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

Abstract

An electrochemical cell according to the present invention comprises a metal plate and an element part. The metal plate has a first surface, a second surface, and a plurality of through holes which include at least one first hole. The second surface is located on the opposite side from the first surface. The plurality of through holes each have a first opening which is located on the first surface. The element part has a first layer which faces the first surface, a solid electrolyte layer, and a first electrode which is located on the opposite side of the solid electrolyte layer from the first layer. The first layer has a protrusion part which extends into the first hole. The protrusion part covers the edge of the first opening of the first hole and at least a portion of the wall surface of the first hole.

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. 2020 / 218431

[0004] 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 through holes including at least one first hole. The second surface is located opposite the first surface. The plurality of through holes have a first opening located in the first surface. The element unit includes a first layer facing the first surface, a solid electrolyte layer, and a first electrode located on the opposite side of the first layer with the solid electrolyte layer in between. The first layer has a protrusion extending into the first hole. The protrusion covers the edge of the first opening of the first hole and at least a portion of the wall surface of the first hole.

[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 the first 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 the first embodiment. FIG. 2A is a cross-sectional view showing an enlarged view of region B in FIG. 1B. FIG. 2B is a partial cross-sectional view showing another example of an electrochemical cell according to the first embodiment. FIG. 2C is a partial cross-sectional view showing another example of an electrochemical cell according to the first embodiment. FIG. 3A is a perspective view showing an example of an electrochemical cell device according to the first embodiment. FIG. 3B is a cross-sectional view taken along line X-X in FIG. 3A. FIG. 3C is a top view showing an example of an electrochemical cell device according to the first embodiment. FIG. 4 is an external perspective view showing an example of a module according to the first embodiment. FIG. 5 is an exploded perspective view schematically showing an example of a module housing device according to the first embodiment. FIG. 6 is a cross-sectional view showing an example of an electrochemical cell according to the second embodiment. FIG. 7A is a cross-sectional view showing an enlarged view of region C in FIG. 6. FIG. 7B is a partial cross-sectional view showing another example of an electrochemical cell according to the second embodiment. Fig. 8 is a cross-sectional view showing an example of an electrochemical cell according to the third embodiment, and Fig. 9 is an enlarged cross-sectional view of a region D shown in Fig. 8 .

[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 2C, 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.

[0014] 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 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 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 elements such as Sr to diffuse, and thus the resistance layer of 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] 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.

[0027] The first intermediate layer 30 may be conductive. The first intermediate layer 30 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 30 may contain inorganic oxides such as titanium dioxide (TiO, CuO, etc.). The first intermediate layer 30 may contain metal particles and conductive oxide particles.

[0028] 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 32a, which will be described later.

[0029] A sealant 9 different from the solid electrolyte layer 6 may be positioned on the side surfaces of the first intermediate layer 30 and 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. Examples of 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 The sealing material 9 may be made of the same material as the solid electrolyte layer 6.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] The metal plate 23 also has a plurality of through holes 23a. The through 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 through holes 23a. The diameter (opening diameter) of the through 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 through 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 through holes 23a. The metal plate 23 may not have a coating on the wall surfaces of the through holes 23a.

[0034] 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.

[0035] 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 metal plate 23 may have one or more protrusions protruding toward the flow path member 25. Furthermore, a sealant 9 may be located on the side surface of the flow path member 25.

[0036] 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 via the slits in the current collecting member 27 and the adhesive.

[0037] 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.

[0038] Furthermore, the surface of the first intermediate layer 30 that is not in contact with the metal plate 23 and the element portion 3 may be covered with a sealing material 9 .

[0039] 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.

[0040] 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.

[0041] <Details of Electrochemical Cell> Next, details of the electrochemical cell according to this embodiment will be further described with reference to Figures 2A to 2C. Figure 2A is an enlarged cross-sectional view of region B shown in Figure 1B.

[0042] 2A , the cell 1 includes a metal plate 23 and an element portion 3. The metal plate 23 has a through-hole 23a. The through-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.

[0043] 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 protruding portion 32. The protruding portion 32 extends into the inside of a first hole, which is at least one of the multiple through holes 23a in the metal plate 23. The protruding portion 32 is positioned so as to cover the edge 23b of the first opening 23a1 and at least a portion of the wall surface 23c of the through hole 23a.

[0044] In this way, first intermediate layer 30 has protrusion 32 extending into through hole 23a so as to cover edge 23b of first opening 23a1 and at least a part of wall surface 23c of through hole 23a, thereby making it difficult for elements to diffuse between element portion 3 and metal plate 23. Therefore, for example, the power generation performance of cell 1 is less likely to deteriorate, thereby improving durability.

[0045] In particular, when at least a portion of the protrusion 32 is in contact with the edge 23 b of the first opening 23 a 1 and at least a portion of the wall surface 23 c of the through hole 23 a, for example, an anchor effect improves the bonding strength between the first intermediate layer 30 and the metal plate 23. Therefore, according to the cell 1 according to this embodiment, for example, durability is improved.

[0046] The protrusion 32 may have a hole 32a as a second hole that opens into the through hole 23a. When the opening diameter of the through hole 23a is d1 and the opening diameter of the hole 32a is d2, d2 can be equal to or smaller than d1. In this case, d2 may be greater than or equal to 1 / 2 × d1. This makes it less likely that the flow of fuel gas inside the through hole 23a will be obstructed, and even if the current density is increased, the voltage will not decrease. Here, the opening diameter of the hole 32a refers to the dimension of an opening 32a2 at the location of the tip 33 of the protrusion 32 along the radial direction of the through hole 23a (the X-axis direction in FIG. 2A ).

[0047] Furthermore, the hole 32a may have a bottom 34 that is closer to the first opening 23a1 than the tip 33 of the protrusion 32. The bottom 34 may be located closer to the solid electrolyte layer 6 (see FIG. 1B ) than the first surface 231. This shortens the distance from the bottom 34 to the element portion 3, making it easier for the fuel gas to flow into the element portion 3 from the through-hole 23a.

[0048] Furthermore, the thickness d3 of the protrusion 32 in the radial direction of the through hole 23a may be 200 μm or less. The thickness d3 may be, for example, ⅓ or less of the opening diameter d1 of the through hole 23a. This increases the bonding strength between the first intermediate layer 30 and the metal plate 23 without impeding the flow of fuel gas inside the through hole 23a. The average value of the thickness d3 may be, for example, 1 μm or more and 10 μm or less.

[0049] Furthermore, the distance d4 of the tip 33 of the protrusion 32 from the edge 23b of the first opening 23a1 may be 10 μm or more. The distance d4 may be 1% or more of the length of the through hole 23a in the Y-axis direction, i.e., the thickness of the metal plate 23. This can increase the bonding strength between the first intermediate layer 30 and the metal plate 23. The distance d4 may be, for example, approximately the same as the thickness of the metal plate 23. Furthermore, the distance d4 may be greater than the thickness of the metal plate 23, i.e., the tip 33 of the protrusion 32 may protrude from the second opening 23a2 to the outside of the through hole 23a. The average value of the distance d4 may be, for example, 10 μm or more and 200 μm or less.

[0050] The protrusion 32 does not have to be continuous in the circumferential direction of the through hole 23 a. In other words, in a cross section along the first surface 231 of the metal plate 23 where the protrusion 32 is located, the wall surface 23 c of the through hole 23 a may have a portion that is covered by the protrusion 32 and a portion that is not covered by the protrusion 32.

[0051] 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 portion 3 less likely to warp or bend.

[0052] The material of the constraining layer 40 exhibits a shrinkage rate similar to that of the material of the solid electrolyte layer 6 during firing. 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.

[0053] 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 inhibit 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 later) may be located inside the through-holes 40a.

[0054] 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 passage 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%.

[0055] 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 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.

[0056] The diffusion layer 50 may contain a larger amount of rare earth element 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.

[0057] The material of the diffusion layer 50 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 warping or deformation of the element portion 3 of the cell 1 having the diffusion layer 50 is reduced.

[0058] Furthermore, the material of the diffusion layer 50 is similar to the material of the anode 5. The temperature at which the material of the diffusion layer 50 starts to shrink is similar to that of the material of the anode 5. On the other hand, the rare earth element oxide contained in the diffusion layer 50 inhibits densification of the diffusion layer 50. As a result, the diffusion layer 50 has appropriate gas permeability while making the element section 3 less likely to deform. Therefore, the cell 1 having the diffusion layer 50 has improved adhesion between the element section 3 and the metal plate 23, and improved durability.

[0059] 2B and 2C are partial cross-sectional views showing another example of the electrochemical cell according to the first embodiment.

[0060] 2B and 2C, the first intermediate layer 30 may have openings 30a that communicate with the holes 32a of the protrusions 32. Furthermore, as shown in FIG. 2C, the diffusion layer 50 may have holes 50a that communicate with the openings 30a of the first intermediate layer 30.

[0061] <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 an electrochemical cell device according to the first embodiment. FIG. 3B is a cross-sectional view taken along line X-X shown in FIG. 3A. FIG. 3C is a top view showing an example of an electrochemical cell device according to the first embodiment.

[0062] As shown in Figure 3A, 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.

[0063] 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.

[0064] 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 fixing material 13.

[0065] 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.

[0066] In the example shown in Fig. 3A, fuel gas is stored in an internal space 22 (see Fig. 3B) 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. 4), which will be described later.

[0067] 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.

[0068] 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 the one gas tank 16 and the two supports 15.

[0069] 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 ).

[0070] 3B, 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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 portion 19 that protrudes outward from 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. 3A.

[0075] 3C, 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] <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 an example of a module according to the first embodiment. Fig. 4 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] <Module Enclosure Device> Fig. 5 is an exploded perspective view schematically illustrating an example of a module enclosure device according to the first embodiment. The module enclosure 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.

[0087] 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 auxiliary equipment accommodating chamber 116 that accommodates auxiliary equipment for operating the module 100. Note that in Fig. 5, the auxiliary equipment accommodated in the auxiliary equipment accommodating chamber 116 is omitted from the illustration.

[0088] 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.

[0089] 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.

[0090] Second Embodiment Fig. 6 is a cross-sectional view showing an example of an electrochemical cell according to a second embodiment. Fig. 7A is an enlarged cross-sectional view of a region C shown in Fig. 6.

[0091] The element unit 3 may have a diffusion layer 50 as a first layer facing the first surface 231 of the metal plate 23. The diffusion layer 50 has a protrusion 52. The protrusion 52 extends into the inside of a first hole, which is at least one of the multiple through holes 23a in the metal plate 23. The protrusion 52 is positioned so as to cover the edge 23b of the first opening 23a1 and at least a portion of the wall surface 23c of the through hole 23a.

[0092] In this way, the diffusion layer 50 has the protrusion 52 extending into the through-hole 23a so as to cover the edge 23b of the first opening 23a1 and at least a part of the wall surface 23c of the through-hole 23a, thereby making it difficult for elements to diffuse between the element unit 3 and the metal plate 23. As a result, for example, the power generation performance of the cell 1A is less likely to deteriorate, thereby improving durability.

[0093] In particular, when at least a portion of the protrusion 52 is in contact with the edge 23 b of the first opening 23 a 1 and at least a portion of the wall surface 23 c of the through-hole 23 a, for example, an anchor effect improves the bonding strength between the diffusion layer 50 and the metal plate 23. Therefore, according to the cell 1A according to this embodiment, for example, durability is improved.

[0094] The protrusion 52 may have a hole 52a as a second hole that opens into the through hole 23a. When the opening diameter of the through hole 23a is d11 and the opening diameter of the hole 52a is d12, the d12 may be equal to or smaller than d11. In this case, d12 may be ≥ 1 / 2 × d11. This makes it difficult for the flow of fuel gas inside the through hole 23a to be obstructed, and even when the current density is increased, the voltage is less likely to decrease. Here, the opening diameter of the hole 52a refers to the dimension of an opening 52a2 at the location of the tip 53 of the protrusion 52 along the radial direction of the through hole 23a (the X-axis direction in FIG. 7A ).

[0095] Furthermore, the thickness d13 of the protrusion 52 in the radial direction of the through hole 23a may be 200 μm or less. The thickness d13 may be, for example, ⅓ or less of the opening diameter d11 of the through hole 23a. This increases the bonding strength between the diffusion layer 50 and the metal plate 23 without impeding the flow of fuel gas inside the through hole 23a. The average value of the thickness d13 may be, for example, 1 μm or more and 10 μm or less.

[0096] Furthermore, the distance d14 of the tip 53 of the protrusion 52 from the edge 23b of the first opening 23a1 may be 10 μm or more. The distance d14 may be 1% or more of the length of the through hole 23a in the Y-axis direction, i.e., the thickness of the metal plate 23. This increases the bonding strength between the diffusion layer 50 and the metal plate 23. The distance d14 may be, for example, approximately the same as the thickness of the metal plate 23. Furthermore, the distance d14 may be greater than the thickness of the metal plate 23, i.e., the tip 53 of the protrusion 52 may protrude from the second opening 23a2 to the outside of the through hole 23a. The average value of the distance d14 may be, for example, 10 μm or more and 200 μm or less.

[0097] The diffusion layer 50 may have holes 50a that communicate with the holes 52a of the protrusions 52. The holes 50a may have openings 50a1 that contact the fuel electrode 5.

[0098] 7B is a partial cross-sectional view showing another example of an electrochemical cell according to the second embodiment. As shown in FIG. 7B , the diffusion layer 50 may have a protrusion 54. The protrusion 54 is located so as to overlap the edge 23 b of the first opening 23 a 1 in a plan view, and is a portion that protrudes from the surface 501 of the diffusion layer 50 that contacts the anode 5 toward the solid electrolyte layer 6 (see FIG. 6 ). The presence of the protrusion 54 in the diffusion layer 50 improves the bonding strength between the anode 5 and the diffusion layer 50, thereby improving the durability of the cell 1A.

[0099] Third Embodiment Fig. 8 is a cross-sectional view showing an example of an electrochemical cell according to a third embodiment. Fig. 9 is an enlarged cross-sectional view of a region D shown in Fig. 8.

[0100] The element unit 3 may have an anode 5 as a first layer facing the first surface 231 of the metal plate 23. The anode 5 has a protruding portion 502. The protruding portion 502 extends into a first hole, which is at least one of the multiple through holes 23a in the metal plate 23. The protruding portion 502 is positioned so as to cover the edge 23b of the first opening 23a1 and at least a portion of the wall surface 23c of the through hole 23a.

[0101] In this way, the anode 5 has the protrusion 502 extending into the through-hole 23a so as to cover the edge 23b of the first opening 23a1 and at least a part of the wall surface 23c of the through-hole 23a, which makes it difficult for elements to diffuse between the element unit 3 and the metal plate 23. Therefore, for example, the power generation performance of the cell 1B is less likely to deteriorate, and durability is improved.

[0102] In particular, when at least a portion of the protrusion 502 is in contact with the edge 23 b of the first opening 23 a 1 and at least a portion of the wall surface 23 c of the through-hole 23 a, for example, an anchor effect improves the bonding strength between the fuel electrode 5 and the metal plate 23. Therefore, according to the cell 1B of this embodiment, for example, durability is improved.

[0103] The protruding portion 502 may have a hole 502a as a second hole that opens into the through-hole 23a. The hole 502a may have a bottom 504 that is closer to the first opening 23a1 than the opening 502a2 where the tip 503 of the protruding portion 502 is located. The bottom 504 may be located closer to the solid electrolyte layer 6 (see FIG. 8 ) than the first surface 231. This shortens the distance from the bottom 504 to the element portion 3, making it easier for the fuel gas to flow into the element portion 3 from the through-hole 23a.

[0104] [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 an electrolysis cell, an electrolysis cell stack device, an electrolysis module, and an electrolysis device can improve electrolysis performance.

[0105] 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.

[0106] In one embodiment, (1) an electrochemical cell includes: a metal plate having a first surface, a second surface located opposite the first surface, and a first opening located on the first surface and a plurality of through holes including at least one first hole; and an element portion including a first layer facing the first surface, a solid electrolyte layer, and a first electrode located on the opposite side of the first layer with the solid electrolyte layer interposed therebetween; wherein the first layer has a protrusion extending into the first hole, and the protrusion covers an edge of the first opening of the first hole and at least a portion of a wall surface of the first hole.

[0107] (2) In the electrochemical cell of (1) above, the protrusion may have a second hole that opens into the first hole and has an opening diameter equal to or smaller than the opening diameter of the first hole.

[0108] (3) In the electrochemical cell of (2) above, the opening diameter of the second hole may be at least half the opening diameter of the first hole.

[0109] (4) In the electrochemical cell of (2) or (3) above, the second hole may have a bottom located closer to the solid electrolyte layer than the first surface.

[0110] (5) In the electrochemical cell of any one of (1) to (4) above, the thickness of the protrusion in the radial direction of the first hole may be 200 μm or less.

[0111] (6) In the electrochemical cell of any one of (1) to (5) above, the tip of the protrusion may be located at a distance of 10 μm or more from the edge of the first opening.

[0112] (7) In the electrochemical cell of any one of (1) to (6) above, the first layer may be made of a porous ceramic having electrical conductivity.

[0113] (8) In the electrochemical cell of any one of (1) to (7) above, the first layer may contain metal particles and conductive oxide particles.

[0114] (9) In the electrochemical cell of any one of (1) to (7) above, the first layer may include metal particles and solid electrolyte particles.

[0115] (10) The electrochemical cell of any one of (1) to (9) above may further include a second electrode located between the first layer and the solid electrolyte layer.

[0116] (11) In the electrochemical cell of any one of (1) to (9) above, the first layer may be a second electrode.

[0117] (12) In the electrochemical cell of any one of (1) to (11) above, the plurality of through holes may have second openings in the second surface.

[0118] In one embodiment, (13) an electrochemical cell device has a cell stack including any one of the electrochemical cells (1) to (12) above.

[0119] In one embodiment, (14) a module includes the electrochemical cell device of (13) above, and a container that houses the electrochemical cell device.

[0120] 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.

[0121] 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.

[0122] REFERENCE SIGNS LIST 1, 1A, 1B Cell 3 Element section 5 Anode 6 Solid electrolyte layer 8 Cathode 9 Sealant 10 Cell stack device 23 Metal plate 23a Through hole 23a1 First opening 23a2 Second opening 23b Edge 23c Wall surface 30 First intermediate layer 32 Protrusion 32a Hole 40 Constraint layer 50 Diffusion layer 100 Module 110 Module accommodating device 231 First surface 232 Second surface

Claims

1. A metal plate having a first surface, a second surface located on the opposite side of the first surface, a first opening located on the first surface, and a plurality of through-holes including at least one first hole; and an element part having a first layer facing the first surface, a solid electrolyte layer, and a first electrode located on the opposite side of the first layer with the solid electrolyte layer interposed therebetween, wherein the first layer has a protruding portion extending inside the first hole, and the protruding portion covers an edge of the first opening of the first hole and at least a part of a wall surface of the first hole. An electrochemical cell.

2. The electrochemical cell according to claim 1, wherein the protruding portion has a second hole that opens into the first hole and has an opening diameter equal to or smaller than the opening diameter of the first hole.

3. The electrochemical cell according to claim 2, wherein the opening diameter of the second hole is 1 / 2 or more of the opening diameter of the first hole.

4. The electrochemical cell according to claim 2 or 3, wherein the second hole has a bottom portion located on the solid electrolyte layer side of the first surface.

5. The electrochemical cell according to any one of claims 1 to 4, wherein a thickness of the protruding portion in a radial direction of the first hole is 200 μm or less.

6. The electrochemical cell according to any one of claims 1 to 5, wherein a tip of the protruding portion is located at a distance of 10 μm or more from an edge of the first opening.

7. The electrochemical cell according to any one of claims 1 to 6, wherein the first layer is a porous ceramic having conductivity.

8. The electrochemical cell according to any one of claims 1 to 7, wherein the first layer includes metal particles and conductive oxide particles.

9. The electrochemical cell according to any one of claims 1 to 7, wherein the first layer includes metal particles and solid electrolyte particles.

10. The electrochemical cell according to any one of claims 1 to 9, further comprising a second electrode located between the first layer and the solid electrolyte layer.

11. The electrochemical cell according to any one of claims 1 to 9, wherein the first layer is a second electrode.

12. The electrochemical cell according to any one of claims 1 to 11, wherein the plurality of through-holes have second openings on the second surface.

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

14. A module including the electrochemical cell device according to claim 13 and a storage container for storing the electrochemical cell device.

15. A module housing device comprising the module according to claim 14, an auxiliary machine for operating the module, and an exterior case for housing the module and the auxiliary machine.

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