Electrochemical cell, electrochemical cell device, module, and module storage device

Abstract

This electrochemical cell is provided with a metal plate, an element part, and a porous member. The metal plate has a first surface, a second surface, and a plurality of holes including the first hole. The second surface is positioned on the opposite side from the first surface. The first hole has a first opening that is positioned on the first surface. The element part has a solid electrolyte layer, a first layer that is positioned between the first surface and the solid electrolyte layer, and a first electrode that is positioned on the side of the solid electrolyte layer opposite from the first layer. The porous member is positioned at least in the first hole that is closer to the second surface than the first opening, and the material of the porous member is different from that of the first layer.

Description

Electrochemical cell, electrochemical cell device, module, and module housing device

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

[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.

[0003] International Publication No. 2016 / 124928

[0004] An electrochemical cell according to one aspect of the embodiment includes a metal plate, an element unit, and a porous member. 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 interposed therebetween. The porous member is located at least in the first hole, closer to the second surface than the first opening, and is made of a different material from the first layer.

[0005] The electrochemical cell device of the present disclosure also includes a cell stack including the electrochemical cell described above.

[0006] The module of the present disclosure includes the electrochemical cell device described above and a container that houses the electrochemical cell device.

[0007] 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.

[0008] FIG. 1A is a plan view showing an example of an electrochemical cell according to an embodiment. FIG. 1B is a cross-sectional view taken along line A-A in FIG. 1A. FIG. 1C is a cross-sectional view showing another example of an electrochemical cell according to an embodiment. FIG. 2A is a partial cross-sectional view showing an example of region B shown in FIG. 1B. FIG. 2B is a partial cross-sectional view showing another example of region B shown in FIG. 1B. FIG. 3A is a partial cross-sectional view showing yet another example of region B shown in FIG. 1B. FIG. 3B is a partial cross-sectional view showing yet another example of region B shown in FIG. 1B. FIG. 3C is a partial cross-sectional view showing yet another example of region B shown in FIG. 1B. FIG. 3D is a partial cross-sectional view showing yet another example of region B shown in FIG. 1B. FIG. 4A is a partial cross-sectional view showing another example of region B shown in FIG. 1B. FIG. 4B is a partial cross-sectional view showing another example of region B shown in FIG. 1B. FIG. 5 is a diagram showing an example of a method for manufacturing an electrochemical cell according to an embodiment. FIG. 6A is a perspective view showing an example of an electrochemical cell device according to an embodiment. FIG. 6B is a cross-sectional view taken along line X-X in FIG. 6A. Fig. 6C is a top view showing an example of an electrochemical cell device according to an embodiment. Fig. 7 is an external perspective view showing an example of a module according to an embodiment. Fig. 8 is an exploded perspective view schematically showing an example of a module housing device according to an embodiment.

[0009] The above-described fuel cell stack device has room for improvement in terms of durability.

[0010] Therefore, there is a need to provide an electrochemical cell, an electrochemical cell device, a module, and a module housing device that can improve durability.

[0011] 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 disclosure is not limited to the embodiments described below.

[0012] 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.

[0013] 1A to 2B, an electrochemical cell according to an 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.

[0014] Fig. 1A is a plan view showing an example of an electrochemical cell according to an embodiment. Fig. 1B is a cross-sectional view taken along line A-A 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.

[0015] 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 description. Furthermore, components similar to those in the electrochemical cells shown in Figures 1A and 1B are denoted by the same reference numerals, and their description will be omitted or simplified.

[0016] 1A and 1B, 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 an anode 5, a solid electrolyte layer 6, and a cathode 8.

[0017] The anode 5 is a second electrode that comes into contact with the fuel gas, which is a reducing gas. The anode 5 has gas permeability. The open porosity of the anode 5 may be, for example, in the range of 30% to 50%, particularly 35% to 45%. The open porosity of the anode 5 may also be referred to as the porosity or void ratio of the anode 5.

[0018] A generally known material can be used for the fuel electrode 5. The fuel electrode 5 is made of a porous conductive ceramic, such as calcium oxide, magnesium oxide, or ZrO in which a rare earth element oxide is solid-solved. ２and Ni and / or NiO may be used. 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 ZrO in which a rare earth element oxide is solid-solved may be used. ２ The stabilized zirconia may contain partially stabilized zirconia. The anode 5 is made of CeO in which La, Nd, or Yb is solid-solved. ２ may include:

[0019] 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 leakage of fuel gas and oxygen-containing gas to occur.

[0020] The material of the solid electrolyte layer 6 is, for example, ZrO in which 3 mol % to 15 mol % of rare earth element oxide is dissolved. ２ The rare earth element oxide may contain, 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 be, for example, ZrO in which Yb, Sc, or Gd is solid-solved. ２ and CeO in which La, Nd or Yb is solid-solved. ２ and BaZrO in which Sc or Yb is solid-solved. ３ and BaCeO in which Sc or Yb is solid-solved. ３ may include:

[0021] 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%, particularly 30% to 50%. The open porosity of the air electrode 8 may also be referred to as the porosity of the air electrode 8.

[0022] There are no particular limitations on the material of the air electrode 8 as long as it is a material that is generally used for air electrodes. ３ Conductive ceramics such as perovskite oxides may also be used.

[0023] 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 O ３ , La ｘ Sr １－ｘ MnO ３ , La ｘ Sr １－ｘ FeO ３ , La ｘ Sr １－ｘ CoO ３ Here, x is 0<x<1, and y is 0<y<1.

[0024] 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 a specific element to diffuse. For example, when an element such as Sr (strontium) contained in the air electrode 8 diffuses into the solid electrolyte layer 6, the solid electrolyte layer 6 becomes covered with SrZrO ３ The diffusion suppression layer 7 makes it difficult for specific elements such as Sr to diffuse, thereby forming a resistive layer such as SrZrO ３ This makes it difficult for compounds such as

[0025] The material of the diffusion-preventing layer 7 is not particularly limited as long as it generally makes it difficult for elements to diffuse between the air electrode 8 and the solid electrolyte layer 6. The material of the diffusion-preventing layer 7 is, for example, cerium oxide (CeO) in which rare earth elements other than Ce (cerium) are dissolved. ２ ) may be included. Examples of such rare earth elements include Gd (gadolinium) and Sm (samarium).

[0026] A sealant 9 different from the solid electrolyte layer 6 may be positioned on the side of the fuel electrode 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. Examples of crystallized glass include SiO ２ -CaO system, MgO-B ２ O ３System, La ２ O ３ -B ２ O ３ -MgO system, La ２ O ３ -B ２ O ３ -ZnO-based, SiO ２ -CaO-ZnO system materials, etc., may be used, and in particular SiO ２ A -MgO-based material may also be used. The sealing material 9 may have electrical insulation properties. The material of the sealing material 9 may be the same as the material of the solid electrolyte layer 6. The sealing material 9 may be positioned so as to surround the side surface of the element portion 3. The sealing material 9 may be in contact with the air electrode 8 or may be spaced apart from the air electrode 8.

[0027] 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 anode 5. 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, 0.3 mm to 0.4 mm.

[0028] The metal plate 23 is electrically conductive. The metal plate 23 may be, for example, a member made of a metal 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.

[0029] The metal plate 23 also has a plurality of holes 23a. The holes 23a 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. The aperture ratio of the region of the metal plate 23 where the holes 23a are formed, when viewed in a plan view along the Y-axis direction, may be, for example, 10% or more. The metal plate 23 may have a coating covering the wall surfaces of the holes 23a. The metal plate 23 may not have a coating on the wall surfaces of the holes 23a.

[0030] The metal plate 23 may be gas permeable, for example. The sealing material 9 may be located on the side surface of the metal plate 23.

[0031] The flow path member 25 is located on the second surface 232 side of the metal plate 23. For example, the flow path member 25 is fixed and electrically joined at the contact portion with the second surface 232 by welding or the like. The flow path member 25 may be fixed and electrically joined to the metal plate 23 by a conductive seal 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 sealant 9 may be located on the side surface of the flow path member 25.

[0032] The flow path member 25 is further fixed and electrically joined to the current collecting member 27 by welding or the like. The current collecting member 27 may be fixed and electrically joined to the flow path member 25 by a conductive adhesive, brazing material, or the like. The current collecting member 27 is fixed and electrically joined 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, for example, through a slit in the current collecting member 27 and the adhesive.

[0033] 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. For example, the flow path member 25 may have a reduction-resistant coating on the surface facing the flow path 24. The flow path member 25 may also have an oxidation-resistant coating on the surface facing the flow path 26. These coatings may be conductive.

[0034] 1B , the flow path member 25 and the current collecting member 27 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.

[0035] 1C is a cross-sectional view showing another example of an electrochemical cell according to the embodiment. As shown in FIG. 1C, a flow path member 25 may be integrated with a current collecting member 27 and have a first convex portion that protrudes toward an adjacent cell 1 along the Y-axis direction and a second convex portion that protrudes toward the opposite side from the first convex portion.

[0036] <Details of Electrochemical Cell> Next, details of the electrochemical cell according to this embodiment will be further described with reference to Figures 2A and 2B. Figure 2A is a partial cross-sectional view showing an example of region B shown in Figure 1B.

[0037] 2A, the cell 1 includes an element unit 3 (see FIG. 1B) and a metal plate 23. The element unit 3 has an anode 5 as a first layer 4 located between a first surface 231 of the metal plate 23 and a solid electrolyte layer 6.

[0038] The metal plate 23 has a plurality of holes 23a. The holes 23a have 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. The diameter (opening diameter) of the first opening 23a1 can be, for example, 100 μm or more. The diameter (opening diameter) of the first opening 23a1 may also be, for example, 0.1 mm to 1.0 mm, particularly 0.3 mm to 0.6 mm.

[0039] The cell 1 further includes a porous member 30. The porous member 30 is located inside a first hole 23a among the plurality of holes 23a. The porous member 30 is located at least in a hole 23a that is closer to the second surface 232 than the first opening 23a1.

[0040] In this way, by positioning the porous member 30 in the hole 23a closer to the second surface 232 than the first opening 23a1, the material of the anode 5 is less likely to enter the hole 23a. This makes it less likely that cracks will occur in the anode 5 and / or the metal plate 23 due to the difference in thermal expansion between the anode 5 as the first layer 4 and the metal plate 23. This improves the durability of the cell 1 according to this embodiment.

[0041] The porous member 30 is gas permeable. The porosity of the porous member 30 may be greater than the porosity of the anode 5 as the first layer 4. This ensures gas permeability through the pores 23a while making it difficult for the material of the anode 5 to enter the pores 23a. This makes it difficult for cracks to occur in the anode 5 and / or the metal plate 23 due to the difference in thermal expansion between the anode 5 as the first layer 4 and the metal plate 23. This improves the durability of the cell 1 according to this embodiment.

[0042] The porous member 30 is made of a different material from the anode 5 serving as the first layer 4. Specifically, the material of the porous member 30 has smaller thermal contraction than the material of the anode 5. This makes it less likely that cracks will occur in the porous member 30 and / or the metal plate 23, or that voids will form between the porous member 30 and the wall surfaces of the holes 23a, which would otherwise be caused by a difference in thermal expansion between the porous member 30 and the metal plate 23, and makes it even more difficult for the material of the anode 5 to enter the holes 23a. This improves the durability of the cell 1 according to this embodiment.

[0043] The porous member 30 may be, for example, a ceramic containing one or more of alumina, forsterite, and titania. The porous member 30 may be a sintered body or a green compact. Alternatively, the porous member 30 may be a mesh-like or fibrous metal material.

[0044] The porous member 30 may contain metal particles and oxide particles, or may contain a metal catalyst.

[0045] Furthermore, the porous member 30 may be positioned so as to block at least a portion of the hole 23a serving as the first hole. This makes it difficult for the material of the first layer 4 to enter the hole 23a. This reduces the likelihood of cracks occurring in the anode 5 and / or the metal plate 23 due to the difference in thermal expansion between the anode 5 serving as the first layer 4 and the metal plate 23, thereby improving the durability of the cell 1 according to this embodiment. Here, "blocking at least a portion" means that the hole 23a is blocked by the porous member 30 at least in a portion between the first opening 23a1 and the second opening 23a2. In other words, when a fluid flowing through the hole 23a passes between the first opening 23a1 and the second opening 23a2, it necessarily passes through the pores of the porous member 30 in at least a portion of the space between them.

[0046] The porous member 30 may also have a contact portion 300 that contacts the first layer 4. This makes it less likely for the anode 5 as the first layer 4 to peel from the metal plate 23 due to the difference in thermal expansion between the anode 5 and the metal plate 23. This improves the durability of the cell 1 according to this embodiment.

[0047] 2B is a partial cross-sectional view showing another example of region B shown in FIG. 2B. As shown in FIG. 2B, the porous member 30 may be positioned so as to cover the second surface 232. This makes it less likely for the porous member 30 to fall off the metal plate 23, thereby improving the durability of the cell 1. Note that the porous member 30 only needs to cover at least a portion of the second surface 232, and may also cover the entire surface of the second surface 232.

[0048] 3A to 3D are partial cross-sectional views showing yet another example of region B shown in Fig. 1B. As shown in Fig. 3A to 3D, hole 23a may have a void 230 on the second opening 23a2 side where porous member 30 is not located.

[0049] As shown in FIG. 3B, the porous member 30 may have a contact portion 300 that contacts the anode 5 as the first layer 4 and is located closer to the second surface 232 than the first opening 23a1.

[0050] Furthermore, as shown in FIG. 3C, the porous member 30 may have a portion where the contact portion 300 that contacts the anode 5 as the first layer 4 is located closer to the solid electrolyte layer 6 than the first opening 23a1.

[0051] 3D , porous member 30 may have, for example, a contact portion 300 on the first opening 23a1 side that contacts the anode 5 as the first layer 4, and a non-contact portion 301 that is spaced apart from the anode 5. The distance in the Y-axis direction between contact portion 300 and first opening 23a1 may be, for example, equal to or less than the thickness of first layer 4. This makes it less likely that cracks will occur in first layer 4 and / or metal plate 23 due to the difference in thermal expansion between first layer 4 and metal plate 23.

[0052] 4A and 4B are partial cross-sectional views showing another example of region B shown in FIG. 1B. As shown in FIG. 4A, cell 1 may have a first intermediate layer 40 located between anode 5 and metal plate 23. First intermediate layer 40 is an example of first layer 4 located between first surface 231 of metal plate 23 and solid electrolyte layer 6. First intermediate layer 40 joins anode 5 and metal plate 23 and fixes element unit 3 (see FIG. 1B) to metal plate 23.

[0053] The first intermediate layer 40 may be conductive. The first intermediate layer 40 may be made of, for example, conductive particles such as Ni and TiO ２ , rare earth element oxides (Y ２ O ３ , CeO ２ etc.), transition metal oxides (Fe ２ O ３ The first intermediate layer 40 may contain inorganic oxides such as silicon dioxide (SiO 2 , CuO, etc.). The first intermediate layer 40 may contain metal particles and conductive oxide particles. These components may include the components contained in the porous member 30.

[0054] The first intermediate layer 40 may be gas permeable. When the first intermediate layer 40 is gas permeable, the first intermediate layer 40 may be positioned so as to cover the holes 23a.

[0055] The first intermediate layer 40 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.

[0056] The cell 1 may further include a constraining layer 50 located between the fuel electrode 5 and the first intermediate layer 40. The constraining layer 50 cooperates with the solid electrolyte layer 6 to make the element portion 3 less susceptible to warping, bending, and the like.

[0057] The material of the constraining layer 50 exhibits a shrinkage rate similar to that of the material of the solid electrolyte layer 6 during firing. The material of the constraining layer 50 may be the same as the material of the solid electrolyte layer 6. The element portion 3 (see FIG. 1B ) obtained by sandwiching the material of the anode 5 between the material of the solid electrolyte layer 6 and the material of the constraining layer 50 and firing the resulting material has little warping or deformation.

[0058] The constraining layer 50 may or may not be gas permeable. When the constraining layer 50 has gas barrier properties comparable to those of the solid electrolyte layer 6, the constraining layer 50 may have a plurality of through-holes 50a penetrating through the thickness direction (Y-axis direction) of the cell 1 so as not to inhibit the inflow of fuel gas to the anode 5. When the constraining layer 50 has through-holes 50a, a portion of the first intermediate layer 40 and / or a diffusion layer 60 (described later) may be located inside the through-holes 50a.

[0059] The cell 1 may further include a diffusion layer 60 in contact with the anode 5. The diffusion layer 60 is located between the anode 5 and the first intermediate layer 40. The diffusion layer 60 is gas permeable and allows the fuel gas flowing through the flow passage 24 to pass through to the anode 5. The open porosity of the diffusion layer 60 may be in the range of, for example, 30% to 50%, particularly 35% to 45%.

[0060] The material of the diffusion layer 60 may be a porous conductive ceramic, such as a ceramic containing calcium oxide, magnesium oxide, or stabilized zirconia or partially stabilized zirconia in which a rare earth element oxide is solid-solved, and Ni and / or NiO. The rare earth element oxide may contain a plurality of rare earth elements selected from, for example, Sc, Y, La, Nd, Sm, Gd, Dy, and Yb.

[0061] The diffusion layer 60 may contain a larger amount of rare earth element than the fuel electrode 5. The diffusion layer 60 may contain zirconia in which a rare earth element oxide is dissolved, and particles of the rare earth element oxide.

[0062] The material of the diffusion layer 60 reduces the shrinkage of the anode 5 during firing, for example. This allows the degree of shrinkage of the anode 5 and the solid electrolyte layer 6 during firing to be similar, and therefore, the cell 1 having the diffusion layer 60 has less warpage or deformation of the element portion 3 (see FIG. 1B ).

[0063] Furthermore, the material of the diffusion layer 60 is similar to the material of the anode 5. The temperature at which the material of the diffusion layer 60 begins to shrink is close to that of the material of the anode 5. When the diffusion layer 60 contains a rare earth element oxide, the rare earth element oxide inhibits densification of the diffusion layer 60. This allows the diffusion layer 60 to have appropriate gas permeability while making the element unit 3 (see FIG. 1B) less likely to deform. Therefore, the cell 1 having the diffusion layer 60 has improved adhesion between the element unit 3 and the metal plate 23, improving durability.

[0064] The porous member 30 is located inside the first hole 23a among the plurality of holes 23a. The porous member 30 is located at least in the hole 23a that is closer to the second surface 232 than the first opening 23a1.

[0065] In this way, by positioning the porous member 30 in the hole 23a closer to the second surface 232 than the first opening 23a1, the material of the first intermediate layer 40 is less likely to enter the hole 23a. This makes it less likely that cracks will occur in the first intermediate layer 40 and / or the metal plate 23 due to the difference in thermal expansion between the first intermediate layer 40 as the first layer 4 and the metal plate 23. This improves the durability of the cell 1 according to this embodiment.

[0066] The porous member 30 is gas permeable. The porosity of the porous member 30 may be greater than the porosity of the first intermediate layer 40 serving as the first layer 4. This ensures gas permeability through the pores 23a while making it difficult for the material of the first intermediate layer 40 to enter the pores 23a. This makes it difficult for cracks to occur in the first intermediate layer 40 and / or the metal plate 23 due to the difference in thermal expansion between the first intermediate layer 40 serving as the first layer 4 and the metal plate 23. This improves the durability of the cell 1 according to this embodiment.

[0067] The porous member 30 is made of a different material from the first intermediate layer 40 serving as the first layer 4. Specifically, the material of the porous member 30 has smaller thermal contraction than the material of the first intermediate layer 40. This makes it less likely that cracks will occur in the porous member 30 and / or the metal plate 23, or that voids will form between the porous member 30 and the wall surfaces of the holes 23a, which are caused by the difference in thermal expansion between the porous member 30 and the metal plate 23, and makes it even more difficult for the material of the first intermediate layer 40 to enter the holes 23a. This improves the durability of the cell 1 according to this embodiment.

[0068] As shown in FIG. 4B , the cell 1 may also have a diffusion layer 60 as the first layer 4 facing the first surface 231 of the metal plate 23 .

[0069] The porous member 30 is located inside the first hole 23a among the plurality of holes 23a. The porous member 30 is located at least in the hole 23a that is closer to the second surface 232 than the first opening 23a1.

[0070] In this way, by positioning the porous member 30 in the hole 23a closer to the second surface 232 than the first opening 23a1, the material of the diffusion layer 60 is less likely to enter the hole 23a. This makes it less likely that cracks will occur in the diffusion layer 60 and / or the metal plate 23 due to the difference in thermal expansion between the diffusion layer 60 as the first layer 4 and the metal plate 23. This improves the durability of the cell 1 according to this embodiment.

[0071] The porous member 30 is gas permeable. The porosity of the porous member 30 may be greater than the porosity of the diffusion layer 60 serving as the first layer 4. This ensures gas permeability through the holes 23a while making it difficult for the material of the diffusion layer 60 to enter the holes 23a. This makes it difficult for cracks to occur in the diffusion layer 60 and / or the metal plate 23 due to the difference in thermal expansion between the diffusion layer 60 serving as the first layer 4 and the metal plate 23. This improves the durability of the cell 1 according to this embodiment.

[0072] The porous member 30 is made of a different material from the diffusion layer 60 serving as the first layer 4. Specifically, the material of the porous member 30 has smaller thermal contraction than the material of the diffusion layer 60. This makes it less likely that cracks will occur in the porous member 30 and / or the metal plate 23, or that voids will form between the porous member 30 and the wall surfaces of the holes 23a, which are caused by the difference in thermal expansion between the porous member 30 and the metal plate 23, and makes it even more difficult for the material of the diffusion layer 60 to enter the holes 23a. This improves the durability of the cell 1 according to this embodiment.

[0073] <Method of Manufacturing Electrochemical Cell> Fig. 5 is a diagram showing an example of a method of manufacturing an electrochemical cell according to an embodiment. Note that in Fig. 5, the steps of arranging the sealing material 9, the flow path member 25, and the current collecting member 27 shown in Fig. 1B are omitted.

[0074] First, a metal plate 23 having a plurality of holes 23a is prepared. Next, a composite member 80 is fabricated by disposing porous members 30 inside the holes 23a (step S1). For example, the composite member 80 may be fabricated by applying ink containing the material of the porous members 30 inside the holes 23a and then performing a heat treatment.

[0075] Next, the fuel electrode 5 is disposed on the first surface 231 of the metal plate 23 (step S2). For example, the fuel electrode 5 can be formed by applying ink containing the material of the fuel electrode 5 onto the first surface 231 and performing a heat treatment.

[0076] Next, the solid electrolyte layer 6 is disposed on the anode 5 (step S3). For example, the solid electrolyte layer 6 can be formed by depositing a film of the material of the solid electrolyte layer 6 on the surface of the anode 5 by vacuum deposition or the like.

[0077] Next, the diffusion-preventing layer 7 and the air electrode 8 are disposed on the solid electrolyte layer 6 (step S4). For example, the diffusion-preventing layer 7 and the air electrode 8 can be formed by applying ink containing the material of the diffusion-preventing layer 7 to the solid electrolyte layer 6, drying it, and then applying ink containing the material of the air electrode 8 and performing a heat treatment. In this manner, the cell 1 having the metal plate 23 and the element portion 3 can be fabricated.

[0078] <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 Figures 6A to 6C. Figure 6A is a perspective view showing an example of an electrochemical cell device according to an embodiment. Figure 6B is a cross-sectional view taken along line XX shown in Figure 6A. Figure 6C is a top view showing an example of an electrochemical cell device according to an embodiment.

[0079] As shown in Figure 6A, the cell stack device 10 comprises a cell stack 11 having multiple cells 1 arranged (stacked) in the thickness direction of the element section 3 (the Y-axis direction shown in Figure 1A), and a fixing member 12.

[0080] 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 the gas tank 16, which are the support member 14, are made of metal and are electrically conductive.

[0081] 6B, 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 fixing material 13.

[0082] 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.

[0083] In the example shown in Fig. 6A, fuel gas is stored in an internal space 22 (see Fig. 6B) formed by a support body 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. 7), which will be described later.

[0084] 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.

[0085] The example shown in FIG. 6A 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. The 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.

[0086] 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 ).

[0087] 6B , the joints between the inner walls of the insertion holes 15a and the lower ends of the cells 1 are filled with and solidified with fixing material 13. 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.

[0088] 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.

[0089] Examples of the crystallized glass include SiO ２ -CaO system, MgO-B ２ O ３ System, La ２ O ３ -B ２ O ３ -MgO-based, La ２ O ３ -B ２ O ３ -ZnO-based, SiO ２ -CaO-ZnO system materials, etc., may be used, and in particular SiO ２ - MgO-based materials may also be used.

[0090] 6B , 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.

[0091] 6B, an end current collecting member 17 is electrically connected to the cell 1 positioned outermost in the arrangement direction of the multiple cells 1. The end current collecting member 17 is connected to a conductive portion 19 that protrudes outside the cell stack 11. The conductive portion 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. 6A.

[0092] 6C, the cell stack device 10 may be a single battery in which two cell stacks 11A, 11B are connected in series. In such a case, the conductive portion 19 of the cell stack device 10 may have a positive terminal 19A, a negative terminal 19B, and a connection terminal 19C.

[0093] The positive electrode terminal 19A is a positive electrode when the power generated by the cell stack 11 is output to the outside. The positive electrode terminal 19A is electrically connected to the end current collector 17 on the positive electrode side 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. The negative electrode terminal 19B is electrically connected to the end current collector 17 on the negative electrode side of the cell stack 11B.

[0094] The connection terminal 19C electrically connects the end current collecting member 17 on the negative electrode side of the cell stack 11A to the end current collecting member 17 on the positive electrode side of the cell stack 11B.

[0095] Although not shown in Figures 6A to 6C, 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.

[0096] <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. 7. Fig. 7 is an external perspective view showing an example of a module according to an embodiment. Fig. 7 shows a state in which the front and rear surfaces, which are parts of the storage container 101, have been removed and the cell stack device 10 of the fuel cell stored inside has been removed to the rear.

[0097] 7, 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.

[0098] 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 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.

[0099] 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.

[0100] Note that, 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, and the like may be disposed as appropriate depending on the arrangement of the cell stack device 10 and the reformer 102.

[0101] 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.

[0102] In such a module 100, as described above, the durability of the module 100 can be improved by accommodating the cell stack device 10, which has improved durability.

[0103] <Module Enclosure Device> Fig. 8 is an exploded perspective view schematically illustrating an example of a module enclosure device according to an embodiment. The module enclosure device 110 according to this embodiment includes an outer case 111, the module 100 shown in Fig. 7, 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. 8.

[0104] An exterior case 111 of a module accommodating device 110 shown in Fig. 8 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 accessories that operate the module 100. Note that in Fig. 8, the accessories accommodated in the accessory accommodating chamber 116 are omitted from the illustration.

[0105] 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.

[0106] In such a module accommodating device 110, as described above, the module 100 with improved durability is provided in the module accommodating chamber 115, thereby making it possible to provide a module accommodating device 110 with improved durability.

[0107] 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 decomposes 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 electrolysis cells, electrolysis cell stack devices, electrolysis modules, and electrolysis devices can improve durability. Solid oxide fuel cells and electrolysis cells are collectively referred to as solid oxide electrochemical cells.

[0108] 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.

[0109] In one embodiment, (1) an electrochemical cell includes: 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 in the first surface; an element portion having 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; and a porous member located at least in the first hole closer to the second surface than the first opening, the porous member being made of a different material from the first layer.

[0110] (2) In the electrochemical cell of (1) above, the porous member may be positioned so as to block at least a portion of the first hole.

[0111] (3) In the electrochemical cell of (1) or (2), the first layer may be a second electrode in contact with the solid electrolyte layer, and the porous member may have a contact portion in contact with the first layer.

[0112] (4) The electrochemical cell of (1) or (2) above may further include a second electrode located between the first layer and the solid electrolyte layer and made of a material different from that of the porous member, and the porous member may have a contact portion in contact with the first layer.

[0113] (5) In the electrochemical cell of (3) or (4) above, the contact portion may have a portion located closer to the solid electrolyte layer than the first opening.

[0114] (6) In the electrochemical cell of (3) or (4) above, the contact portion may have a portion located at the first opening or closer to the second surface than the first opening.

[0115] (7) In the electrochemical cell of any one of (1) to (6) above, the porous member may cover at least a portion of the second surface.

[0116] (8) In the electrochemical cell of any one of (1) to (7) above, the porosity of the porous member may be greater than the porosity of the first layer.

[0117] (9) In the electrochemical cell of any one of (1) to (8) above, the porous member may be a ceramic containing one or more of alumina, forsterite, and titania.

[0118] (10) In the electrochemical cell of any one of (1) to (9) above, the porous member may contain metal particles and oxide particles.

[0119] (11) In the electrochemical cell of any one of (1) to (10) above, the porous member may contain a metal catalyst.

[0120] (12) In the electrochemical cell of any one of (1) to (11) above, the first opening may have a diameter of 100 μm or more.

[0121] In one embodiment, (13) an electrochemical cell device has a cell stack including any one of the electrochemical cells (1) to (12) above.

[0122] In one embodiment, (14) a module includes the electrochemical cell device of (13) above, and a container that houses the electrochemical cell device.

[0123] In one embodiment, (15) a module housing device includes the module of (14) above, an auxiliary device for operating the module, and an exterior case for housing the module and the auxiliary device.

[0124] 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.

[0125] REFERENCE SIGNS LIST 1 cell 3 element section 4 first layer 5 fuel electrode 6 solid electrolyte layer 8 air electrode 9 sealing material 10 cell stack device 23 metal plate 30 porous member 40 first intermediate layer 50 constraining layer 60 diffusion layer 100 module 110 module housing device

Claims

1. An electrochemical cell comprising: 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 having 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 in between; and a porous member located at least in the first hole closer to the second surface than the first opening, the porous member being made of a different material from the first layer.

2. The electrochemical cell according to claim 1, wherein the porous member is positioned so as to block at least a portion of the first hole.

3. An electrochemical cell according to claim 1 or 2, wherein the first layer is a second electrode in contact with the solid electrolyte layer, and the porous member has a contact portion in contact with the first layer.

4. An electrochemical cell according to claim 1 or 2, further comprising a second electrode located between the first layer and the solid electrolyte layer and made of a material different from that of the porous member, the porous member having a contact portion in contact with the first layer.

5. The electrochemical cell according to claim 3 or 4, wherein the contact portion has a portion located closer to the solid electrolyte layer than the first opening.

6. The electrochemical cell according to claim 3 or 4, wherein the contact portion has a portion located at the first opening or closer to the second surface than the first opening.

7. The electrochemical cell according to any one of claims 1 to 6, wherein the porous member covers at least a portion of the second surface.

8. An electrochemical cell according to any one of claims 1 to 7, wherein the porosity of the porous member is greater than the porosity of the first layer.

9. The electrochemical cell according to any one of claims 1 to 8, wherein the porous member is a ceramic containing one or more of alumina, forsterite, and titania.

10. The electrochemical cell according to any one of claims 1 to 9, wherein the porous member contains metal particles and oxide particles.

11. The electrochemical cell according to any one of claims 1 to 10, wherein the porous member contains a metal catalyst.

12. An electrochemical cell according to any one of claims 1 to 11, wherein the diameter of the first opening is 100 μm or more.

13. An electrochemical cell device comprising a cell stack comprising the electrochemical cell according to any one of claims 1 to 12.

14. A module comprising the electrochemical cell device according to claim 13 and a container for housing the electrochemical cell device.

15. A module housing device comprising: the module according to claim 14; an auxiliary device for operating said module; and an exterior case for housing said module and said auxiliary device.

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