Electrochemical cell, electrochemical cell apparatus, module, and module housing apparatus

Abstract

To provide an electrochemical cell, an electrochemical cell apparatus, a module, and a module housing apparatus capable of improving durability.SOLUTION: An electrochemical cell comprises a metal plate and an element part. The metal plate has a first surface, a second surface, and a plurality of holes including a first hole. The second surface is located on an opposite side to the first surface. The first hole has a first opening located on the first surface. The element part comprises a solid electrolyte layer, a first layer positioned between the first surface and the solid electrolyte layer, and a first electrode positioned on an opposite side to the first layer across the solid electrolyte layer. The element part has, in a planar view, a first portion overlapping with the first opening. A surface of the first layer located on a side opposite to the solid electrolyte layer is formed such that a central section of the first portion is farther from the first opening than an edge section of the first portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to electrochemical cells, electrochemical cell devices, modules and module housing devices. [Background technology]

[0002] In recent years, various fuel cell stack devices having multiple fuel cell units have been proposed as next-generation energy sources. A fuel cell unit is a type of electrochemical cell that can generate electric power using a fuel gas such as a hydrogen-containing gas and an oxygen-containing gas such as air. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2016 / 124928 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional fuel cell stack devices have room for improvement in terms of durability.

[0005] An object of one aspect of the embodiment is to provide an electrochemical cell, an electrochemical cell device, a module, and a module housing device that can improve durability. [Means for solving the problem]

[0006] An electrochemical cell according to one aspect of the embodiment includes a metal plate and an element unit. The metal plate has a first surface, a second surface, and a plurality of holes including a first hole. The second surface is located opposite the first surface. The first hole has a first opening located in the first surface. The element unit includes a solid electrolyte layer, a first layer located between the first surface and the solid electrolyte layer, and a first electrode located on the opposite side of the first layer with the solid electrolyte layer sandwiched between them. The element unit has a first portion that overlaps with the first opening in a planar view. On the surface of the first layer located opposite the solid electrolyte layer, the center of the first portion is farther from the first opening than the edge of the first portion.

[0007] The electrochemical cell device of the present disclosure also includes a cell stack including the electrochemical cell described above.

[0008] The module of the present disclosure includes the electrochemical cell device described above and a container that houses the electrochemical cell device.

[0009] The module housing device of the present disclosure includes the module described above, an auxiliary device for operating the module, and an exterior case for housing the module and the auxiliary device. [Effects of the Invention]

[0010] According to one aspect of the embodiment, it is possible to provide an electrochemical cell, an electrochemical cell device, a module, and a module housing device that can improve durability. [Brief explanation of the drawings]

[0011] [Figure 1A] FIG. 1A is a plan view showing an example of an electrochemical cell according to a first embodiment. [Figure 1B] FIG. 1B is a cross-sectional view taken along line AA shown in FIG. 1A. [Figure 1C] FIG. 1C is a cross-sectional view showing another example of the electrochemical cell according to the first embodiment. [Figure 2] FIG. 2 is an enlarged cross-sectional view of region B shown in FIG. 1B. [Figure 3A] FIG. 3A is a perspective view showing an example of an electrochemical cell device according to the first embodiment. [Figure 3B] FIG. 3B is a cross-sectional view taken along line XX shown in FIG. 3A. [Figure 3C] FIG. 3C is a top view showing an example of the electrochemical cell device according to the first embodiment. [Figure 4] FIG. 4 is an external perspective view illustrating an example of the module according to the first embodiment. [Figure 5] FIG. 5 is an exploded perspective view schematically illustrating an example of a module housing device according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing an example of an electrochemical cell according to the second embodiment. [Figure 7] FIG. 7 is an enlarged cross-sectional view of a region C shown in FIG. [Figure 8] FIG. 8 is a cross-sectional view showing an example of an electrochemical cell according to the third embodiment. [Figure 9] FIG. 9 is an enlarged cross-sectional view of a region D shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of an electrochemical cell, an electrochemical cell device, a module, and a module housing device disclosed in the present application will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

[0013] It should also be noted that the drawings are schematic and that the dimensional relationships and ratios of elements may differ from reality. Furthermore, the drawings may contain parts whose dimensional relationships and ratios differ from one another.

[0014] [First embodiment] <Electrochemical cell configuration> First, with reference to Figures 1A to 2, an electrochemical cell according to a first embodiment will be described using an example of a solid oxide fuel cell. The electrochemical cell device may include a cell stack having a plurality of electrochemical cells. An electrochemical cell device having a plurality of electrochemical cells will be simply referred to as a cell stack device.

[0015] Fig. 1A is a plan view showing an example of an electrochemical cell according to a first embodiment. Fig. 1B is a cross-sectional view taken along line AA shown in Fig. 1A. Figs. 1A and 1B show enlarged views of parts of each component of the electrochemical cell. Hereinafter, the electrochemical cell may be simply referred to as a cell.

[0016] For ease of understanding, Figures 1A and 1B illustrate a three-dimensional Cartesian coordinate system including a Z axis, with the vertical upward direction as the positive direction and the vertical downward direction as the negative direction. This Cartesian coordinate system may also be shown in other drawings used in the following explanation. Furthermore, components similar to those in the electrochemical cells shown in Figures 1A and 1B are denoted by the same reference numerals, and their explanations will be omitted or simplified.

[0017] 1A, the cell 1 according to this embodiment includes an element section 3, a metal plate 23, and a flow path member 25. The element section 3 includes a fuel electrode 5, a solid electrolyte layer 6, and a cathode 8.

[0018] The fuel electrode 5 is a second electrode that comes into contact with the fuel gas, which is a reducing gas. The fuel electrode 5 has gas permeability. The open porosity of the fuel electrode 5 may be, for example, in the range of 30% to 50%, and particularly 35% to 45%. The open porosity of the fuel electrode 5 may also be referred to as the porosity or void ratio of the fuel electrode 5.

[0019] The anode 5 may be made of a generally known material. The anode 5 may be made of porous conductive ceramics, such as ceramics containing calcium oxide, magnesium oxide, or ZrO2 solid-solubilized with rare earth element oxides, and Ni and / or NiO. The rare earth element oxide may contain, for example, a plurality of rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. Calcium oxide, magnesium oxide, or ZrO2 solid-solubilized with rare earth element oxides is sometimes referred to as stabilized zirconia. Stabilized zirconia may include partially stabilized zirconia. The anode 5 may also include CeO2 solid-solubilized with La, Nd, or Yb.

[0020] The solid electrolyte layer 6 is an electrolyte and transfers ions between the fuel electrode 5 and the air electrode 8. At the same time, the solid electrolyte layer 6 has gas barrier properties and makes it difficult for the fuel gas and oxygen-containing gas to leak.

[0021] The material of the solid electrolyte layer 6 may be, for example, ZrO2 with 3 mol % to 15 mol % of a rare earth element oxide dissolved therein. The rare earth element oxide may include, for example, one or more rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. The solid electrolyte layer 6 may include, for example, ZrO2 with Yb, Sc, or Gd dissolved therein, CeO2 with La, Nd, or Yb dissolved therein, BaZrO3 with Sc or Yb dissolved therein, or BaCeO3 with Sc or Yb dissolved therein.

[0022] The air electrode 8 is a first electrode that comes into contact with an oxygen-containing gas. The air electrode 8 has gas permeability. The open porosity of the air electrode 8 may be, for example, in the range of 20% to 50%, and particularly in the range of 30% to 50%. The open porosity of the air electrode 8 may also be referred to as the porosity of the air electrode 8.

[0023] There are no particular restrictions on the material of the air electrode 8 as long as it is one that is generally used for air electrodes. The material of the air electrode 8 may be, for example, a conductive ceramic such as a so-called ABO3 type perovskite oxide.

[0024] The material of the air electrode 8 may be, for example, a composite oxide in which Sr (strontium) and La (lanthanum) coexist at the A site. Examples of such composite oxides include La x Sr 1-x Co y Fe 1-y O3, La x Sr 1-x MnO3, La x Sr 1-x FeO3, La x Sr 1-x CoO3, etc. Note that x is 0 <x<1、yは0<y<1である。

[0025] The element unit 3 may also have a diffusion-preventing layer 7 located between the solid electrolyte layer 6 and the air electrode 8. When the element unit 3 has the diffusion-preventing layer 7, the diffusion-preventing layer 7 makes it difficult for certain elements to diffuse. For example, when Sr (strontium) contained in the air electrode 8 diffuses into the solid electrolyte layer 6, a resistive layer of SrZrO3 is formed in the solid electrolyte layer 6. The diffusion-preventing layer 7 makes it difficult for Sr to diffuse, thereby making it difficult for SrZrO3 to form.

[0026] The material of the diffusion-preventing layer 7 is not particularly limited as long as it generally prevents diffusion of elements between the air electrode 8 and the solid electrolyte layer 6. The material of the diffusion-preventing layer 7 may include, for example, cerium oxide (CeO2) in which a rare earth element other than Ce (cerium) is dissolved. Examples of such rare earth elements include Gd (gadolinium) and Sm (samarium).

[0027] The element unit 3 may also have a first intermediate layer 30 located between the anode 5 and the metal plate 23. The first intermediate layer 30 is an example of a first layer located between the first surface 231 of the metal plate 23 and the solid electrolyte layer 6. The first intermediate layer 30 joins the element unit 3 including itself to the metal plate 23, and fixes the element unit 3 to the metal plate 23.

[0028] The first intermediate layer 30 may be conductive. The first intermediate layer 30 may contain, for example, conductive particles such as Ni and inorganic oxides such as TiO, rare earth element oxides (Y2O3, CeO2, etc.), and transition metal oxides (Fe2O3, CuO, etc.). The first intermediate layer 30 may contain metal particles and conductive oxide particles.

[0029] The first intermediate layer 30 may be gas permeable. When the first intermediate layer 30 is gas permeable, the first intermediate layer 30 may be positioned so as to cover the holes 23a described below.

[0030] A sealant 9 different from the solid electrolyte layer 6 may be positioned on the side of the anode 5. The material of the sealant 9 may be dense glass or ceramic. The material of the sealant 9 may be, for example, amorphous glass or crystallized glass. As the crystallized glass, for example, any of SiO2-CaO-based, MgO-B2O3-based, La2O3-B2O3-MgO-based, La2O3-B2O3-ZnO-based, and SiO2-CaO-ZnO-based materials may be used, and in particular, SiO2-MgO-based materials may be used. The sealant 9 may have electrical insulation properties. Alternatively, the material of the sealant 9 may be the same as the material of the solid electrolyte layer 6. The sealant 9 may be positioned so as to surround the side of the element section 3.

[0031] The first intermediate layer 30 may be configured as a single layer using a single material, or may be configured as a laminated layer in which a plurality of materials are superimposed.

[0032] The metal plate 23 has a first surface 231 and a second surface 232 located at both ends in the thickness direction (Y-axis direction). The first surface 231 is located so as to face the first intermediate layer 30. The second surface 232 is located on the opposite side of the first surface 231. The thickness of the metal plate 23 may be, for example, 0.1 mm to 1.0 mm, and particularly 0.2 mm to 0.5 mm.

[0033] The metal plate 23 is electrically conductive. The metal plate 23 may be, for example, a metal member containing chromium. The metal plate 23 may be, for example, a stainless steel such as a ferritic stainless steel or an austenitic stainless steel having high heat resistance. The metal plate 23 may be, for example, a nickel-chromium alloy or an iron-chromium alloy. The metal plate 23 may contain, for example, a metal oxide. The metal plate 23 may have a coating covering the surface. The metal plate 23 may not have a coating on the surface.

[0034] The metal plate 23 also has a plurality of holes 23a. The holes 23a are through-holes that penetrate between the first surface 231 and the second surface 232. The fuel gas flowing through the flow path 24, which will be described later, is supplied to the fuel electrode 5 of the element section 3 through the holes 23a. The diameter (opening diameter) of the holes 23a may be, for example, 0.1 mm to 1.0 mm, particularly 0.3 mm to 0.6 mm. In a plan view of the metal plate 23 along the Y-axis direction, the opening ratio in the region where the holes 23a are formed may be, for example, 10% or more. The metal plate 23 may have a coating that covers the wall surfaces of the holes 23a. The metal plate 23 does not need to have a coating on the wall surfaces of the holes 23a.

[0035] The metal plate 23 may be, for example, gas permeable. Also, the sealing material 9 may be located on the side surface of the metal plate 23.

[0036] The flow path member 25 is located on the second surface 232 side of the metal plate 23. The flow path member 25 is fixed and electrically joined by, for example, welding or the like at the contact portion with the second surface 232. The flow path member 25 may be fixed and electrically joined to the metal plate 23 with a conductive sealing material, brazing material, or the like. The space located between the metal plate 23 and the flow path member 25 is a flow path 24 through which the fuel gas flows. The fuel gas flowing through the flow path 24 permeates the metal plate 23 and is supplied to the anode 5. The flow path member 25 may have one or more protrusions protruding toward the metal plate 23. Furthermore, a sealing material 9 may be located on the side surface of the flow path member 25.

[0037] The flow path member 25 is further fixed and electrically connected to the current collecting member 27 by welding or the like. The current collecting member 27 may be fixed and electrically connected to the flow path member 25 by a conductive adhesive or brazing material. The current collecting member 27 is fixed and electrically connected to the air electrode 8 of an adjacent cell 1 via an adhesive (not shown). The space located between the current collecting member 27 and the flow path member 25 is a flow path 26 through which an oxygen-containing gas flows. The oxygen-containing gas flowing through the flow path 26 is supplied to the air electrode 8 of the adjacent cell 1 via the slits in the current collecting member 27 and the adhesive.

[0038] The flow path member 25 and the current collecting member 27 are made of a dense metal or alloy. The flow path member 25 makes it difficult for the fuel gas flowing through the flow path 24 and the oxygen-containing gas flowing through the flow path 26 to leak. The flow path member 25 and the current collecting member 27 may have a coating layer. For example, the surface of the flow path member 25 facing the flow path 24 may have a coating layer that is resistant to reduction, and the surface of the flow path member 25 facing the flow path 26 may have a coating layer that is resistant to oxidation. These coating layers may be electrically conductive.

[0039] Furthermore, the surface of the first intermediate layer 30 that is not in contact with the metal plate 23 and the element section 3 may be covered with a sealing material 9 .

[0040] 1B, the shapes of the flow path member 25 and the current collecting member 27 are not limited to those shown in Fig. 1B. They may have any shape as long as they electrically connect adjacent cells 1 and make it difficult for the fuel gas and oxygen-containing gas to leak.

[0041] 1C is a cross-sectional view showing another example of the electrochemical cell according to the first embodiment. As shown in FIG. 1C, the flow path member 25 may be integrated with the current collecting member 27 and have a first convex portion that protrudes toward the adjacent cell 1 along the Y-axis direction and a second convex portion that protrudes toward the opposite side from the first convex portion.

[0042] <Details of the electrochemical cell> Next, the electrochemical cell according to this embodiment will be described in further detail with reference to Fig. 2. Fig. 2 is an enlarged cross-sectional view of region B shown in Fig. 1B.

[0043] As shown in Fig. 2, the cell 1 includes a metal plate 23 and an element section 3. The metal plate 23 has a hole 23a. The hole 23a has a first opening 23a1 and a second opening 23a2 located at both ends in the thickness direction (Y-axis direction). The first opening 23a1 is an opening located on a first surface 231 of the metal plate 23. The second opening 23a2 is an opening located on a second surface 232 of the metal plate 23.

[0044] The element portion 3 has a first portion 3a and a second portion 3b. The first portion 3a is a portion that overlaps with the first opening 23a1 in a plan view. The second portion 3b is a portion other than the first portion 3a.

[0045] The element portion 3 has a first intermediate layer 30 as a first layer facing the first surface 231. The first intermediate layer 30 has a surface 300 located in the first portion 3a on the side opposite to the solid electrolyte layer 6. In the surface 300, a central portion 3a1 of the first portion 3a is farther from the first surface 231 than an edge portion 3a2 of the first portion 3a.

[0046] In this way, the surface 300 of the first intermediate layer 30 is formed so that the central portion 3a1 of the first portion 3a is farther from the first surface 231 than the edge portion 3a2 of the first portion 3a, which makes it less likely that cracks will occur in the first intermediate layer 30 and / or that the first intermediate layer 30 will peel off from the metal plate 23 due to the difference in thermal expansion between the first intermediate layer 30 and the metal plate 23. This improves the durability of the cell 1 according to this embodiment.

[0047] Here, the edge portion 3a2 refers to a portion of the first region 3a that is close to the corner 23b where the wall surface 23c of the first opening 23a1 intersects with the first surface 231. Furthermore, the central portion 3a1 refers to a portion of the first region 3a that is surrounded by the edge portion 3a2.

[0048] 2, the solid electrolyte layer 6 has a surface 61 located on the metal plate 23 side and a surface 62 located on the opposite side to the surface 61. The surface 61 located in the first region 3a may have a central portion 3a1 that is farther away from the first surface 231 than the edge portion 3a2. The surface 62 located in the first region 3a may have a central portion 3a1 that is farther away from the first surface 231 than the edge portion 3a2. In other words, in a cross section perpendicular to the first surface 231, the solid electrolyte layer 6 located in the first region 3a may have an arch shape that protrudes to the opposite side of the hole 23a serving as the first hole.

[0049] In this way, the solid electrolyte layer 6 located at the first portion 3a has an arch shape that protrudes to the opposite side of the hole 23a, thereby improving the elasticity of the solid electrolyte layer 6 located at the first portion 3a in the thickness direction (Y-axis direction) and increasing the strength of the element portion 3 against bending and expansion / contraction, thereby further improving the durability of the cell 1.

[0050] Furthermore, when the diameter of the first opening 23a1 is d1 and the distance from the first surface 231 at the central portion 3a1 of the first region 3a to the first intermediate layer 30 serving as the first layer is d2, d2 / d1≦0.95 may be satisfied. This increases the strength of the element portion 3 against bending and expansion / contraction. This further improves the durability of the cell 1.

[0051] Furthermore, when the diameter of first opening 23a1 is d1 and the distance from surface 300 of first intermediate layer 30, which serves as the first layer facing first surface 231, to solid electrolyte layer 6 is d3, d1 / d3≧1 may be satisfied. This increases the strength of element section 3 against bending and expansion / contraction. This further improves the durability of cell 1.

[0052] The cell 1 may further include a constraining layer 40 located between the fuel electrode 5 and the first intermediate layer 30. The constraining layer 40 cooperates with the solid electrolyte layer 6 to make the element section 3 less susceptible to warping or bending.

[0053] The material of the constraining layer 40 exhibits a similar shrinkage rate during firing as the material of the solid electrolyte layer 6. The material of the constraining layer 40 may be the same as the material of the solid electrolyte layer 6. The element unit 3 obtained by sandwiching the material of the anode 5 of the element unit 3 between the material of the solid electrolyte layer 6 and the material of the constraining layer 40 and firing the resulting element unit 3 has little warping or deformation.

[0054] The constraining layer 40 may or may not be gas permeable. When the constraining layer 40 has gas barrier properties comparable to those of the solid electrolyte layer 6, the constraining layer 40 may have a plurality of through-holes 40a penetrating through the thickness direction (Y-axis direction) of the cell 1 so as not to impede the inflow of fuel gas to the anode 5. When the constraining layer 40 has through-holes 40a, a portion of the first intermediate layer 30 and / or a diffusion layer 50 described below may be located inside the through-holes 40a.

[0055] The cell 1 may further include a diffusion layer 50 in contact with the anode 5. The diffusion layer 50 is located between the anode 5 and the first intermediate layer 30. The diffusion layer 50 is gas permeable, and allows the fuel gas flowing through the flow passages 24 to pass through to the anode 5. The open porosity of the diffusion layer 50 may be in the range of, for example, 30% to 50%, particularly 35% to 45%.

[0056] The material of the diffusion layer 50 may be a porous conductive ceramic, such as a ceramic containing calcium oxide, magnesium oxide, or stabilized zirconia or partially stabilized zirconia in which rare earth element oxides are solid-solved, and Ni and / or NiO. The rare earth element oxides may contain a plurality of rare earth elements selected from, for example, Sc, Y, La, Nd, Sm, Gd, Dy, and Yb.

[0057] The diffusion layer 50 may contain a larger amount of rare earth elements than the fuel electrode 5. The diffusion layer 50 may contain zirconia in which a rare earth element oxide is dissolved, and particles of the rare earth element oxide.

[0058] The material of the diffusion layer 50, for example, reduces the shrinkage of the anode 5 during firing. This allows the degree of shrinkage of the anode 5 and the solid electrolyte layer 6 during firing to be similar, and therefore, the warping or deformation of the element portion 3 of the cell 1 having the diffusion layer 50 is reduced.

[0059] Furthermore, the material of the diffusion layer 50 is similar to that of the anode 5, and the temperature at which the material of the diffusion layer 50 begins to shrink is similar to that of the material of the anode 5, while the rare earth element oxide inhibits densification of the diffusion layer 50. As a result, the diffusion layer 50 has appropriate gas permeability and makes deformation of the element unit 3 less likely to occur. Therefore, the cell 1 having the diffusion layer 50 has improved adhesion between the element unit 3 and the metal plate 23, and improved durability.

[0060] This structure can be fabricated, for example, as follows. A solvent and a binder are added to powders of the materials for the diffusion layer 50, the anode 5, and the solid electrolyte layer 6, respectively, and slurries for the diffusion layer 50, the anode 5, and the solid electrolyte layer 6 are prepared using a ball mill or the like. Using the prepared slurries, green sheets for the diffusion layer 50, the anode 5, and the solid electrolyte layer 6 are fabricated by a sheet forming method. The green sheet for the diffusion layer 50 is laminated on the first surface 231 of the metal plate 23, and then the green sheet for the anode 5 and the green sheet for the solid electrolyte layer 6 are laminated thereon to obtain a laminate. If necessary, the laminate may be pressurized using a cold isostatic press (CIP) or the like. The resulting laminate is fired at a temperature of approximately 1000°C to 1200°C, and the diffusion-suppressing layer 7 and the cathode 8 are then formed, thereby obtaining the cell 1 according to this embodiment. The solid electrolyte layer 6 may also be fabricated using a vacuum process such as sputtering or a film-forming method such as thermal spraying, instead of the sheet forming method.

[0061] The diffusion layer 50 and the anode 5 have a smaller thermal expansion coefficient than the metal plate 23 and are less likely to shrink than the metal plate 23 during cooling. Therefore, the first portion 3a of the element unit 3, which is not in contact with the metal plate 23 and is located above the hole 23a, curves so as to protrude to the opposite side of the hole 23a. Furthermore, the diffusion layer 50 is relatively difficult to sinter, which makes it less likely for deformation of the element unit 3 to occur due to the difference in sintering shrinkage between the anode 5 and the solid electrolyte layer 6. As a result, when each green sheet is sintered, cracks caused by tensile stress generated by the metal plate 23 are less likely to occur in the first layer and / or other portions of the element unit 3.

[0062] <Configuration of electrochemical cell device> Next, an electrochemical cell device according to this embodiment using the above-described cell 1 will be described with reference to Figs. 3A to 3C. Fig. 3A is a perspective view showing an example of the electrochemical cell device according to the first embodiment. Fig. 3B is a cross-sectional view taken along line XX shown in Fig. 3A. Fig. 3C is a top view showing an example of the electrochemical cell device according to the first embodiment.

[0063] As shown in FIG. 3A, the cell stack device 10 includes a cell stack 11 having a plurality of cells 1 arranged (stacked) in the thickness direction of the element section 3 (the Y-axis direction shown in FIG. 1A), and a fixing member 12.

[0064] The fixing member 12 has a fixing material 13 and a support member 14. The support member 14 supports the cell 1. The fixing material 13 fixes the cell 1 to the support member 14. The support member 14 also has a support 15 and a gas tank 16. The support 15 and gas tank 16, which are the support member 14, are made of metal and are electrically conductive.

[0065] 3B, the support body 15 has insertion holes 15a into which the lower ends of the plurality of cells 1 are inserted. The lower ends of the plurality of cells 1 and the inner wall of the insertion holes 15a are joined with a fixing material 13.

[0066] The gas tank 16 has an opening for supplying a reaction gas to the cells 1 through the insertion holes 15a, and a recessed groove 16a located around the opening. The outer peripheral edge of the support 15 is joined to the gas tank 16 by a bonding material 21 filled in the recessed groove 16a of the gas tank 16.

[0067] In the example shown in FIG. 3A, fuel gas is stored in an internal space 22 formed by a support 15, which is the support member 14, and a gas tank 16. A gas circulation pipe 20 is connected to the gas tank 16. The fuel gas is supplied to the gas tank 16 through this gas circulation pipe 20, and is supplied from the gas tank 16 to a flow path 24 (see FIG. 1B) inside the cell 1. The fuel gas supplied to the gas tank 16 is generated in a reformer 102 (see FIG. 4), which will be described later.

[0068] The hydrogen-rich fuel gas can be produced by steam reforming the raw fuel, etc. When the fuel gas is produced by steam reforming, the fuel gas contains water vapor.

[0069] The example shown in FIG. 3A includes two rows of cell stacks 11, two supports 15, and a gas tank 16. Each of the two rows of cell stacks 11 has a plurality of cells 1. Each cell stack 11 is fixed to a corresponding support 15. The gas tank 16 has two through-holes on its top surface. A support 15 is disposed in each through-hole. An internal space 22 is formed by one gas tank 16 and two supports 15. The cell stack device 10 may include only one cell stack 11, or may include three or more cell stacks 11.

[0070] The shape of the insertion hole 15a is, for example, an oval shape when viewed from above. For example, the length of the insertion hole 15a in the arrangement direction of the cells 1, i.e., the thickness direction (Y-axis direction shown in FIG. 1A), is greater than the distance between the two end current collecting members 17 located at both ends of the cell stack 11. For example, the width of the insertion hole 15a is greater than the length of the cell 1 in the width direction (X-axis direction shown in FIG. 1A).

[0071] 3B, the joints between the inner walls of the insertion holes 15a and the lower ends of the cells 1 are filled with a fixing material 13 and solidified. This bonds and fixes the inner walls of the insertion holes 15a to the lower ends of the multiple cells 1, respectively, and also bonds and fixes the lower ends of the cells 1 to each other. The gas flow paths 2a of each cell 1 communicate with the internal space 22 of the support member 14 at their lower ends.

[0072] A material with low conductivity, such as glass, can be used for the fixing material 13 and the bonding material 21. Specific materials for the fixing material 13 and the bonding material 21 include amorphous glass, and in particular, crystallized glass.

[0073] As the crystallized glass, for example, any of materials such as SiO2-CaO, MgO-B2O3, La2O3-B2O3-MgO, La2O3-B2O3-ZnO, and SiO2-CaO-ZnO may be used, and in particular, SiO2-MgO materials may be used.

[0074] 3B, a conductive member 18 is interposed between adjacent cells 1 among the plurality of cells 1. The conductive member 18 electrically connects one adjacent cell 1 to the other adjacent cell 1 in series. More specifically, the conductive member 18 connects the fuel electrode 5 of one cell 1 to the air electrode 8 of the other cell 1. The conductive member 18 may be the current collecting member 27 shown in FIG. 1B, or may be a member separate from the current collecting member 27.

[0075] As shown in Fig. 3B, an end current collecting member 17 is electrically connected to the cell 1A located on the outermost side in the arrangement direction of the multiple cells 1. The end current collecting member 17 is connected to a conductive part 19 that protrudes outward from the cell stack 11. The conductive part 19 collects electricity generated by power generation in the cells 1 and extracts it to the outside. Note that the end current collecting member 17 is not shown in Fig. 3A.

[0076] 3C, the cell stack device 10 may be a single battery in which two cell stacks 11A and 11B are connected in series. In this case, the conductive part 19 of the cell stack device 10 may have a positive terminal 19A, a negative terminal 19B, and a connection terminal 19C.

[0077] The positive electrode terminal 19A is a positive electrode when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the positive electrode side end current collecting member 17 of the cell stack 11A. The negative electrode terminal 19B is a negative electrode when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the negative electrode side end current collecting member 17 of the cell stack 11B.

[0078] The connection terminal 19C electrically connects the end current collecting member 17 on the negative electrode side of the cell stack 11A and the end current collecting member 17 on the positive electrode side of the cell stack 11B.

[0079] Although not shown in Figures 3A to 3C, the cell stack device 10 may also be provided with a second gas tank at the top of the cell stack 11, which fixes the upper ends of multiple cells 1 and collects gas discharged from the flow path 24 inside the cells 1.

[0080] <module> Next, a module according to an embodiment of the present disclosure using the above-described cell stack device 10 will be described with reference to Fig. 4. Fig. 4 is an external perspective view showing the module according to the first embodiment. Fig. 4 shows a state in which the front and rear surfaces, which are part of the storage container 101, have been removed and the cell stack device 10 of the fuel cell stored inside has been pulled out to the rear.

[0081] 4, the module 100 includes a storage container 101 and a cell stack device 10 housed in the storage container 101. A reformer 102 is disposed above the cell stack device 10.

[0082] The reformer 102 reforms raw fuel such as natural gas or kerosene to generate fuel gas, which is then supplied to the cell 1. The raw fuel is supplied to the reformer 102 through a raw fuel supply pipe 103. The reformer 102 may also include a vaporizer 102a that vaporizes water, and a reformer 102b. The reformer 102b includes a reforming catalyst (not shown) and reforms the raw fuel into fuel gas. Such a reformer 102 can perform steam reforming, a highly efficient reforming reaction.

[0083] The fuel gas produced in the reformer 102 is supplied to the flow path 24 of the cell 1 (see FIG. 1B) through the gas distribution pipe 20, the gas tank 16, and the support member 14.

[0084] When the cell stack device 10 includes a second gas tank above the cell stack 11, the reformer 102 may be disposed in a location other than above the cell stack device 10. The raw fuel supply pipe 103, the gas circulation pipe 20, etc. may be disposed appropriately depending on the arrangement of the cell stack device 10 and the reformer 102.

[0085] Furthermore, in the module 100 having the above-described configuration, the temperature inside the module 100 during normal power generation becomes approximately 500°C to 1000°C as the cells 1 generate power.

[0086] In such a module 100, as described above, by accommodating the cell stack device 10, which has improved durability, the module 100 can be made to have improved durability.

[0087] <Module storage device> Fig. 5 is an exploded perspective view showing an example of a module housing device according to the first embodiment. The module housing device 110 according to this embodiment includes an outer case 111, the module 100 shown in Fig. 4, and auxiliary equipment (not shown). The auxiliary equipment operates the module 100. The module 100 and the auxiliary equipment are housed in the outer case 111. Note that some components are omitted in Fig. 5.

[0088] An exterior case 111 of a module accommodating device 110 shown in Fig. 5 has support columns 112 and an exterior plate 113. A partition plate 114 divides the interior of the exterior case 111 into upper and lower sections. The space above the partition plate 114 in the exterior case 111 is a module accommodating chamber 115 that accommodates the module 100, and the space below the partition plate 114 in the exterior case 111 is an accessory accommodating chamber 116 that accommodates accessory equipment for operating the module 100. Note that in Fig. 5, the accessory equipment accommodated in the accessory accommodating chamber 116 is omitted.

[0089] The partition plate 114 also has an air flow port 117 for allowing air from the auxiliary equipment housing chamber 116 to flow toward the module housing chamber 115. The exterior plate 113 that constitutes the module housing chamber 115 has an exhaust port 118 for exhausting air from within the module housing chamber 115.

[0090] In such a module housing device 110, as described above, the module housing chamber 115 is provided with the module 100 having improved durability, so that the module housing device 110 can have improved durability.

[0091] [Second embodiment] Fig. 6 is a cross-sectional view showing an example of an electrochemical cell according to the second embodiment, and Fig. 7 is an enlarged cross-sectional view of a region C shown in Fig. 6.

[0092] The element unit 3 of the cell 1A may have a diffusion layer 50 as a first layer facing the first surface 231 of the metal plate 23. As shown in Fig. 7, the diffusion layer 50 has a surface 500 located in the first region 3a on the side opposite the solid electrolyte layer 6. In the surface 500, a central portion 3a1 of the first region 3a is farther from the first surface 231 than an edge portion 3a2 of the first region 3a is.

[0093] In this way, the surface 500 of the diffusion layer 50 is formed so that the central portion 3a1 of the first portion 3a is farther from the first surface 231 than the edge portion 3a2 of the first portion 3a is, which reduces the likelihood of cracks in the diffusion layer 50 and / or peeling of the diffusion layer 50 from the metal plate 32 due to the difference in thermal expansion between the diffusion layer 50 and the metal plate 23. This improves the durability of the cell 1 according to this embodiment.

[0094] 7, in a cross section perpendicular to the first surface 231, the solid electrolyte layer 6 located in the first portion 3a may have an arch shape that protrudes to the opposite side of the hole 23a serving as the first hole.

[0095] In this way, the solid electrolyte layer 6 located at the first portion 3a has an arch shape that protrudes to the opposite side of the hole 23a, thereby improving the elasticity of the solid electrolyte layer 6 located at the first portion 3a in the thickness direction (Y-axis direction) and increasing the strength of the element portion 3 against bending and expansion / contraction, thereby further improving the durability of the cell 1.

[0096] Furthermore, when the diameter of the first opening 23a1 is d11 and the distance from the first surface 231 at the central portion 3a1 of the first section 3a to the diffusion layer 50 as the first layer is d12, d12 / d11≦0.95 may be satisfied. This increases the strength of the element section 3 against bending and expansion / contraction. This further improves the durability of the cell 1A.

[0097] Furthermore, when the diameter of first opening 23a1 is d11 and the distance from surface 500 of diffusion layer 50 serving as the first layer facing first surface 231 to solid electrolyte layer 6 is d13, d11 / d13≧1 may be satisfied. This increases the strength of element portion 3 against bending and expansion / contraction, further improving the durability of cell 1A.

[0098] [Third embodiment] Fig. 8 is a cross-sectional view showing an example of an electrochemical cell according to Embodiment 3. Fig. 9 is an enlarged cross-sectional view of region D shown in Fig. 8.

[0099] The element unit 3 of the cell 1B may have an anode 5 as a first layer facing the first surface 231 of the metal plate 23. As shown in Fig. 9, the anode 5 has a surface 51 located in the first region 3a on the side opposite the solid electrolyte layer 6. The surface 51 is such that a central portion 3a1 of the first region 3a is farther from the first surface 231 than an edge portion 3a2 of the first region 3a is.

[0100] In this way, surface 51 of fuel electrode 5 is formed so that center 3a1 of first portion 3a is farther from first surface 231 than edge 3a2 of first portion 3a is, which makes it less likely that cracks will occur in fuel electrode 5 and / or that fuel electrode 5 will peel off from metal plate 32 due to the difference in thermal expansion between fuel electrode 5 and metal plate 23. This improves the durability of cell 1 according to this embodiment.

[0101] Furthermore, as shown in FIG. 9, in a cross section perpendicular to the first surface 231, the solid electrolyte layer 6 located at the first portion 3a may have an arch shape that protrudes to the opposite side of the hole 23a serving as the first hole.

[0102] In this way, the solid electrolyte layer 6 located in the first portion 3a has an arch shape that protrudes to the opposite side of the hole 23a, which improves the elasticity of the solid electrolyte layer 6 located in the first portion 3a in the thickness direction (Y-axis direction) and increases the strength of the element portion 3 against bending and expansion / contraction, thereby further improving the durability of the cell 1B.

[0103] Furthermore, when the diameter of the first opening 23a1 is d21 and the distance from the first surface 231 at the central portion 3a1 of the first section 3a to the fuel electrode 5 as the first layer is d22, d22 / d21≦0.95 may be satisfied. This increases the strength of the element section 3 against bending and expansion / contraction. This further improves the durability of the cell 1B.

[0104] Furthermore, when the diameter of first opening 23a1 is d21 and the distance from surface 51 of fuel electrode 5, which serves as the first layer facing first surface 231, to solid electrolyte layer 6 is d23, d21 / d23≧1 may be satisfied. This increases the strength of element section 3 against bending and expansion / contraction, further improving the durability of cell 1B.

[0105] [Other embodiments] In the above-described embodiments, a fuel cell, a fuel cell stack device, a fuel cell module, and a fuel cell device are shown as examples of an "electrochemical cell," "electrochemical cell device," "module," and "module housing device." However, other examples may be an electrolysis cell, an electrolysis cell stack device, an electrolysis module, and an electrolysis device, respectively. The electrolysis cell has a first electrode and a second electrode, and decomposes water vapor into hydrogen and oxygen, or carbon dioxide into carbon monoxide and oxygen, when supplied with electric power. Furthermore, in the above-described embodiments, an oxide ion conductor or a hydrogen ion conductor is shown as an example of the electrolyte material of the electrochemical cell, but a hydroxide ion conductor may also be used. Such an electrolysis cell, an electrolysis cell stack device, an electrolysis module, and an electrolysis device can improve electrolysis performance.

[0106] The present disclosure has been described in detail above, but the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible within the scope that does not deviate from the gist of the present disclosure.

[0107] In one embodiment, (1) an electrochemical cell includes a metal plate having a first surface, a second surface opposite the first surface, and a plurality of holes including a first hole having a first opening located on the first surface; an element portion including a solid electrolyte layer, a first layer located between the first surface and the solid electrolyte layer, and a first electrode located on the opposite side of the first layer with the solid electrolyte layer interposed therebetween; Equipped with the element portion has a first portion that overlaps with the first opening portion in a plan view, On the surface of the first layer located opposite the solid electrolyte layer, the center of the first portion is farther from the first opening than the edge of the first portion.

[0108] (2) In the electrochemical cell of (1) above, in a cross section perpendicular to the first surface, the solid electrolyte layer located in the first portion may have an arch shape protruding to the opposite side of the first hole.

[0109] (3) In the electrochemical cell of (1) or (2) above, when the diameter of the first opening is d1 and the distance from the first surface to the first layer at the center of the first portion is d2, d2 / d1≦0.95 may be satisfied.

[0110] (4) In the electrochemical cell of any one of (1) to (3) above, when the diameter of the first opening is d1 and the distance from the surface of the first layer opposite to the first surface to the solid electrolyte layer is d3, d1 / d3≧1 may be satisfied.

[0111] In one embodiment, (5) the electrochemical cell device has a cell stack including any one of the electrochemical cells (1) to (4) above.

[0112] In one embodiment, the module (6) comprises the electrochemical cell device (5) described above, and a container for housing the electrochemical cell device.

[0113] In one embodiment, the module storage device (7) includes the module (6) and Auxiliary equipment for operating the module; and an exterior case that houses the module and the auxiliary equipment.

[0114] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0115] 1,1A,1B cells 3. Element section 5 Fuel electrode 6 Solid electrolyte layer 8 Air electrode 9. Encapsulating materials 10 Cell stack device 23 Metal plate 30 First Middle Class 40 restraint layer 50 Diffusion Layer 100 modules 110 Module storage device

Claims

1. a metal plate having a first surface, a second surface opposite to the first surface, and a plurality of holes including a first hole having a first opening located on the first surface; an element portion including a solid electrolyte layer, a first layer located between the first surface and the solid electrolyte layer, and a first electrode located on the opposite side of the first layer with the solid electrolyte layer interposed therebetween; Equipped with the element portion has a first portion that overlaps with the first opening portion in a plan view, The surface of the first layer located on the opposite side to the solid electrolyte layer has a center of the first portion that is farther from the first opening than an edge of the first portion. Electrochemical cell.

2. In a cross section perpendicular to the first surface, the solid electrolyte layer located at the first portion has an arch shape protruding to the opposite side of the first hole.

10. The electrochemical cell of claim 1.

3. When the diameter of the first opening is d1 and the distance from the first surface to the first layer at the center of the first portion is d2, d2 / d1≦0.95 10. The electrochemical cell of claim 1.

4. When the diameter of the first opening is d1 and the distance from the surface of the first layer opposite the first surface to the solid electrolyte layer is d3, d1 / d3≧1 10. The electrochemical cell of claim 1.

5. A cell stack comprising the electrochemical cell according to any one of claims 1 to 4. Electrochemical cell apparatus.

6. The electrochemical cell device according to claim 5 ; a container for housing the electrochemical cell device; A module comprising:

7. A module according to claim 6; Auxiliary equipment for operating the module; an exterior case that houses the module and the auxiliary equipment; A module housing device comprising:

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