Electrochemical cell device, module, and module housing device

Abstract

To provide an electrochemical cell device, a module, and a module storage device which have a high durability.SOLUTION: The electrochemical cell device includes a cell stack and a conductive member. The cell stack has a plurality of element parts lining in a first direction. The conductive member is located among the element parts. The cell stack includes a first region located in the center part in the first direction and a second region located in an end part of the first direction. The conductive member in the first region has a first site and a second site with a smaller resistivity than that of the first site. The conductive member in the second region has a larger resistivity than that of the second site.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to electrochemical cell devices, modules and module housing devices. [Background technology]

[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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-180164 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-220022 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional fuel cell stack devices, for example, there are cases where variations in temperature occur during power generation, and there is room for improvement in durability.

[0005] One aspect of the embodiment aims to provide a highly durable electrochemical cell device, module, and module housing device. [Means for solving the problem]

[0006] An electrochemical cell device according to one aspect of the embodiment includes a cell stack and a conductive member. The cell stack has a plurality of element units aligned in a first direction. The conductive members are respectively positioned between the plurality of element units. The cell stack has a first region positioned in a central portion in the first direction and a second region positioned at an end portion in the first direction. The conductive member positioned in the first region has a first portion and a second portion having a lower resistivity than the first portion. The conductive member positioned in the second region has a higher resistivity than the second portion.

[0007] An electrochemical cell device according to one aspect of the embodiment includes a cell stack and a conductive member. The cell stack has a plurality of element units arranged in a first direction. The conductive members are located between the plurality of element units. The cell stack has a first region located in a central portion in the first direction and a second region located at an end portion in the first direction. The conductive member located in the first region has a first member and a second member having a lower resistivity than the first member. The conductive member located in the second region has a higher resistivity than the second member.

[0008] The module of the present disclosure includes the electrochemical cell device described above and a container that houses the electrochemical cell device.

[0009] 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]

[0010] According to one aspect of the embodiment, it is possible to provide a highly durable electrochemical cell device, a module, and a module housing device. [Brief explanation of the drawings]

[0011] [Figure 1A] FIG. 1A is a cross-sectional view showing an example of an electrochemical cell according to a first embodiment. [Figure 1B]FIG. 1B is a side view of an example of the electrochemical cell according to the first embodiment, viewed from the air electrode side. [Figure 1C] FIG. 1C is a side view of an example of an electrochemical cell according to the first embodiment, viewed from the interconnector side. [Figure 2A] FIG. 2A is a perspective view showing an example of an electrochemical cell device according to the first 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 the electrochemical cell device according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing an example of the temperature distribution in the electrochemical cell device. [Figure 4] FIG. 4 is an enlarged cross-sectional view of the electrochemical cell device according to the first embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing an example of the conductive member according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along the line AA shown in FIG. [Figure 7A] FIG. 7A is a cross-sectional view illustrating an example of the conductive member according to the first embodiment. [Figure 7B] FIG. 7B is a cross-sectional view showing another example of the conductive member according to the first embodiment. [Figure 7C] FIG. 7C is a cross-sectional view showing another example of the conductive member according to the first embodiment. [Figure 7D] FIG. 7D is a cross-sectional view showing another example of the conductive member according to the first embodiment. [Figure 8] FIG. 8 is an external perspective view illustrating an example of the module according to the first embodiment. [Figure 9] FIG. 9 is an exploded perspective view schematically illustrating an example of a module housing device according to the first embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing another example of the electrochemical cell device according to the first embodiment. [Figure 11]FIG. 11 is a perspective view showing an example of an electrochemical cell device according to the second embodiment. [Figure 12] FIG. 12 is a cross-sectional view showing an example of the temperature distribution in a flat-plate electrochemical cell device. [Figure 13] FIG. 13 is a cross-sectional view showing an example of an electrochemical cell device according to the second embodiment. [Figure 14] FIG. 14 is a cross-sectional view showing an example of the first region R1 shown in FIG. [Figure 15] FIG. 15 is a cross-sectional view showing another example of the electrochemical cell device according to the second embodiment. [Figure 16A] FIG. 16A is a cross-sectional view showing an example of an electrochemical cell constituting the electrochemical cell device according to the third embodiment. [Figure 16B] FIG. 16B is a cross-sectional view showing another example of the electrochemical cell according to the third embodiment. [Figure 16C] FIG. 16C is a cross-sectional view showing another example of the electrochemical cell according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of 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.

[0013] 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.

[0014] [First embodiment] <Electrochemical cell> First, with reference to Figures 1A to 1C, an electrochemical cell constituting an electrochemical cell device according to a first 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.

[0015] Fig. 1A is a cross-sectional view showing an example of an electrochemical cell according to an embodiment, Fig. 1B is a side view of the example of an electrochemical cell according to an embodiment as seen from the air electrode side, and Fig. 1C is a side view of the example of an electrochemical cell according to an embodiment as seen from the interconnector side. Note that Figs. 1A to 1C show enlarged views of parts of each component of the electrochemical cell. Hereinafter, the electrochemical cell may also be simply referred to as a cell.

[0016] 1A to 1C, cell 1 is a hollow, flat, elongated plate. As shown in Fig. 1B, the shape of the entire cell 1 as viewed from the side is, for example, a rectangle with a side length in the length direction L of 5 cm to 50 cm and a length in the width direction W perpendicular to the length direction L of 1 cm to 10 cm. The thickness of the entire cell 1 in the thickness direction T is, for example, 1 mm to 5 mm.

[0017] 1A, the cell 1 includes a conductive support substrate 2, an element section 3, and an interconnector 4. 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.

[0018] The element section 3 is provided on the flat surface n1 of the support substrate 2. The element section 3 has a fuel electrode layer 5, a solid electrolyte layer 6, and an air electrode layer 8. In the example shown in FIG. 1A, the interconnector 4 is located on the flat surface n2 of the cell 1. The cell 1 may also have an intermediate layer 7 between the solid electrolyte layer 6 and the air electrode layer 8.

[0019] 1B, the air electrode layer 8 does not extend to the lower end of the cell 1. At the lower end of the cell 1, only the solid electrolyte layer 6 is exposed on the surface of the flat face n1. As shown in FIG. 1C, the interconnector 4 may extend to the lower end of the cell 1. At the lower end of the cell 1, the interconnector 4 and the solid electrolyte layer 6 are exposed on the surface. As shown in FIG. 1A, the solid electrolyte layer 6 is exposed on the surface of a pair of arc-shaped side faces m of the cell 1. The interconnector 4 does not have to extend to the lower end of the cell 1.

[0020] Each of the components that make up the cell 1 will be described below.

[0021] The support substrate 2 has gas flow channels 2a therein through which gas flows. The example of the support substrate 2 shown in FIG. 1A has six gas flow channels 2a. The support substrate 2 is gas permeable, allowing the fuel gas flowing through the gas flow channels 2a to permeate to the fuel electrode layer 5. The support substrate 2 may be conductive. The conductive support substrate 2 collects electricity generated in the element section 3 to the interconnector 4.

[0022] The material of the support substrate 2 includes, for example, an iron group metal component and an inorganic oxide. The iron group metal component may be, for example, Ni (nickel) and / or NiO. The inorganic oxide may be, for example, a specific rare earth element oxide. The rare earth element oxide may include, for example, one or more rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb.

[0023] A commonly known material can be used for the fuel electrode layer 5. The fuel electrode layer 5 may be made of porous conductive ceramics, such as ceramics containing calcium oxide, magnesium oxide, or ZrO2 solid-solubilized with rare earth element oxides, and Ni and / or NiO. 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 ZrO2 solid-solubilized with rare earth element oxides is sometimes referred to as stabilized zirconia. Stabilized zirconia also includes partially stabilized zirconia.

[0024] The solid electrolyte layer 6 is an electrolyte and transfers ions between the fuel electrode layer 5 and the air electrode layer 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.

[0025] The material of the solid electrolyte layer 6 may be, for example, ZrO2 solid-solubilized with 3 mol % to 15 mol % of a rare earth element oxide, calcium oxide, or magnesium oxide. 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 contain, for example, CeO2 solid-solubilized with La, Nd, Sm, Gd, or Yb, BaZrO3 solid-solubilized with Sc or Yb, or BaCeO3 solid-solubilized with Sc or Yb.

[0026] The air electrode layer 8 is gas permeable. The open porosity of the air electrode layer 8 may be, for example, in the range of 20% to 50%, and particularly in the range of 30% to 50%.

[0027] There are no particular restrictions on the material of the air electrode layer 8, as long as it is one that is generally used for air electrodes. The material of the air electrode layer 8 may be, for example, a conductive ceramic such as a so-called ABO3-type perovskite oxide.

[0028] The material of the air electrode layer 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 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。

[0029] Furthermore, when the element section 3 includes an intermediate layer 7, the intermediate layer 7 functions as a diffusion suppression layer. When elements such as Sr (strontium) contained in the air electrode layer 8 diffuse into the solid electrolyte layer 6, a resistive layer such as SrZrO3 is formed in the solid electrolyte layer 6. The intermediate layer 7 makes it difficult for Sr to diffuse, thereby making it difficult for SrZrO3 and other electrically insulating oxides to form.

[0030] There are no particular restrictions on the material of intermediate layer 7, as long as it is generally used as an element diffusion prevention layer between air cathode layer 8 and solid electrolyte layer 6. The material of intermediate layer 7 may include, for example, cerium oxide (CeO2) in which a rare earth element other than Ce (cerium) is dissolved. Examples of such rare earth elements that may be used include Gd (gadolinium) and Sm (samarium).

[0031] Furthermore, the interconnector 4 is dense and makes it difficult for leakage of the fuel gas flowing through the gas flow channel 2a located inside the support substrate 2 and the oxygen-containing gas flowing outside the support substrate 2 to occur. The interconnector 4 may have a relative density of 93% or more, particularly 95% or more.

[0032] The material for the interconnector 4 may be a lanthanum chromite-based perovskite oxide (LaCrO3-based oxide), a lanthanum strontium titanium-based perovskite oxide (LaSrTiO3-based oxide), or the like. These materials are conductive and are resistant to reduction and oxidation even when in contact with a fuel gas such as a hydrogen-containing gas and an oxygen-containing gas such as air. Alternatively, a metal or alloy may be used as the material for the interconnector 4.

[0033] <Electrochemical cell device> Next, an electrochemical cell device according to this embodiment using the above-described cell 1 will be described with reference to Figures 2A to 2C. Figure 2A is a perspective view showing an example of the electrochemical cell device according to the first 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 electrochemical cell device according to the first 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 fixing members 12, 12a.

[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, for example, 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 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.

[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. 7), 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] The example shown in FIG. 2A includes two rows of cell stacks 11, a support member 14, 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 each of the supports 15. The gas tank 16 has two through-holes on its top surface. A support 15 is disposed in each of the through-holes. An internal space 22 is formed by the one gas tank 16 and the two supports 15. Although FIG. 2A shows a cell stack device 10 having two rows of cell stacks 11, the electrochemical cell device may have one row of cell stacks 11, or three or more rows of cell stacks 11.

[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, the joints between the inner walls of the insertion holes 15a and the lower ends of the cells 1 are filled with a fixing material 13 and solidified. 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 gas flow paths 2a of each cell 1 communicate with the internal space 22 of the support member 14 at their lower ends.

[0043] 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.

[0044] As the crystallized glass, for example, any of materials such as SiO2-CaO, MgO-B2O3, La2O3-B2O3-MgO, La2O3-B2O3-ZnO, and SiO2-CaO-ZnO may be used, and in particular, SiO2-MgO materials may be used.

[0045] 2B, a conductive member 18 is interposed between adjacent cells 1 among the plurality of cells 1. The conductive member 18 electrically connects the anode layer 5 of one adjacent cell 1 to the air cathode layer 8 of the other cell 1 in series. More specifically, the conductive member 18 connects the interconnector 4 electrically connected to the anode layer 5 of one adjacent cell 1 to the air cathode layer 8 of the other cell 1. When the interconnector 4 is made of a metal or an alloy, the interconnector 4 and the conductive member 18 may be integrated, or the conductive member 18 may also serve as the interconnector 4. Details of the conductive member 18 will be described later.

[0046] 2B, an end current collecting member 17 is electrically connected to the cell 1 located at the outermost position in the arrangement direction of the multiple cells 1. The end current collecting member 17 is connected to a conductive part 19 that protrudes to the outside of the cell stack 11. The conductive part 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. 2A.

[0047] 2C, the cell stack device 10 has two cell stacks 11A and 11B connected in series to function as a single battery. 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 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 electrode side end current collecting member 17 of the cell stack 11A. The negative electrode terminal 19B is a negative electrode when the power generated by the cell stack 11 is output to the outside, 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] <Temperature distribution during power generation> Next, the temperature distribution during power generation in the electrochemical cell device will be described with reference to FIG. 3. FIG. 3 is a cross-sectional view showing an example of the temperature distribution in the electrochemical cell device. The cell stack device 10X shown in FIG. 3 corresponds to an enlarged view of a portion of the cell stack 11 included in the cell stack device 10 shown in FIG. 2B. Note that FIG. 3 shows simplified illustrations of, for example, the cells 1, conductive members 18, etc. Also, in other drawings described later, simplified illustrations of components may be used. For ease of explanation, the number of cells 1 included in the cell stack device is shown as eight in FIG. 3 and FIG. 4 described later.

[0051] As shown in FIG. 3, a conductive member 18 extending in the length direction is located between adjacent cells 1 in the thickness direction T of the cells 1, electrically connecting the adjacent cells 1 to each other. In the cell stack device 10X, during power generation, temperatures t1 to t6 are in the order of t1>t2>t3>t4>t5>t6, which are located in the center of the thickness direction T (first direction) of the cells 1 and at the upper end side in the length direction L away from the fixing material 13, and the temperature is higher. Furthermore, the temperature during power generation decreases toward the end sides in the thickness direction T away from this portion and toward the lower end side in the length direction L. Therefore, the first region R1 located in the center of the thickness direction T (first direction) of the cells 1 becomes higher than the second regions R2 located at both ends of the thickness direction T (first direction) of the cells 1, for example, and durability is likely to decrease.

[0052] Therefore, in this embodiment, a conductive member 18 having different resistivities is applied between the first region R1 and the second region R2. Fig. 4 is an enlarged cross-sectional view of the electrochemical cell device according to the first embodiment.

[0053] 4, the conductive member 18 located in the first region R1 has a first portion 181 and a second portion 182 having a lower resistivity than the first portion 181. As a result, the resistivity of the conductive member 18 located in the first portion 181, which is a portion that is prone to high temperatures, is made higher than that of the other portions, thereby reducing the amount of current flow, and the conductive member 18 located in the other portion, the second portion 182, has a lower resistivity, thereby increasing the amount of current flow. This reduces temperature variations during power generation and increases the durability of the electrochemical cell device.

[0054] Furthermore, the conductive member 183 located in the second region R2 has a higher resistivity than the second portion 182. This actively promotes a temperature rise in the second region R2, which is less likely to become hot, through resistance heating of the conductive member 183. This reduces temperature variations during power generation, improving battery performance.

[0055] The conductive member 183 as a whole only needs to have a higher resistivity than the second portion 182. The conductive member 183 may have a higher resistivity than the first portion 181, or may have the same or lower resistivity as the first portion. The conductive member 183 may have a high resistance portion and a low resistance portion. When the conductive member 183 has a high resistance portion and a low resistance portion, the difference in resistivity between the high resistance portion and the low resistance portion is smaller than the difference in resistivity between the first portion 181 and the second portion 182. The low resistance portion of the conductive member 183 may have the same resistivity as the second portion 182 or a lower resistivity than the second portion 182. The conductive member 183 does not have to have a low resistance portion.

[0056] Here, an example of a specific configuration of the conductive member 18 will be described with reference to Figures 5 and 6. Figure 5 is a cross-sectional view showing an example of the conductive member according to the first embodiment.

[0057] 5, the conductive member 18 has a connection portion 18a connected to cell 1A, which is one of the adjacent cells 1, and a connection portion 18b connected to cell 1B, which is the other cell 1. The conductive member 18 also has linking portions 18c at both ends in the width direction W, which connect the connection portions 18a and 18b. This allows the conductive member 18 to electrically connect the cells 1 adjacent to each other in the thickness direction T.

[0058] Furthermore, the connecting portions 18a and 18b have contact portions 18a1 and 18b1 that come into contact with the cells 1A and 1B, and non-contact portions 18a2 and 18b2 that do not come into contact with the cells 1A and 1B.

[0059] Fig. 6 is a cross-sectional view taken along line AA in Fig. 5. The conductive member 18 extends in the longitudinal direction L of the cell 1. The conductive member 18 has a comb-like shape in cross section, and the connection portions 18a and 18b extend alternately from the coupling portion 18c toward the cells 1A and 1B.

[0060] Next, specific examples of conductive member 18 having first portion 181 and second portion 182 will be described with reference to Figures 7A to 7D. Figure 7A is a cross-sectional view showing an example of the conductive member according to the first embodiment.

[0061] As shown in FIG. 7A, the conductive member 18 has a substrate 180 and a coating 30 covering the substrate 180. The substrate 180 is electrically conductive and heat resistant. The substrate 180 contains chromium. The substrate 180 is, for example, stainless steel. The substrate 180 may also contain, for example, a metal oxide.

[0062] The coating 30 has insulating or low insulating properties. The coating 30 contains, for example, chromium oxide (Cr2O3), aluminum oxide (Al2O3), or a composite oxide containing Al and / or Si. The conductive member 18 shown in FIG. 7A has a first portion 181 and a second portion 182 that have different resistivities due to the difference in thickness of the coating 30. That is, the resistivity of the first portion 181, where the coating 30 is thicker than the second portion 182, is higher than the resistivity of the second portion 182.

[0063] 7B to 7D are cross-sectional views showing other examples of the conductive member according to the first embodiment.

[0064] As shown in FIG. 7B, the conductive member 18 differs from the conductive member 18 shown in FIG. 7A in that the conductive member 18 has a coating 31 covering the substrate 180 instead of the coating 30.

[0065] The coating 31 is conductive. The coating 31 contains, for example, a conductive metal material and / or metal oxide. The conductive member 18 shown in FIG. 7B has a first portion 181 and a second portion 182 with different resistivities due to the difference in thickness of the coating 31. That is, the resistivity of the second portion 182, where the thickness of the coating 31 is greater than that of the first portion 181, is lower than the resistivity of the first portion 181. The conductive metal oxide contained in the coating 31 is, for example, a composite oxide having a spinel structure, for example, Zn(Co) such as ZnMnCoO4. x Mn 1-x )2O4(0 <x<1)、Mn 1.5 Co 1.5O4, MnCo2O4, CoMn2O4, etc. The conductive metal oxide may be a so-called ABO3 type perovskite oxide.

[0066] The conductive member 18 may have both the coating 30 and the coating 31 having higher conductivity than the coating 30. The conductive member 18 may have, for example, the coating 30 covering the substrate 180, and the coating 31 further covering the coating 30. In this case, the thickness of the coating 30 in the second portion 182 may be smaller and / or the thickness of the coating 31 in the second portion 182 may be larger than that in the first portion 181.

[0067] 7C differs from the conductive member 18 shown in FIG. 7A in that the conductive member 18 shown in FIG. 7C has coatings 32 and 33 that cover the substrate 180 instead of the coating 30.

[0068] The coatings 32 and 33 are conductive or insulating. The coating 32 has higher insulating properties than the coating 33. Alternatively, the coating 33 has higher conductivity than the coating 32.

[0069] The conductive member 18 shown in FIG. 7C has a first portion 181 and a second portion 182 with different resistivities due to the coatings 32, 33 being made of different materials. That is, the resistivity of the second portion 182, which has a coating 33 that is less insulating or more conductive than the coating 32, is lower than the resistivity of the first portion 181. The coatings 32, 33 may be made of the same material but with different porosities. If the porosity of the coating 32 is higher than that of the coating 33, the coating 32 will have higher insulating properties or lower conductivity than the coating 33. The materials of the coatings 32, 33 may be the same materials as those contained in the coatings 30, 31.

[0070] 7D has regions 180a and 180b made of different materials in base material 180. Region 180b has higher conductivity than region 180a. As a result, the resistivity of second region 182 is lower than the resistivity of first region 181.

[0071] As described above, the conductive member 18 according to this embodiment may be fabricated by any method. The coatings 30 and 31 shown in FIGS. 7A and 7B may be formed, for example, by changing the number of applications and / or the concentration of the dipping solution in a dipping method, or by changing the film-forming electrode in an electrodeposition or plating method. The coatings 32 and 33 shown in FIG. 7C may be formed, for example, by changing the type of dipping solution in a dipping method. The conductive member 18 shown in FIG. 7D may be formed, for example, by welding or joining.

[0072] <module> Next, a module according to this embodiment 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 first embodiment. Fig. 8 shows a state in which the front and rear surfaces, which are part of the storage container 101, have been removed and the cell stack device 10 of the fuel cell stored inside has been pulled out to the rear.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] Furthermore, in the module 100 having the above-described configuration, during normal power generation, the temperature inside the module 100 reaches approximately 500°C to 1000°C due to the combustion, power generation by the cells 1, and the like.

[0077] 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.

[0078] <Module storage device> Fig. 9 is an exploded perspective view showing an example of a module housing device according to the first embodiment. The module housing device 110 includes an outer case 111, the module 100 shown in Fig. 8, and auxiliary equipment (not shown). The auxiliary equipment operates the module 100. The module 100 and the auxiliary equipment are housed in the outer case 111. Note that some components are omitted in Fig. 9.

[0079] An exterior case 111 of a module accommodating device 110 shown in Fig. 9 has support columns 112 and an exterior plate 113. A partition plate 114 divides the interior of the exterior case 111 into upper and lower sections. The space above the partition plate 114 in the exterior case 111 is a module accommodating chamber 115 that accommodates the module 100, and the space below the partition plate 114 in the exterior case 111 is an accessory accommodating chamber 116 that accommodates accessories that operate the module 100. Note that in Fig. 8, the accessories accommodated in the accessory accommodating chamber 116 are omitted.

[0080] 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.

[0081] In such a module housing device 110, as described above, highly durable modules 100 are provided in the module housing chamber 115, so that the module housing device 110 can be made highly durable.

[0082] FIG. 10 is a cross-sectional view showing another example of the electrochemical cell device according to the first embodiment. The cell stack device 10 shown in FIG. 10 differs from the conductive member 18 according to the above-described embodiment in that the conductive member 18 includes a first member 18A and a second member 18B having different resistivities. The resistivity of the second member 18B is configured to be lower than the resistivity of the first member 18A, and the first member 18A and the second member 18B are disposed between adjacent cells 1. In this way, even when the first member 18A and the second member 18B having different resistivities are used as the conductive member 18, the temperature variation in the first region R1 (see FIG. 4) is reduced. Therefore, according to this modification, the durability of the cell stack device 10 is increased.

[0083] The first member 18A and the second member 18B can be fabricated, for example, in accordance with the first portion 181 and the second portion 182 shown in Figures 7A to 7D. The first member 18A and the second member 18B may be in contact with each other or spaced apart. Spaced apart, the current flowing through the first member 18A can be more reliably reduced, thereby increasing the durability of the cell stack device 10.

[0084] [Second embodiment] FIG. 11 is a perspective view showing an example of an electrochemical cell device according to a second embodiment. The cell stack device 10A shown in FIG. 11 is an electrochemical cell device in which flat-plate electrochemical cells, each having an element unit 3A and conductive members 18 sandwiching the element unit 3A, are stacked. The element unit 3A has a solid electrolyte layer (e.g., solid electrolyte layer 6), and a first electrode layer (e.g., fuel electrode layer 5) and a second electrode layer (e.g., air electrode layer 8) sandwiching the solid electrolyte layer. The conductive member 18 has a flow path (not shown) through which a reactant gas flows, and the flow path is sealed with a sealing member (not shown) or the like. End current collecting members 91 and 92 are located at both ends of the cell stack device 10A.

[0085] FIG. 12 is a cross-sectional view showing an example of temperature distribution in a flat-plate electrochemical cell. As shown in FIG. 12, during power generation, temperatures t11 to t15 of the cell stack device 10Y are highest in the center of the cell stack device 10Y in the order t11 > t12 > t13 > t14 > t15. Furthermore, the temperature during power generation decreases toward both ends in the Y-axis direction and Z-axis direction, away from the center. Therefore, the first region R1 located at the center of the element unit 3A in the thickness direction (Z-axis direction) becomes hotter than the second region R2 located at both ends in the thickness direction (Z-axis direction) of the element unit 3A, for example, which tends to reduce durability. While FIG. 12 shows a cross-section along the YZ plane, the same can be said for a cross-section along the ZX plane.

[0086] Therefore, in this embodiment, conductive members 18 having different resistivities are applied between the first region R1 and the second region R2. Fig. 13 is a cross-sectional view showing an example of an electrochemical cell device according to the second embodiment.

[0087] 13, the conductive member 18 located in the first region R1 has a first portion 181 and a second portion 182 having a lower resistivity than the first portion 181. As a result, the resistivity of the conductive member 18 located in the first portion 181, which is a portion that is prone to high temperatures, is made higher than that of the other portions, thereby reducing the amount of current flow, and the conductive member 18 located in the other portion, the second portion 182, has a lower resistivity, thereby increasing the amount of current flow. This reduces temperature variations during power generation and increases the durability of the electrochemical cell device.

[0088] Furthermore, the conductive member 183 located in the second region R2 has a higher resistivity than the second portion 182. This actively promotes a temperature rise in the second region R2, which is less likely to become hot, through resistance heating of the conductive member 183. This reduces temperature variations during power generation, improving battery performance.

[0089] Fig. 14 is a cross-sectional view showing an example of the first region R1 shown in Fig. 13. In the conductive members 18 located in the first region R1 of the cell stack device 10A, conductive member 18-1 connected to one adjacent element unit 3A and conductive member 18-2 connected to the other adjacent element unit 3A are electrically connected via conductive member 18-3, which is an interconnector. Hereinafter, conductive members 18-1 to 18-3 located between element units 3A may be collectively referred to as conductive member 18.

[0090] As described above, the temperature near the center of the cell stack device 10A, which becomes hot during power generation, is difficult to reduce, which can result in variations in temperature within the cell stack device 10A. Specifically, the temperature in the center of the cell stack device 10A rises more than on the outer edge side, which is farther from the center of the cell stack device 10A, and for example, the temperature becomes higher than that suitable for power generation, which can easily reduce durability.

[0091] 14, temperature variations may be reduced by applying a conductive member 18 having a first portion 181 and a second portion 182 between element units 3A located in a first region R1 of the cell stack device 10A. Specifically, the conductive member 18 is positioned so that the first portion 181 is connected to the central portion between the element units 3A in the X-axis direction and / or the Y-axis direction, and the second portion 182 is connected to a portion away from the central portion between the element units 3A in the X-axis direction and / or the Y-axis direction. The resistivity of the first portion 181 is greater than the resistivity of the second portion 182.

[0092] As a result, the amount of current flowing through the first portion 181 is less than that through the second portion 182, reducing the temperature rise in the first portion 181. Therefore, according to this embodiment, the durability of the cell stack device 10A is increased.

[0093] In the above, conductive members 18-1 to 18-3 have been collectively described as conductive member 18, but conductive member 18-3, which is different from conductive members 18-1 and 18-2, may be used as a third member, and conductive members 18-1 and 18-2 may be connected in series.

[0094] FIG. 15 is a cross-sectional view showing another example of an electrochemical cell device according to the second embodiment. The cell stack device 10B shown in FIG. 15 differs from the conductive member 18 shown in FIG. 14 in that the conductive member 18 located in the first region R1 includes a first member 18A and a second member 18B having different resistivities. The resistivity of the second member 18B is lower than that of the first member 18A, and the first member 18A and the second member 18B are disposed between adjacent element units 3A. In this way, even when the first member 18A and the second member 18B having different resistivities are used as the conductive member 18, the temperature rise in the central portion of the cell stack device 10B is reduced. Therefore, this modification improves the durability of the cell stack device 10B.

[0095] Furthermore, the conductive member 183 located in the second region R2 (see FIG. 13) has a higher resistivity than the second portion 182 or the second member 18B. This actively promotes temperature rise in the second region R2, which is less likely to become hot, through resistance heating of the conductive member 183. This reduces temperature variations during power generation, improving battery performance. Note that, like the conductive member 18 located in the first region R1, the conductive member 183 located in the second region R2 may also be configured such that the conductive member 18-1 connected to one adjacent element unit 3A and the conductive member 18-2 connected to the other adjacent element unit 3A are electrically connected via the conductive member 18-3, which is an interconnector.

[0096] [Third embodiment] Fig. 16A is a cross-sectional view showing an example of an electrochemical cell constituting an electrochemical cell device according to the third embodiment. Figs. 16B and 16C are cross-sectional views showing another example of an electrochemical cell according to the third embodiment. In this embodiment, a cell stack device 10C is formed by applying the cell 1 shown in Figs. 16A to 16C to the cell stack device 10 shown in Fig. 2A or 11.

[0097] As shown in FIGS. 16A to 16C, the cell 1 includes an element section 3C in which an anode layer 5, a solid electrolyte layer 6, an intermediate layer 7, and an air cathode layer 8 are stacked, and a support substrate 2. The support substrate 2 has through-holes or pores at a portion of the element section 3C that contacts the anode layer 5, and includes a member 120 located outside the gas flow path 2a. The support substrate 2 allows gas to flow between the gas flow path 2a and the element section 3C. The support substrate 2 may include, for example, one or more metal members. The material of the metal member may be an alloy containing chromium. The metal member may have a conductive coating layer. The support substrate 2 is a conductive member that electrically connects adjacent cells 1 to each other. The element section 3C may be formed directly on the support substrate 2, or may be bonded to the support substrate 2 with a bonding material.

[0098] In the example shown in Fig. 16A, the side surface of the fuel electrode layer 5 is covered with a solid electrolyte layer 6, which airtightly seals the gas flow channel 2a through which the fuel gas flows. As shown in Fig. 16B, the side surface of the fuel electrode layer 5 may be covered and sealed with a dense sealing material 9. The sealing material 9 covering the side surface of the fuel electrode layer 5 may have electrical insulating properties. The material of the sealing material 9 may be, for example, glass or ceramics.

[0099] Furthermore, the gas flow path 2a of the support substrate 2 may be formed by a member 120 having projections and recesses as shown in FIG. 16C.

[0100] In this embodiment, the member 120 is joined to the air cathode layer 8 of another adjacent cell 1 via another conductive member such as an inter-cell connecting member and a bonding material. Note that the member 120 may also be in direct contact with the air cathode layer 8 of another cell 1 without the intervention of another conductive member or the like.

[0101] In this embodiment, a cell 1 including a support substrate 2 (conductive member 18) having a first portion 181 and a second portion 182 is arranged in a first region R1 of a cell stack device 10C. Specifically, the first portion 181 of the support substrate 2 (conductive member 18) is positioned in a portion 1a of the cell 1 that is relatively hot, and the second portion 182 is positioned in a portion 1b of the cell 1 that is relatively cold. Because the resistivity of the first portion 181 is higher than that of the second portion 182, the amount of current flowing through the first portion 181 is lower than that of the second portion 182, and the temperature rise in the portion 1a is reduced. Therefore, this embodiment improves the durability of the support substrate 2 (conductive member 18) and the cell stack device 10. Note that in FIGS. 16A to 16C, the portion 1a of the cell 1 that is hot is shown as being close to the center of the element unit 3B as in the second embodiment. However, the portion 1a of the cell 1 that is hot may be close to the fuel gas outlet as in the first embodiment.

[0102] 3, 4, 12, and 13. The first region R1 and the second region R2 can be set as appropriate depending on the structure, characteristics, etc. of the cell stack. For example, one conductive member 18 sandwiched between two cells 1 located adjacent to the first region R1 at the center of the cell stack may have a first portion and a second portion, and one conductive member 18 located in the second region R2 at one end of the cell stack may have a resistivity higher than that of the second portion 182.

[0103] Furthermore, the arrangement and ratio of the first portion 181 and the second portion 182 of the conductive member 18 located in the first region R1 can be set appropriately depending on the structure of the cell 1 located in the first region R1.

[0104] <Other variations> 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 a "battery chemical cell," a "battery chemical cell device," a "module," and a "module housing device." However, other examples may be an electrolytic cell, an electrolytic cell stack device, an electrolytic module, and an electrolytic device, respectively. The electrolytic cell has a hydrogen electrode and an oxygen electrode, and decomposes water vapor into hydrogen 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.

[0105] Although the present disclosure has been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible within the scope that does not deviate from the gist of the present disclosure.

[0106] As described above, an electrochemical cell device according to the embodiment (for example, a cell stack device 10) includes a cell stack 11 and a conductive member 18. The cell stack 11 has a plurality of element units 3 arranged in a first direction. The conductive members 18 are located between the plurality of element units 3. The cell stack 11 has a first region R1 located in the center in the first direction and a second region R2 located at an end in the first direction. The conductive member 18 located in the first region R1 has a first portion 181 and a second portion 182 having a lower resistivity than the first portion 181. The conductive member 183 located in the second region R2 has a higher resistivity than the second portion 182. This makes it possible to provide a conductive member 18 with high durability.

[0107] Moreover, an electrochemical cell device (for example, a cell stack device 10) of the present disclosure includes a cell stack 11 and a conductive member 18. The cell stack 11 has a plurality of element units 3 aligned in a first direction. The conductive members 18 are located between the plurality of element units 3. The cell stack 11 has a first region R1 located in the center in the first direction and a second region R2 located at an end in the first direction. The conductive member 18 located in the first region R1 has a first member 18A and a second member 18B having a lower resistivity than the first member 18A. The conductive member 183 located in the second region R2 has a higher resistivity than the second member 18B. This makes it possible to provide an electrochemical cell device with high durability.

[0108] Furthermore, the module 100 of the present disclosure includes the electrochemical cell device described above and a container 101 that houses the electrochemical cell device, thereby making it possible to provide the module 100 with high durability.

[0109] The module housing device 110 of the present disclosure includes the above-described module 100, accessories for operating the module 100, and an exterior case 111 for housing the module 100 and the accessories. This allows the module housing device 110 to be highly durable.

[0110] 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]

[0111] 1 cell 3. Element section 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 100 modules 110 Module storage device 181 Part 1 182 Part 2 183 Conductive materials

Claims

1. a cell stack having a plurality of element units aligned in a first direction; a conductive member positioned between each of the plurality of element portions; Equipped with the cell stack has a first region located in a center portion in the first direction and a second region located at an end portion in the first direction, the conductive member located in the first region has a first portion located in a central portion in a second direction intersecting the first direction, and a second portion located at an end portion in the second direction and having a resistivity lower than that of the first portion, The conductive member located in the second region has a higher resistivity than the second portion. Electrochemical cell apparatus.

2. The first region has a higher maximum temperature than the second region.

10. The electrochemical cell device of claim 1.

3. The electrochemical cell device according to claim 1 or 2; a container for housing the electrochemical cell device; A module comprising:

4. A module according to claim 3; 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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