Conductive member, cell, cell stack device, module, and module accommodating device

Abstract

To provide a conductive member, a cell, a cell-stack device, a module, and a module storage device with a high durability.SOLUTION: The conductive member includes: a base material including chromium; and a coating film covering the base material. The conductive member has a ring-shaped protruding unit taken in planer view, protruding away from the base material.SELECTED DRAWING: Figure 6B

Description

[Technical Field]

[0001] The present disclosure relates to a conductive member, a cell, a cell stack device, a module, and a module housing device. [Background technology]

[0002] In recent years, various fuel cell stack devices have been proposed as next-generation energy sources. These devices are composed of an array of multiple fuel cell cells, which are a type of cell that can generate electricity using fuel gas (hydrogen-containing gas) and oxygen-containing gas (air). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2009 / 131180 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a fuel cell stack device, the cells are electrically connected in series by current collecting members containing, for example, Cr.

[0005] However, this structure leaves room for improvement in durability of the joints between the current collecting members and the cells.

[0006] One aspect of the embodiment has been made in view of the above, and aims to provide a highly durable conductive member, a cell, a cell stack device, a module, and a module housing device. [Means for solving the problem]

[0007] According to one embodiment, a conductive member includes a chromium-containing substrate and a coating covering the substrate. The coating has a protrusion that is annular in plan view and protrudes away from the substrate.

[0008] The cell of the present disclosure includes an element portion, the conductive member described above, and a bonding material positioned between the first surface of the coating and the element portion, and the protrusion is positioned on the first surface.

[0009] The cell stack device of the present disclosure includes a plurality of the cells described above.

[0010] The module of the present disclosure also includes the cell stack device described above and a storage container that stores the cell stack device.

[0011] 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. [Effects of the Invention]

[0012] According to one aspect of the embodiment, it is possible to provide a highly durable conductive member, a cell, a cell stack device, a module, and a module housing device. [Brief explanation of the drawings]

[0013] [Figure 1A] FIG. 1A is a cross-sectional view showing an example of a cell according to an embodiment. [Figure 1B] FIG. 1B is a side view of an example of a cell according to an embodiment, viewed from the air electrode side. [Figure 1C] FIG. 1C is a side view of an example of a cell according to an embodiment, viewed from the interconnector side. [Figure 2A] FIG. 2A is a perspective view showing an example of a cell stack device according to an embodiment. [Figure 2B] FIG. 2B is a cross-sectional view taken along line XX shown in FIG. 2A. [Figure 2C] FIG. 2C is a top view showing an example of a cell stack device according to an embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing an example of a conductive member according to an embodiment. [Figure 4]FIG. 4 is an enlarged view of area A shown in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along the line BB shown in FIG. [Figure 6A] FIG. 6A is an enlarged view of area C shown in FIG. [Figure 6B] FIG. 6B is an enlarged view of region E shown in FIG. 6A. [Figure 6C] FIG. 6C is a plan view of the coating shown in FIG. 6B. [Figure 7] FIG. 7 is a plan view illustrating an example of a conductive member according to an embodiment. [Figure 8] FIG. 8 is an external perspective view showing an example of a module according to the embodiment. [Figure 9] FIG. 9 is an exploded perspective view schematically illustrating an example of a module housing device according to an embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a cell according to the first modification of the embodiment. [Figure 11] FIG. 11 is an enlarged cross-sectional view of a conductive member according to the first modification of the embodiment. [Figure 12] FIG. 12 is a perspective view showing a flat cell according to the second modification of the embodiment. [Figure 13] FIG. 13 is a partial cross-sectional view of the flat cell shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the conductive member, cell, cell stack device, module, and module housing device disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below.

[0015] 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.

[0016] <Cell configuration> First, with reference to FIGS. 1A to 1C, a description will be given using an example of a solid oxide fuel cell as a cell constituting a cell stack device according to an embodiment.

[0017] Fig. 1A is a cross-sectional view showing an example of a cell 1 according to an embodiment, Fig. 1B is a side view of the example of the cell 1 according to an embodiment as seen from the air electrode 5 side, and Fig. 1C is a side view of the example of the cell 1 according to an embodiment as seen from the interconnector 6 side. Figs. 1A to 1C show enlarged views of parts of each component of the cell 1.

[0018] 1A to 1C, cell 1 is a hollow, flat, elongated plate. As shown in Fig. 1B, the shape of the entire cell 1 when viewed from the side is, for example, a rectangle with sides of 5 cm to 50 cm in the length direction L and 1 cm to 10 cm in the width direction W perpendicular to the length direction L. The overall thickness of this cell 1 (thickness direction T) is 1 mm to 5 mm.

[0019] 1A, the cell 1 includes a conductive support substrate 2, an element section, and an interconnector 6. The support substrate 2 is columnar, having a pair of opposing flat surfaces n1, n2 and a pair of arc-shaped side surfaces m connecting the flat surfaces n1, n2.

[0020] The element section is provided on one flat surface n1 of the support substrate 2. The element section has a fuel electrode 3, a solid electrolyte layer 4, and an air electrode 5. In the example shown in FIG. 1A, an interconnector 6 is provided on the other flat surface n2 of the cell 1.

[0021] As shown in FIG. 1B, the air electrode 5 does not extend to the lower end of the cell 1. At the lower end of the cell 1, only the solid electrolyte layer 4 is exposed on the surface. As shown in FIG. 1C, the interconnector 6 extends to the lower end of the cell 1. At the lower end of the cell 1, the interconnector 6 and the solid electrolyte layer 4 are exposed on the surface. As shown in FIG. 1A, the solid electrolyte layer 4 is exposed on the surface of a pair of arc-shaped side surfaces m of the cell 1.

[0022] Each of the components that make up the cell 1 will be described below.

[0023] 1A shows an example in which six gas channels 2a are provided. The support substrate 2 has gas permeability to allow the fuel gas to pass through to the anode 3, and is also conductive to collect current via the interconnector 6.

[0024] The material of the support substrate 2 is composed of, for example, an iron group metal component and an inorganic oxide, for example, the iron group metal component is Ni and / or NiO, and the inorganic oxide is a specific rare earth element oxide.

[0025] A commonly known material can be used for the fuel electrode 3. The fuel electrode 3 can be formed from a porous conductive ceramic, such as ZrO2 (referred to as stabilized zirconia and including partially stabilized zirconia) in which a rare earth element oxide is dissolved, and Ni and / or NiO. For example, Y2O3 or the like is used as this rare earth element oxide.

[0026] The solid electrolyte layer 4 functions as an electrolyte that bridges ions between the fuel electrode 3 and the air electrode 5, and at the same time has gas barrier properties to prevent leakage of fuel gas and oxygen-containing gas.

[0027] The solid electrolyte layer 4 is formed of, for example, ZrO2 in which 3 to 15 mol % of a rare earth element oxide is dissolved. As the rare earth element oxide, for example, Y2O3 is used. However, the solid electrolyte layer 4 may be formed of other materials as long as they have the above-mentioned properties.

[0028] There are no particular restrictions on the material of the air electrode 5, as long as it is a material generally used for air electrodes. The air electrode 5 can be formed, for example, from a conductive ceramic made of a so-called ABO3-type perovskite oxide.

[0029] The material of the air electrode 5 may be, for example, a composite oxide in which Sr and La coexist at the A site. Examples of such composite oxides include La x Sr 1-x Co y Fe 1-y O3, La x Sr 1-x MnO3, La x Sr 1-x FeO3, La x Sr 1-x CoO3, etc. Note that x is 0 <x<1、yは0<y<1である。

[0030] The air electrode 5 is gas permeable and preferably has an open porosity of 20% or more, particularly in the range of 30% to 50%.

[0031] Lanthanum chromite-based perovskite oxides (LaCrO3-based oxides) or lanthanum strontium titanium-based perovskite oxides (LaSrTiO3-based oxides) are preferably used as the material for the interconnector 6. These materials are electrically conductive and are not reduced or oxidized even when in contact with a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air, etc.).

[0032] Furthermore, the interconnector 6 is dense to prevent leakage of the fuel gas flowing through the gas flow path 2a formed in the support substrate 2 and the oxygen-containing gas flowing outside the support substrate 2, and preferably has a relative density of 93% or more, particularly 95% or more.

[0033] <Configuration of cell stack device> Next, a cell stack device 10 according to this embodiment using the above-described cell 1 will be described with reference to Figures 2A to 2C. Figure 2A is a perspective view showing an example of the cell stack device 10 according to this embodiment, Figure 2B is a cross-sectional view taken along line XX shown in Figure 2A, and Figure 2C is a top view showing an example of the cell stack device 10 according to this embodiment.

[0034] As shown in FIG. 2A, the cell stack device 10 includes a cell stack 11 having a plurality of cells 1 arranged (stacked) in a thickness direction T of the cells 1 (see FIG. 1A), and a fixing member 12.

[0035] 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 gas tank 16, which are the support member 14, are made of metal and are electrically conductive.

[0036] 2B, 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 a fixing material 13.

[0037] The gas tank 16 has an opening for supplying a reaction gas to the cells 1 through the insertion holes 15a, and has a recessed groove 16a provided around the opening. One end 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.

[0038] In the example shown in FIG. 2A, fuel gas is stored in an internal space 22 formed by a support 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 gas flow path 2a (see FIG. 1A) inside the cell 1. The fuel gas supplied to the gas tank 16 is generated in a reformer 102 (see FIG. 8), which will be described later.

[0039] 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.

[0040] In the example shown in Fig. 2A, two rows of cell stacks 11 each having a plurality of cells 1 are provided, and the two rows of cell stacks 11 are each fixed to a support 15. Two through holes are provided in the upper surface of the gas tank 16. Supports 15 are arranged in the two through holes so as to align with insertion holes 15a. An internal space 22 is formed by one gas tank 16 and two supports 15.

[0041] The shape of the insertion hole 15a is, for example, an oval shape when viewed from above. For example, the length of the insertion hole 15a in the arrangement direction of the cells 1, i.e., the thickness direction T, is greater than the distance between the two end current collecting members 17 located at both ends of the cell stack 11. For example, the width of the insertion hole 15a is greater than the length of the cell 1 in the width direction W (see FIG. 1A).

[0042] 2B, solidified fixing material 13 is filled in the joints between the inner walls of insertion holes 15a and the lower ends of cells 1. This bonds and fixes the inner walls of insertion holes 15a to the lower ends of the multiple cells 1, respectively, and also bonds and fixes the lower ends of cells 1 to each other. The gas flow path 2a of each cell 1 communicates with the internal space 22 of support member 14 at its lower end.

[0043] A material with low conductivity, such as glass, can be used for the fixing material 13 and the bonding material 21. A specific material may be amorphous glass, but crystallized glass is preferable.

[0044] As the crystallized glass, for example, SiO2-CaO system, MgO-B2O3 system, La2O3-B2O3-MgO system, La2O3-B2O3-ZnO system, SiO2-CaO-ZnO system can be used, but any material among SiO2-MgO system may also be used.

[0045] 2B, a conductive member 18 is interposed between adjacent cells 1 to electrically connect the adjacent cells 1 (more specifically, the fuel electrode 3 of one cell 1 and the air electrode 5 of the other cell 1) in series. Details of the conductive member 18 connected to the cells 1 will be described later.

[0046] 2B, an end current collecting member 17 is connected to the cell 1 located at the outermost position in the arrangement direction of the multiple cells 1. The end current collecting member 17 is connected to a conductive part 19 that protrudes to the outside of the cell stack 11. The conductive part 19 has the function of collecting electricity generated by the cells 1 and extracting it to the outside. Note that the end current collecting member 17 is not shown in FIG. 2A.

[0047] 2C, the cell stack device 10 functions as a single battery by connecting two cell stacks 11A and 11B in series, each of which has a row of cells 1. Therefore, the conductive part 19 of the cell stack device 10 is divided into a positive terminal 19A, a negative terminal 19B, and a connection terminal 19C.

[0048] The positive electrode terminal 19A functions as a positive electrode when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the positive electrode side end current collecting member 17 of the cell stack 11A. The negative electrode terminal 19B functions as a negative electrode when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the negative electrode side end current collecting member 17 of the cell stack 11B.

[0049] The connection terminal 19C electrically connects the end current collecting member 17 on the negative electrode side of the cell stack 11A and the end current collecting member 17 on the positive electrode side of the cell stack 11B.

[0050] <Details of conductive materials> Next, details of the conductive member 18 according to the embodiment will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view showing an example of the conductive member according to the embodiment.

[0051] As shown in Fig. 3, the conductive member 18 has a joint 18a joined to one cell 1 and a joint 18b joined to the other cell 1. The conductive member 18 also has connection portions 18c at both ends in the width direction W, which connect the joint portions 18a and 18b. This allows the conductive member 18 to connect the cells 1 adjacent to each other in the thickness direction T. Note that Fig. 3 illustrates a simplified shape of the cell 1.

[0052] Furthermore, the joints 18a and 18b have surfaces 181 and 182. The surface 181 faces the cell 1. The surface 182 faces the joints 18b and 18a. Hereinafter, the conductive member 18 will be further described with reference to FIG. 4.

[0053] Fig. 4 is an enlarged view of region A shown in Fig. 3. As shown in Fig. 4, the conductive member 18 (joint portion 18a) is joined to the cell 1 via a bonding material 50. The bonding material 50 has electrical conductivity and heat resistance, and appropriately establishes conduction between the cells 1 via the conductive member 18. The bonding material 50 is a bonding material that is joined to, for example, the air electrode 5 of the cell 1 (see Fig. 1A).

[0054] The conductive member 18 has a substrate 42 and a coating 43. The substrate 42 has electrical conductivity and heat resistance. The substrate 42 contains chromium (Cr). The substrate 42 is, for example, stainless steel.

[0055] The coating 43 covers the substrate 42. The coating 43 is electrically conductive. The coating 43 is, for example, a conductive oxide such as ZnMnCoO4. The coating 43 can be disposed on the surface of the substrate 42 by, for example, electrodeposition coating.

[0056] By covering the surface of the base material 42 with the coating 43, it is possible to prevent chromium (Cr) contained in the base material 42 from being desorbed into the oxidizing atmosphere (external space 23) during high-temperature operation, thereby improving the durability of the conductive member 18.

[0057] The coating 43 is located on surfaces 181 and 182 of the conductive member 18. The surface 181 has surfaces 181a and 181b. The surface 181a is a contact surface where the coating 43 comes into contact with the bonding material 50 and is an example of a first surface. The surface 181b is an exposed surface where the coating 43 is exposed to the external space 23 and is an example of a second surface. The external space 23 is a space where the air electrode 5 of the cell 1 is exposed and is filled with an oxygen-containing gas (such as air). In other words, the external space 23 is an oxidizing atmosphere.

[0058] However, there is a risk that the durability of the cell stack device 10 will decrease if cracks occur in the bonding material 50 or if the bonding material 50 peels off from the conductive member 18.

[0059] Therefore, in the embodiment, the surface roughness of the portion of the coating 43 located on the surface of the conductive member 18 that faces the bonding material 50 is increased. In the embodiment, the surface 181a serving as the first surface of the coating 43 that faces the bonding material 50 has a larger surface roughness than the surfaces of other portions of the coating 43, for example, the surfaces 181b and 182 serving as the second surface that are exposed to the oxidizing atmosphere (external space 23).

[0060] This can improve the adhesion between the bonding material 50 and the coating 43 of the conductive member 18. This can prevent the bonding material 50 from peeling off from the conductive member 18 or from breaking. Therefore, according to the embodiment, the durability of the cell stack device 10 can be improved.

[0061] Although the above description has been given taking the joint 18a of the conductive member 18 as an example, the same applies to the joint 18b, and detailed description thereof will be omitted.

[0062] 4, surface 181 is divided into surface 181a and surface 181b by boundary 181c facing the end of bonding material 50. However, this is not limiting and, for example, surface 181 may have an intermediate surface (not shown) located between surface 181a and surface 181b. In such a case, the intermediate surface may have, for example, the same surface roughness as surface 181a, or may have the same surface roughness as surface 181b. Furthermore, the intermediate surface may have, for example, a surface roughness intermediate between surface 181a and surface 181b. Furthermore, the intermediate surface may face bonding material 50 or may be exposed to an oxidizing atmosphere (external space 23).

[0063] The conductive member 18 according to this embodiment will be further described below with reference to FIGS. 5 to 6C.

[0064] Fig. 5 is a cross-sectional view taken along line BB shown in Fig. 3. Fig. 6A is an enlarged view of region C shown in Fig. 5.

[0065] The conductive member 18 extends in the longitudinal direction L of the cell 1. As shown in Fig. 5, a plurality of joints 18a, 18b of the conductive member 18 are alternately positioned along the longitudinal direction L of the cell 1. The conductive member 18 is in contact with the cell 1 at each of the joints 18a, 18b.

[0066] 6A, the conductive member 18 (joint portion 18b) is joined to the element portion of the cell 1 via a bonding material 50. The bonding material 50 is located between the surface 181 of the conductive member 18 and the cell 1, and bonds the conductive member 18 and the cell 1 together.

[0067] The coating 43 covering the base material 42 of the conductive member 18 has surfaces 181 to 184. Surface 181 is located opposite to the cell 1 with the bonding material 50 interposed therebetween. Surface 181 is surface 181a that contacts the bonding material 50. Surface 182 is located on the opposite side of surface 181 with the base material 42 in between, and is exposed to an oxidizing atmosphere. Surfaces 183 and 184 connect surface 181 and surface 182. Surfaces 183 and 184 have surfaces 183a and 184a that face the bonding material 50 as a result of a portion of the conductive member 18 being embedded in the bonding material 50, and surfaces 183b and 184b that are exposed to the oxidizing atmosphere, respectively.

[0068] The surfaces 181a, 183a, and 184a serving as first surfaces facing the bonding material 50 have larger surface roughness than the surfaces 182, 183b, and 184b serving as second surfaces exposed to an oxidizing atmosphere.

[0069] This can improve the adhesion between the bonding material 50 and the coating 43 of the conductive member 18. This can prevent the bonding material 50 from peeling off from the conductive member 18 or from breaking. Therefore, according to the embodiment, the durability of the cell stack device 10 can be improved.

[0070] The surfaces 181a, 183a, and 184a serving as the first surfaces may have the same surface roughness or may have different surface roughnesses.

[0071] Although the above description has been given taking the joint 18b of the conductive member 18 as an example, the same applies to the joint 18a, and detailed description thereof will be omitted.

[0072] (Evaluation method) The surface roughness of the first and second surfaces can be determined based on the arithmetic mean roughness Ra defined in JIS B0633;2001. The arithmetic mean roughness Ra is calculated by image analysis of a cross section perpendicular to each surface (surfaces 181a, 183a, and 184a as first surfaces and surfaces 181b, 182, 183b, and 184b as second surfaces). First, the conductive member 18 and the bonding material 50 are cut out and embedded in resin. The cross section perpendicular to the surface whose surface roughness is to be measured is polished using abrasive grains, lapping film (approximately #8000), or the like to obtain a mirror-finished cross section. The obtained cross section is photographed using a scanning electron microscope, optical microscope, or the like, and the obtained image is analyzed to calculate the arithmetic mean roughness Ra of each surface. The surface roughness of the first and second surfaces, described below, can also be calculated in a similar manner.

[0073] (Manufacturing method) The coating 43 of the conductive member 18 according to the embodiment can be formed by methods such as thermal spraying, vapor deposition, electrodeposition, sputtering, etc. Alternatively, the coating 43 may be formed by applying a coating material to the surface of the substrate 42 and then baking the applied material.

[0074] Furthermore, the first and second surfaces of the coating 43 may be formed, for example, by polishing a portion of the surface of the coating 43 that corresponds to the second surface, and the remaining portion serving as the first surface. Furthermore, the first and second surfaces may be formed by changing the various conditions used in forming the coating 43. For example, in electrodeposition, multiple bubbles may be generated on the surface of the electrodeposited film, which corresponds to the material of the coating 43. The bubbles present on the surface of the electrodeposited film are reflected in the surface shape of the coating 43 as bubble marks. Therefore, the first and second surfaces may be positioned by controlling the generation of such bubbles or by partially removing bubbles attached to the surface of the electrodeposited film to adjust the area ratio of the bubble marks.

[0075] <Coating surface shape> Next, an example of the surface shape of the coating 43 facing the bonding material 50 will be described with reference to Figures 6B and 6C. Figure 6B is an enlarged view of region E shown in Figure 6A. Figure 6C is a plan view of the coating shown in Figure 6B.

[0076] As shown in Figures 6B and 6C, the coating 43 has a protrusion 430 that protrudes away from the substrate 42. The protrusion 430 has an annular shape in plan view. In the example shown in Figures 6B and 6C, the protrusion 430 is the portion of the coating 43 located between the outer edge 432 and the inner edge 433 in plan view. The thickness h1 of the coating 43 located outside the protrusion 430 refers to the value obtained by measuring the portion located outside the outer edge 432 using an optical interference film thickness meter. If the obtained thickness h1 varies from one measurement location to another, the average value is used as the thickness h1. If the thickness h1 varies from one measurement location to another, five measurements are taken, and the average of the three values excluding the maximum and minimum values is used as the thickness h1. Unless otherwise specified, the dimensions of the coating 43 in the following description are calculated based on the results of measurements using an optical interference film thickness meter.

[0077] As shown in FIG. 6B , the thickness h1 of the coating 43 located outside the protrusion 430 is greater than the thickness h3 of the coating 43 located inside the protrusion 430. This increases the contact area between the bonding material 50 facing the protrusion 430 and the coating 43, thereby improving adhesion between the bonding material 50 and the coating 43. This prevents the bonding material 50 from peeling off from the coating 43 of the conductive member 18 or from breaking. Therefore, according to the embodiment, the durability of the cell stack device 10 can be improved. The thickness h3 refers to the average thickness of the coating 43 at the outer surface 434 of the coating 43 located inside the inner edge 433 of the protrusion 430. The outer surface 434 may be parallel to the interface with the substrate 42 or may be inclined relative to the interface with the substrate 42. The outer surface 434 may be flat or curved.

[0078] Furthermore, the protrusions 430 have a maximum height h2 that is 110% or more of the thickness h1 of the coating 43 located outside the protrusions 430. This increases the contact area between the bonding material 50 facing the protrusions 430 and the coating 43, thereby improving the adhesion between the bonding material 50 and the coating 43. This makes it possible to prevent the bonding material 50 from peeling off from the coating 43 of the conductive member 18 or to prevent the bonding material 50 from breaking. Therefore, according to the embodiment, the durability of the cell stack device 10 can be improved. Note that the maximum height h2 refers to the maximum value of the thickness of the coating 43 at the top 431 of the protrusions 430.

[0079] Furthermore, the protrusions 430 have an outer diameter D of 50 μm or more and 100 μm or less. This allows the bonding material 50 facing the protrusions 430 to be in appropriate contact with the coating 43, thereby improving the adhesion between the bonding material 50 and the coating 43. This makes it possible to prevent the bonding material 50 from peeling off from the coating 43 of the conductive member 18 or to prevent the bonding material 50 from breaking. Therefore, according to the embodiment, the durability of the cell stack device 10 can be improved. The outer diameter D refers to the circle-equivalent diameter when the outer edge 432 of the protrusions 430 is viewed in plan.

[0080] By positioning such convex portions 430, it is possible to form a first surface having a greater surface roughness than the second surface. Note that convex portions 430 may be positioned on the second surface of coating 43. In this case, the surface roughness of the first surface can be increased by making the area ratio of convex portions 430 positioned on the first surface greater than the area ratio of convex portions 430 positioned on the second surface.

[0081] Fig. 7 is a plan view showing an example of a conductive member according to an embodiment. As shown in Fig. 7, the conductive member 18 extends in the longitudinal direction L of the cell 1. The conductive member 18 has a first portion S1 close to the air inlet (not shown) and a second portion S2 close to the air outlet.

[0082] Here, the first surface of the coating 43 located at the second portion S2 may have a surface roughness greater than that of the first surface of the coating 43 located at the first portion S1.

[0083] In the cell stack device 10 according to the embodiment, the cells 1 and conductive members 18 located in the second region S2 are more likely to be displaced than the cells 1 and conductive members 18 located in the first region S1, and a load is more likely to be applied to the joint between the bonding material 50 and the conductive members 18. For this reason, by making the surface roughness of the first surface located in the second region S2 greater than the surface roughness of the first surface located in the first region S1, it is possible to improve durability, for example.

[0084] Here, the ratio (L1:L2) of the length L1 of the first portion S1 to the length L2 of the second portion S2 with respect to the total length L3 of the conductive member 18 located in the longitudinal direction L of the cell 1 can be, for example, 1:5 to 5:1.

[0085] <module> Next, a module 100 according to an embodiment of the present disclosure using the above-described cell stack device 10 will be described with reference to Fig. 8. Fig. 8 is an external perspective view showing the module according to the embodiment, with the front and rear surfaces, which are part of the storage container 101, removed and the cell stack device 10 of the fuel cell stored inside removed to the rear.

[0086] 8, the module 100 is configured by housing a cell stack device 10 in a housing container 101. Also, above the cell stack device 10, a reformer 102 for generating fuel gas to be supplied to the cells 1 is disposed.

[0087] The reformer 102 generates fuel gas by reforming raw fuel such as natural gas or kerosene supplied through a raw fuel supply pipe 103. The reformer 102 is preferably configured to be capable of performing steam reforming, which is an efficient reforming reaction. The reformer 102 can perform steam reforming by including a vaporization section 102a for vaporizing water and a reforming section 102b in which a reforming catalyst (not shown) for reforming the raw fuel into fuel gas is disposed.

[0088] The fuel gas produced in the reformer 102 is supplied to the fixing member 12 through the gas flow pipe 20, and is then supplied from the fixing member 12 to a gas flow channel 2a (see FIG. 1A) provided inside the cell 1.

[0089] Furthermore, in the module 100 having the above-described configuration, during normal power generation, the temperature inside the module 100 reaches approximately 500 to 1000°C due to the combustion and power generation by the cells 1.

[0090] In such a module 100, as described above, by accommodating a highly durable cell stack device 10, the module 100 can be made highly durable.

[0091] <Module storage device> Fig. 9 is an exploded perspective view showing an example of a module housing device according to an embodiment. A module housing device 110 according to an embodiment includes an outer case, the module 100 shown in Fig. 8, and auxiliary equipment (not shown). The auxiliary equipment operates the module 100. The module 100 and auxiliary equipment are housed in the outer case. Note that some components are omitted in Fig. 9.

[0092] The exterior case of the module accommodating device 110 shown in Fig. 9 has support posts 111 and an exterior plate 112. A partition plate 113 divides the interior of the exterior case into upper and lower sections. The space above the partition plate 113 in the exterior case is a module accommodating chamber 114 that accommodates the module 100, and the space below the partition plate 113 in the exterior case is an accessory accommodating chamber 115 that accommodates the accessories that operate the module 100. Note that the accessories accommodated in the accessory accommodating chamber 115 are not shown in Fig. 9.

[0093] The partition plate 113 also has an air flow port 116 for allowing air from the auxiliary equipment housing chamber 115 to flow toward the module housing chamber 114. The exterior plate 112 that constitutes the module housing chamber 114 has an exhaust port 117 for exhausting air from within the module housing chamber 114.

[0094] In such a module housing device 110, as described above, highly durable modules 100 are provided in the module housing chamber 114, so that the module housing device 110 can be made highly durable.

[0095] <Various modified examples> Next, conductive members according to various modifications of the embodiment will be described with reference to FIGS.

[0096] In the above-described embodiment, a so-called "vertical stripe type" cell is exemplified, in which only one element unit including a fuel electrode, a solid electrolyte layer, and an air electrode is provided on the surface of a support substrate. However, the present invention can also be applied to a horizontal stripe type cell stack device in which so-called "horizontal stripe type" cells are stacked, in which element units are provided at multiple locations spaced apart from each other on the surface of a support substrate, and adjacent element units are electrically connected.

[0097] In addition, although the present embodiment illustrates the use of a hollow flat-plate type support substrate, the present invention can also be applied to a cell stack device that uses a cylindrical support substrate. Furthermore, as will be described later, the present invention can also be applied to a flat-plate type cell stack device in which so-called "flat-plate type" cells are stacked in the thickness direction.

[0098] In addition, in the above embodiment, an example was shown in which the fuel electrode was provided on the support substrate and the air electrode was arranged on the surface of the cell, but the present invention can also be applied to a cell stack device in which the opposite arrangement is used, i.e., the air electrode is provided on the support substrate and the fuel electrode is arranged on the surface of the cell.

[0099] In the above embodiment, examples of the "cell", "cell stack device", "module" and "module accommodating device" include a fuel cell, a fuel cell stack device, a fuel cell Although a module and a fuel cell device are shown, other examples may be an electrolysis cell, an electrolysis cell stack device, an electrolysis module and an electrolysis device, respectively.

[0100] FIG. 10 is a cross-sectional view showing a cell according to a first modification of the embodiment. FIG. 11 is an enlarged cross-sectional view of a conductive member according to the first modification of the embodiment. As shown in FIG. 10, in a cell stack device 10A, a plurality of support substrates 71 extend in a longitudinal direction L from a pipe 73 that circulates fuel gas. A gas flow path 74 through which gas from the pipe 73 flows is provided inside the support substrate 71. The support substrates 71 are electrically connected to each other via a conductive member 78. The conductive member 78 is located between the element portions 1A that each support substrate 71 has, and connects adjacent support substrates 71.

[0101] 11, the conductive member 78 is bonded to the element units 1A of adjacent cells via bonding materials 50a and 50b. The bonding material 50a is located between a surface 781a of the conductive member 78 and one of the cells (element units 1A), bonding the conductive member 78 to the one cell. The bonding material 50b is located between a surface 781b of the conductive member 78 and the other cell (element unit 1A), bonding the conductive member 78 to the other cell.

[0102] The conductive member 78 has a substrate 82 and a coating 83. Each part constituting the conductive member 78 can be made of, for example, the same material as the conductive member 18 described above. Furthermore, the conductive member 78 may be made of a material different from that of the conductive member 18.

[0103] The coating 83 covers the substrate 82 over the entire area in the arrangement direction and the length direction L of the cells.

[0104] The coating 83 also has surfaces 781a, 781b, 783, and 784. The surface 781a faces the bonding material 50a. The surface 781b faces the bonding material 50b. The surfaces 783 and 784 are exposed to an oxidizing atmosphere.

[0105] Here, the surfaces 781a and 781b serving as the first surfaces have greater surface roughness than the surfaces 783 and 784 serving as the second surfaces. This can improve the adhesion between the bonding materials 50a and 50b and the coating 43. This can prevent the bonding materials 50a and 50b from peeling off from the coating 43 of the conductive member 18 or from breaking. Therefore, according to the embodiment, the durability of the cell stack device 10A can be improved.

[0106] In the example shown in FIG. 11, the bonding materials 50a and 50b face only the surfaces 781a and 781b, but this is not limiting, and they may face parts of the surfaces 783 and 784 as well.

[0107] Fig. 12 is a perspective view showing a flat plate cell according to Modification 2 of the embodiment, and Fig. 13 is a partial cross-sectional view of the flat plate cell shown in Fig. 12.

[0108] 12, cell 1B has an element section 90 in which an anode 3, a solid electrolyte layer 4, and an air electrode 5 are stacked. In a cell stack device in which a plurality of flat plate-type cells are stacked, for example, the plurality of cells 1B are electrically connected by conductive members 91, 92, which are adjacent metal layers. The conductive members 91, 92 electrically connect adjacent cells 1B to each other and have gas flow paths that supply gas to the anode 3 or the air electrode 5.

[0109] 13, in this modification, the conductive member 92 has a gas flow path 99 that supplies gas to the air electrode 5. The conductive member 92 is bonded to the element section 90 (air electrode 5) via a bonding material 50c.

[0110] The conductive member 92 has a substrate 95 and a coating 96. Each part constituting the conductive member 92 can be made of, for example, the same material as the conductive members 18 and 78 described above. The conductive member 92 may also be made of a material different from that of the conductive members 18 and 78.

[0111] The coating 96 covers the entire substrate 95 facing the gas flow passages 99 .

[0112] The coating 96 has surfaces 921 to 923. The surface 921 faces the bonding material 50c. The surfaces 922 and 923 are exposed to the oxidizing atmosphere (gas flow path 99).

[0113] Here, the surface 921 serving as the first surface has a greater surface roughness than the surfaces 922 and 923 serving as the second surfaces. This can improve the adhesion between the bonding material 50c and the coating 96. This can prevent the bonding material 50c from peeling off from the coating 96 of the conductive member 92 or from breaking. Therefore, according to the embodiment, it is possible to improve the durability of a cell stack device in which the cells 1B are stacked.

[0114] In the example shown in FIG. 13, the bonding material 50c faces only the surface 921, but this is not limiting, and the bonding material 50c may face a part of the surface 922.

[0115] 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.

[0116] As described above, the cell stack device 10 according to the embodiment includes multiple cells 1, a conductive member 18, and a bonding material 50. The cells 1 have an element portion. The conductive member 18 has a chromium-containing substrate 42 and a coating 43 that covers the substrate 42. The bonding material 50 is located between a first surface of the coating 43 and the element portion. The first surface has a greater surface roughness than the second surface of the coating 43, which is exposed to an oxidizing atmosphere. This increases the durability of the cell stack device 10.

[0117] Furthermore, the module 100 according to the embodiment includes the cell stack device 10 described above and a storage container 101 that stores the cell stack device 10. This allows the module 100 to have high durability.

[0118] Furthermore, the module housing device 110 according to the embodiment includes the above-described module 100, accessories for operating the module 100, and an exterior case for housing the module 100 and the accessories. This allows the module housing device 110 to be highly durable.

[0119] 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. [Explanation of symbols]

[0120] 1 cell 10 Cell stack device 11 Cell stack 12 Fixing member 13 Fixing material 14 Support member 15 Support 16 Gas Tank 17 End current collecting member 18 Conductive material 42 Base material 43 Coating 100 modules 110 Module storage device

Claims

1. A substrate containing chromium and a coating covering the substrate, The surface of the coating has a convex portion that is annular in plan view and protrudes in a direction away from the substrate, The coating is a conductive oxide Conductive material.

2. A conductive member joined to a cell having an element portion via a joining material, The conductive member has a base material containing chromium and a coating covering the base material, The surface of the coating has a convex portion that is annular in plan view and protrudes in a direction away from the substrate, The bonding material is located between the protrusion and the element portion. Conductive material.

3. The protrusion has an outer diameter of 50 μm or more and 100 μm or less. The conductive member according to claim 1 or 2.

4. The convex portion has a maximum height of 110% or more of the thickness of the coating located outside the convex portion. The conductive member according to any one of claims 1 to 3.

5. The thickness of the coating located outside the protrusion is greater than the thickness of the coating located inside the protrusion. The conductive member according to any one of claims 1 to 4.

6. The coating is electrically conductive The conductive member according to any one of claims 1 to 5.

7. The coating has a thickness of 10 μm or more. The conductive member according to any one of claims 1 to 6.

8. an element portion; The conductive member according to any one of claims 1 to 7, a bonding material positioned between the first surface of the coating and the element portion; Equipped with The protrusion is located on the first surface. cell.

9. The first surface has a surface roughness greater than that of the second surface of the coating that is exposed to an oxidizing atmosphere. The cell of claim 8.

10. the conductive member has a first portion near the air inlet and a second portion near the air outlet; The first surface located in the second portion has a surface roughness greater than that of the first surface located in the first portion.

10. A cell according to claim 8 or 9.

11. the protrusions are further located on a second surface of the coating exposed to an oxidizing atmosphere, The area ratio of the convex portions located on the first surface is greater than the area ratio of the convex portions located on the second surface. It's bigger than A cell according to any one of claims 8 to 10.

12. A plurality of cells according to any one of claims 8 to 11 are provided. Cell stack device.

13. The cell stack device according to claim 12; a storage container for storing the cell stack device; A module comprising:

14. A module according to claim 13; Auxiliary equipment for operating the module; an exterior case that houses the module and the auxiliary equipment; A module housing device comprising:

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