Electrochemical cell, electrochemical cell device, module, and module-accommodating device

Abstract

This electrochemical cell comprises a first element part and a flow path member. The flow path member has a first surface facing the first element part, and a second surface that is positioned on the opposite side from the first surface and faces a second element part different from the first element part. The flow path member has a first flat part including a first flat surface facing toward the first element part, and one or more first protruding parts protruding from the first flat part toward the first element part. Each first protruding part has a first cavity that opens toward the second 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 2023-93447 A

[0004] An electrochemical cell according to one aspect of the embodiment includes a first element portion and a flow path member. The flow path member has a first surface facing the first element portion and a second surface located on the opposite side of the first surface and facing a second element portion different from the first element portion. The flow path member has a first flat portion including a first flat surface facing the first element portion, and one or more first protrusions protruding from the first flat portion toward the first element portion. The first protrusions have a first cavity opening toward the second 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 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 cross-sectional view showing an example of an electrochemical cell device according to an embodiment. FIG. 1B is a plan view of an example of an electrochemical cell according to an embodiment, viewed from the air electrode side. FIG. 1C is a plan view of an example of a flow path member included in an electrochemical cell according to an embodiment, viewed from the fuel electrode side. FIG. 1D is a cross-sectional view showing another example of an electrochemical cell device according to an embodiment. FIG. 2A is an enlarged plan view of region R1 shown in FIG. 1C. FIG. 2B is a cross-sectional view taken along line A-A shown in FIG. 2A. FIG. 2C is a cross-sectional view taken along 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. 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] The above-described fuel cell stack device has room for improvement in terms of power generation performance.

[0010] Therefore, it is desired to provide an electrochemical cell, an electrochemical cell device, a module, and a module housing device that can improve performance.

[0011] Hereinafter, embodiments of an electrochemical cell, an electrochemical cell device, a module, and a module housing device disclosed in the present application will be described in detail with reference to the accompanying drawings. However, the disclosure is not limited to the embodiments described below.

[0012] It should also be noted that the drawings are schematic and that the dimensional relationships and ratios of elements may differ from reality. Furthermore, the drawings may contain parts whose dimensional relationships and ratios differ from one another.

[0013] 1A to 1C, an electrochemical cell according to an embodiment will be described using an example of a solid oxide fuel cell. The electrochemical cell device may include a cell stack having a plurality of electrochemical cells. An electrochemical cell device having a plurality of electrochemical cells will be simply referred to as a cell stack device.

[0014] FIG. 1A is a cross-sectional view showing an example of an electrochemical cell device according to an embodiment. FIG. 1B is a plan view of an example of an electrochemical cell according to an embodiment, viewed from the air electrode side. FIG. 1C is a plan view of an example of a flow path member of an electrochemical cell according to an embodiment, viewed from the fuel electrode side. Note that FIGS. 1A to 1C show enlarged views of portions of each component of the electrochemical cell. Hereinafter, the electrochemical cell may also be simply referred to as a cell.

[0015] 1A to 1C illustrate a three-dimensional Cartesian coordinate system including a Z-axis, with the vertically upward direction being the positive direction and the vertically downward direction being the negative direction. This Cartesian coordinate system may also be shown in other drawings used in the following explanation. Furthermore, the same reference numerals are used to designate components similar to those of the electrochemical cells shown in FIGS. 1A to 1C, and their explanations will be omitted or simplified.

[0016] 1A, a cell stack device 10 according to this embodiment includes a cell 1. The cell 1 includes a support member 2, an element portion 3, and a flow path member 30.

[0017] The support member 2 is electrically conductive. The support member 2 may be, for example, a metal plate containing chromium. The support member 2 may be, for example, a stainless steel such as a ferritic stainless steel or an austenitic stainless steel having high heat resistance. The support member 2 may be, for example, a nickel-chromium alloy or an iron-chromium alloy. The support member 2 may contain, for example, a metal oxide. The support member 2 may have a coating covering the surface. The support member 2 does not have to have a coating on the surface.

[0018] The support member 2 may also have openings penetrating in the thickness direction (Y-axis direction). The fuel gas flowing through the flow path 2a is supplied to the fuel electrode 5 of the element section 3 through these openings. The diameter of the openings may be, for example, 0.01 mm to 0.8 mm, particularly 0.3 mm to 0.6 mm. The aperture ratio in the region where the openings are formed may be, for example, 10% or more. The support member 2 may have a coating covering the wall surfaces of the openings. The support member 2 does not need to have a coating on the wall surfaces of the openings.

[0019] The support member 2 may be gas permeable, for example. In such a case, the support member 2 does not need to have an opening penetrating in the thickness direction (Y-axis direction).

[0020] The element section 3 has an anode 5, a solid electrolyte layer 6, and an air electrode 8. 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 is sometimes referred to as the porosity or void ratio of the anode 5.

[0021] 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:

[0022] 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.

[0023] 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. ２and BaZrO in which Sc or Yb is solid-solved. ３ and BaCeO in which Sc or Yb is solid-solved. ３ may include:

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The element unit 3 may also have an intermediate layer (not shown) located between the solid electrolyte layer 6 and the air electrode 8. When the element unit 3 has an intermediate layer, the intermediate layer functions, for example, as a diffusion suppression layer. When elements such as Sr (strontium) contained in the air electrode 8 diffuse into the solid electrolyte layer 6, SrZrO ３ The intermediate layer 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

[0028] The material of the intermediate layer 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 is, for example, cerium oxide (CeO ２ ) may be included. Examples of such rare earth elements include Gd (gadolinium) and Sm (samarium).

[0029] The cell 1 may further include a constraining layer (not shown). The constraining layer is located between the element portion 3 and the support member 2. The constraining layer cooperates with the solid electrolyte layer 6 to make the element portion 3 less susceptible to warping, bending, and the like.

[0030] 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.

[0031] 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.

[0032] The cell 1 may further include a gas diffusion layer (not shown). The gas diffusion layer is located between the fuel electrode 5 and the support member 2. The gas diffusion layer has gas permeability and allows the fuel gas flowing through a flow path 2a (described later) to pass through 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%.

[0033] 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.

[0034] The cell 1 may further include an adhesive (not shown). The adhesive is located between the element portion 3 and the support member 2. The adhesive bonds the element portion 3 and the support member 2 together, and fixes the element portion 3 to the support member 2.

[0035] 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 SiO 2 , CuO, etc.

[0036] The adhesive may be gas permeable. The solid electrolyte layer 6 may be positioned so as to cover the side surface of the adhesive.

[0037] The flow path member 30 is located between the first element portion 3A and the second element portion 3B, which is a separate element portion 3 from the first element portion 3A. The flow path member 30 is located between the anode 5 of the first element portion 3A and the cathode 8 of the second element portion 3B. The material of the flow path member 30 may be a dense metal or alloy. The flow path member 30 has a first surface 31 facing the first element portion 3A and a second surface 32 facing the second element portion 3B. The flow path member 30 reduces leakage of the fuel gas flowing on the first surface 31 side and the oxygen-containing gas flowing on the second surface 32 side. The flow path member 30 may have a coating layer. For example, the first surface 31 of the flow path member 30 may have a coating layer having reduction resistance. The second surface 32 may have a coating layer having oxidation resistance. These coating layers may be electrically conductive.

[0038] The flow path member 30 is fixed and electrically joined to the support member 2 by, for example, welding or the like at the contact portion. The flow path member 30 may be fixed and electrically joined to the support member 2 by a conductive sealing material, brazing material, or the like. A flow path 2a through which the fuel gas flows is located between the first surface 31 of the flow path member 30 and the support member 2. The fuel gas flowing through the flow path 2a permeates the support member 2 and is supplied to the anode 5.

[0039] The second surface 32 is fixed to and electrically joined to the air electrode 8, for example, via a conductive adhesive. A space through which an oxygen-containing gas flows is located between the flow path member 30 and the air electrode 8.

[0040] 1C , the first surface 31 of the flow path member 30 facing the anode 5 across the support member 2 may have a first portion 311 and a second portion 312. The first portion 311 is located in the center in the X-axis direction facing the anode 5. The second portions 312 are located at both ends in the X-axis direction adjacent to the first portion 311.

[0041] The flow path member 30 has a first end 41 and a second end 42 located at opposite ends in the Z-axis direction. The fuel gas flows, for example, from the first end 41 toward the second end 42 through a flow path 2a located between the first portion 311 of the first surface 31 and the support member 2. Details of the flow path member 30 will be described later.

[0042] 1D is a cross-sectional view showing another example of an electrochemical cell device according to an embodiment. As shown in FIG. 1D, a sealant 9 different from the solid electrolyte layer 6 may be located on the side surface of the fuel electrode 5 and the solid electrolyte layer 6. The sealant 9 may be dense glass or ceramic. The material of the sealant 9 may be, for example, amorphous glass or crystallized glass. Examples of crystallized glass include SiO ２ -CaO system, MgO-B ２ O ３ System, La ２ O ３ -B ２ O ３ -MgO system, La ２ O ３ -B ２ O ３ -ZnO-based, SiO ２ -CaO-ZnO system materials, etc., may be used, and in particular SiO ２ - An MgO-based material may be used. The sealing material 9 may have electrical insulating properties.

[0043] <Details of Flow Channel Member> Next, details of the flow channel member 30 will be further described with reference to Figures 1A to 1C and 2A to 2C. Figure 2A is an enlarged plan view of region R1 shown in Figure 1C. Figure 2B is a cross-sectional view taken along line A-A shown in Figure 2A. Figure 2C is a cross-sectional view taken along line B-B shown in Figure 2A.

[0044] The first portion 311 of the flow path member 30 has a flat portion 30A including a flat surface 31a as a first flat surface, and one or more convex portions 31b. The flat surface 31a is positioned so as to face the first element portion 3A (see FIG. 1A).

[0045] The protrusion 31b is a first protrusion located so as to protrude from the flat portion 30A toward the first element portion 3A (see FIG. 1A). The protrusion 31b has a top portion 31ba and a side surface portion 31bb.

[0046] The top portion 31ba may be in contact with the support member 2. This increases the contact area between the support member 2 and the flow path member 30, improving the shape retention of the support member 2. Furthermore, by increasing the contact area between the support member 2 and the flow path member 30, stable current flow performance can be obtained, and the power generation performance of the cell 1 is improved.

[0047] The top portion 31ba may have a flat surface 31b1 as a second flat surface. Here, the flat surface 31a as the first flat surface and the flat surface 31b1 as the second flat surface located on the top portion 31ba refer to a portion that is approximately parallel to the surface of the first element portion 3A that faces the flow path member 30. The flat surfaces 31a and 31b1 may have irregularities.

[0048] The side surface portion 31bb is a portion that connects the top portion 31ba and the flat portion 30A. The side surface portion 31bb includes a side surface 31b2. The side surface 31b2 may be inclined with respect to the thickness direction (Y-axis direction) of the first element portion 3A.

[0049] Furthermore, the protrusion 31b has a cavity 32c as a first cavity that opens toward the second element portion 3B (see FIG. 1A ). In this way, the flow path member 30 has the protrusion 31b having the cavity 32c, thereby improving the heat dissipation properties of the flow path member 30 and the power generation performance of the cell 1.

[0050] The cavity 32c has a top surface 32c1 and a peripheral surface 32c2. The top surface 32c1 refers to a portion of the surface of the cavity 32c that is close to the first element portion 3A. The peripheral surface 32c2 is a portion that connects the top surface 32c1 and the flat surface 32a. The flat surface 32a is a surface of the flat portion 30A of the flow path member 30 that is located on the second surface 32 side that faces the second element portion 3B. The flat surface 32a may have irregularities. Furthermore, the flat surface 32a may be approximately parallel to the flat surface 31a, or may not be parallel to it.

[0051] Furthermore, the thickness t1 of the top portion 31ba may be smaller than the thickness t2 of the flat portion 30A. This improves the flexibility of the flow path member 30 and increases the strength of the element portion 3 and / or the flow path member 30 against bending, expansion and contraction, etc. This further improves the durability of the cell 1.

[0052] Furthermore, by making the thickness t1 of the top portion 31ba smaller than the thickness t2 of the flat portion 30A, the conduction distance of the flow path member 30 is shortened, and the power generation performance of the cell 1 is further improved.

[0053] Furthermore, the thickness (wall thickness) t3 of the side portion 31bb may be equal to or less than the thickness t1 of the top portion 31ba. This improves the flexibility of the flow path member 30 and increases the strength of the element portion 3 and / or the flow path member 30 against bending, expansion and contraction, etc. This further improves the durability of the cell 1.

[0054] Here, the thickness t1 of the top portion 31ba can be, for example, 0.08 mm or more and 1.6 mm or less. The thickness t2 of the flat portion 30A can be, for example, 0.1 mm or more and 2.0 mm or less. The thickness (wall thickness) t3 of the side portion 31bb can be, for example, 0.05 mm or more and 1.0 mm or less. The thicknesses t1 to t3 can be measured as follows. For example, a sample in which a portion of the cell 1 including the flat portion 31A and the convex portion 31b of the flow path member 30 is embedded in resin is polished to obtain a cross-section of the flow path member 30. The obtained cross-section of the flow path member 30 is observed using a scanning electron microscope (SEM) or the like to obtain a cross-sectional image including the flat portion 30A and the convex portion 31b. The thicknesses t1 to t3 can be measured using the obtained cross-sectional image. Note that the thicknesses t1 to t3 are the average values ​​obtained by measuring the thickness of each portion at two or more locations for one convex portion 31b and the flat portion 30A adjacent to it. Furthermore, the average value of the thickness t1 of two or more protrusions 31b may be smaller than the average value of the thickness t2 of the two or more protrusions 31b adjacent to the two or more protrusions 31b. The average value of the thickness (wall thickness) t3 of two or more protrusions 31b may be equal to or smaller than the average value of the thickness t1. Furthermore, when the flow path member 30 has a plurality of protrusions 31b, the plurality of protrusions 31b may include a protrusion 31b whose thickness t1 is equal to or greater than the thickness t2, or may include a protrusion 31b whose thickness t3 is greater than the thickness t1.

[0055] Furthermore, the convex portion 31b may be located on the first surface 31 and / or the second surface 32 and may have an uneven portion smaller than the height h1 of the convex portion 31b along the thickness direction of the first element portion 3A. The convex portion 31b may have, for example, an uneven portion 31b3 located on the first surface 31 or an uneven portion 32c3 located on the second surface 32. The uneven portion 31b and / or the uneven portion 32c3 of the convex portion 31b can convect the fuel gas flowing on the first surface 31 side of the flow path member 30 and / or the oxygen-containing gas flowing on the second surface 32 side. This allows for efficient heat exchange of the fuel gas and / or the oxygen-containing gas, further improving the power generation performance of the cell 1. The position and shape of the uneven portion 31b3 and / or the uneven portion 32c3 are not limited to those shown in the figures. The protrusion 31b may have, for example, uneven portions 31b3 and / or uneven portions 32c3 formed in a stepped shape on the side surface 31b2 and / or the peripheral surface 32c2.

[0056] The flow path member 30 may further include one or more convex portions 32b. As shown in Fig. 2B, the convex portion 32b is a second convex portion that protrudes from the flat portion 30A toward the second element portion 3B. As shown in Fig. 2A, when viewed in plan from the first element portion 3A side, the convex portion 32b may be located between adjacent convex portions 31b.

[0057] A flow path 40 through which an oxygen-containing gas flows is formed in the space formed between the flat portion 30A and the second element portion 3B. The oxygen-containing gas flows, for example, from the first end 41 to the second end 42 shown in FIG. 1C while avoiding the multiple protrusions 32b (see FIGS. 2A and 2B). The oxygen-containing gas may also flow, for example, from the second end 42 to the first end 41.

[0058] The protrusion 32b may be in contact with the second element portion 3B. This increases the contact area between the second element portion 3B and the flow path member 30, thereby achieving stable current-carrying performance. This improves the power generation performance of the cell 1.

[0059] Furthermore, when the flow path member 30 is viewed in plan from the first element portion 3A side, a flat portion 30A (see FIG. 2C ) may be located between the convex portions 31 b and 32 b. Such a shape of the flow path member 30 may be located, for example, in a region 34 arranged at the center of the first portion 311 that overlaps with the element portion 3 in plan view. This makes it easier to quickly release heat transferred from the element portion 3 to the flow path member 30, which tends to improve the power generation performance of the cell 1.

[0060] Furthermore, when viewed in plan from the first element portion 3A side, the flow path member 30 may have a region where only the flat portion 30A is located between adjacent convex portions 31b. Such a shape of the flow path member 30 may be located, for example, in regions 35 and 36 that are closer to the first end 41 and the second end 42 than the region 34. This makes it easier to ensure a flow path 2a from the fuel gas inlet corresponding to the first end 41 to the outlet corresponding to the second end 42, which tends to improve the power generation performance of the cell 1.

[0061] Furthermore, the convex portions 31b and 32b may have different shapes. For example, when viewed in plan from the first element portion 3A side, the convex portions 31b may have a substantially circular shape, while the convex portions 32b may have a shape extending in a first direction along the flat surface 31b1. As described above, the convex portions 31b contribute, for example, to maintaining the shape of the support member 2 and providing electrical continuity between the support member 2 and the flow path member 30. On the other hand, the convex portions 32b, for example, branch the flow of oxygen-containing gas flowing through the flow path 40 at multiple locations, thereby making it easier to improve thermal uniformity in the second element portion 3B via the flow path member 30. In this way, by making the shapes of the convex portions 31b and 32b different from each other depending on the purpose, the power generation performance of the cell 1 is further improved.

[0062] 2B, the protrusion 32b may have a cavity 31c as a second cavity that opens toward the first element portion 3A (see FIG. 1A). In this way, when the flow path member 30 has the protrusion 32b with the cavity 31c, the heat dissipation property of the flow path member 30 is further improved, and the power generation performance of the cell 1 is further improved.

[0063] A flow path 2a through which the fuel gas flows is formed in the space formed between the flat surface 31a and the support member 2. The fuel gas flows from the first end 41 side toward the second end 42 side shown in FIG. 1C so as to avoid the protrusion 31b.

[0064] 2B , the height h1 of the convex portion 31b can be, for example, 0.2 mm or more and 4.0 mm or less. The height h1 corresponds to, for example, the width of the flow path 2a located between the support member 2 and the flow path member 30. Furthermore, in the region of the first portion 311 in plan view that has the convex portion 31b, the area ratio where the convex portion 31b is located can be, for example, 0.0005% or more and 25% or less, or even 0.005% or more and 1.5% or less.

[0065] The region of the first portion 311 having the convex portion 31b is, for example, a region that includes multiple convex portions 31b within the region, such as regions 34 to 36 shown in FIG. 1C, and whose outline is in contact with the convex portion 31b located at the outermost periphery. The shape of the region having the convex portion 31b may be, for example, a shape in which the perimeter of a polygon formed by connecting the outlines of all the convex portions 31b located within the region is minimized. By disposing such a flow path member 30, the power generation performance of the cell 1 is likely to be further improved. Note that one or more convex portions 31b may have a convex portion 31b whose top 31ba is spaced apart from the support member 2.

[0066] Furthermore, when the flow path member 30 is viewed in plan from the first element portion 3A side, the convex portion 31b may be provided at a position midway between adjacent convex portions 32b.

[0067] The height h2 of the protrusion 32b can be, for example, 0.1 mm to 5 mm, or even 0.3 mm to 3.5 mm. The height h2 corresponds to, for example, the width of the flow path 40 located between the flow path member 30 and the second element portion 3B. The height h1 of the protrusion 31b may be equal to or less than the height h2 of the protrusion 32b.

[0068] Furthermore, in the region of the first portion 311 having the protrusions 32b in plan view, the area ratio where the protrusions 32b are located can be, for example, 1% to 60% or less, or even 3% to 45% or less. By setting the area ratio where the protrusions 32b are located to 1% or more, the flat portion 30A is less likely to come into contact with the element portion 3, and the structure of the flow path 40 can be maintained. By setting the area ratio where the protrusions 32b are located to 60% or less, the oxygen-containing gas can be circulated without stagnating from the supply port to the discharge port, and the oxygen-containing gas necessary for power generation can be supplied to the air electrode 8 of the second element portion 3B. The region of the first portion 311 having the protrusions 32b can be defined in the same way as the region having the protrusions 31b.

[0069] The flat portion 30A of the first portion 311 and the second portion 312 may be at different distances from the first element portion 3A. For example, the flat portion 30A may be located farther from the first element portion 3A than the first surface 31 located in the second portion 312. The first surface 31 may have an intermediate portion located between the first portion 311 and the second portion 312.

[0070] 2A , the plurality of protrusions 32b may include one or more protrusions 32b1 and one or more protrusions 32b2. The protrusions 32b1 are protrusions 32b that are arranged spaced apart from each other in a second direction different from the first direction when viewed in plan from the first element portion 3A side.

[0071] The protrusion 32b1 may have a portion extending in a direction different from the first direction. The protrusion 32b1 may have a portion extending in a second direction. This improves the rigidity of the flow path member 30 and the performance of the cell 1.

[0072] The protrusions 32b2 may have a portion extending in a direction different from the first direction. The protrusions 32b2 may have a portion extending in a third direction. This improves the rigidity of the flow path member 30, and further improves the performance of the cell 1.

[0073] Furthermore, the multiple protrusions 32b may be arranged such that the angle between the second direction and / or the third direction and the first direction is 30° or more and 60° or less. For example, the protrusion 32b1 may be arranged such that the angle between the second direction and the first direction is 30° or more and 60° or less. The protrusion 32b2 may be arranged such that the angle between the third direction and the first direction is 30° or more and 60° or less. This improves the rigidity of the flow path member 30, and further improves the performance of the cell 1.

[0074] 2A, two or more protrusions 32b1 positioned side by side in the second direction are arranged so as to be positioned on a straight line extending in the second direction, but this is not limited to this. For example, when two or more protrusions 32b1 are positioned on two or more straight lines extending parallel to the second direction, they are also defined as being positioned side by side in the second direction.

[0075] <Configuration of Electrochemical Cell Device> Next, an electrochemical cell device according to this embodiment using the above-described electrochemical cell 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.

[0076] As shown in FIG. 3A, the cell stack device 10 includes a cell stack 11 having a plurality of cells 1 arranged (stacked) in the thickness direction (Y-axis direction) of the cells 1, and a fixing member 12.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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 2a (see Fig. 1A) inside the cell 1. The fuel gas supplied to the gas tank 16 is generated in a reformer 104 (see Fig. 4), which will be described later.

[0081] 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.

[0082] 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.

[0083] 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 T, 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: see FIG. 1A ).

[0084] 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 2a of each cell 1 communicate with the internal space 22 of the support member 14 at their lower ends.

[0085] 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.

[0086] Examples of the crystallized glass include SiO ２ -CaO system, MgO-B ２ O ３ System, La ２ O ３ -B ２ O ３ -MgO system, La ２ O ３ -B ２ O ３ -ZnO-based, SiO ２ -CaO-ZnO system materials, etc., may be used, and in particular SiO ２ - MgO-based materials may also be used.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] The positive terminal 19A is a positive electrode when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the positive-side end current collecting member 17 of the cell stack 11A. The negative terminal 19B is a negative electrode when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the negative-side end current collecting member 17 of the cell stack 11B.

[0091] 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.

[0092] <Module> Next, a module according to an embodiment of the present disclosure using the above-described cell stack device 10 will be described with reference to Fig. 4. Fig. 4 is an external perspective view showing an example of a module according to an embodiment. Fig. 4 shows a state in which the front and rear surfaces, which are parts of the storage container 101, have been removed and the cell stack device 10 of the fuel cell stored inside has been removed to the rear.

[0093] 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.

[0094] 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.

[0095] The fuel gas produced in the reformer 102 is supplied to the flow path 2 a of the cell 1 (see FIG. 1A) through the gas distribution pipe 20 , the gas tank 16 , and the support member 14 .

[0096] 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.

[0097] In such a module 100, as described above, by accommodating the cell stack device 10 that improves power generation performance, the module 100 can be made to have improved power generation performance.

[0098] <Module Enclosure Device> Next, a module enclosure device according to an embodiment of the present disclosure using the above-described module 100 will be described with reference to FIG. 5. FIG. 5 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. 4, and auxiliary equipment (not shown). The auxiliary equipment operates the module 100. The module 100 and the auxiliary equipment are housed in the outer case 111. Note that some components are omitted in FIG. 5.

[0099] 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.

[0100] 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.

[0101] In such a module accommodating device 110, as described above, by providing the module 100 with improved power generation performance in the module accommodating chamber 115, the module accommodating device 110 can be made to have improved power generation performance.

[0102] 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 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. Furthermore, in the above-described embodiments, an oxide ion conductor or a hydrogen ion conductor is shown as an example of the electrolyte material of the electrochemical cell, but a hydroxide ion conductor may also be used. Such an electrolysis cell, an electrolysis cell stack device, an electrolysis module, and an electrolysis device can improve electrolysis performance.

[0103] 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.

[0104] In one embodiment, (1) an electrochemical cell comprises: a first element portion; and a flow path member having a first surface facing the first element portion; and a second surface located on the opposite side of the first surface facing a second element portion different from the first element portion; wherein the flow path member has a first flat portion including a first flat surface facing the first element portion; and one or more first convex portions protruding from the first flat portion toward the first element portion; and the first convex portions have a first cavity opening toward the second element portion.

[0105] (2) In the electrochemical cell of (1) above, the first convex portion may have a top portion and a side portion connecting the top portion and the first flat portion, and the thickness of the top portion may be smaller than the thickness of the first flat portion.

[0106] (3) In the electrochemical cell of (2) above, the thickness of the side portion may be equal to or less than the thickness of the top portion.

[0107] (4) In the electrochemical cell of any one of (1) to (3) above, the first convex portion may be located on the first surface and / or the second surface and may have an unevenness that is smaller than the height of the first convex portion along the thickness direction of the first element portion.

[0108] (5) In the electrochemical cell of any one of (1) to (4) above, the flow path member may have one or more second convex portions protruding from the first flat portion toward the second element portion, and when viewed in a plan view from the first element portion side, the second convex portions may be located between adjacent first convex portions.

[0109] (6) In the electrochemical cell of (5) above, the first flat portion may be located between the first convex portion and the second convex portion when viewed from above from the first element portion side.

[0110] (7) In the electrochemical cell of (5) or (6) above, when viewed in plan from the first element portion side, there may be a region in which only the first flat portion is located between adjacent first convex portions.

[0111] (8) In the electrochemical cell of any one of (5) to (7) above, the first convex portion and the second convex portion may have different shapes.

[0112] (9) In the electrochemical cell of any one of (5) to (8) above, the second convex portion may have a second cavity that opens toward the first element portion.

[0113] In one embodiment, (10) an electrochemical cell device has a cell stack including any one of the electrochemical cells (1) to (9) above.

[0114] In one embodiment, (11) a module includes the electrochemical cell device of (10) above, and a container that houses the electrochemical cell device.

[0115] In one embodiment, (12) a module housing device includes: the module of (11); an auxiliary device for operating the module; and an exterior case for housing the module and the auxiliary device.

[0116] 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.

[0117] REFERENCE SIGNS LIST 1 cell 2 support member 3 element portion 3A first element portion 3B second element portion 5 fuel electrode 6 solid electrolyte layer 8 air electrode 10 cell stack device 30 flow path member 30A flat portion 31 first surface 31a, 32a flat surface 31b, 32b convex portion 31c, 32c cavity 32 second surface 100 module 110 module accommodating device

Claims

1. An electrochemical cell comprising: a first element portion; and a flow path member having a first surface facing the first element portion and a second surface located on the opposite side of the first surface facing a second element portion different from the first element portion, wherein the flow path member has a first flat portion including a first flat surface facing the first element portion, and one or more first convex portions protruding from the first flat portion toward the first element portion, and the first convex portions have a first cavity opening toward the second element portion.

2. The electrochemical cell according to claim 1, wherein the first convex portion has a top and a side portion connecting the top and the first flat portion, and the thickness of the top is smaller than the thickness of the first flat portion.

3. The electrochemical cell according to claim 2, wherein the thickness of the side portion is equal to or less than the thickness of the top portion.

4. An electrochemical cell according to any one of claims 1 to 3, wherein the first convex portion is located on the first surface and / or the second surface and has unevenness that is smaller than the height of the first convex portion along the thickness direction of the first element portion.

5. An electrochemical cell according to any one of claims 1 to 4, wherein the flow path member has one or more second convex portions protruding from the first flat portion towards the second element portion, and when viewed in a plan view from the first element portion side, the second convex portions are located between adjacent first convex portions.

6. The electrochemical cell according to claim 5, wherein, when viewed in a plan view from the first element portion side, the first flat portion is located between the first convex portion and the second convex portion.

7. An electrochemical cell as described in claim 5 or 6, having a region in which only the first flat portion is located between adjacent first convex portions when viewed in a plan view from the first element portion side.

8. The electrochemical cell according to any one of claims 5 to 7, wherein the first convex portion and the second convex portion have mutually different shapes.

9. An electrochemical cell according to any one of claims 5 to 8, wherein the second convex portion has a second cavity that opens toward the first element portion.

10. An electrochemical cell device comprising a cell stack comprising the electrochemical cell according to any one of claims 1 to 9.

11. A module comprising: the electrochemical cell device according to claim 10; and a container for housing the electrochemical cell device.

12. A module housing device comprising: a module according to claim 11; an auxiliary device for operating said module; and an exterior case for housing said module and said auxiliary device.

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