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

Abstract

This electrochemical cell has a flow path member and an element part. The flow path member has a first portion having a flat plate shape, a first folded-back portion, and a second folded-back portion. The first portion has a first surface and a second surface that is located on the opposite side of the first surface. The first folded-back portion and the second folded-back portion are respectively folded back from both ends in the first direction along the first surface, and face the second surface. The element part faces the first surface. Each of the first folded-back portion and the folded-back portion has a joint portion inside the contour of the element part when viewed in plan from the element part.

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] JP 2018-174115 A JP 2010-526402 A

[0004] An electrochemical cell according to one aspect of the embodiment includes a flow path member and an element portion. The flow path member includes a flat first portion, a first folded portion, and a second folded portion. The first portion includes a first surface and a second surface located opposite the first surface. The first folded portion and the second folded portion are folded back from both ends in a first direction along the first surface, respectively, to face the second surface. The element portion faces the first surface. The first folded portion and the second folded portion each have a joint portion inside the outline of the element portion when viewed from above the element portion.

[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 plan view showing an example of an electrochemical cell according to an embodiment. FIG. 1B is a cross-sectional view showing an example of line A-A shown in FIG. 1A. FIG. 2A is a plan view showing another example of an electrochemical cell according to an embodiment. FIG. 2B is a cross-sectional view showing an example of line B-B shown in FIG. 2A. 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 shown in FIG. 3A. FIG. 3C is a top view showing an example of an electrochemical cell device according to an embodiment. FIG. 4A is a perspective view showing an example of a conductive member according to an embodiment. FIG. 4B is a cross-sectional view showing an example of a conductive member that connects electrochemical cells according to an embodiment. FIG. 5 is a cross-sectional view showing another example of a conductive member that connects electrochemical cells according to an embodiment. FIG. 6 is an external perspective view showing an example of a module according to an embodiment. FIG. 7 is an exploded perspective view schematically showing an example of a module housing device according to an embodiment. FIG. 8 is a plan view showing another example of an electrochemical cell according to an embodiment.

[0009] In the above-described fuel cell stack device, there is room for improvement in the reliability of the cells including the flow path members that also serve as supports for supporting the fuel cells, for example.

[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 reliability.

[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 showing an example of a line AA shown in Fig. 1A. Figs. 1A and 1B show enlarged views of parts of each component of the electrochemical cell. Hereinafter, the electrochemical cell may be simply referred to as a cell.

[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 , a cell 1 according to the embodiment includes an element section 3 and a flow path member 30. The element section 3 has an anode 5, a solid electrolyte layer 6, and a cathode 8. The element section 3 is fixed to the flow path member 30.

[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. Having gas permeability means that gas can flow through open pores, voids, etc. 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 is sometimes 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-dissolved may be used. ２ The stabilized zirconia may contain partially stabilized zirconia. The anode 5 is made of CeO in which an oxide of La, Nd, or Yb is dissolved. 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 ３ Here, x is 0<x<1, and y is 0<y<1.

[0024] 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 is filled with SrZrO, which has a high electrical resistance. ３ The intermediate layer 7 makes it difficult for elements such as Sr to diffuse, and thus the solid electrolyte layer 6 is formed with a resistive phase such as SrZrO. ３ This makes it difficult for compounds such as

[0025] 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 may be, for example, cerium oxide (CeO ２ ) may be included. Examples of such rare earth elements include Gd (gadolinium) and Sm (samarium).

[0026] 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 flow path member 30 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.

[0027] 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.

[0028] 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.

[0029] The element section 3 may further include a gas diffusion layer (not shown). The gas diffusion layer may be located between the fuel electrode 5 and the flow path member 30. The gas diffusion layer has gas permeability and allows the fuel gas flowing through a flow path 188 (described later) to permeate to the fuel electrode 5. The open porosity of the gas diffusion layer may be in the range of, for example, 30% to 50%, particularly 35% to 45%.

[0030] 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.

[0031] The cell 1 may further include an adhesive (not shown). The adhesive may be located between the element section 3 and the flow path member 30. The adhesive bonds the element section 3 and the flow path member 30 together, and fixes the element section 3 to the flow path member 30.

[0032] The adhesive may be conductive. For example, the adhesive may be a mixture of 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 copper, copper oxide ...

[0033] The adhesive may be gas permeable. The solid electrolyte layer 6 may be positioned so as to cover the side surface of the adhesive.

[0034] The adhesive may be formed as a single layer using a single material, or may be formed as a laminate of multiple materials.

[0035] As shown in FIG. 1B , 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-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 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.

[0036] <Configuration of Flow Channel Member> Next, the configuration of the flow channel member 30 according to this embodiment will be further described. As shown in Fig. 1A , when the cell 1 is viewed in plan from the air electrode 8 side, the flow channel member 30 has one end 30a and the other end 30b located at opposite ends along the X-axis direction, which is a first direction along a first surface 31a (see Fig. 1B ).

[0037] 1B , the flow path member 30 has a first portion 311, a first folded portion 312, and a second folded portion 313. The first portion 311 is a flat portion extending along the ZX plane. The first portion 311 has a first surface 31a and a second surface 31b. The element portion 3 is bonded to the first surface 31a. The second surface 31b is located on the opposite side of the first surface 31a. The second surface 31b is located so as to face the first folded portion 312 and the second folded portion 313.

[0038] The first portion 311 has a first end 311a and a second end 311b located at opposite ends along the first direction (X-axis direction). The first end 311a is located at the end on the positive side of the X-axis. The second end 311b is located at the end on the negative side of the X-axis.

[0039] The first portion 311 also has a plurality of holes 310. The holes 310 are through-holes that penetrate between the first surface 31a and the second surface 31b. The fuel gas that flows through a flow path 34 (described later) along the Z axis is supplied to the fuel electrode 5 of the element portion 3 through the holes 310. When viewed in a plan view in the Y axis direction, the aperture ratio of the region of the first portion 311 where the holes 310 are formed may be, for example, 10% or more. The first portion 311 may have a coating that covers the wall surfaces of the holes 310. The first portion 311 may not have a coating on the wall surfaces of the holes 310.

[0040] The first folded portion 312 and the second folded portion 313 are positioned to face the second surface 31b and are folded back from both ends in the first direction (X-axis direction) along the first surface 31a. Specifically, the first folded portion 312 is positioned to face the first portion 311 located closer to the first end 311a than the center in the first direction (X-axis direction). The second folded portion 313 is positioned to face the first portion 311 located closer to the second end 311b than the center in the first direction (X-axis direction).

[0041] The first folded portion 312 has an end surface 318 that faces the second folded portion 313. The second folded portion 313 has an end surface 319 that faces the first folded portion 312. The end surface 318 and the end surface 319 are located apart from each other.

[0042] The first folded portion 312 has a joint 316. The second folded portion 313 has a joint 317. The joints 316 and 317 each have a portion that overlaps with the element portion 3 when viewed from above. In other words, the first folded portion 312 and the second folded portion 313 each have the joints 316 and 317 inside the outline of the element portion 3 when viewed from above. This makes it less likely that stress concentration will occur due to thermal deformation of the flow path member 30 compared to when the joints are located outside the outline of the element portion 3, for example, near one end 30a and / or the other end 30b. Furthermore, even if the flow path member 30 is thermally deformed, cracks are less likely to occur in the fixing material 13 (see Figures 3A to 3C described below) that fixes the cell 1. This improves the reliability of the cell 1 according to this embodiment.

[0043] The flow path member 30 may further have a first connecting portion 314 and a second connecting portion 315. The first connecting portion 314 is located between the first end 311a of the first portion 311 and the first folded portion 312. The second connecting portion 315 is located between the second end 311b of the first portion 311 and the second folded portion 313.

[0044] The first connecting portion 314 and the second connecting portion 315 may each protrude in an arc shape outward from the first portion 311 along the first direction (X-axis direction). Specifically, the first connecting portion 314 may be located so as to include one end 30a of the flow path member 30, as shown in FIG. 1A . The first connecting portion 314 may have a curved outer surface. The second connecting portion 315 may be located so as to include the other end 30b of the flow path member 30. The second connecting portion 315 may have a curved outer surface.

[0045] The first connecting portion 314 may seamlessly connect the first end 311a and the first folded portion 312. The second connecting portion 315 may seamlessly connect the second end 311b and the second folded portion 313. That is, the flow path member 30 may have a first member 31 in which the first folded portion 312, the first connecting portion 314, the first part 311, the second connecting portion 315, and the second folded portion 313 are integrally formed. The first member 31 may be formed by, for example, press molding and / or bending. The first connecting portion 314 and the second connecting portion 315 may be bent portions formed by press molding and / or bending of the first member 31.

[0046] The flow path member 30 may further include a second member 32 facing the first member 31. The second member 32 may be located away from the second surface 31b. The space between the second member 32 and the second surface 31b may be a flow path 34 through which the fuel gas flows.

[0047] The second member 32 may be joined to the joints 316, 317 of the first folded portion 312 and the second folded portion 313, respectively. In other words, the second member 32 may be joined and fixed to the first folded portion 312 and the second folded portion 313 at the joints 316, 317. The joining of the first folded portion 312 and the second folded portion 313 to the second member 32 at the joints 316, 317 may be, for example, welding, glass sealing using a glass sealing material, brazing using a brazing material, or adhesion using an adhesive such as ceramic. Furthermore, the first folded portion 312 and the second folded portion 313 may be joined to the second member 32 by a combination of the above-mentioned methods.

[0048] The material of the flow path member 30 may be, for example, stainless steel. The flow path member 30 may have, for example, a base material containing Cr and a coating of a conductive oxide covering the base material. For example, the materials of the coatings may be different, so that the materials of the first member 31 and the second member 32 are different.

[0049] The second member 32 may have higher oxidation resistance than the first member 31. Here, having high oxidation resistance means that the mass increase per unit area due to oxidation is small when held in an air atmosphere at a maximum temperature of 1000°C for 200 hours.

[0050] The second member 32 has higher oxidation resistance than the first member 31, which can improve the durability of the element section 3 fixed to or connected to the flow path member 30. This makes it easier to ensure the desired cell performance.

[0051] The second member 32 may have insulating properties. In other words, the second member 32 does not need to have the function of passing current. Current flows between adjacent electrochemical elements through the first member 31. As such, since the first member 31 is a current path, there is a tendency to use a material that has excellent electrical conductivity even if it has low oxidation resistance for the first member 31. On the other hand, the second member 32 of this embodiment does not need to be a current path, and an insulating material that has excellent oxidation resistance can be used.

[0052] The second member 32 may be electrically conductive. The second member 32 may be made of the same material as the first member 31 and have a thicker oxide film or coating layer than the first member 31. When the second member 32 is electrically conductive, the second member 32 may be fixed to the joints 316 and 317 of the first folded portion 312 and the second folded portion 313, respectively, using, for example, a conductive sealant or brazing material, and may be electrically joined to the first member 31.

[0053] The second member 32 may have gas barrier properties, thereby reducing gas leakage through the second member 32. The fuel gas flowing through the flow path 34 located between the second member 32 and the second surface 31b is supplied to the anode 5 through the holes 310 in the first portion 311. The second member 32 may have one or more protrusions 32a protruding toward the second surface 31b.

[0054] The material of the flow path member 30 may be, for example, a dense metal or alloy. The flow path member 30 may be, for example, a member made of a metal containing chromium. The flow path member 30 may be, for example, a stainless steel such as a ferritic stainless steel or an austenitic stainless steel having high heat resistance. The flow path member 30 may be, for example, a nickel-chromium alloy or an iron-chromium alloy. The flow path member 30 may contain, for example, a metal oxide.

[0055] The flow path member 30 may also have a coating. For example, the flow path member 30 may have a reduction-resistant coating on the surface facing the flow path 34. The flow path member 30 may have an oxidation-resistant coating on the surface not facing the flow path 34. These coatings may be electrically conductive.

[0056] Furthermore, when the second member 32 has higher oxidation resistance than the first member 31, the second member 32 may have, for example, a coating that is thicker than that of the first member 31, at least on the surface that does not face the flow path 34, or may have a coating of oxide ceramics such as alumina or forsterite that has better oxidation resistance than the first member 31. The material of the second member 32 may be the same as or different from the material of the first member 31. The material of the second member 32 may be, for example, Al-containing ferritic stainless steel having an oxide film on its surface. The second member 32 may be, for example, entirely made of a material such as oxide ceramics having high oxidation resistance, such as alumina or forsterite.

[0057] FIG. 2A is a plan view showing another example of an electrochemical cell according to an embodiment. FIG. 2B is a cross-sectional view showing an example of line B-B shown in FIG. 2A . In the flow path member 30, as shown in FIG. 2B , an end face 318 of a first folded portion 312 and an end face 319 of a second folded portion 313 may be butted against each other and joined at a joint 316. As shown in FIG. 2A , the joint 316 overlaps the element portion 3 when viewed from the element portion 3 in a plan view. In other words, the first folded portion 312 and the second folded portion 313 are joined at the joint 316 located inside the outline of the element portion 3 when viewed from the element portion 3 in a plan view. This reduces the likelihood of stress concentration due to thermal deformation of the flow path member 30 compared to when the joint is located outside the outline of the element portion 3, for example, near one end 30 a and the other end 30 b. Furthermore, even if the flow path member 30 is thermally deformed, cracks are less likely to occur in, for example, the fixing material 13 (see FIGS. 3A to 3C described later) that fixes the cell 1. This improves the reliability of the cell 1 according to this embodiment.

[0058] 2B shows the case where the end face 318 and the end face 319 are joined in abutting relation, but the end face 318 and the end face 319 may also be joined in an overlapping relation. Also, while FIGS. 2A and 2B show the case where the joint 316 is located approximately midway between the one end 30a and the other end 30b, the joint 316 may be located inside the outline of the element portion 3 when viewed from above. The joint 316 may be located, for example, closer to the one end 30a or closer to the other end 30b than midway between the one end 30a and the other end 30b.

[0059] 2B , the flow path member 30 may further include a first connecting portion 314 and a second connecting portion 315. The first connecting portion 314 and the second connecting portion 315 may each protrude in an arc shape outward from the first portion 311 along the first direction (X-axis direction).

[0060] 2B may not have the second member 32. In the flow path member 30, the first folded portion 312 and the second folded portion 313 may be located away from the second surface 31b of the first portion 311. In this case, the space between the first folded portion 312 and the second folded portion 313 and the second surface 31b may be the flow path 34 through which the fuel gas flows. The first folded portion 312 and the second folded portion 313 may have one or more protrusions 32a protruding toward the second surface 31b.

[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 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.

[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 1B), 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 34 (see Fig. 1B) inside the cell 1. The fuel gas supplied to the gas tank 16 may be generated in a reformer 102 (see Fig. 6), which will be described later.

[0067] The hydrogen-rich fuel gas can be produced by steam reforming the raw fuel, etc. The fuel gas produced by steam reforming may contain steam.

[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. The internal space 22 is formed by one gas tank 16 and two supports 15. The cell stack device 10 may include only one cell stack 11, or may include three or more cell stacks 11.

[0069] 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. 1B ), 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 ).

[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 first flow paths 50 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, which will be described later, 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 30 shown in FIG. 1A, or may be a member separate from the flow path member 30.

[0074] 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.

[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 188 inside the conductive member 18.

[0079] <Conductive Member> Fig. 4A is a perspective view showing an example of a conductive member according to the embodiment, and Fig. 4B is a cross-sectional view showing an example of a conductive member that connects electrochemical cells according to the embodiment.

[0080] The conductive member 18 according to this embodiment has two current collecting portions 18a and a connecting portion 18b arranged along the X-axis direction. The connecting portions 18b are located at both ends of the two current collecting portions 18a. As a result, the conductive member 18 has a structure in which the current collecting portions 18a and the connecting portions 18b are arranged alternately in the X-axis direction.

[0081] As shown in Fig. 4B, the cell stack device 10 has cells 1A and 1B adjacent to each other in the thickness direction (Y-axis direction) of the cell 1. A conductive member 18 is located between cells 1A and 1B. Note that Fig. 4B and Fig. 5, which will be described later, illustrate the shape of the cell 1 in a simplified manner.

[0082] The current collecting portion 18a is electrically connected to the cell 1A or the cell 1B. The current collecting portion 18a has first current collecting portions 181 and second current collecting portions 182 arranged alternately in the Z-axis direction. The first current collecting portions 181 and the second current collecting portions 182 extend along the width direction of the cell 1 (the X-axis direction).

[0083] The first current collector 181 has a surface 181a facing the cell 1A. The first current collector 181 is electrically connected to the cell 1A via the surface 181a.

[0084] The second current collector 182 has a surface 182a facing the cell 1B. The second current collector 182 is electrically connected to the cell 1B via the surface 182a.

[0085] The connection portions 18b electrically connect the first current collecting portion 181 and the second current collecting portion 182 of each current collecting portion 18a. The connection portions 18b also electrically connect the adjacent current collecting portions 18a. This allows the entire conductive member 18 to be electrically conductive.

[0086] In this way, by having the first current collecting portion 181 and the second current collecting portion 182, the conductive member 18 can buffer the variation even if there is a variation in the spacing between adjacent cells 1 across the conductive member 18. This makes it easier to ensure appropriate electrical connection between the cells 1.

[0087] FIG. 5 is a cross-sectional view showing another example of a conductive member connecting electrochemical cells according to the embodiment. As shown in FIG. 5, the conductive member 18 may have three current collectors 18a arranged along the X-axis direction. For example, if the length of the current collectors 18a along the X-axis direction is the same as the length of the current collectors 18a of the conductive member 18 shown in FIG. 4B, the length of the conductive member 18 along the X-axis direction will be greater than that of the conductive member 18 shown in FIG. 4B. Therefore, the conductive member 18 shown in FIG. 5 can appropriately connect cells 1 whose length along the X-axis direction is greater than that of the conductive member 18 shown in FIG. 4B.

[0088] Furthermore, when the length of conductive member 18 along the X-axis direction is the length of conductive member 18 shown in Fig. 4B, the length of current collecting portion 18a along the X-axis direction is shorter than that of current collecting portion 18a shown in Fig. 4B. Therefore, according to conductive member 18 shown in Fig. 5, for example, it is possible to increase the mechanical strength.

[0089] The number of current collecting portions 18a arranged along the X-axis direction may be four or more. The number and length of current collecting portions 18a of the conductive member 18 can be changed as appropriate depending on the material of the conductive member 18 and / or the performance required of the conductive member 18. The material of the conductive member 18 may be the same as or different from the material of the flow path member 30.

[0090] <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. 6. Fig. 6 is an external perspective view showing an example of a module according to an embodiment. Fig. 6 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.

[0091] 6, 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.

[0092] 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.

[0093] The fuel gas produced in the reformer 102 is supplied to the flow path 34 of the cell 1 (see FIG. 1B) through the gas distribution pipe 20, the gas tank 16, and the support member 14.

[0094] 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.

[0095] 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.

[0096] In such a module 100, as described above, the module 100 is configured to house the cell stack device 10 that can improve reliability, thereby making it possible to make the module 100 more reliable.

[0097] <Module Enclosure Device> Fig. 7 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. 6, 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. 7.

[0098] An exterior case 111 of a module accommodating device 110 shown in Figure 7 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 Figure 7, the accessories accommodated in the accessory accommodating chamber 116 are omitted from the illustration.

[0099] 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.

[0100] In such a module accommodating device 110, as described above, the module 100 capable of improving reliability is provided in the module accommodating chamber 115, thereby making it possible to make the module accommodating device 110 capable of improving reliability.

[0101] 8 is a plan view showing another example of an electrochemical cell according to an embodiment. As shown in Fig. 8, when viewed from above from the element unit 3, joints 316a and 317a may be provided inside the outline of the element unit 3. Both ends of the flow channel 34 along the Z-axis direction may be gas-sealed, for example, by caps and / or crimping (not shown).

[0102] The first member 31 of the flow path member 30 may have openings 310a and 310b penetrating the first portion 311 in the thickness direction. The openings 310a and 310b are in communication with the flow path 34. The fuel gas flowing through the flow path 34 may be supplied to the inside of the flow path 34 via the opening 310a. Furthermore, the fuel gas discharged from the element portion 3 of the cell may be discharged to the outside of the flow path 34 via the opening 310b.

[0103] 1B , in the cell 1 according to this embodiment, the first folded portion 312 and the second folded portion 313 each have joints 316, 317 inside the outline of the element portion 3 when viewed in plan from the element portion 3. This makes it less likely that stress concentration will occur due to thermal deformation of the flow path member 30 compared to when joints are located outside the outline of the element portion 3, for example, near one end 30 a and the other end 30 b. Furthermore, even if the flow path member 30 is thermally deformed, cracks are less likely to occur in the sealing material (not shown) that seals both ends of the flow path 34 along the Z-axis direction. This improves the reliability of the cell 1 according to this embodiment.

[0104] 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 hydrogen electrode as a first electrode and an oxygen electrode as 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. In addition, in the above-described embodiments, an oxide ion conductor or a hydrogen ion conductor is shown as an example of the electrolyte material of the electrochemical cell, but a hydroxide ion conductor may also be used. Such electrolysis cells, electrolysis cell stack devices, electrolysis modules, and electrolysis devices can improve reliability. Solid oxide fuel cells and electrolysis cells are collectively referred to as solid oxide electrochemical cells.

[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 flat first portion having a first surface and a second surface located opposite the first surface; a flow path member having a first fold portion and a second fold portion folded back from both ends in a first direction along the first surface and facing the second surface; and an element portion facing the first surface, wherein the first fold portion and the second fold portion each have a joint portion inside the outline of the element portion when viewed in a plan view from the element portion.

[0107] (2) In the electrochemical cell of (1) above, the flow path member may include a first member having the first portion, the first folded portion, and the second folded portion, and a second member positioned apart from the second surface and facing the second surface, and the second member may be joined to the joining portions of the first folded portion and the second folded portion, respectively.

[0108] (3) In the electrochemical cell of (1) above, the first folded portion and the second folded portion may be joined at the joint portion.

[0109] (4) In the electrochemical cell of any one of (1) to (3) above, the first portion has a first end and a second end located at opposite ends along the first direction, the flow path member has a first connection portion that seamlessly connects the first end and the first folded portion, and a second connection portion that seamlessly connects the second end and the second folded portion, and the first connection portion and the second connection portion may each protrude in an arc shape outside the first portion along the first direction.

[0110] In one embodiment, the electrochemical cell device (5) has a cell stack including any one of the electrochemical cells (1) to (4) above.

[0111] In one embodiment, (6) a module includes the electrochemical cell device of (5) above, and a container that houses the electrochemical cell device.

[0112] In one embodiment, (7) a module housing device includes the module of (6) above, an auxiliary device configured to operate the module, and an outer case housing the module and the auxiliary device.

[0113] 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.

[0114] REFERENCE SIGNS LIST 1 cell 3 element section 5 fuel electrode 6 solid electrolyte layer 8 air electrode 9 sealing material 10 cell stack device 18 conductive member 30 flow path member 31 first member 32 second member 100 module 110 module housing device

Claims

1. An electrochemical cell comprising: a flat first section having a first surface and a second surface located opposite the first surface; a flow path member having first and second fold portions folded back from both ends in a first direction along the first surface and facing the second surface; and an element section facing the first surface, wherein the first fold portion and the second fold portion each have a joint portion inside the outline of the element section when viewed in a plan view from the element section.

2. The electrochemical cell according to claim 1, wherein the flow path member comprises a first member having the first section, the first folded portion, and the second folded portion, and a second member positioned apart from the second surface and facing the second surface, and the second member is joined to the joining portions of the first folded portion and the second folded portion.

3. The electrochemical cell according to claim 1, wherein the first folded portion and the second folded portion are joined at the joint.

4. An electrochemical cell according to any one of claims 1 to 3, wherein the first portion has a first end and a second end located at opposite ends along the first direction, the flow path member has a first connection portion that seamlessly connects the first end and the first folded portion, and a second connection portion that seamlessly connects the second end and the second folded portion, and the first connection portion and the second connection portion each protrude in an arc shape outside the first portion along the first direction.

5. An electrochemical cell device having a cell stack including the electrochemical cell according to any one of claims 1 to 4.

6. A module comprising the electrochemical cell device according to claim 5 and a container that houses the electrochemical cell device.

7. A module housing device comprising: a module according to claim 6; an accessory configured to operate said module; and an outer case housing said module and said accessory.

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