60 with gas sealing properties, thereby preventing the source gas supplied from the hydrogen electrode side space S1 to the hydrogen electrode current collecting layer 13 from returning to the hydrogen electrode side space S1 via the frame 60.

[0027] In this embodiment, the source gas flows from left to right in Fig. 1 . Therefore, although not shown in Fig. 1 , a gas supply port is located on the left side of the hydrogen electrode-side space S1, and a gas exhaust port is located on the right side of the hydrogen electrode-side space S1. In this specification, as shown in Fig. 1 , the gas supply port side of the center C1 of the hydrogen electrode-side space S1 is referred to as the "supply side," and the gas exhaust port side of the center C1 of the hydrogen electrode-side space S1 is referred to as the "exhaust side." The center C1 of the hydrogen electrode-side space S1 is the center of a straight line connecting the geometric centers of the gas supply port and the gas exhaust port.

[0028] The electronic conductivity of the frame 60 may be lower than that of the hydrogen electrode current collecting layer 13. The frame 60 may have electronic insulation. The electronic conductivity of the frame 60 is not particularly limited, but may be, for example, 10 －１ It is possible to make it S / m or less.

[0029] The method for forming the frame portion 60 is not particularly limited, and methods such as extrusion molding, tape casting, print lamination, casting, and dry pressing can be used.

[0030] [Hydrogen Electrode Current Collector Layer 13] The hydrogen electrode current collector layer 13 functions as a support for the electrolysis cell 10 together with the support substrate 12. The hydrogen electrode current collector layer 13 has a plurality of embedded portions 70, first layer portions 80, and second layer portions 90. One of the embedded portions 70 and the first layer portions 80 and second layer portions 90 is a required component, while the other of the first layer portions 80 and second layer portions 90 is an optional component.

[0031] Each embedded portion 70 is embedded in a corresponding through hole 40 of the support substrate 12. Each embedded portion 70 is continuous with the first layer portion 80. Each embedded portion 70 is continuous with the second layer portion 90. Each embedded portion 70 is disposed between the first layer portion 80 and the second layer portion 90 in the thickness direction (Z-axis direction) of the support substrate 12. The detailed configuration of each embedded portion 70 will be described later.

[0032] The first layer portion 80 is disposed between each embedded portion 70 and the hydrogen electrode active layer 14. The first layer portion 80 is formed integrally with each embedded portion 70. The first layer portion 80 is disposed on the beam portion 50. The first layer portion 80 covers the hydrogen electrode active layer 14 side of the beam portion 50 of the support substrate 12.

[0033] The second layer portion 90 is disposed on the opposite side of the first layer portion 80 with respect to each embedded portion 70. The second layer portion 90 is formed integrally with each embedded portion 70. The second layer portion 90 is disposed on the beam portion 50. The second layer portion 90 covers the side of the support substrate 12 opposite the hydrogen electrode active layer 14 from the beam portion 50.

[0034] The hydrogen electrode current collecting layer 13 is a porous body having electronic conductivity. The hydrogen electrode current collecting layer 13 contains nickel (Ni). In the case of co-electrolysis, Ni is used to reduce the amount of H generated. ２ and CO contained in the raw material gas ２ It also functions as a thermal catalyst that promotes the thermal reaction with Ni to maintain an appropriate gas composition for methanation, reverse water gas shift reaction, etc. During operation of the electrolysis cell 10, Ni is basically present in the form of metal Ni, but may also be present in part in the form of nickel oxide (NiO).

[0035] The hydrogen electrode current collecting layer 13 contains a 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.

[0036] The porosity of the hydrogen electrode current collecting layer 13 is not particularly limited, but may be, for example, 20% to 40%. The thickness of the hydrogen electrode current collecting layer 13 is not particularly limited, but may be, for example, 150 μm to 1000 μm. In the Z-axis direction, the thickness of the hydrogen electrode current collecting layer 13 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.

[0037] [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 13. The hydrogen electrode active layer 14 is covered with the electrolyte layer 15.

[0038] The source gas is supplied to the hydrogen electrode active layer 14 through the hydrogen electrode current collecting layer 13. In this embodiment, the source gas contains at least H ２ Contains O.

[0039] 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.

[0040] Hydrogen electrode active layer 14: H2O+2e-→H2+O2- (1)

[0041] 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.

[0042] 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)

[0043] The hydrogen electrode active layer 14 is a porous body having electronic conductivity. The hydrogen electrode active layer 14 may also have ionic conductivity. The hydrogen electrode active layer 14 is made of, for example, YSZ, CSZ, ScSZ, GDC, (SDC), or (La, Sr)(Cr, Mn)O. ３ , (La,Sr)TiO ３ , Sr２ (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.

[0044] 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 50 μm.

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

[0046] [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 that the electrolyte layer 15 is sandwiched between the hydrogen electrode active layer 14 and the reaction prevention layer 16.

[0047] 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 60.

[0048] The electrolyte layer 15 absorbs the O generated in the hydrogen electrode active layer 14. ２－ The electrolyte layer 15 has a function of transmitting the ionic current to the oxygen electrode layer 17. The electrolyte layer 15 is a dense body that has ionic conductivity but not electronic conductivity. The electrolyte layer 15 can be made of, for example, YSZ, GDC, ScSZ, SDC, lanthanum gallate (LSGM), or the like.

[0049] 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.

[0050] The method for forming the electrolyte layer 15 is not particularly limited, and tape casting, screen printing, casting, dry pressing, or the like can be used.

[0051] [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.

[0052] The reaction prevention layer 16 is made of an ion-conductive material, such as GDC or SDC.

[0053] 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.

[0054] 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.

[0055] [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.

[0056] The oxygen electrode layer 17 reacts with O 2 transferred from the hydrogen electrode active layer 14 via the electrolyte layer 15 in accordance with the chemical reaction of the following formula (5): ２－ From O ２ The O generated in the oxygen electrode layer 17 ２ is released into the oxygen electrode side space S2.

[0057] Oxygen electrode layer 17: 2O ２－ →O ２ +4e － ...(5)

[0058] The oxygen electrode layer 17 is a porous material having ionic and electronic conductivity. The oxygen electrode layer 17 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).

[0059] 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.

[0060] The method for forming the oxygen electrode layer 17 is not particularly limited, and tape casting, screen printing, casting, dry pressing, or the like can be used.

[0061] (Separator 20) The separator 20 is electrically connected to the hydrogen electrode current collecting layer 13 via the current collecting member 25. The separator 20 has a connection portion 20a that contacts the current collecting member 25.

[0062] The separator 20 is made of a metal material having electronic conductivity. The 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 separator 20 is not particularly limited, but can be set to 4% by mass or more and 30% by mass or less.

[0063] The separator 20 may contain Ti (titanium) or Zr (zirconium). The Ti content in the separator 20 is not particularly limited, but can be 0.01 mol % or more and 1.0 mol % or less. The Al content in the separator 20 is not particularly limited, but can be 0.01 mol % or more and 0.4 mol % or less. The separator 20 may contain Ti in the form of TiO ２ (titania), or Zr may be contained as ZrO ２It may be contained as (zirconia).

[0064] At least a portion of the surface of the separator 20 may be covered with an oxide film formed by oxidation of the constituent elements of the separator 20. A typical example of the oxide film is a chromium oxide film.

[0065] (Current Collector 25) The current collector 25 electrically connects the hydrogen electrode current collecting layer 13 and the connection portion 20a of the separator 20. As shown in FIG. 1 , the current collector 25 is disposed in the hydrogen electrode side space S1 between the hydrogen electrode current collecting layer 13 and the separator 20.

[0066] The current collecting member 25 has electron conductivity and air permeability. The current collecting member 25 may be made of a porous material such as nickel, a nickel alloy, or stainless steel. The size, shape, and position of the current collecting member 25 may be changed as appropriate. For example, in this embodiment, the current collecting member 25 is in contact with the hydrogen electrode current collecting layer 13 and the frame 60, but it does not have to be in contact with the frame 60.

[0067] (Sealing portion 30) The sealing portion 30 positions the frame portion 60 relative to the separator 20. The sealing portion 30 is a dense body. The sealing portion 30 seals the gap between the electrolysis cell 10 and the separator 20. This prevents gases from mixing between the hydrogen electrode side space S1 and the oxygen electrode side space S2.

[0068] In this embodiment, the sealing portion 30 is connected to the electrolyte layer 15 and the frame portion 60 of the support substrate 12, but if the beam portion 50 is not breathable, the sealing portion 30 does not need to be connected to the electrolyte layer 15.

[0069] The sealing portion 30 preferably has electronic insulation properties, which can prevent a short circuit from occurring between the hydrogen electrode current collecting layer 13 and the separator 20. The sealing portion 30 can be made of, for example, glass, glass ceramics (crystallized glass), a composite of glass and ceramics, or the like.

[0070] (Detailed Structure of Each Embedded Portion 70) The detailed structure of each embedded portion 70 in the hydrogen electrode current collecting layer 13 will be described with reference to Figs. 2 and 3. Fig. 2 is a partially enlarged view of Fig. 1. Fig. 2 illustrates a cross section along the thickness direction (Z-axis direction). Fig. 3 is a cross section taken along line A-A in Fig. 2. Fig. 3 illustrates a cross section perpendicular to the thickness direction.

[0071] 2 and 3 show two through holes 40. In the following description, the through hole 40 located on the supply side will be referred to as the "first through hole 40a," and the embedded portion 70 embedded in the first through hole 40a will be referred to as the "first embedded portion 70a." Furthermore, the through hole 40 located on the discharge side will be referred to as the "second through hole 40b," and the embedded portion 70 embedded in the second through hole 40b will be referred to as the "second embedded portion 70b."

[0072] The first embedded portion 70a includes a first void 71a. The first void 71a is in contact with the inner circumferential surface T1 of the first through hole 40a and extends along the thickness direction (Z-axis direction). The inclusion of the first void 71a in the first embedded portion 70a provides an expansion margin for the first embedded portion 70a between the first embedded portion 70a and the first through hole 40a. Therefore, even if the operation of the electrolysis cell apparatus 1 is stopped and Ni contained in the first embedded portion 70a is oxidized to NiO, causing volume expansion, stress concentration between the first embedded portion 70a and the first through hole 40a can be suppressed. Therefore, cracks can be suppressed from occurring in the first embedded portion 70a. Furthermore, the first void 71a also functions as a flow path for the source gas, thereby improving the gas diffusion of the source gas.

[0073] 2, the first void 71a extending along the thickness direction means that the thickness (height) of the first void 71a in the thickness direction is greater than the width of the first void 71a in the X-axis direction. The width of the first void 71a in the X-axis direction can be, for example, 10 μm or more and 100 μm or less. The thickness of the first void 71a in the thickness direction is preferably 90% or less of the thickness of the beam member 51 in the thickness direction.

[0074] 3, the first void 71a is formed in a ring shape along the inner circumferential surface T1 of the first through hole 40a, which prevents stress from concentrating between the first embedded portion 70a and the first through hole 40a over the entire circumference of the first embedded portion 70a, thereby further preventing cracks from occurring in the first embedded portion 70a.

[0075] As shown in FIG. 3 , the width of the first void 71a located on the supply side is wider the closer it is to the source gas supply side. Specifically, the width W1 of the first void 71a on the supply side is wider than the width W2 of the first void 71a on the central side. This allows for a larger expansion margin in the supply-side portion of the first embedded portion 70a to which air is more likely to be supplied from the supply port. Therefore, even if the supply-side portion of the first embedded portion 70a expands relatively significantly, stress concentration between the supply-side portion and the first through-hole 40a can be suppressed, thereby further suppressing the occurrence of cracks in the first embedded portion 70a.

[0076] The second embedded portion 70b includes a second void 71b. The second void 71b is in contact with the inner circumferential surface T2 of the second through hole 40b and extends along the thickness direction (Z-axis direction). The inclusion of the second void 71b in the second embedded portion 70b provides an expansion margin for the second embedded portion 70b between the second embedded portion 70b and the second through hole 40b. Therefore, even if the operation of the electrolysis cell apparatus 1 is stopped and Ni contained in the second embedded portion 70b is oxidized to NiO, causing volume expansion, stress concentration between the second embedded portion 70b and the second through hole 40b can be suppressed. This suppresses the occurrence of cracks in the second embedded portion 70b. Furthermore, the second void 71b also functions as a flow path for the source gas, thereby improving the gas diffusion of the source gas.

[0077] The second gap 71b extending in the thickness direction means that the thickness (height) of the second gap 71b in the thickness direction is greater than the width of the second gap 71b in the X-axis direction in FIG.

[0078] 3, the second void 71b is formed in a ring shape along the inner circumferential surface T2 of the second through hole 40b, which prevents stress from concentrating between the second embedded portion 70b and the second through hole 40b over the entire circumference of the second embedded portion 70b, thereby further preventing cracks from occurring in the second embedded portion 70b.

[0079] As shown in FIG. 3 , the width of the second void 71b located on the discharge side is wider the closer it is to the source gas discharge side. Specifically, the width W3 of the second void 71b on the discharge side is wider than the width W4 of the second void 71b on the central side. This allows for a larger expansion margin in the discharge side portion of the second embedded portion 70b, where air is more likely to be supplied from the discharge port. Therefore, even if the discharge side portion of the second embedded portion 70b expands relatively significantly, stress concentration between the second embedded portion 70b and the second through-hole 40b can be suppressed, thereby further suppressing the occurrence of cracks in the second embedded portion 70b.

[0080] The hydrogen electrode current collecting layer 13 having the above configuration can be fabricated as follows. First, a pore-forming material is placed at a desired position on the inner circumferential surface of each through-hole 40 in the support substrate 12. Next, each through-hole 40 in the support substrate 12 is filled with a paste containing the constituent material of the hydrogen electrode current collecting layer 13. Next, the paste containing the constituent material of the hydrogen electrode current collecting layer 13 is applied to cover one surface of each beam member 51. Next, the paste containing the constituent material of the hydrogen electrode current collecting layer 13 is applied to cover the other surface of each beam member 51. Next, the paste is heat-treated (at 350°C or higher, for 1 hour or longer) to form the hydrogen electrode current collecting layer 13. During this process, the pore-forming material is removed by the heat treatment, thereby forming the first voids 71a and the second voids 71b.

[0081] (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.

[0082] [Variation 1] In the above embodiment, the hydrogen electrode current collecting layer 13 has the first layer portion 80 and the second layer portion 90. However, it is not necessary for the hydrogen electrode current collecting layer 13 to have at least one of the first layer portion 80 and the second layer portion 90.

[0083] [Modification 2] In the above embodiment, the first void 71a and the second void 71b are each formed in an annular shape as shown in Fig. 3, but this is not limited thereto. At least one of the first void 71a and the second void 71b does not have to be formed in an annular shape. The cross-sectional shape of the void 71 in a cross section perpendicular to the thickness direction may be an island shape, a linear shape, an L-shape, a C-shape, or the like.

[0084] [Modification 3] In the above embodiment, the embedded portion 70 has two voids 71 ​​(first void 71a and second void 71b), but the number and positions of the voids 71 ​​can be changed as appropriate.

[0085] [Modification 4] In the above embodiment, the width of the gap 71 is wider as it is closer to the source gas supply side or discharge side, but this is not limiting. The width of the gap 71 can be changed as appropriate.

[0086] [Modification 5] In the above embodiment, the hydrogen electrode current collecting layer 13 has a plurality of embedded portions 70, but the number of embedded portions 70 may be one or more.

[0087] [Modification 6] In the above embodiment, the support substrate 12 has the frame portion 60 , but it does not have to have the frame portion 60 .

[0088] [Variation 7] 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 interchanged, and a source gas is passed through the outer surface of the hydrogen electrode active layer 14. The hydrogen electrode current collecting layer 13 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 13 described in the above embodiment.

[0089] [Variation 8] 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 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 cell cells that use oxide ions or protons as carriers.

[0090] DESCRIPTION OF SYMBOLS 1...Electrolytic cell device, 10...Electrolytic cell, 12...Support substrate, 13...Hydrogen electrode current collecting layer, 14...Hydrogen electrode active layer, 15...Electrolyte layer, 16...Reaction prevention layer, 17...Oxygen electrode layer, 20...Separator, 25...Current collecting member, 30...Sealing portion, 40...Through hole, 40a...First through hole, T1...Inner peripheral surface, 40b...Second through hole, T2...Inner peripheral surface, 50...Beam portion, 51...Beam member, 60...Frame portion, 70...Embedded portion, 70a...First embedded portion, 70b...Second embedded portion, 71a...First gap, 71b...Second gap, 80...First layered portion, 90...Second layered portion

Claims

1. A support substrate having through holes, A current collector layer having an embedded portion embedded in the through hole, A first electrode layer is disposed on the current collector layer, The second electrode layer and An electrolyte layer disposed between the first electrode layer and the second electrode layer, Equipped with, The buried portion includes a gap in contact with the inner circumferential surface of the through hole. The aforementioned void extends along the thickness direction of the support substrate, In the cross-section perpendicular to the thickness direction, the width of the void is wider the closer it is to the supply side or discharge side of the raw material gas supplied to the current collector layer. Electrochemical cell.

2. In the cross-section perpendicular to the thickness direction, the void is formed in an annular shape along the inner circumferential surface of the through hole. The electrochemical cell according to claim 1.