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

Abstract

This electrochemical cell includes an element part and a metal plate. The metal plate has a first surface facing the element part and a second surface positioned on the side opposite to the first surface. The metal plate has a plurality of holes that are open in the first surface and has a perforated region facing the element part. The perforated region has a first section including a first end of a pair of ends in a first direction parallel to the first surface, and a second section located closer to the center in the first direction than the first section. When the area ratio occupied by the plurality of holes in the first section is defined as a first area ratio and the area ratio occupied by the plurality of holes in the second section is defined as a second area ratio, the first area ratio is less than the second area ratio.

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] Japanese Patent Application Laid-Open No. 2017-208232

[0004] An electrochemical cell according to one aspect of the embodiment includes an element unit and a metal plate. The metal plate has a first surface facing the element unit and a second surface located opposite the first surface. The metal plate includes a plurality of holes opening on the first surface, forming a perforated region facing the element unit. The perforated region has a first portion including a first end of a pair of ends in a first direction along the first surface, and a second portion located more centrally in the first direction than the first portion. When a first area ratio is defined as an area ratio occupied by the plurality of holes in the first portion and a second area ratio is defined as an area ratio occupied by the plurality of holes in the second portion, the first area ratio is smaller than the second area ratio.

[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 also 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 also includes the module described above, an accessory configured to operate the module, and an exterior case housing the module and the accessory.

[0008] FIG. 1A is a cross-sectional view showing an example of an electrochemical cell device according to an embodiment. FIG. 1B is a plan view of an example of an electrochemical cell according to an embodiment, viewed from the air electrode side. FIG. 2A is a cross-sectional view showing an example of an element unit. FIG. 2B is a cross-sectional view showing another example of an element unit. FIG. 3 is a plan view showing an example of a metal plate included in an electrochemical cell according to an embodiment. FIG. 4A is a plan view showing an example of an arrangement of holes in a perforated region. FIG. 4B is a plan view showing another example of an arrangement of holes in a perforated region. FIG. 5 is a plan view showing an enlarged example of a portion of the metal plate shown in FIG. 3. FIG. 6A is a plan view showing an example of a perforated region. FIG. 6B is a plan view showing an example of a perforated region. FIG. 6C is a plan view showing an example of a perforated region. FIG. 6D is a plan view showing an example of a perforated region. FIG. 6E is a plan view showing an example of a perforated region. FIG. 6F is a plan view showing an example of a perforated region. FIG. 6G is a plan view showing an example of a perforated region. FIG. 6H is a plan view showing an example of a perforated region. FIG. 6I is a plan view showing an example of a perforated region. FIG. 6J is a plan view showing an example of a perforated region. FIG. 6K is a plan view showing an example of a perforated region. FIG. 6L is a plan view showing an example of a perforated region. FIG. 6M is a plan view showing an example of a perforated region. FIG. 6N is a plan view showing an example of a perforated region. FIG. 6O is a plan view showing an example of a perforated region. FIG. 6P is a plan view showing an example of a perforated region. FIG. 6Q is a plan view showing an example of a perforated region. FIG. 6R is a plan view showing an example of a perforated region. FIG. 7A is a perspective view showing an example of an electrochemical cell device according to an embodiment. FIG. 7B is a cross-sectional view taken along line X-X shown in FIG. 7A. FIG. 7C is a top view showing an example of an electrochemical cell device according to an embodiment. FIG. 8 is an external perspective view showing an example of a module according to an embodiment. FIG. 9 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 cross-sectional view showing an example of an electrochemical cell device according to an embodiment. Fig. 1B is a plan view of an example of an electrochemical cell according to an embodiment, viewed from the air electrode side. Note that Figs. 1A and 1B show enlarged views of parts of each component of the electrochemical cell. Hereinafter, the electrochemical cell may also 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, a cell stack device 10 according to this embodiment includes a cell 1. The cell 1 includes an element portion 3, a metal plate 20, and a flow path member 22.

[0017] Fig. 2A is a cross-sectional view showing an example of the element unit. Fig. 2B is a cross-sectional view showing another example of the element unit. As shown in Fig. 2A, the element unit 3 has an anode 5, a solid electrolyte layer 6, and an cathode 8.

[0018] The anode 5 is an 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.

[0019] 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. ２ and 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:

[0020] The solid electrolyte layer 6 is a solid oxide electrolyte. The solid electrolyte layer 6 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, making it difficult for leakage of fuel gas and oxygen-containing gas to occur.

[0021] 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:

[0022] The air electrode 8 is an 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.

[0023] 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.

[0024] The material of the air electrode 8 may be, for example, a composite oxide in which Sr (strontium) and La (lanthanum) coexist at the A site. Examples of such composite oxides include La ｘ Sr １－ｘ Co ｙ Fe １－ｙ 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.

[0025] The element unit 3 may also have an intermediate layer 7 located between the solid electrolyte layer 6 and the air electrode 8. When the element unit 3 has the intermediate layer 7, the intermediate layer 7 makes it difficult for a specific element to diffuse. For example, when a specific element such as Sr (strontium) contained in the air electrode 8 diffuses into the solid electrolyte layer 6, the solid electrolyte layer 6 becomes SrZrO ３ The intermediate layer 7 is formed as a resistive layer by making it difficult for specific elements such as Sr to diffuse. ３ This makes it difficult for compounds such as

[0026] The material of the intermediate layer 7 is not particularly limited as long as it generally prevents diffusion of elements between the air electrode 8 and the solid electrolyte layer 6. The material of the intermediate 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).

[0027] The element unit 3 may further include a constraining layer (not shown). The constraining layer may be located between the fuel electrode 5 and the metal plate 20 of the element unit 3. The constraining layer cooperates with the solid electrolyte layer 6 to make the element unit 3 less susceptible to warping, bending, and the like.

[0028] The material of the constraining layer may exhibit a shrinkage rate similar to that of the material of the solid electrolyte layer 6 during firing. The material of the constraining layer 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 and firing the resulting element unit 3 has little warping or deformation.

[0029] The constraining layer may or may not be gas permeable. When the constraining layer has gas barrier properties comparable to those of the solid electrolyte layer 6, the constraining layer can be partially disposed so as not to obstruct the inflow of fuel gas to the anode 5.

[0030] The element section 3 may further include a gas diffusion layer (not shown). The gas diffusion layer may be located between the anode 5 and the metal plate 20. The gas diffusion layer has gas permeability and allows the fuel gas flowing through a first flow path 21 (described later) to pass through to the anode 5. The open porosity of the gas diffusion layer may be in the range of, for example, 30% to 50%, particularly 35% to 45%.

[0031] The material of the gas diffusion layer 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.

[0032] The element portion 3 may further include an adhesive (not shown). The adhesive may be located between the element portion 3 and the metal plate 20. The adhesive bonds the element portion 3 and the metal plate 20 together, and fixes the element portion 3 to the metal plate 20.

[0033] The adhesive may be conductive. For example, the adhesive may be a mixture of conductive particles such as Ni, TiO2, and rare earth oxide (Y), ２ O ３ , CeO ２ etc.), transition metal oxides (Fe ２ O ３ The inorganic oxide may include inorganic oxides such as SiO 2 , CuO, etc.

[0034] The adhesive may be gas permeable. The solid electrolyte layer 6 may be positioned so as to cover the side surface of the adhesive.

[0035] The adhesive may be formed as a single layer using a single material, or may be formed as a laminate of multiple materials.

[0036] 2B, a sealant 9 different from the solid electrolyte layer 6 may be located on the side of the anode 5. The material of the sealant 9 may be dense glass or ceramic. The material of the sealant 9 may be, for example, amorphous glass or crystallized glass. Examples of crystallized glass include SiO ２ -CaO system, MgO-B ２ O ３ System, 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 be used. The sealing material 9 may have electrical insulating 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 surfaces of the element portion 3.

[0037] 1A and 1B, the cell 1 according to the embodiment will be further described. The metal plate 20 has a first surface 201 and a second surface 202. The first surface 201 is positioned to face the element portion 3.

[0038] The second surface 202 is located on the opposite side to the first surface 201. The second surface 202 is located so as to face the flow path member 22. The first flow path 21 may be located between the second surface 202 and the flow path member 22.

[0039] The metal plate 20 also has a plurality of holes 20a. The holes 20a are through-holes that penetrate between the first surface 201 and the second surface 202. The fuel gas flowing through the first flow path 21 along the Z-axis is supplied to the anode 5 of the element unit 3 through the holes 20a. The metal plate 20 may have a coating that covers the wall surfaces of the holes 20a. The metal plate 20 does not necessarily have to have a coating on the wall surfaces of the holes 20a.

[0040] The metal plate 20 also has a perforated region 25. The perforated region 25 includes a plurality of holes 20a that open to the first surface 201, and is a portion that faces the element portion 3. Details of the plurality of holes 20a and the perforated region 25 will be described later.

[0041] The metal plate 20 is electrically conductive. The metal plate 20 may be, for example, a member made of a metal containing chromium. The metal plate 20 may be, for example, a stainless steel such as a ferritic stainless steel or an austenitic stainless steel, which has high heat resistance. The metal plate 20 may be, for example, a nickel-chromium alloy or an iron-chromium alloy. The metal plate 20 may contain, for example, a metal oxide. The metal plate 20 may have a coating covering the surface. The metal plate 20 does not have to have a coating on the surface.

[0042] The flow path member 22 has a surface 221 and a surface 222. The surface 221 may be located so as to face the metal plate 20. The first flow path 21 may be located between the surface 221 and the metal plate 20. The flow path member 22 may have one or more protrusions that protrude from the surface 221 toward the metal plate 20.

[0043] The surface 222 may be located on the opposite side to the surface 221. The surface 222 may be an outer surface located on the opposite side to the flow path surface on which the first flow path 21 is located. The surface 222 may be located so as to face the element portion 3 located adjacent to the cell 1.

[0044] The material of the flow path member 22 may be a dense metal or alloy. The flow path member 22 makes it difficult for the fuel gas flowing on the surface 221 side facing the first flow path 21 and the oxygen-containing gas flowing on the surface 222 side to leak. The flow path member 22 may have a coating layer. For example, the surface 221 of the flow path member 22 may have a coating layer that is resistant to reduction. Furthermore, the surface 222 may have a coating layer that is resistant to oxidation. These coating layers may be electrically conductive.

[0045] <Details of the Multiple Holes and Perforated Region> FIG. 3 is a plan view showing an example of a metal plate included in an electrochemical cell according to an embodiment. As shown in FIG. 3, the perforated region 25 has edges 25a to 25d and corners C1 to C4. The edges 25a to 25d and the corners C1 to C4 are located along the boundary between the portion of the first surface 201 of the metal plate 20 that contacts the element unit 3 and the portion that does not contact the first surface 201. The shape of the perforated region 25 in plan view may be, for example, rectangular. The shape of the perforated region 25 in plan view corresponds to the outline of the element unit 3 facing the metal plate 20. In other words, the shape of the perforated region 25 in plan view corresponds to the shape of the element unit 3.

[0046] The perforated region 25 has a first portion 251 and a second portion 252. The first portion 251 is located at an end in a first direction along the first surface 201, i.e., the Z-axis direction. The first direction (Z-axis direction) may be the length direction of the metal plate 20. The first portion 251 may have a portion 251a including the end 25a and a portion 251b including the end 25c, of a pair of ends 25a, 25c of the perforated region 25 in the first direction (Z-axis direction). The end 25a is an example of a first end located at one end of the perforated region 25 in the first direction (Z-axis direction). The end 25c is an example of a second end located at the other end of the perforated region 25 in the first direction (Z-axis direction).

[0047] The second portion 252 is located closer to the center of the perforated region 25 in the first direction (Z-axis direction) than the first portion 251. The second portion 252 may be located between the portion 251a and the portion 251b.

[0048] When the area ratio occupied by the plurality of holes 20a in the first portion 251 is defined as a first area ratio and the area ratio occupied by the plurality of holes 20a in the second portion 252 is defined as a second area ratio, the first area ratio is smaller than the second area ratio. As a result, the contact area between the element portion 3 and the metal plate 20 in the first portion 251 is larger than that in the second portion 252, and the adhesion between the element portion 3 and the metal plate 20 in the first portion 251 is improved. Therefore, peeling of the element portion 3 from the metal plate 20 due to the difference in thermal expansion between the metal plate 20 and the element portion 3 is less likely to occur, and the durability of the cell 1 according to this embodiment is improved.

[0049] 4A and 4B are plan views showing an example of an arrangement of holes in a perforated region, respectively, and another example of an arrangement of holes in a perforated region.

[0050] As shown in FIG. 4A, the metal plate 20 may have a plurality of holes 20a aligned at equal intervals in a first direction (Z-axis direction) and a second direction perpendicular to the first direction (Z-axis direction) and along the first surface 201, i.e., the X-axis direction.

[0051] On the other hand, as shown in FIG. 4B, the metal plate 20 may have a plurality of holes 20a arranged in a staggered pattern at equal intervals in the first direction (Z-axis direction).

[0052] The perforated region 25 may also have a non-perforated portion 20a0 where no holes 20a are located. The non-perforated portion 20a0 refers to a portion where holes 20a are expected to be located if multiple holes 20a are regularly arranged in the perforated region 25 facing the element unit 3, but where no holes 20a are actually located. The perforated region 25 may have a non-perforated portion 20a0, for example, at and near the end 25a and / or end 25d of the first portion 251. This increases the contact area between the element unit 3 and the metal plate 20 in the first portion 251 compared to the second portion 252, thereby improving adhesion between the element unit 3 and the metal plate 20 in the first portion 251. This reduces the likelihood of peeling of the element unit 3 from the metal plate 20 due to a difference in thermal expansion between the metal plate 20 and the element unit 3, thereby improving the durability of the cell 1 according to this embodiment.

[0053] The shape, arrangement, and spacing of the holes 20a are merely examples and are not limited to those shown in Figures 4A and 4B. The shape of the holes 20a when viewed from above on the first surface 201 side may be, for example, circular, elliptical, rectangular, etc. When the holes 20a when viewed from above on the first surface 201 side have a shape other than circular, the diameter of the holes 20a may be a circle-equivalent diameter. Furthermore, the centers of the holes 20a may be the geometric center.

[0054] 5 is a plan view showing an example in which a portion of the metal plate shown in FIG. 3 is enlarged. The average diameter of the holes 20a may be, for example, 10 μm or more and 1500 μm or less. Furthermore, when the average diameter of the holes 20a is d and the diameter of the holes 20a is D, d and D may have a relationship of, for example, 0.75×d≦D≦1.25×d. The diameter (D) of the holes 20a is not shown.

[0055] Furthermore, when the distance between the centers 20ac of adjacent holes 20a in the first direction (Z-axis direction) is Lp1, d and Lp1 may have a relationship of, for example, d<Lp1≦3×d.

[0056] Furthermore, the range of the perforated region 25 that is a distance of 2×Lp1 or less from the first end (end 25a) in the first direction (Z-axis direction) is defined as the first region 251, and the range of the perforated region 25 that is a distance of Lp1 or less from the center in the first direction (Z-axis direction) is defined as the second region 252. In this case, the first area ratio may be 50% or less of the second area ratio. This increases the contact area between the element unit 3 and the metal plate 20 in the first region 251 compared to the second region 252, thereby improving the adhesion between the element unit 3 and the metal plate 20 in the first region 251. Therefore, peeling of the element unit 3 from the metal plate 20 due to the difference in thermal expansion between the metal plate 20 and the element unit 3 is less likely to occur, and the durability of the cell 1 according to this embodiment is improved.

[0057] In addition, in the perforated region 25 of the metal plate 20, a direction perpendicular to the first direction (Z-axis direction) and along the first surface 201 is defined as a second direction (X-axis direction). When the distance between the centers 20ac of the holes 20a adjacent to each other in the second direction (X-axis direction) is defined as Lp2, d and Lp2 may have a relationship of, for example, d<Lp2≦3×d.

[0058] Furthermore, the first region 251 may include at least one pair of holes 20a having an Lp2 greater than the maximum value of Lp2 in the second region 252. This further increases the contact area between the element unit 3 and the metal plate 20 in the first region 251 compared to the second region 252, further improving the adhesion between the element unit 3 and the metal plate 20 in the first region 251. This makes it even less likely that the element unit 3 will peel off from the metal plate 20 due to the difference in thermal expansion between the metal plate 20 and the element unit 3, and further improves the durability of the cell 1 according to this embodiment.

[0059] 6A to 6R, examples of the arrangement of holes 20a in perforated region 25 will be described. Figures 6A to 6R are plan views showing examples of perforated regions.

[0060] As shown in FIGS. 6A to 6R, in the perforated region 25, the area ratio occupied by the plurality of holes 20a in a first portion 251 (see FIG. 3) including the end 25a is defined as a first area ratio, and the area ratio occupied by the plurality of holes 20a in a second portion 252 (see FIG. 3) located on the positive side of the Z axis from the end 25a is defined as a second area ratio. The first area ratio is smaller than the second area ratio. As a result, the contact area between the element portion 3 and the metal plate 20 in the first portion 251 is larger than that in the second portion 252, thereby improving the adhesion between the element portion 3 and the metal plate 20 in the first portion 251. Therefore, peeling of the element portion 3 from the metal plate 20 due to the difference in thermal expansion between the metal plate 20 and the element portion 3 is less likely to occur, and the durability of the cell 1 according to this embodiment is improved.

[0061] Furthermore, the number of holes 20a per unit area in the first portion 251 (see FIG. 3 ) including the end 25a may be smaller than the number of holes 20a per unit area in the second portion 252 (see FIG. 3 ) located closer to the positive Z-axis direction side than the end 25a (near the center of the perforated region 25). This makes it easier for the contact area between the element portion 3 and the metal plate 20 in the first portion 251 to be larger than that in the second portion 252, and makes it easier for the adhesion between the element portion 3 and the metal plate 20 in the first portion 251 to be improved. This makes it harder for the element portion 3 to peel off from the metal plate 20 due to the difference in thermal expansion between the metal plate 20 and the element portion 3, and improves the durability of the cell 1 according to this embodiment.

[0062] 6A, in the perforated region 25, the distance L1 from a corner C1 facing one corner of the element unit 3 to the nearest opening may be equal to or greater than Lp1 (see FIG. 5). This makes it easier for the contact area between the element unit 3 and the metal plate 20 in the first portion 251 near the corner C1 to be larger than that in the second portion 252, which makes it easier to improve the adhesion between the element unit 3 and the metal plate 20 in the first portion 251. This makes it even harder for the element unit 3 to peel off from the metal plate 20 due to the difference in thermal expansion between the metal plate 20 and the element unit 3, and the durability of the cell 1 according to this embodiment is further improved.

[0063] 6A to 6R illustrate the arrangement of holes 20a in the portion of perforated region 25 near corner C1, but the arrangement of holes 20a in the portions near corners C2 to C4 can also be the same as the arrangement of holes 20a illustrated in Figures 6A to 6R. The arrangement of holes 20a in perforated region 25 in a plan view may or may not have, for example, rotational symmetry and / or mirror symmetry.

[0064] <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 7A to 7C. Figure 7A is a perspective view showing an example of an electrochemical cell device according to an embodiment. Figure 7B is a cross-sectional view taken along line XX shown in Figure 7A. Figure 7C is a top view showing an example of an electrochemical cell device according to an embodiment.

[0065] As shown in Figure 7A, 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.

[0066] 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.

[0067] 7B, 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.

[0068] 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 31 filled in the recessed groove 16a of the gas tank 16.

[0069] In the example shown in Fig. 7A, fuel gas is stored in an internal space 32 (see Fig. 7B) formed by a support body 15, which is the support member 14, and a gas tank 16. A gas circulation pipe 30 is connected to the gas tank 16. The fuel gas is supplied to the gas tank 16 through this gas circulation pipe 30, and is supplied from the gas tank 16 to a first flow path 21 (see Fig. 1A) inside the cell 1. The fuel gas supplied to the gas tank 16 is generated in a reformer 102 (see Fig. 8), which will be described later.

[0070] 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 may contain steam.

[0071] The example shown in FIG. 7A 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 32 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.

[0072] The shape of the insertion hole 15a may be, 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 ), may be 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 may be greater than the length of the cell 1 in the width direction (X-axis direction shown in FIG. 1B ).

[0073] 7B , 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 first flow paths 21 of each cell 1 communicate with the internal space 32 of the support member 14 at their lower ends.

[0074] A material with low electrical conductivity, such as glass, can be used for the fixing material 13 and the bonding material 31. Specific materials for the fixing material 13 and the bonding material 31 include amorphous glass, and in particular, crystallized glass.

[0075] 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 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 - MgO-based materials may also be used.

[0076] 7B , 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 flow path member 22 shown in FIG. 1A or may be a member separate from the flow path member 22.

[0077] 7B, an end current collecting member 17 is electrically connected to the cell 1 located at the outermost position in the arrangement direction of the multiple cells 1. The end current collecting member 17 is connected to a conductive portion 19 that protrudes to the outside of 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. 7A.

[0078] 7C, 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.

[0079] 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.

[0080] 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.

[0081] Although not shown in Figures 7A to 7C, 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 first flow path 21 inside the cells 1.

[0082] <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. 8. Fig. 8 is an external perspective view showing an example of a module according to an embodiment. Fig. 8 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.

[0083] 8, the module 100 includes a cell stack device 10 and a storage container 101 that stores the cell stack device 10. A reformer 102 may be disposed above the cell stack device 10.

[0084] 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.

[0085] The fuel gas produced in the reformer 102 is supplied to the first flow path 21 of the cell 1 (see FIG. 1A) through the gas distribution pipe 30, the gas tank 16, and the support member 14.

[0086] 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 30, and the like may be disposed as appropriate depending on the arrangement of the cell stack device 10 and the reformer 102.

[0087] 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.

[0088] In such a module 100, as described above, the durability of the module 100 can be improved by accommodating the cell stack device 10 with improved durability.

[0089] <Module Enclosure Device> Fig. 9 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. 8, and auxiliary equipment (not shown). The auxiliary equipment operates the module 100. The outer case 111 accommodates the module 100 and the auxiliary equipment. Note that some components are omitted in Fig. 9.

[0090] An exterior case 111 of a module accommodating device 110 shown in Fig. 9 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. The space below the partition plate 114 in the exterior case 111 is an accessory accommodating chamber 116 that accommodates accessories configured to operate the module 100. Note that in Fig. 9, the accessories accommodated in the accessory accommodating chamber 116 are omitted from the illustration.

[0091] 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.

[0092] 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.

[0093] [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. An 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 are less likely to deteriorate in electrolysis performance. Solid oxide fuel cells and electrolysis cells are collectively referred to as solid oxide electrochemical cells.

[0094] 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.

[0095] In one embodiment, (1) an electrochemical cell comprises: an element portion; and a metal plate having a first surface facing the element portion and a second surface located opposite the first surface; the metal plate includes a plurality of holes opening on the first surface and has a perforated region facing the element portion; the perforated region has a first portion including a first end of a pair of ends in a first direction along the first surface; and a second portion located more centrally in the first direction than the first portion; when an area ratio occupied by the plurality of holes in the first portion is defined as a first area ratio, and an area ratio occupied by the plurality of holes in the second portion is defined as a second area ratio, the first area ratio is smaller than the second area ratio.

[0096] (2) In the electrochemical cell of (1) above, the number of the pores per unit area in the first region may be smaller than the number of the pores per unit area in the second region.

[0097] (3) In the electrochemical cell of (1) or (2) above, when the distance between the centers of adjacent holes in the first direction is Lp1, the range of the perforated region that is a distance from the first end that is 2×Lp1 or less is defined as the first portion, and the range of the perforated region that is a distance from the center in the first direction that is Lp1 or less is defined as the second portion, the first area ratio may be 50% or less of the second area ratio.

[0098] (4) In the electrochemical cell of any one of (1) to (3) above, when the distance between the centers of adjacent holes in a second direction perpendicular to the first direction and along the first surface is Lp2, the first region may include at least one pair of holes having Lp2 larger than the maximum value of Lp2 in the second region.

[0099] (5) In the electrochemical cell of any one of (1) to (4) above, when the diameter of the holes in the perforated region is D and the average diameter of the holes is d, D and d may have a relationship of 0.75 × d≦D≦1.25 × d.

[0100] In one embodiment, (6) the electrochemical cell device has a cell stack including any one of the electrochemical cells (1) to (5) above.

[0101] In one embodiment, (7) a module includes the electrochemical cell device of (6) above, and a container that houses the electrochemical cell device.

[0102] In one embodiment, (8) a module housing device includes the module of (7) above, an auxiliary device configured to operate the module, and an outer case housing the module and the auxiliary device.

[0103] 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.

[0104] REFERENCE SIGNS LIST 1 cell 3 element portion 5 fuel electrode 6 solid electrolyte layer 8 air electrode 9 sealing material 10 cell stack device 20 metal plate 20a hole 25 perforated region 100 module 110 module receiving device 251 first portion 252 second portion

Claims

1. An electrochemical cell comprising: an element portion; and a metal plate having a first surface facing the element portion and a second surface located opposite the first surface, wherein the metal plate includes a plurality of holes opening into the first surface and has a perforated region facing the element portion, wherein the perforated region has a first portion including a first end of a pair of ends in a first direction along the first surface, and a second portion located more centrally in the first direction than the first portion, wherein a first area ratio is an area ratio occupied by the plurality of holes in the first portion, and a second area ratio is an area ratio occupied by the plurality of holes in the second portion, wherein the first area ratio is smaller than the second area ratio.

2. The electrochemical cell of claim 1, wherein the number of pores per unit area in the first region is smaller than the number of pores per unit area in the second region.

3. An electrochemical cell as described in claim 1 or 2, wherein, when the distance between the centers of adjacent holes in the first direction is Lp1, the range of the perforated region that is a distance from the first end that is 2 x Lp1 or less is defined as the first portion, and the range of the perforated region that is a distance from the center in the first direction that is Lp1 or less is defined as the second portion, the first area ratio is 50% or less of the second area ratio.

4. An electrochemical cell according to any one of claims 1 to 3, wherein, when the distance between the centers of adjacent holes in a second direction perpendicular to the first direction and along the first surface is Lp2, the first region includes at least one pair of holes having Lp2 larger than the maximum value of Lp2 in the second region.

5. The electrochemical cell according to any one of claims 1 to 4, wherein, when the diameter of the pores in the perforated region is D and the average diameter of the pores is d, D and d have the relationship 0.75 x d ≦ D ≦ 1.25 x d.

6. An electrochemical cell device having a cell stack comprising the electrochemical cell according to any one of claims 1 to 5.

7. A module comprising the electrochemical cell device according to claim 6 and a container that houses the electrochemical cell device.

8. A module housing device comprising: a module according to claim 7; an accessory configured to operate said module; and an outer case housing said module and said accessory.

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