Electroconductive member, electrochemical cell device, module, and module accommodation device

Abstract

This electroconductive member has a first region and a second region that has a resistivity different from that of the first section. This electrochemical cell device comprises an electroconductive member and an electrochemical cell connected to the electroconductive member. The electrochemical cell has a first section which is connected to the first region, and a second section which is connected to the second region. The temperature of the first section is higher than that of the second section. The resistivity of the first region is higher than that of the second region.

Description

Conductive member, electrochemical cell device, module, and module housing device

[0001] The present disclosure relates to an electrically conductive member, an electrochemical cell device, a module, and a module housing device.

[0002] In recent years, various fuel cell stack devices having multiple fuel cell units have been proposed as next-generation energy sources. A fuel cell unit is a type of electrochemical cell that can generate electric power using a fuel gas such as a hydrogen-containing gas and an oxygen-containing gas such as air.

[0003] JP 2021-180164 A JP 2015-220022 A

[0004] The conductive member according to one aspect of the embodiment has a first portion and a second portion having a different resistivity than the first portion.

[0005] The present disclosure also provides an electrochemical cell device including the conductive member described above and an electrochemical cell connected to the conductive member. The electrochemical cell has a first portion connected to the first location and a second portion connected to the second location. The temperature of the first portion is higher than the temperature of the second portion. The resistivity of the first portion is higher than the resistivity of the second portion.

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

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

[0008] FIG. 1A is a cross-sectional view showing an example of an electrochemical cell according to the first embodiment. FIG. 1B is a side view of an example of an electrochemical cell according to the first embodiment, viewed from the air electrode side. FIG. 1C is a side view of an example of an electrochemical cell according to the first embodiment, viewed from the interconnector side. FIG. 2A is a perspective view showing an example of an electrochemical cell device according to the first embodiment. FIG. 2B is a cross-sectional view taken along line X-X shown in FIG. 2A. FIG. 2C is a top view showing an example of an electrochemical cell device according to the first embodiment. FIG. 3 is an enlarged cross-sectional view of the electrochemical cell device according to the first embodiment. FIG. 4 is a cross-sectional view showing an example of a conductive member included in the electrochemical cell device according to the first embodiment. FIG. 5 is a cross-sectional view taken along line A-A shown in FIG. 4. FIG. 6A is a cross-sectional view showing an example of a conductive member included in the electrochemical cell device according to the first embodiment. FIG. 6B is a cross-sectional view showing another example of a conductive member included in the electrochemical cell device according to the first embodiment. FIG. 6C is a cross-sectional view showing another example of a conductive member included in the electrochemical cell device according to the first embodiment. FIG. 6D is a cross-sectional view showing another example of a conductive member included in the electrochemical cell device according to the first embodiment. FIG. 7 is an external perspective view showing an example of a module according to the first embodiment. FIG. 8 is an exploded perspective view schematically showing an example of a module housing device according to the first embodiment. FIG. 9 is an enlarged cross-sectional view of the electrochemical cell device according to the second embodiment. FIG. 10 is a top view showing an example of an electrochemical cell device according to the third embodiment. FIG. 11 is a perspective view showing an example of an electrochemical cell included in the electrochemical cell device according to the fourth embodiment. FIG. 12 is a perspective view showing an example of a temperature distribution in a flat electrochemical cell. FIG. 13 is a longitudinal cross-sectional view showing an example of a conductive member included in the electrochemical cell device according to the fourth embodiment. FIG. 14 is a longitudinal cross-sectional view showing an example of a conductive member included in the electrochemical cell device according to the fifth embodiment. FIG. 15A is a transverse cross-sectional view showing an example of an electrochemical cell included in the electrochemical cell device according to the sixth embodiment. FIG. 15B is a transverse cross-sectional view showing another example of an electrochemical cell included in the electrochemical cell device according to the sixth embodiment. Fig. 15C is a cross-sectional view showing another example of an electrochemical cell included in the electrochemical cell device according to Embodiment 6. Fig. 16 is a diagram comparing the durability of electrochemical cell devices.

[0009] 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.

[0010] Therefore, there is a need to provide a highly durable conductive member, electrochemical cell device, module, and module housing device.

[0011] Hereinafter, embodiments of the conductive member, electrochemical cell 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 disclosure is not limited to the embodiments described below.

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

[0013] 1A to 1C, an electrochemical cell 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.

[0014] 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.

[0015] 1A to 1C, the 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.

[0016] 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.

[0017] The element section 3 is provided on the flat surface n1 of the support substrate 2. The element section 3 has an anode layer 5, a solid electrolyte layer 6, and an air cathode 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 cathode layer 8.

[0018] 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 surface 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 arcuate side surfaces m of the cell 1. The interconnector 4 does not have to extend to the lower end of the cell 1.

[0019] Each of the components that make up the cell 1 will be described below.

[0020] 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 has gas permeability, 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.

[0021] 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.

[0022] A generally known material can be used for the fuel electrode layer 5. The fuel electrode layer 5 is made of a porous conductive ceramic, such as calcium oxide, magnesium oxide, or ZrO in which a rare earth element oxide is solid-solved. ２ and Ni and / or NiO may be used. The rare earth element oxide may contain, for example, a plurality of rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. Calcium oxide, magnesium oxide, or ZrO in which a rare earth element oxide is solid-solved may be used. ２ The stabilized zirconia may include partially stabilized zirconia.

[0023] 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.

[0024] The material of the solid electrolyte layer 6 is, for example, ZrO in which 3 mol % to 15 mol % of rare earth element oxide, calcium oxide, and magnesium oxide are solid-solved. ２ The rare earth element oxide may contain, for example, one or more rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. The solid electrolyte layer 6 may be, for example, CeO in which La, Nd, Sm, Gd, or Yb is solid-solved. ２ and BaZrO in which Sc or Yb is solid-solved. ３ and BaCeO in which Sc or Yb is solid-solved. ３ may include:

[0025] 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%.

[0026] There are no particular restrictions on the material of the air electrode layer 8 as long as it is a material that is generally used for air electrodes. ３ Conductive ceramics such as perovskite oxides may also be used.

[0027] 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 O ３ , La ｘ Sr １－ｘ MnO ３ , La ｘ Sr １－ｘ FeO ３ , La ｘ Sr １－ｘ CoO ３ Here, x is 0<x<1, and y is 0<y<1.

[0028] Furthermore, when the element section 3 has the 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, the solid electrolyte layer 6 is filled with, for example, SrZrO ３ The intermediate layer 7 is formed as an electrical resistance layer such as SrZrO by making it difficult for Sr to diffuse. ３ It makes it difficult for other oxides with electrical insulating properties to form.

[0029] The material of the intermediate layer 7 is not particularly limited as long as it generally prevents diffusion of elements between the air cathode layer 8 and the solid electrolyte layer 6. The material of the intermediate layer 7 is, for example, cerium oxide (CeO) in which rare earth elements other than Ce (cerium) are dissolved. ２ ) may be included. Examples of such rare earth elements include Gd (gadolinium) and Sm (samarium).

[0030] Furthermore, the interconnector 4 is dense and makes it difficult for leakage of the fuel gas flowing through the gas flow passage 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.

[0031] The material of the interconnector 4 is a lanthanum chromite-based perovskite oxide (LaCrO ３ -based oxides), lanthanum strontium titanium-based perovskite-type oxides (LaSrTiO ３ These materials are electrically conductive and are not easily reduced or oxidized even when in contact with a fuel gas such as a hydrogen-containing gas and an oxygen-containing gas such as air. The material of the interconnector 4 may be a metal or an alloy.

[0032] 2A to 2C, an electrochemical cell device according to this embodiment using the above-described cell 1 will be described. Fig. 2A is a perspective view showing an example of the electrochemical cell device according to the first embodiment, Fig. 2B is a cross-sectional view taken along line X-X shown in Fig. 2A, and Fig. 2C is a top view showing an example of the electrochemical cell device according to the first embodiment.

[0033] As shown in FIG. 2A, the cell stack device 10 includes a cell stack 11 having a plurality of cells 1 arranged (stacked) in the thickness direction T of the cells 1 (see FIG. 1A), and a fixing member 12.

[0034] The fixing member 12 has a fixing material 13 and a support member 14. The support member 14 supports the cell 1. The fixing material 13 fixes the cell 1 to the support member 14. The support member 14 also has a support 15 and a gas tank 16. The support 15 and the gas tank 16, which are the support member 14, are made of, for example, metal and are electrically conductive.

[0035] The cell stack device 10 may also include a fixing member 12a positioned opposite the fixing member 12 across the cell stack 11. The fixing member 12 fixes the lower end side of the cell 1, and the fixing member 12a fixes the upper end side of the cell 1. Note that the fixing member 12a is not shown in Figures 2A to 2C.

[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 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, supplied from the gas tank 16 to a gas flow path 2a (see FIG. 1A ) inside the cell 1, and discharged from the upper end side of 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. When the cell stack device 10 includes a fixing member 12a, the fuel gas discharged from the upper end side of the cell 1 to the fixing member 12a may be further discharged and treated through a gas discharge pipe (not shown), or may be supplied again through the reformer to the cell stack 11 or to a cell stack other than the cell stack 11.

[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 and a support member 14. The support member 14 includes two supports 15 and a gas tank 16. Each of the two rows of cell stacks 11 includes a plurality of cells 1. Each cell stack 11 is fixed to each support 15. The gas tank 16 has two through-holes on its top surface. A support 15 is disposed in each through-hole. The internal space 22 is formed by one gas tank 16 and two supports 15. When the cell stack device 10 includes a fixing member 12a (not shown), the support member 14a may include two supports and a gas tank, just like the support member 14. While FIG. 2A shows the cell stack device 10 with two rows of cell stacks 11, the cell stack device may include 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 and solidified with fixing material 13. This bonds and fixes the inner walls of the insertion holes 15a to the lower ends of the multiple cells 1, respectively, and also bonds and fixes the lower ends of the cells 1 to each other. The 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] Examples of the crystallized glass include SiO ２ -CaO system, MgO-B ２ O ３ System, La ２ O ３ -B ２ O３ -MgO-based, La ２ O ３ -B ２ O ３ -ZnO-based, SiO ２ -CaO-ZnO system materials, etc., may be used, and in particular SiO ２ - MgO-based materials may also be used.

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

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

[0050] <Conductive Member> Next, details of the conductive member 18 of the electrochemical cell device according to the first embodiment will be further described with reference to FIG. 3. FIG. 3 is an enlarged cross-sectional view of the electrochemical cell device according to the first embodiment. The cell stack device 10 shown in FIG. 3 corresponds to an enlarged view of the cell stack 11 of the cell stack device 10 shown in FIG. 2B. Note that FIG. 3 illustrates, for example, the cells 1, the conductive member 18, and the like in a simplified form. Furthermore, in other drawings described below, components may also be illustrated in a simplified form.

[0051] As shown in Fig. 3, a conductive member 18 extending in the longitudinal direction is located between adjacent cells 1 in the thickness direction T. The cells 1 have gas flow paths 2a through which gas flows. The gas flow paths 2a have a supply port 2a1 and an outlet 2a2. The fuel gas stored in the internal space 22 is supplied to the supply port 2a1. The outlet 2a2 discharges the fuel gas from inside the cells 1.

[0052] Such a cell stack device 10 may experience temperature variations during power generation. Specifically, the temperature of the portion 1a of the cell 1, which is closer to the outlet 2a2, increases more than the temperature of the portion 1b of the cell 1, which is closer to the supply port 2a1. As a result, the portion 1a of the cell 1 may become, for example, at a temperature higher than that suitable for power generation, which may reduce durability.

[0053] Therefore, in this embodiment, temperature variations are reduced by applying a conductive member 18 having a first portion 181 and a second portion 182 with different electrical resistivities between adjacent cells 1 in the thickness direction T. Specifically, the conductive member 18 is positioned so that the first portion 181 is connected to the portion 1a and the second portion 182 is connected to the portion 1b. The electrical resistivity of the first portion 181 is greater than the electrical resistivity of the second portion 182. Hereinafter, electrical resistivity may be simply referred to as resistivity, and electrical resistance may be simply referred to as resistance.

[0054] As a result, the amount of current flowing through the first portion 181 is less than that through the second portion 182, suppressing resistance heating in the first portion 181. As a result, the temperature rise in the first portion 181 and the portion 1a of the cell 1 connected thereto is less than that in the second portion and the portion 1b of the cell 1 connected thereto. Therefore, according to this embodiment, the durability of the conductive member 18 and the cell stack device 10 is increased.

[0055] For example, the first portion 181 may be the end portion of the conductive member 18 on the discharge port side, and the second portion 182 may be the end portion of the conductive member 18 on the supply port side. Furthermore, where the length l from the end portion of the conductive member 18 on the discharge port side to the end portion on the supply port side is given as l, the first portion 181 may be a portion that is l / 3 away from the end portion of the conductive member 18 on the discharge port side, and the second portion 182 may be a portion that is l / 3 away from the end portion of the conductive member 18 on the supply port side.

[0056] The electrical resistance of the first portion 181 located between the cells 1A and 1B may be greater than the electrical resistance of the second portion 182 located between the cells 1A and 1B by, for example, 0.05 Ω or more. When the difference between the electrical resistance of the first portion 181 and the electrical resistance of the second portion 182 is 0.05 Ω or more, the amount of current flowing through the first portion 181 is reduced, reducing resistance heating in the first portion 181 and increasing the durability of the conductive member 18 and the cell stack device 10.

[0057] The half of the conductive member 18 located on the discharge outlet side may be referred to as the first portion 181, and the half located on the supply port side may be referred to as the second portion 182. Furthermore, where l is the length from the end of the conductive member 18 on the discharge outlet side to the end on the supply port side, the portion of the conductive member 18 extending from the end on the discharge port side to l / 3 may be referred to as the first portion 181, and the portion of the conductive member 18 extending from the end on the supply port side to l / 3 may be referred to as the second portion 182. The resistivity of the first portion 181 may be greater than the resistivity of the second portion 182 by 0.8 Ω·m or more. When the resistivity of the first portion 181 is greater than the resistivity of the second portion 182 by 0.8 Ω·m or more, the amount of current flowing through the first portion 181 is significantly reduced. Note that the resistivity may be an average value obtained by measuring, for example, three or more arbitrary points at each portion.

[0058] An example of a specific configuration of the conductive member 18 will now be described with reference to Figures 4 and 5. Figure 4 is a cross-sectional view showing an example of the conductive member included in the electrochemical cell device according to the first embodiment.

[0059] 4, the conductive member 18 has a connection portion 18a connected to cell 1A, one of the adjacent cells 1, and a connection portion 18b connected to cell 1B, the other cell 1. The conductive member 18 also has connecting portions 18c at both ends in the width direction W, which connect the connecting 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.

[0060] 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.

[0061] Fig. 5 is a cross-sectional view taken along line A-A in Fig. 4. 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.

[0062] 6A to 6D, specific examples of the conductive member 18 having the first portion 181 and the second portion 182 will be described. Fig. 6A is a cross-sectional view showing an example of the conductive member included in the electrochemical cell device according to the first embodiment.

[0063] 6A , the conductive member 18 may have a substrate 180 and a coating 30 covering the substrate 180. The substrate 180 has electrical conductivity and heat resistance. The substrate 180 contains chromium. The substrate 180 is, for example, stainless steel. The substrate 180 may also contain, for example, a metal oxide.

[0064] The coating 30 has electrical insulating properties or low electrical conductivity. The coating 30 is made of, for example, chromium oxide (Cr ２ O ３ ), aluminum oxide (Al ２ O ３6A includes a first portion 181 and a second portion 182 having different resistivities due to the difference in thickness of the coating 30. That is, the resistivity of the first portion 181, in which the coating 30 is thicker than the second portion 182, is higher than the resistivity of the second portion 182.

[0065] 6B to 6D are cross-sectional views showing other examples of the conductive member of the electrochemical cell device according to the first embodiment.

[0066] As shown in FIG. 6B, the conductive member 18 may have a substrate 180 and a coating 31 covering the substrate 180 .

[0067] The coating 31 is conductive. The coating 31 contains, for example, a conductive metal material and / or a metal oxide. As shown in FIG. 6B , the conductive member 18 may have a first portion 181 and a second portion 182 with different resistivities by varying the thickness of the coating 31. That is, the resistivity of the second portion 182, where the coating 31 is thicker than the first portion 181, is lower than the resistivity of the first portion 181. The conductive metal oxide contained in the coating 31 may be, for example, a composite oxide having a spinel structure, such as ZnMnCoO ４ Zn(Co ｘ Mn １－ｘ ) ２ O ４ (0<x<1), Mn １．５ Co １．５ O ４ , MnCo ２ O ４ , CoMn ２ O ４ The conductive metal oxide may be a so-called ABO ３ The oxide may be a perovskite oxide.

[0068] 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 may be smaller in the second portion 182 than in the first portion 181. Furthermore, the thickness of the coating 31 may be greater in the second portion 182 than in the first portion 181.

[0069] As shown in FIG. 6C, the conductive member 18 may have a substrate 180 and coatings 32 and 33 covering the substrate 180 .

[0070] The coatings 32 and 33 are conductive or insulating. The coating 32 may be more insulating than the coating 33. The coating 33 may be more conductive than the coating 32.

[0071] 6C , conductive member 18 may have first portion 181 and second portion 182 with different resistivities by using different materials for coatings 32, 33. That is, second portion 182, which has coating 33 that is less insulating or more conductive than coating 32, has a lower resistivity than first portion 181.

[0072] The coatings 32 and 33 may be made of the same material but with different porosities. If the porosity of the coating 32 is greater than that of the coating 33, the coating 32 will have higher insulating properties than the coating 33. If the porosity of the coating 32 is greater than that of the coating 33, the coating 32 will have lower conductivity than the coating 33. The materials of the coatings 32 and 33 may be the same materials as those contained in the coatings 30 and 31.

[0073] 6D , the conductive member 18 may have portions 180a and 180b in which the material of the substrate 180 is different from each other. The portion 180b has higher conductivity than the portion 180a. As a result, the resistivity of the second portion 182 is lower than the resistivity of the first portion 181.

[0074] As described above, the conductive member 18 of the electrochemical cell device according to this embodiment may be fabricated by any method. The coatings 30 and 31 shown in FIGS. 6A and 6B 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. 6C may be formed, for example, by changing the type of dipping solution in a dipping method. The conductive member 18 shown in FIG. 6D may be formed, for example, by welding or joining.

[0075] <Module> Next, a module 100 according to this embodiment using the above-described cell stack device 10 will be described with reference to Fig. 7. Fig. 7 is an external perspective view showing the module according to the first embodiment. Fig. 7 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.

[0076] 7, the module 100 includes a storage container 101 and a cell stack device 10 housed in the storage container 101. A reformer 102 is disposed above the cell stack device 10.

[0077] The reformer 102 reforms raw fuel such as natural gas or kerosene to generate fuel gas, which is then supplied to the cell 1. The raw fuel is supplied to the reformer 102 through a raw fuel supply pipe 103. The reformer 102 may include a vaporizer 102a that vaporizes water, and a reformer 102b. The reformer 102b includes a reforming catalyst (not shown) and reforms the raw fuel into fuel gas. Such a reformer 102 can perform steam reforming, a highly efficient reforming reaction.

[0078] The fuel gas produced in the reformer 102 is supplied to the gas flow channel 2 a of the cell 1 (see FIG. 1A) through the gas flow pipe 20 and the fixing member 12 .

[0079] Furthermore, in the module 100 having the above-described configuration, the temperature inside the module 100 during normal power generation becomes approximately 500°C to 1000°C due to the combustion of gas and the power generation of the cells 1, etc.

[0080] In such a module 100, as described above, the highly durable cell stack device 10 is provided, and thus the module 100 can be made highly durable.

[0081] <Module Enclosure Device> Fig. 8 is an exploded perspective view showing an example of a module enclosure device according to the first embodiment. The module enclosure device 110 includes an outer case 111, the module 100 shown in Fig. 7, and auxiliary equipment (not shown). The auxiliary equipment operates the module 100. The module 100 and the auxiliary equipment are housed in the outer case 111. Note that Fig. 8 omits some components.

[0082] An exterior case 111 of a module accommodating device 110 shown in Fig. 8 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 from the illustration.

[0083] 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.

[0084] In such a module accommodating device 110, as described above, highly durable modules 100 are provided in the module accommodating chamber 115, so that the module accommodating device 110 can be made highly durable.

[0085] Second Embodiment FIG. 9 is an enlarged cross-sectional view of an electrochemical cell device according to a second embodiment. The cell stack device 10 shown in FIG. 9 differs from the conductive member 18 of the cell stack device 10 according to the first embodiment in that the conductive member 18 includes a first conductive member 18A and a second conductive member 18B having different resistivities. The resistivity of the second conductive member 18B is lower than that of the first conductive member 18A, and the first conductive member 18A and the second conductive member 18B are disposed between adjacent cells 1. Thus, even when the first conductive member 18A and the second conductive member 18B having different resistivities are used as the conductive member 18, the temperature rise in the first conductive member 18A and the portion 1a of the cell 1 is reduced. Therefore, the electrochemical cell device according to this embodiment improves the durability of the conductive member 18 and the cell stack device 10.

[0086] The first conductive member 18A and the second conductive member 18B can be fabricated, for example, in accordance with the first portion 181 and the second portion 182 shown in Figures 6A to 6D. The first conductive member 18A and the second conductive member 18B may be in contact with each other or spaced apart. Spaced apart, the current flowing through the first conductive member 18A can be further reduced, thereby increasing the durability of the conductive member 18 and the cell stack device 10.

[0087] [Third Embodiment] Fig. 10 is a top view showing an example of an electrochemical cell device according to a third embodiment. The cell stack device 10 shown in Fig. 10 has a cell stack 11 including a plurality of cells 1 arranged in a thickness direction T (first direction). The cell stack 11 has a cell stack 11A (first cell stack) and a cell stack 11B (second cell stack) adjacent to each other in a width direction W (second direction) of the cells 1.

[0088] Thus, in a cell stack device 10 having cell stacks 11A and 11B, heat generated during power generation can accumulate between the cell stacks 11A and 11B, causing variations in temperature within the cell stack device 10. Specifically, the temperature of the portion 11Aa of the cell stack 11A that is closer to the cell stack 11B rises more than the temperature of the portion 11Ab that is further away from the cell stack 11B. As a result, the temperature of the portion 11Aa becomes higher than that suitable for power generation, and durability is likely to decrease.

[0089] 10 , temperature variations may be reduced by applying a conductive member 18 having a first portion 181 and a second portion 182 between cells 1 in cell stack 11A, the first portion 181 having a first resistivity that varies depending on the distance from cell stack 11B. Specifically, the conductive member 18 is positioned so that the first portion 181 is connected to the cell 1 located in portion 11Aa, and the second portion 182 is connected to the cell 1 located in portion 11Ab. The resistivity of the first portion 181 is greater than the resistivity of the second portion 182.

[0090] As a result, the amount of current passing through the portion 11Aa having the cells 1 connected to the first portion 181 is reduced compared to the portion 11Ab having the cells 1 connected to the second portion 182, and the temperature rise in the first conductive member 18A and the portion 11Aa is reduced. Therefore, the electrochemical cell device according to this embodiment improves the durability of the conductive member 18 and the cell stack device 10.

[0091] [Fourth Embodiment] Fig. 11 is a perspective view showing an example of an electrochemical cell included in an electrochemical cell device according to a fourth embodiment. The cell 1 shown in Fig. 11 is a flat-plate electrochemical cell having an element unit 3B and conductive members 91 and 92 sandwiching the element unit 3B. The element unit 3B 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 members 91 and 92 each have flow paths 97 and 98 through which reactant gases flow, and these flow paths are sealed with a sealing member (not shown) or the like.

[0092] 12 is a plan view showing an example of the temperature distribution in a flat electrochemical cell. As shown in Fig. 12, separators 40 are positioned around element unit 3B and are in contact with conductive members 91 and 92. Furthermore, on surface 3a of element unit 3B facing conductive member 91 or 92, the temperature rises in a portion close to center P1 of element unit 3B during power generation of cell 1, and the temperature decreases concentrically toward the outer edge away from center P1.

[0093] 13 is a longitudinal cross-sectional view showing an example of a conductive member included in an electrochemical cell device according to the fourth embodiment. In a cell stack device 10B in which a plurality of cells 1 are stacked, a conductive member 91 of one adjacent cell 1 and a conductive member 92 of another adjacent cell 1 are electrically connected via an interconnector 93, which is a conductive member. Hereinafter, the conductive members 91, 92 and the interconnector 93 located between the element portions 3B may be collectively referred to as a conductive member 18.

[0094] As described above, the temperature is difficult to decrease near the center P1 of the element unit 3B, which becomes hot during power generation, and this can result in variations in temperature within the cell stack device 10. Specifically, the temperature of the part of the cell 1 that is close to the center P1 of the element unit 3B increases more than that of the outer edge side that is farther away from the center P1 of the element unit 3B, and for example, the temperature becomes higher than that suitable for power generation, which can easily reduce durability.

[0095] 13 , temperature variations may be reduced by applying a conductive member 18 having a first portion 181 and a second portion 182 whose resistivity varies depending on the distance from the center P1 between the element units 3B of the cell stack device 10B. Specifically, the conductive member 18 is positioned so that the first portion 181 is connected to the first electrode layer of the element unit 3B close to the center P1, and the second portion 182 is connected to the first electrode layer of the element unit 3B farther from the center P1. The resistivity of the first portion 181 is greater than the resistivity of the second portion 182.

[0096] As a result, the amount of current passing through the portion having the element unit 3B connected to the first portion 181 is lower than that passing through the portion having the element unit 3B connected to the second portion 182, and the temperature rise in the first portion 181 and the portion connected to it is reduced. Therefore, the electrochemical cell device according to this embodiment improves the durability of the conductive member 18 and the cell stack device 10B.

[0097] In the above, the conductive members 91, 92 and the interconnector 93 are collectively described as the conductive member 18, but the interconnector 93, which is different from the conductive members 91, 92, may be used as a third conductive member, and the conductive members 91, 92 may be connected in parallel.

[0098] Fifth Embodiment FIG. 14 is a longitudinal cross-sectional view showing an example of a conductive member included in an electrochemical cell device according to a fifth embodiment. As shown in FIG. 14 , a cell stack device 10C may include a first conductive member 18A and a second conductive member 18B having different resistivities as the conductive member 18. The resistivity of the second conductive member 18B is lower than that of the first conductive member 18A, and the first conductive member 18A and the second conductive member 18B are disposed between adjacent cells 1. Even when the first conductive member 18A and the second conductive member 18B having different resistivities are used as the conductive member 18, the temperature rise in the first conductive member 18A and the cells 1 connected thereto is reduced. Therefore, the electrochemical cell device according to this embodiment improves the durability of the conductive member 18 and the cell stack device 10C.

[0099] 15A is a cross-sectional view showing an example of an electrochemical cell included in an electrochemical cell device according to a sixth embodiment, and FIGS. 15B and 15C are cross-sectional views showing other examples of the electrochemical cell included in the electrochemical cell device according to the sixth embodiment.

[0100] As shown in FIGS. 15A to 15C , 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 location in contact with the anode layer 5 of the element section 3C, 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 plates. The material of the metal plate may contain chromium. The metal plate 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.

[0101] 15A, the side surfaces of the anode layer 5 are covered with a solid electrolyte layer 6, which airtightly seals a gas flow channel 2a through which the fuel gas flows. As shown in Fig. 15B, the side surfaces of the anode layer 5 may be covered and sealed with a dense sealant 9 containing glass or ceramic. The sealant 9 covering the side surfaces of the anode layer 5 may have electrical insulation properties.

[0102] 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. 15C.

[0103] In the sixth 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.

[0104] In the sixth embodiment, the support substrate 2 (conductive member 18) also has a first portion 181 and a second portion 182 with different resistivities. As in the electrochemical cell devices according to the first to fourth embodiments, the support substrate 2 (conductive member 18) may have the first portion 181 located in the portion 1a of the cell 1 that is at a high temperature, and the second portion 182 located in the portion 1b of the cell 1 that is at a relatively low temperature. Because the resistivity of the first portion 181 is greater than that of the second portion 182, the amount of current flowing through the portion 1a of the cell 1 connected to the first portion 181 is less than that of the portion 1b of the cell 1 connected to the second portion 182, thereby reducing the temperature rise in the first portion 181 and the portion 1a. Therefore, the electrochemical cell device according to this embodiment improves the durability of the support substrate 2 (conductive member 18) and the cell stack device 10. In Figures 15A to 15C, the part 1a of the cell 1 that becomes hot is shown as being the part near the center of the element part 3C as in the second embodiment, but for example, the part 1a of the cell 1 that becomes hot may be the part near the fuel gas outlet side as in the first embodiment.

[0105] Experimental Example 1 A cell stack device 10 (cell stack 11) shown in FIG. 5 was fabricated. The size of the cells 1 was a hollow flat plate measuring 170 mm (length direction L) × 27 mm (width direction W) × 2.3 mm (thickness direction T). The shape of the conductive member 18 was comb-like as shown in FIGS. 4 and 5 , with the first portion 181 and the second portion 182 having the same shape. Specifically, the conductive member 18 was fabricated so that the contact area between the cells 1 and the connection portions 18a, 18b was 21 mm × 0.8 mm × 60 pieces, of which 30 pieces were the first portion 181 and 30 pieces were the second portion 182. The conductive member 18 shown in FIG. 6A was used. The cell stack 11 had 32 cells 1, and the temperature difference was evaluated for the cells 1 located in the center of the cell stack 11. The temperature of cell 1 was measured by placing thermocouples at each part of cell 1 corresponding to first part 181 and second part 182, with the length l of the longitudinal direction L of conductive member 18 as the reference, and with a position approximately l / 3 away from the end on the outlet side as the first part 181 and a position approximately l / 3 away from the end on the supply side as the second part 182.

[0106] <Experimental Example 2> The temperature difference was evaluated in the cell 1 located in the center of the cell stack 11 fabricated in the same manner as in Experimental Example 1, except that the cell stack device 10 shown in FIG. 9 was used instead of the cell stack device 10 shown in FIG. 5.

[0107] <Experimental Example 3> The temperature difference was evaluated in the cell 1 located at the center of the cell stack 11 fabricated in the same manner as in Experimental Example 1, except that a conductive member 18 with a uniform resistivity was used instead of the cell stack device 10 shown in Figure 5.

[0108] Experimental Example 4 A cell stack device 10B shown in FIG. 13 was fabricated. The size of the cell 1 was 200 mm × 200 mm × 3.2 mm. The shape of the conductive member 18 was such that the contact area of ​​the first portion 181 (140 mm × 140 mm) and the second portion 182 (the remaining portion excluding the first portion 181) were the same. The cell stack device 10B had 20 cells 1, and the temperature difference was evaluated for the cell 1 located in the center of the cell stack device 10B. The temperature of the cell 1 was measured using thermocouples placed 30 mm away from the center P1 and 80 mm away from the center P.

[0109] <Experimental Example 5> Instead of the cell stack device 10B shown in Figure 13, a cell stack device 10C shown in Figure 14 was fabricated in the same manner as in Experimental Example 4, and the temperature difference was evaluated in the cell 1 located in the center of the cell stack device 10C.

[0110] <Experimental Example 6> The temperature difference was evaluated in cell 1 located in the center of a cell stack device fabricated in the same manner as in Experimental Example 4, except that a conductive member 18 with a uniform resistivity was used instead of the cell stack device 10B shown in Figure 13.

[0111] Figure 16 is a diagram comparing the durability of electrochemical cell devices. Acceleration tests were conducted at test temperatures of 950°C, 900°C, and 850°C for the temperature of the fuel gas supplied to the cell, and the time it took for the voltage drop from the initial value to reach 10% was measured. Specifically, the current density of each cell stack device set at each test temperature was 0.4 A / cm. ２The temperature of each cell stack device was adjusted to 750°C, and every 100 hours, the temperature of each cell stack device was lowered from the test temperature to 750°C, and voltage measurements were performed. After voltage measurements, each cell stack device was set back to the test temperature, and the accelerated test was continued. At each test temperature, an acceleration coefficient was calculated from the time it took for the measured voltage to drop to a value 10% lower than the initial value, and the time it took for the voltage to drop to a value 10% lower than the initial value when continuously operated at 750°C (endurance time) was estimated. In Figure 16, the durability was evaluated by calculating the relative endurance time based on Experimental Examples 3 and 6.

[0112] 16 , the durability of both Experimental Examples 1 and 2 was improved compared to Experimental Example 3. The durability of both Experimental Examples 4 and 5 was improved compared to Experimental Example 6. In this way, the conductive member 18 according to each embodiment improved durability, and the durability of the cell stack using the conductive member 18 was also improved.

[0113] [Other Embodiments] In the above-described embodiments, a fuel cell, a fuel cell stack device, a fuel cell module, and a fuel cell device are shown as examples of 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 first electrode layer and a second electrode layer, and decomposes water vapor into hydrogen and oxygen, or carbon dioxide into carbon monoxide and oxygen, when supplied with electric power. Such an electrolytic cell, electrolytic cell stack device, electrolytic module, and electrolytic device have high durability.

[0114] 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.

[0115] As described above, the conductive member 18 according to the embodiment has the first portion 181 and the second portion 182 having a resistivity different from that of the first portion 181. This makes it possible to provide a conductive member 18 with high durability.

[0116] Moreover, an electrochemical cell device (e.g., cell stack device 10) of the present disclosure includes the conductive member 18 described above and an electrochemical cell (e.g., cell 1) connected to the conductive member 18. The electrochemical cell has a first portion (e.g., portion 1a) connected to a first portion 181 and a second portion (e.g., portion 1b) connected to a second portion 182. The temperature of the first portion is higher than the temperature of the second portion, and the resistivity of the first portion 181 is higher than the resistivity of the second portion 182. This makes it possible to provide an electrochemical cell device with high durability.

[0117] Furthermore, an electrochemical cell device (e.g., cell stack device 10C) of the present disclosure includes a solid electrolyte layer, an electrochemical cell (e.g., cell 1), a first conductive member 18A, and a second conductive member 18B. The second conductive member 18B is spaced apart from the first conductive member 18A. The resistivity of the first conductive member 18A is different from the resistivity of the second conductive member 18B. This makes it possible to provide an electrochemical cell device with high durability.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] REFERENCE SIGNS LIST 1 Cell 10 Cell stack device 11 Cell stack 12 Fixing member 13 Fixing material 14 Supporting member 15 Support body 16 Gas tank 17 End current collecting member 18 Conductive member 100 Module 110 Module accommodating device 181 First portion 182 Second portion

Claims

1. The insulating layer has a first portion and a second portion having a different resistivity than the first portion. Conductive material.

2. The conductive member according to claim 1 ; an electrochemical cell connected to the conductive member; Equipped with the electrochemical cell having a first portion connected to the first location and a second portion connected to the second location; the temperature of the first portion is higher than the temperature of the second portion; The resistivity of the first portion is greater than the resistivity of the second portion. Electrochemical cell setup.

3. The conductive member according to claim 1 ; an electrochemical cell connected to the conductive member; Equipped with the electrochemical cell has a supply port through which a reactant gas is supplied and a discharge port through which the reactant gas is discharged, the first portion is connected to a portion of the electrochemical cell located near the outlet side; the second portion is connected to a portion of the electrochemical cell located near the supply inlet; The resistivity of the first portion is greater than the resistivity of the second portion. Electrochemical cell setup.

4. a cell stack including a plurality of electrochemical cells arranged in a first direction and the conductive member according to claim 1 electrically connecting the plurality of electrochemical cells; the cell stack includes a first cell stack and a second cell stack adjacent to each other in a second direction intersecting the first direction, In the first cell stack, the first portion is connected to a portion of the electrochemical cell located near the second cell stack; the second portion is connected to a portion of the electrochemical cell that is located away from the second cell stack; The resistivity of the first portion is greater than the resistivity of the second portion. Electrochemical cell setup.

5. The conductive member according to claim 1 ; an electrochemical cell connected to the conductive member; Equipped with the electrochemical cell has an element portion facing the conductive member, the first portion is connected near a center of the element portion, the second portion is connected near an outer edge of the element portion away from a center thereof, The resistivity of the first portion is greater than the resistivity of the second portion. Electrochemical cell setup.

6. an electrochemical cell having a solid electrolyte layer and a first electrode layer and a second electrode layer sandwiching the solid electrolyte layer; a first conductive member connected to the first electrode layer; a second conductive member connected to the first electrode layer and spaced apart from the first conductive member; Equipped with The resistivity of the first conductive member is different from the resistivity of the second conductive member. Electrochemical cell setup.

7. a third conductive member that connects the first conductive member and the second conductive member in parallel 7. The electrochemical cell device of claim 6.

8. An electrochemical cell device according to any one of claims 2 to 7; A container for housing the electrochemical cell device; A module comprising:

9. A module according to claim 8; Auxiliary equipment for operating the module; an exterior case that houses the module and the auxiliary equipment; A module housing device comprising: