Electrochemical cell, electrochemical cell device, module, and module accommodation device

Abstract

This electrochemical cell comprises a metal plate and an element section. The element section has a flat plate shape and is disposed on the metal plate. The element section has a solid electrolyte layer, a first electrode, and a second electrode. The solid electrolyte layer has a first surface located on a metal plate side, and a second surface on the opposite side to the first surface. The first electrode faces the first surface. The second electrode faces the second surface. When viewed in plan from a second electrode side, the solid electrolyte layer has a central part with an area centroid, and an edge part. When the distance from the metal plate to the second surface at the area centroid is L0 and the distance from the metal plate to the second surface at the edge part is L1, the solid electrolyte layer has a portion where L1 is smaller than L0.

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. 2020-140923

[0004] An electrochemical cell according to one aspect of the embodiment includes a metal plate and an element unit. The element unit is flat and disposed on the metal plate. The element unit includes a solid electrolyte layer having a first surface facing the metal plate and a second surface opposite the first surface, a first electrode facing the first surface, and a second electrode facing the second surface. When viewed from the second electrode side, the solid electrolyte layer has a center portion including a surface center of gravity and an edge portion. When the distance from the metal plate at the surface center of gravity to the second surface is L0 and the distance from the metal plate at the edge portion to the second surface is L1, the solid electrolyte layer has a portion where L1 is smaller than L0.

[0005] An electrochemical cell device according to one aspect of the embodiment includes a cell stack including the electrochemical cell described above.

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

[0007] The module housing device of the present disclosure includes the module described above, an auxiliary device for operating the module, and an exterior case for housing the module and the auxiliary device.

[0008] FIG. 1A is a plan view showing an example of an electrochemical cell according to an embodiment. FIG. 1B is a cross-sectional view taken along line A-A in FIG. 1A. FIG. 1C is a cross-sectional view showing another example of an electrochemical cell according to an embodiment. FIG. 2 is a cross-sectional view showing another example of an electrochemical cell according to an embodiment. FIG. 3A is a perspective view showing an example of an electrochemical cell device according to an 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 an embodiment. FIG. 4 is an external perspective view showing an example of a module according to an embodiment. FIG. 5 is an exploded perspective view schematically showing an example of a module housing device according to an embodiment.

[0009] In the above-described fuel cell stack device, there is room for improvement in the durability of the electrochemical cells.

[0010] Therefore, there is a need to provide highly durable electrochemical cells, electrochemical cell devices, modules, and module housing devices.

[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 and 1B, an electrochemical cell according to an embodiment will be described using an example of a solid oxide fuel cell. The electrochemical cell device may include a cell stack having a plurality of electrochemical cells. An electrochemical cell device having a plurality of electrochemical cells will be simply referred to as a cell stack device.

[0014] Fig. 1A is a plan view showing an example of an electrochemical cell according to an embodiment. Fig. 1B is a cross-sectional view taken along line A-A shown in Fig. 1A. Figs. 1A and 1B show enlarged views of parts of each component of the electrochemical cell. Hereinafter, the electrochemical cell may be simply referred to as a cell.

[0015] For ease of understanding, Figures 1A and 1B illustrate a three-dimensional Cartesian coordinate system including a Z axis, with the vertical upward direction as the positive direction and the vertical downward direction as the negative direction. This Cartesian coordinate system may also be shown in other drawings used in the following description. Furthermore, components similar to those in the electrochemical cells shown in Figures 1A and 1B are denoted by the same reference numerals, and their description will be omitted or simplified.

[0016] 1A and 1B , the cell 1 according to this embodiment includes an element section 3, a first intermediate layer 30, a metal plate 32, and a flow path member 34. The element section 3 includes an anode 5, a solid electrolyte layer 6, and a cathode 8.

[0017] The anode 5 is a first 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. 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:

[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 second 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 ３Here, 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 has the function of making it difficult for a specific element to diffuse. For example, when an element such as Sr (strontium) contained in the air electrode 8 diffuses into the solid electrolyte layer 6, the solid electrolyte layer 6 becomes covered with SrZrO ３ The diffusion suppression layer 7 makes it difficult for elements such as Sr to diffuse, and thus a resistive layer such as SrZrO ３ This makes it difficult for compounds such as

[0025] The material of the diffusion prevention layer 7 is not particularly limited as long as it generally makes it difficult for Sr to diffuse. For example, the material of the diffusion prevention layer 7 is cerium oxide (CeO ２ ) may be included. Examples of such rare earth elements include Gd (gadolinium) and Sm (samarium).

[0026] The first intermediate layer 30 is located between the first surface 321 of the metal plate 32 and the element portion 3. The first intermediate layer 30 bonds the element portion 3 and the metal plate 32 together, and fixes the element portion 3 to the metal plate 32.

[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 inorganic oxide may include inorganic oxides such as SiO 2 , CuO, etc.

[0028] The first intermediate layer 30 may have gas barrier properties. When the first intermediate layer 30 has gas barrier properties, the first intermediate layer 30 may have a through-hole (not shown) that overlaps with an opening 32 a (described later) in a plan view.

[0029] The first intermediate layer 30 may be gas permeable. When the first intermediate layer 30 is gas permeable, the first intermediate layer 30 may be positioned so as to cover an opening 32a, which will be described later.

[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 32 has a first surface 321 and a second surface 322 located at both ends in the thickness direction (Y-axis direction).

[0032] The metal plate 32 is electrically conductive. The metal plate 32 may be, for example, a member made of a metal containing chromium. The metal plate 32 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 32 may be, for example, a nickel-chromium alloy or an iron-chromium alloy. The metal plate 32 may contain, for example, a metal oxide. The metal plate 32 may have a coating covering the surface. The metal plate 32 does not have to have a coating on the surface.

[0033] The metal plate 32 also has an opening 32a. The opening 32a is a through-hole that penetrates between the first surface 321 and the second surface 322. The fuel gas flowing through a flow path 35 (described later) is supplied to the fuel electrode 5 of the element section 3 through the opening 32a. The diameter of the opening 32a may be, for example, 0.1 mm to 0.5 mm, particularly 0.3 mm to 0.4 mm. In a plan view of the metal plate 32 along the Y-axis direction, the aperture ratio of the region where the opening 32a is formed may be, for example, 10% or more. The metal plate 32 may have a coating that covers the wall surface of the opening 32a. The metal plate 32 does not need to have a coating on the wall surface of the opening 32a.

[0034] The metal plate 32 may be gas permeable, for example. In such a case, the metal plate 32 does not need to have the opening 32a.

[0035] The flow path member 34 is located on the second surface 322 side of the metal plate 32. The flow path member 34 is fixed and electrically joined by, for example, welding or the like at the contact portion with the second surface 322. The flow path member 34 may be fixed and electrically joined to the metal plate 32 by a conductive sealing material, brazing material, or the like. The space located between the metal plate 32 and the flow path member 34 is a flow path 35 through which the fuel gas flows. The fuel gas flowing through the flow path 35 permeates the metal plate 32 and is supplied to the anode 5. The metal plate 32 may have one or more protrusions protruding toward the flow path member 34.

[0036] The flow path member 34 is further fixed and electrically joined to the current collecting member 36 by welding or the like. The current collecting member 36 may be fixed and electrically joined to the flow path member 34 by a conductive sealing material, brazing material, or the like. The current collecting member 36 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 36 and the flow path member 34 is a flow path 37 through which an oxygen-containing gas flows. The oxygen-containing gas flowing through the flow path 37 is supplied to the air electrode 8 of the adjacent cell 1 via a slit and adhesive (not shown) in the current collecting member 36.

[0037] The flow path member 34 and the current collecting member 36 are made of a dense metal or alloy. The flow path member 34 makes it difficult for the fuel gas flowing through the flow path 35 and the oxygen-containing gas flowing through the flow path 37 to leak. The flow path member 34 and the current collecting member 36 may have a coating layer. For example, the surface of the flow path member 34 facing the flow path 35 may have a coating layer that is resistant to reduction. Furthermore, the surface of the flow path member 34 facing the flow path 37 may have a coating layer that is resistant to oxidation. These coating layers may be electrically conductive.

[0038] The element section 3 may further include a diffusion layer (not shown) located between the anode 5 and the first intermediate layer 30. The diffusion layer is gas permeable and allows the fuel gas flowing through the flow path 35 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%.

[0039] 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.

[0040] Furthermore, the cell 1 may further include, for example, a constraining layer (not shown) located between the element portion 3 and the first intermediate layer 30. The constraining layer cooperates with the solid electrolyte layer 6 to make the element portion 3 less susceptible to warping, bending, and the like.

[0041] The material of the constraining layer exhibits 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.

[0042] 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.

[0043] 1B , the shapes of the flow path member 34 and the current collecting member 36 may be any shape that electrically connects adjacent cells 1 and makes it difficult for the fuel gas and oxygen-containing gas to leak.

[0044] 1C is a cross-sectional view showing another example of an electrochemical cell according to an embodiment. As shown in FIG. 1C, the flow path member 34 may be integrated with the current collecting member 36 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.

[0045] <Arrangement and Shape of Element Section and First Intermediate Layer> Returning to FIGS. 1A and 1B, the arrangement and shape of the element section 3 and first intermediate layer 30 of the cell 1 will be further described.

[0046] 1A, the cell 1 is positioned such that the element unit 3 overlaps a metal plate 32 that is substantially rectangular in plan view. Line A-A shown in Fig. 1A is a line segment that extends along the X axis, and overlaps with the center of gravity P of the surface of the solid electrolyte layer 6 of the element unit 3 when viewed from the air electrode 8 side.

[0047] The element part 3 has a solid electrolyte layer 6 having a first surface 61 located on the metal plate 32 side and a second surface 62 opposite the first surface 61, a fuel electrode 5 facing the first surface 61, and an air electrode 8 facing the second surface 62 via a diffusion suppression layer 7.

[0048] The solid electrolyte layer 6 has a central portion 6a including the center of gravity P of the surface and edge portions 6b. The edge portions 6b are portions of the solid electrolyte layer 6 located at both ends in the X-axis direction. Here, the edge portions 6b refer to portions of the solid electrolyte layer 6 whose length from the ends in the X-axis direction is up to 5% of the entire length of the solid electrolyte layer 6. The central portion 6a is located in the center in the X-axis direction and is sandwiched between the edge portions 6b. The edge portions 6b may have a portion on the second surface 62 that does not face the air electrode 8. For example, when viewed from the air electrode 8 side in FIGS. 1A and 1B, the outline of the solid electrolyte layer 6 is located inside the outline of the air electrode 8, but the outline of the solid electrolyte layer 6 may also be located outside the outline of the air electrode 8.

[0049] When the distance from the metal plate 32 at the center of gravity P to the second surface 62 is L0 and the distance from the metal plate 32 at the edge 6b to the second surface 62 is L1, there is a portion where L1 is smaller than L0. Furthermore, the cross-sectional shape of the element portion 3 is such that the central portion 6a is farther from the metal plate 32 than the edge portion 6b, i.e., is substantially convex.

[0050] In this way, by having the solid electrolyte layer 6 having a portion where L1 is smaller than L0, cracks caused by thermal stress are less likely to occur in the element portion 3. Therefore, the durability of the cell 1 according to this embodiment is improved.

[0051] Furthermore, the average value of L1 at each portion of the edge portion 6b may be equal to or less than L0, which makes it even more difficult for cracks caused by thermal stress to occur in the element portion 3. As a result, the durability of the cell 1 according to this embodiment is improved.

[0052] Furthermore, when the distance from the metal plate 32 to the second surface 62 in the central portion 6a is L2, the average value of L1 may be equal to or less than the average value of L2. This makes it less likely for cracks due to thermal stress to occur in the element portion 3. As a result, the durability of the cell 1 according to this embodiment is improved.

[0053] L0, L1, and L2 can be measured, for example, by observing a cross section of the cell 1 along the X-axis direction using a scanning electron microscope (SEM) or the like. The average value of L1 and the average value of L2 can be calculated using L1 and L2 measured at any three locations, for example, in the central portion 6a and the edge portion 6b. In this case, L2 may or may not include L0. Furthermore, the average value of L1 may be greater than L0.

[0054] In addition, the first intermediate layer 30 is located between the metal plate 32 and the fuel electrode 5. This reduces interference between the fuel electrode 5 located near the edge 6b and the metal plate 32, improving the performance of the cell 1.

[0055] Furthermore, the first intermediate layer 30 located between the edge portion 6 b and the metal plate 32 may have a portion whose thickness is smaller than the thickness of the first intermediate layer 30 located between the central portion 6 a and the metal plate 32. This makes it possible to avoid the cell 1 from becoming large in size.

[0056] Next, another example of the cell 1 according to the embodiment will be described with reference to Fig. 2. Fig. 2 is a cross-sectional view showing another example of the electrochemical cell according to the embodiment. As shown in Fig. 2, the cell 1 may have a portion between the metal plate 32 and the edge portion 6b where the first intermediate layer 30 is not located.

[0057] The cell 1 may also have a second intermediate layer 31 located between the metal plate 32 and the edge portion 6b. The second intermediate layer 31 may have a smaller porosity than the first intermediate layer 30. This reduces the likelihood of leakage of the fuel gas and oxygen-containing gas, improving the performance of the cell 1. The second intermediate layer 31 may be located not only between the metal plate 32 and the edge portion 6b, but also outside the edge portion 6b. The second intermediate layer may be in contact with the diffusion-suppressing layer 7 and further with the air electrode 8. The cell 1 shown in FIGS. 1B and 1C may have a second intermediate layer 31.

[0058] The material of the second intermediate layer 31 may be dense glass or ceramic. The material of the second intermediate layer 31 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 second intermediate layer 31 may be made of an electrically insulating material. The material of the second intermediate layer 31 may be the same as the material of the solid electrolyte layer 6.

[0059] <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 3A to 3C. Figure 3A is a perspective view showing an example of an electrochemical cell device according to an embodiment. Figure 3B is a cross-sectional view taken along line XX shown in Figure 3A. Figure 3C is a top view showing an example of an electrochemical cell device according to an embodiment.

[0060] As shown in Figure 3A, the cell stack device 10 includes a cell stack 11 having multiple cells 1 arranged (stacked) in the thickness direction of the cells 1 (the Y-axis direction shown in Figure 1A), and a fixing member 12.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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 35 (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. The internal space 22 may also be referred to as a space containing fuel gas and having a reducing atmosphere.

[0065] 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.

[0066] 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.

[0067] 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. 1A ).

[0068] 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 flow paths 35 of each cell 1 communicate with the internal space 22 of the support member 14 at their lower ends.

[0069] A material with low electrical 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.

[0070] 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.

[0071] 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 flow path member 34 and / or the current collecting member 36 shown in FIG. 1B. The conductive member 18 may be a member separate from the flow path member 34 and the current collecting member 36.

[0072] 3B, an end current collecting member 17 is electrically connected to the cell 1 positioned outermost in the arrangement direction of the multiple cells 1. The end current collecting member 17 is connected to a conductive portion 19 that protrudes outside the cell stack 11. The conductive portion 19 collects electricity generated by power generation in the cells 1 and extracts it to the outside. Note that the end current collecting member 17 is not shown in FIG. 3A.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] <Module> Next, a module according to this embodiment 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 this embodiment. Fig. 4 shows a state in which the front and rear surfaces, which are part of the storage container 101, have been removed and the cell stack device 10 of the fuel cell stored inside has been taken out to the rear.

[0077] 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.

[0078] 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.

[0079] The fuel gas produced in the reformer 102 is supplied to the flow path 35 of the cell 1 (see FIG. 1B) through the gas distribution pipe 20, the gas tank 16, and the support member 14.

[0080] Furthermore, in the module 100 having the above-described configuration, the temperature inside the module 100 during normal power generation reaches approximately 500°C to 1000°C due to the combustion of gas and the power generation of the cells 1.

[0081] In such a module 100, as described above, the module 100 is configured to house a cell stack device 10 having multiple cells 1 whose durability is resistant to deterioration, thereby making it possible to make the module 100 resistant to deterioration in durability.

[0082] <Module Enclosure Device> Fig. 5 is an exploded perspective view that schematically illustrates 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. 5, 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 Fig. 5 omits some components.

[0083] 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.

[0084] 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.

[0085] In such a module accommodating device 110, as described above, the module accommodating chamber 115 is provided with a module 100 whose durability is unlikely to deteriorate, thereby making it possible to provide a module accommodating device 110 whose durability is unlikely to deteriorate.

[0086] 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, electrolysis cell stack device, electrolysis module, and electrolysis device can improve electrolysis performance and are less likely to deteriorate in durability.

[0087] 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.

[0088] In one embodiment, (1) an electrochemical cell includes a metal plate and a flat-plate element portion disposed on the metal plate, wherein the element portion includes a solid electrolyte layer having a first surface located on the metal plate side and a second surface opposite the first surface, a first electrode facing the first surface, and a second electrode facing the second surface, wherein, when viewed from a plane from the second electrode side, the solid electrolyte layer has a center portion including a surface center of gravity and an edge portion, and wherein, when a distance from the metal plate at the surface center of gravity to the second surface is defined as L0 and a distance from the metal plate at the edge portion to the second surface is defined as L1, the solid electrolyte layer has a portion where L1 is smaller than L0.

[0089] (2) In the electrochemical cell of (1) above, the average value of L1 may be equal to or less than L0.

[0090] (3) The electrochemical cell of (1) or (2) above may further include a first intermediate layer located between the metal plate and the first electrode.

[0091] (4) In the electrochemical cell of (3) above, the first intermediate layer located between the edge portion and the metal plate may have a portion whose thickness is smaller than a thickness of the first intermediate layer located between a center portion of the solid electrolyte layer and the metal plate.

[0092] (5) In the electrochemical cell of (3) or (4) above, there may be a portion between the metal plate and the edge where the first intermediate layer is not located.

[0093] (6) The electrochemical cell of (5) above may further include a second intermediate layer positioned between the metal plate and the edge portion, the second intermediate layer having a lower porosity than the first intermediate layer.

[0094] In one embodiment, (7) an electrochemical cell includes a metal plate and a flat element portion disposed on the metal plate, wherein the element portion includes a solid electrolyte layer having a first surface located on the metal plate side and a second surface opposite to the first surface, a first electrode facing the first surface, and a second electrode facing the second surface, wherein, when viewed from a plane from the second electrode side, the solid electrolyte layer has a center portion including a center of gravity of the surface and an edge portion, wherein the distance from the metal plate at the center portion to the second surface is defined as L2, and the distance from the metal plate at the edge portion to the second surface is defined as L1, and the average value of L1 is smaller than the average value of L2.

[0095] In one embodiment, the electrochemical cell device (8) has a cell stack including any one of the electrochemical cells (1) to (7) above.

[0096] In one embodiment, (9) a module includes the electrochemical cell device of (8) above, and a container that houses the electrochemical cell device.

[0097] In one embodiment, (10) a module housing device includes the module of (9) above, an auxiliary device for operating the module, and an exterior case for housing the module and the auxiliary device.

[0098] 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.

[0099] REFERENCE SIGNS LIST 1 cell 3 element section 5 fuel electrode 6 solid electrolyte layer 8 air electrode 10 cell stack device 11 cell stack 12 fixing member 13 fixing material 14 support member 15 support 16 gas tank 17 end current collecting member 18 conductive member 30 first intermediate layer 31 second intermediate layer 32 metal plate 100 module 110 module accommodating device

Claims

1. A metal plate and A flat plate-shaped element portion arranged on the metal plate and Equipped with, The element portion comprises a solid electrolyte layer having a first surface located on the metal plate side and a second surface opposite to the first surface, a first electrode facing the first surface, and a second electrode facing the second surface. When viewed from the second electrode side in a plan view, the solid electrolyte layer has a central portion including the surface center of gravity and an edge portion. Let L0 be the distance from the metal plate to the second surface at the centroid of the surface. If the distance from the metal plate to the second surface at the edge is L1, The portion of L1 is smaller than the portion of L0. Electrochemical cell.

2. The average value of L1 is less than or equal to L0. The electrochemical cell according to claim 1.

3. The present invention further comprises a first intermediate layer located between the metal plate and the first electrode. The electrochemical cell according to claim 1.

4. The first intermediate layer located between the edge and the metal plate has a portion that is less thick than the first intermediate layer located between the central portion and the metal plate. The electrochemical cell according to claim 3.

5. The metal plate and the edge portion have a portion where the first intermediate layer is not located. The electrochemical cell according to claim 3.

6. The present invention further comprises a second intermediate layer located between the metal plate and the edge, having a lower porosity than the first intermediate layer. The electrochemical cell according to claim 5.

7. A metal plate and A flat plate-shaped element portion arranged on the metal plate and Equipped with, The element portion comprises a solid electrolyte layer having a first surface located on the metal plate side and a second surface opposite to the first surface, a first electrode facing the first surface, and a second electrode facing the second surface. When viewed from the second electrode side in a plan view, the solid electrolyte layer has a central portion including the surface center of gravity and an edge portion. Let L2 be the distance from the metal plate in the central part to the second surface. If the distance from the metal plate to the second surface at the edge is L1, The average value of L1 is smaller than the average value of L2. Electrochemical cell.

8. A cell stack comprising an electrochemical cell according to any one of claims 1 to 7 Electrochemical cell apparatus.

9. The electrochemical cell apparatus according to claim 8, A storage container for housing the electrochemical cell apparatus and A module equipped with the following features.

10. The module according to claim 9, Auxiliary equipment for operating the aforementioned module, An outer case housing the module and the auxiliary equipment A module housing device equipped with the following features.