Conductive member, electrochemical cell device, module, module housing device, conductive material, and conductive powder material

Abstract

Reduces the increase in internal resistance. The conductive member includes a substrate and a coating layer. The substrate contains chromium. The coating layer covers the substrate. The coating layer includes a conductive oxide and a first oxide, which is an oxide of a first element having a first ionization energy and a free energy of formation of an oxide whose absolute values ​​are smaller than those of chromium.

Description

[Technical Field]

[0001] This disclosure relates to conductive members, electrochemical cell devices, modules, module housing devices, slurries, methods for manufacturing conductive members, conductive materials, and conductive powder materials. [Background technology]

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

[0003] [Patent Document 1] International Publication No. 2009 / 131180 [Overview of the Initiative]

[0004] A conductive member according to one embodiment comprises a substrate and a coating layer. The substrate contains chromium. The coating layer covers the substrate. The coating layer contains a conductive oxide and a first oxide which is an oxide of a first element whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium.

[0005] Furthermore, the electrochemical cell apparatus of this disclosure comprises two or more electrochemical cells having element parts and the conductive member described above.

[0006] Furthermore, the module of this disclosure comprises the electrochemical cell apparatus described above and a housing container for housing the electrochemical cell apparatus.

[0007] Furthermore, the module housing device of this disclosure comprises the module described above, auxiliary equipment for operating the module, and an outer case for housing the module and the auxiliary equipment. [Brief explanation of the drawing]

[0008] [Figure 1A] Figure 1A is a cross-sectional view showing an example of an electrochemical cell according to the first embodiment. [Figure 1B] Figure 1B is a side view of an example of an electrochemical cell according to the first embodiment as viewed from the air electrode side. [Figure 1C] Figure 1C is a side view of an example of an electrochemical cell according to the first embodiment as viewed from the interconnector side. [Figure 2A] Figure 2A is a perspective view showing an example of an electrochemical cell device according to the first embodiment. [Figure 2B] Figure 2B is a cross-sectional view taken along the X-X line shown in Figure 2A. [Figure 2C] Figure 2C is a top view showing an example of an electrochemical cell device according to the first embodiment. [Figure 3] Figure 3 is a cross-sectional view showing an example of a conductive member according to the embodiment. [Figure 4A] Figure 4A is a cross-sectional view taken along the A-A line shown in Figure 3. [Figure 4B] Figure 4B is an enlarged view of the region B shown in Figure 4A. [Figure 4C] Figure 4C is an enlarged view of the coating layer shown in Figure 4B. [Figure 5] Figure 5 is an external perspective view showing an example of a module according to the first embodiment. [Figure 6] Figure 6 is an exploded perspective view schematically showing an example of a module housing device according to the first embodiment. [Figure 7A] Figure 7A is a cross-sectional view showing an electrochemical cell according to the second embodiment. [Figure 7B] Figure 7B is an enlarged cross-sectional view of a conductive member according to the second embodiment. [Figure 8A] Figure 8A is a perspective view showing an electrochemical cell according to the third embodiment. [Figure 8B] Figure 8B is a partial cross-sectional view of the electrochemical cell shown in Figure 8A. [Figure 9A]Figure 9A is a cross-sectional view showing an example of an electrochemical cell according to the fourth embodiment. [Figure 9B] Figure 9B is a cross-sectional view showing another example of an electrochemical cell according to the fourth embodiment. [Figure 9C] Figure 9C is a cross-sectional view showing another example of an electrochemical cell according to the fourth embodiment. [Figure 9D] Figure 9D is an enlarged view of region C shown in Figure 9A. [Figure 10] Figure 10 is a schematic diagram showing an example of a conductive powder material according to the embodiment. [Figure 11] Figure 11 is a schematic diagram showing an example of a slurry according to the embodiment. [Figure 12] Figure 12 is a flowchart illustrating an example of a method for manufacturing a conductive member according to the embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the conductive member, electrochemical cell apparatus, module, module housing apparatus, slurry, method for manufacturing the conductive member, conductive material, and conductive powder material disclosed in this application will be described in detail with reference to the attached drawings. However, this disclosure is not limited to the embodiments described below.

[0010] Furthermore, it should be noted that drawings are schematic representations, and the dimensional relationships and proportions of each element may differ from reality. Moreover, there may be discrepancies in dimensional relationships and proportions between drawings themselves.

[0011] [First Embodiment] <Configuration of an electrochemical cell> First, with reference to Figures 1A to 1C, an example of a solid oxide fuel cell will be used as an electrochemical cell according to the first embodiment. The electrochemical cell device may include a cell stack having multiple electrochemical cells. An electrochemical cell device having multiple electrochemical cells will simply be referred to as a cell stack device.

[0012] Figure 1A is a cross-sectional view showing an example of an electrochemical cell according to the first embodiment, Figure 1B is a side view of an example of an electrochemical cell according to the first embodiment viewed from the air electrode side, and Figure 1C is a side view of an example of an electrochemical cell according to the first embodiment viewed from the interconnector side. Figures 1A to 1C show enlarged views of some of the components of the electrochemical cell. Hereinafter, the electrochemical cell may simply be referred to as a cell.

[0013] In the examples shown in Figures 1A to 1C, cell 1 is a hollow, flat plate type, elongated in shape. As shown in Figure 1B, the overall shape of cell 1 when viewed from the side is, for example, a rectangle with a length of 5 cm to 50 cm along the length direction L, and a width direction W perpendicular to this length direction L with a length of 1 cm to 10 cm. The overall thickness T of cell 1 is 1 mm to 5 mm.

[0014] As shown in Figure 1A, cell 1 comprises a conductive support substrate 2, an element section 3, and an interconnector 4. The support substrate 2 is columnar in shape, having a pair of opposing flat surfaces n1, n2, and a pair of arc-shaped side surfaces m connecting the flat surfaces n1, n2.

[0015] The element unit 3 is provided on one flat surface n1 of the support substrate 2. This element unit 3 includes a fuel electrode 5, a solid electrolyte layer 6, and an air electrode 8. In the example shown in Figure 1A, an interconnector 4 is provided on the other 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 8.

[0016] Furthermore, as shown in Figure 1B, the air electrode 8 does not extend to the lower end of cell 1. At the lower end of cell 1, only the solid electrolyte layer 6 is exposed on the surface of the flat surface n1. Also, as shown in Figure 1C, the interconnector 4 may extend to the lower end of cell 1. At the lower end of cell 1, the interconnector 4 and the solid electrolyte layer 6 are exposed on the surface. Note that, as shown in Figure 1A, the solid electrolyte layer 6 is exposed on the surface of the pair of arc-shaped side surfaces m of cell 1. The interconnector 4 does not necessarily have to extend to the lower end of cell 1.

[0017] The following describes each component that makes up Cell 1.

[0018] The support substrate 2 has gas channels 2a inside through which gas flows. An example of the support substrate 2 shown in Figure 1A has six gas channels 2a. The support substrate 2 is gas permeable and allows the fuel gas flowing through the gas channels 2a to pass through to the fuel electrode 5. The support substrate 2 may also be conductive. A conductive support substrate 2 collects the electricity generated by the power generation element into the interconnector 4.

[0019] 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.

[0020] The fuel electrode 5 can be made from materials that are generally known. The fuel electrode 5 may be made from porous conductive ceramics, such as ceramics containing calcium oxide, magnesium oxide, or ZrO2 in which rare earth element oxides are in solid solution, and Ni and / or NiO. These rare earth element oxides may include, for example, multiple rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. Calcium oxide, magnesium oxide, or ZrO2 in which rare earth element oxides are in solid solution is sometimes referred to as stabilized zirconia. Stabilized zirconia also includes partially stabilized zirconia.

[0021] The solid electrolyte layer 6 is an electrolyte that facilitates the transfer of ions between the fuel electrode 5 and the air electrode 8. At the same time, the solid electrolyte layer 6 has gas barrier properties, making it difficult for leaks between the fuel gas and the oxygen-containing gas to occur.

[0022] The material of the solid electrolyte layer 6 may be, for example, ZrO2 in which 3 mol% to 15 mol% of rare earth element oxides are dissolved. The rare earth element oxides may include, 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, ZrO2 in which Yb, Sc, or Gd are dissolved, CeO2 in which La, Nd, or Yb are dissolved, BaZrO3 in which Sc or Yb are dissolved, or BaCeO3 in which Sc or Yb are dissolved.

[0023] The air electrode 8 is gas permeable. The open porosity of the air electrode 8 may be, for example, 20% or more, and particularly in the range of 30% to 50%.

[0024] The material of the air electrode 8 is not particularly limited as long as it is a material commonly used for air electrodes. For example, the material of the air electrode 8 may be a conductive ceramic such as a so-called ABO3 type perovskite oxide.

[0025] The material of the air electrode 8 may be, for example, a composite oxide in which Sr (strontium) and La (lanthanum) coexist at the A site. Examples of such composite oxides include La x Sr 1-x Co y Fe 1-y O3, La x Sr 1-x MnO3, La x Sr 1-x FeO3, La x Sr 1-x CoO3 and the like. Here, x is 0 < x < 1 and y is 0 < y < 1.

[0026] Also, when the element part 3 has the intermediate layer 7, the intermediate layer 7 has a function as a diffusion suppression layer. When elements such as Sr (strontium) contained in the air electrode 8 diffuse into the solid electrolyte layer 6, a resistance layer such as SrZrO3 is formed in such a solid electrolyte layer 6. The intermediate layer 7 suppresses the diffusion of Sr and makes it difficult for SrZrO3 and other oxides having electrical insulation to be formed.

[0027] The material of the intermediate layer 7 is not particularly limited as long as it is generally used for a Sr diffusion suppression layer. The material of the intermediate layer 7 includes, for example, cerium oxide (CeO2) in which rare earth elements excluding Ce (cerium) are solid-dissolved. As such rare earth elements, Gd (gadolinium), Sm (samarium), etc. are used.

[0028] Also, the interconnector 4 is dense and hardly causes leakage of the fuel gas flowing through the gas flow path 2a inside the support substrate 2 and the oxygen-containing gas flowing outside the support substrate 2. The interconnector 4 may have a relative density of 93% or more, particularly 95% or more.

[0029] The material for the interconnector 4 may be a lanthanum chromite-based perovskite oxide (LaCrO3-based oxide) or a lanthanum strontium titanium-based perovskite oxide (LaSrTiO3-based oxide). These materials are conductive and are resistant to reduction and oxidation even when in contact with fuel gas (hydrogen-containing gas) and oxygen-containing gas (such as air).

[0030] <Configuration of an electrochemical cell system> Next, the electrochemical cell apparatus according to this embodiment using the cell 1 described above will be explained with reference to Figures 2A to 2C. Figure 2A is a perspective view showing an example of the electrochemical cell apparatus according to the first embodiment, Figure 2B is a cross-sectional view of line XX shown in Figure 2A, and Figure 2C is a top view showing an example of the electrochemical cell apparatus according to the first embodiment.

[0031] As shown in Figure 2A, the cell stacking device 10 comprises a cell stack 11 having a plurality of cells 1 arranged (stacked) in the thickness direction T (see Figure 1A) of the cell 1, and a fixing member 12.

[0032] The fixing member 12 includes 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 includes a support body 15 and a gas tank 16. The support body 15 and the gas tank 16, which make up the support member 14, are made of, for example, metal.

[0033] As shown in Figure 2B, the support 15 has an insertion hole 15a into which the lower ends of the multiple cells 1 are inserted. The lower ends of the multiple cells 1 and the inner wall of the insertion hole 15a are joined together by a fixing member 13.

[0034] The gas tank 16 has an opening that supplies reaction gas to multiple cells 1 through an insertion hole 15a, and a groove 16a located around the opening. The outer end of the support 15 is joined to the gas tank 16 by a bonding material 21 that is filled into the groove 16a of the gas tank 16.

[0035] In the example shown in Figure 2A, fuel gas is stored in the internal space 22 formed by the support member 14, which is the support body 15, and the gas tank 16. A gas flow pipe 20 is connected to the gas tank 16. Fuel gas is supplied to the gas tank 16 through this gas flow pipe 20 and then supplied from the gas tank 16 to the gas flow path 2a (see Figure 1A) inside the cell 1. The fuel gas supplied to the gas tank 16 is generated in the reformer 102 (see Figure 5), which will be described later.

[0036] Hydrogen-rich fuel gas can be produced by steam reforming of the raw fuel. When fuel gas is produced by steam reforming, the fuel gas contains water vapor.

[0037] The example shown in Figure 2A comprises two rows of cell stacks 11, two support members 15, and a gas tank 16. Each of the two rows of cell stacks 11 has multiple cells 1. Each cell stack 11 is fixed to each support member 15. The gas tank 16 has two through holes on its top surface. Each support member 15 is positioned in each through hole. The internal space 22 is formed by the one gas tank 16 and the two support members 15.

[0038] The shape of the insertion hole 15a is, for example, oval when viewed from above. The length of the insertion hole 15a is, for example, greater than the distance between the two end current collectors 17 located at both ends of the cell stack 11, in the direction of arrangement of the cell 1, i.e., the thickness direction T. The width of the insertion hole 15a is, for example, greater than the length of the cell 1 in the width direction W (see Figure 1A).

[0039] As shown in Figure 2B, the joint between the inner wall of the insertion hole 15a and the lower end of the cell 1 is filled with and solidified with fixing material 13. This joins and fixes the inner wall of the insertion hole 15a to the lower ends of multiple cells 1, and also joins and fixes the lower ends of the cells 1 to each other. The gas passage 2a of each cell 1 communicates with the internal space 22 of the support member 14 at its lower end.

[0040] The fixing material 13 and the bonding material 21 can be made of materials with low conductivity, such as glass. Specific materials for the fixing material 13 and the bonding material 21 may include amorphous glass, and in particular, crystallized glass may be used.

[0041] As the crystallized glass, any of the following materials may be used, for example: SiO2-CaO system, MgO-B2O3 system, La2O3-B2O3-MgO system, La2O3-B2O3-ZnO system, SiO2-CaO-ZnO system, and in particular, SiO2-MgO system materials may be used.

[0042] Furthermore, as shown in Figure 2B, a conductive member 18 is interposed between adjacent cells 1 among the multiple cells 1. The conductive member 18 electrically connects the fuel electrode 5 of one adjacent cell 1 and the air electrode 8 of the other cell 1 in series. More specifically, the conductive member 18 connects the interconnector 4, which is electrically connected to the fuel electrode 5 of one adjacent cell 1, to the air electrode 8 of the other cell 1.

[0043] Furthermore, as shown in Figure 2B, the end current collector 17 is electrically connected to the outermost cell 1 in the arrangement direction of the multiple cells 1. The end current collector 17 is connected to a conductive part 19 that protrudes to the outside of the cell stack 11. The conductive part 19 collects the electricity generated by the cell 1 and draws it out to the outside. Note that the end current collector 17 is not shown in Figure 2A.

[0044] Furthermore, as shown in Figure 2C, the cell stack device 10 consists of two cell stacks 11A and 11B connected in series, functioning as a single battery. Therefore, the conductive part 19 of the cell stack device 10 is distinguished into a positive terminal 19A, a negative terminal 19B, and a connection terminal 19C.

[0045] The positive terminal 19A is the positive terminal when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the positive terminal end current collector 17 of the cell stack 11A. The negative terminal 19B is the negative terminal when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the negative terminal end current collector 17 of the cell stack 11B.

[0046] The connection terminal 19C electrically connects the negative terminal end current collector 17 of the cell stack 11A to the positive terminal end current collector 17 of the cell stack 11B.

[0047] <Details of conductive material> Next, the details of the conductive member 18 according to the first embodiment will be described with reference to Figures 3 to 4C. Figure 3 is a cross-sectional view showing an example of the conductive member according to the embodiment.

[0048] As shown in Figure 3, the conductive member 18 has a connecting portion 18a that connects to one cell 1 and a connecting portion 18b that connects to 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. In this way, the conductive member 18 can electrically connect adjacent cells 1 in the thickness direction T. Note that the shape of the cell 1 is simplified in Figure 3.

[0049] Furthermore, the connecting portions 18a and 18b have a surface 181 facing cell 1 and a surface 182 facing connecting portions 18b and 18a.

[0050] Figure 4A is a cross-sectional view along line AA shown in Figure 3. Figure 4B is an enlarged view of region B shown in Figure 4A.

[0051] The conductive member 18 extends along the length L of the cell 1. As shown in Figure 4A, multiple connection portions 18a and 18b of the conductive member 18 are located alternately along the length L of the cell 1. The conductive member 18 is in contact with the cell 1 at each of the connection portions 18a and 18b.

[0052] Furthermore, as shown in Figure 4B, the conductive member 18 has a base material 40 and a coating layer 43. The conductive member 18 also has opposing surfaces 181 and 182 with the base material 40 in between. The conductive member 18 also has surfaces 183 and 184 connecting surfaces 181 and 182.

[0053] The conductive member 18 (connecting portion 18b) is joined to the cell 1 via a bonding material 50. The bonding material 50 is located between the surface 181 of the conductive member 18 and the cell 1, and joins the conductive member 18 to the cell 1. Surfaces 182 to 184 are exposed to an oxidizing atmosphere, such as air.

[0054] Furthermore, the conductive member 18 has a base material 40 and a coating layer 43. The base material 40 is conductive and heat resistant. The base material 40 contains chromium. The base material 40 is, for example, stainless steel. The base material 40 may also contain, for example, a metal oxide.

[0055] Furthermore, the base material 40 may have a laminated structure. In the example shown in Figure 4B, the base material 40 has a first base material layer 41 and a second base material layer 42. The second base material layer 42 has a higher chromium content than the first base material layer 41. The second base material layer 42 contains, for example, chromium oxide (Cr2O3). By having the second base material layer 42 in this way, the durability of the conductive member 18 is increased. Note that the base material 40 may have the second base material layer 42 in part, or may not have the second base material layer 42 at all. Furthermore, the base material 40 may have a further laminated structure.

[0056] The coating layer 43 coats the substrate 40. The coating layer 43 has a conductive oxide. Such oxide may contain, for example, Mn (manganese) and Co (cobalt). The oxide may also contain elements other than Mn and Co, such as Zn (zinc) and Al (aluminum). Such oxide may be a composite oxide having a spinel structure. Examples of composite oxides having such a structure include ZnMnCoO4 and other Zn(Co x Mn 1-x )2O4(0 <x<1)、Mn 1.5 Co1.5 O4, MnCo2O4, CoMn2O4, etc. may also be used. In such composite oxides, for example, the ratio of Fe to the total metal elements contained in the composite oxide may be 60 atomic percent or less.

[0057] Furthermore, the coating layer 43 may contain oxides of elements whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium. Examples of such oxides of elements include Y2O3, CeO2, EuO, and PrO2. Hereinafter, elements whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium will be referred to as the first element, and oxides of the first element will be referred to as the first oxide. For example, the coating layer 43 contains one or more of the first oxides. The first oxide may also contain elements other than the first element, such as Gd (gadolinium), Sm (samarium), Yb (ytterbium), etc. In the first oxide, for example, the first element may be substituted with Gd, Sm, or Yb in a proportion of 30 atomic percent or less.

[0058] Thus, because the coating layer 43 contains the specific oxides and the first oxide described above, the second substrate layer 42 is less likely to grow, and the conductive member 18 is less likely to experience an increase in internal resistance. This reduces the degradation of the battery performance of cell 1.

[0059] Next, we will further explain the details of the coating layer 43 using Figure 4C. Figure 4C is an enlarged view of the coating layer shown in Figure 4B.

[0060] As shown in Figure 4C, the coating layer 43 may contain oxide particles 45 and first oxide particles 46. The oxide particles 45 have a conductive oxide. The oxide particles 45 may have a composite oxide having a spinel structure. The first oxide particles 46 have a first oxide.

[0061] The coating layer 43 may be a sintered body or a compacted powder. Furthermore, the coating layer 43 may be crystalline or amorphous. Also, a mixture of crystalline and amorphous phases may be present in the coating layer 43.

[0062] Furthermore, the coating layer 43 may contain 5% to 50% by volume of first oxide particles 46. By setting the content of first oxide particles 46 within this range, for example, the second substrate layer 42 becomes less likely to grow, and the internal resistance of the conductive member 18 becomes less likely to increase. This reduces the deterioration of the battery performance of cell 1. Note that the volume ratio (%) of the first oxide particles 46 is calculated by taking the volume of oxide particles 45 in the coating layer 43 as v 45 The volume of the first oxide particle 46 is v 46 When each of these is defined, (v 46 / (v 45 +v 46 It can be calculated as )) × 100.

[0063] Furthermore, the first oxide particles 46 of the coating layer 43 may have an average particle size of 0.1 μm or more and 5 μm or less. By setting the average particle size of the first oxide particles 46 within this range, for example, the second substrate layer 42 becomes less likely to grow, and the conductive member 18 is less likely to experience an increase in internal resistance. This reduces the deterioration of the battery performance of cell 1. The average particle size of the first oxide particles 46 may be 1 μm or less, and even 0.5 μm or less. The average particle size of the first oxide particles 46 may be smaller than the average particle size of the oxide particles 45. When the particle size of the first oxide particles 46 is small, the second substrate layer 42 tends to grow less easily.

[0064] The coating layer 43 may have a higher porosity in the portion furthest from the substrate 40 than in the portion closer to the substrate 40. The conductive member 18 may also have SiO2 between the first substrate layer 41 and the second substrate layer 42. The SiO2 may be in layered or particulate form. Furthermore, the surface of the second substrate layer 42 facing the first substrate layer 41, the surface facing the coating layer 43, or both may have a line-average roughness of about 0.1 μm to 3 μm. For reasons that are not entirely clear, a higher content of the first oxide particles 46 in the coating layer 43 tends to increase the line-average roughness of each of the above surfaces of the second substrate layer 42. If the surface roughness of the surface of the second substrate layer 42 facing the coating layer 43 is high, the coating layer 43 becomes less likely to peel off from the substrate 40. The second substrate layer 42 may have, for example, a wavy cross-sectional shape.

[0065] The spinel structure of the oxide particles 45 in the coating layer 43 can be confirmed, for example, by identifying the crystalline phase using an X-ray diffractometer (XRD) in a cross-section of the conductive member 18.

[0066] Furthermore, the content of the first oxide particles 46 in the coating layer 43 can be confirmed, for example, by mapping the first element in the cross-section of the conductive member 18 using HAADF-STEM (high-angle annular dark-field scanning transmission electron microscope), FIB-SEM (focused ion beam scanning electron microscope), or EPMA (electron probe microanalyzer). In addition, the average particle size of the first oxide particles 46 can be calculated as the equivalent circle diameter based on the results of observing the cross-section of the coating layer 43 with an SEM (scanning electron microscope).

[0067] The coating layer 43 can be formed by methods such as printing, immersion, thermal spraying, vapor deposition, electrodeposition, and sputtering. Alternatively, for example, a conductive material may be applied to the surface of the substrate 40, and then fired and sintered to form the coating layer 43.

[0068] The conductive member 18 may have an outer layer (not shown) that further covers the coating layer 43. The outer layer may be located between the coating layer 43 and the bonding material 50. The outer layer may be a conductive ceramic such as a so-called ABO3 type perovskite oxide, like the material of the air electrode 8 described above. The outer layer may or may not contain the first oxide. The coating layer 43 may contain a conductive perovskite oxide.

[0069] <module> Next, a module 100 according to the embodiment of this disclosure using the cell stack device 10 described above will be explained with reference to Figure 5. Figure 5 is an external perspective view of a module according to the first embodiment, showing the 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 housed inside has been taken out to the rear.

[0070] As shown in Figure 5, module 100 comprises a storage container 101 and a cell stack device 10 housed within the storage container 101. A reformer 102 is positioned above the cell stack device 10.

[0071] The reformer 102 reforms raw fuels such as natural gas and kerosene to produce fuel gas, which is then supplied to cell 1. The raw fuels are supplied to the reformer 102 through a raw fuel supply pipe 103. The reformer 102 may also include a vaporization section 102a for vaporizing water and a reforming section 102b. The reforming section 102b is equipped with a reforming catalyst (not shown) and reforms the raw fuels into fuel gas. Such a reformer 102 can perform steam reforming, which is a highly efficient reforming reaction.

[0072] The fuel gas generated in the reformer 102 is then supplied to the gas flow path 2a of cell 1 (see Figure 1A) through the gas flow pipe 20, the gas tank 16, and the support member 14.

[0073] Furthermore, in the module 100 with the above configuration, the temperature inside the module 100 during normal power generation is approximately 500 to 1000°C due to the combustion of gas and the power generation of cell 1.

[0074] In such a module 100, as described above, a cell stack device 10 that reduces the degradation of battery performance is housed within it, thereby making the module 100 capable of reducing the degradation of battery performance.

[0075] <Module housing device> Figure 6 is an exploded perspective view showing an example of a module housing device according to the first embodiment. The module housing device 110 according to this embodiment comprises an outer case 111, a module 100 shown in Figure 5, 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 Figure 6.

[0076] The outer casing 111 of the module housing device 110 shown in Figure 6 has support columns 112 and outer panels 113. Partition plates 114 divide the inside of the outer casing 111 into upper and lower sections. The space above the partition plates 114 inside the outer casing 111 is the module housing chamber 115 for housing the module 100, and the space below the partition plates 114 inside the outer casing 111 is the auxiliary equipment housing chamber 116 for housing the auxiliary equipment that operates the module 100. Note that in Figure 6, the auxiliary equipment housed in the auxiliary equipment housing chamber 116 is omitted from the illustration.

[0077] Furthermore, the partition plate 114 has an air circulation port 117 for allowing air from the auxiliary equipment storage room 116 to flow towards the module storage room 115. The outer panel 113 that constitutes the module storage room 115 has an exhaust port 118 for exhausting the air inside the module storage room 115.

[0078] In such a module housing device 110, as described above, a module 100 that reduces the degradation of battery performance is provided in the module housing chamber 115, thereby making the module housing device 110 capable of reducing the degradation of battery performance.

[0079] In the above embodiment, a case using a hollow flat support substrate was illustrated, but it can also be applied to a cell stacking device using a cylindrical support substrate.

[0080] [Second Embodiment] Next, the cell and cell stack apparatus according to the second embodiment will be described with reference to Figures 7A and 7B.

[0081] In the above-described embodiment, a so-called "vertical stripe type" was exemplified, in which only one element section including a fuel electrode, a solid electrolyte layer, and an air electrode is provided on the surface of the support substrate. However, this can also be applied to a horizontal stripe type cell stack device in which a so-called "horizontal stripe type" of cell is arranged, in which element sections are provided at multiple locations on the surface of the support substrate that are far apart from each other, and adjacent element sections are electrically connected.

[0082] Figure 7A is a cross-sectional view showing an electrochemical cell according to a second embodiment. The cell stack device 10A has a plurality of cells 1A extending in the longitudinal direction L from a pipe 73 through which fuel gas flows. Each cell 1A has a plurality of element sections 3A on a support substrate 2. Inside the support substrate 2, there is a gas flow path 2a through which the gas from the pipe 73 flows. Each element section 3A on the support substrate 2 is electrically connected by a connecting layer (not shown). The plurality of cells 1A are electrically connected to each other via a conductive member 18. The conductive member 18 is located between the element sections 3A of each cell 1A and connects adjacent cells 1A. Specifically, it electrically connects the air electrode of the element section 3A of one of the adjacent cells 1A to an interconnector that is electrically connected to the fuel electrode of the element section 3A of the other cell 1A.

[0083] Figure 7B is an enlarged cross-sectional view of a conductive member according to the second embodiment. As shown in Figure 7B, the conductive member 18 is joined to adjacent cells 1A via a bonding material 50. The conductive member 18 also has opposing surfaces 181 and 182 with the base material 40 in between. The conductive member 18 also has surfaces 183 and 184 connecting surfaces 181 and 182.

[0084] The conductive member 18 is joined to the cell 1A via a bonding material 50. The bonding material 50 is located between the surface 181 of the conductive member 18 and the element portion 3A of one cell 1A, and between the surface 182 of the conductive member 18 and the element portion 3A of the other cell 1A, and joins the conductive member 18 to a pair of cells 1A facing each other with the conductive member 18 in between. Also, surfaces 183 and 184 are exposed to an oxidizing atmosphere, such as air.

[0085] The conductive member 18 comprises a base material 40 and a coating layer 43. The base material 40 also comprises a first base material layer 41 and a second base material layer 42. Each part constituting the conductive member 18 can be made of a material such as the conductive member 18 according to the first embodiment described above.

[0086] The coating layer 43 is located between the substrate 40 and the element portion 3A of the cell 1A. The coating layer 43 has a conductive oxide. The coating layer 43 may have, for example, a composite oxide having a spinel structure. Such a composite oxide may have, for example, a ratio of Fe to the total metal elements contained in the composite oxide of 60 atomic percent or less. The coating layer 43 may contain composite oxide particles having such a composite oxide.

[0087] Furthermore, the coating layer 43 has a first oxide which is an oxide of a first element whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium. The coating layer 43 may also contain first oxide particles having such a first oxide.

[0088] Thus, because the coating layer 43 contains the specific oxides described above, the second base layer 42 is less likely to grow, and the conductive member 18 is less likely to experience an increase in internal resistance due to the growth of the second base layer 42. As a result, the battery performance of cell 1A is less likely to deteriorate, and the deterioration of the battery performance of the cell stack device 10A can be reduced. The conductive member 18 may also have an outer layer (not shown) that further covers the coating layer 43. The outer layer may be located between the coating layer 43 and the bonding material 50. The outer layer may be a conductive ceramic such as a so-called ABO3 type perovskite oxide, like the material of the air electrode 8 described above.

[0089] [Third Embodiment] Figure 8A is a perspective view showing an electrochemical cell according to the third embodiment. Figure 8B is a partial cross-sectional view of the electrochemical cell shown in Figure 8A.

[0090] As shown in Figure 8A, cell 1B, which is a planar electrochemical cell, has an element section 3B in which a fuel electrode 5, a solid electrolyte layer 6, and an air electrode 8 are stacked. In a cell stack device in which multiple planar cells are stacked, for example, multiple cells 1B are electrically connected by conductive members 91 and 92, which are metal layers adjacent to each other. The conductive members 91 and 92 electrically connect adjacent cells 1B and also have gas channels that supply gas to the fuel electrode 5 or the air electrode 8.

[0091] As shown in Figure 8B, in this embodiment, the conductive member 92 has a gas channel 93 for supplying gas to the air electrode 8. The conductive member 92 is joined to the element portion 3B (air electrode 8) via a bonding material 50. Alternatively, the conductive member 92 may be in direct contact with the element portion 3B without using the bonding material 50. In other words, in this modified example, the conductive member 92 may be directly connected to the element portion 3B without using the bonding material 50.

[0092] The conductive member 92 has a base material 40 and a coating layer 43. The base material 40 also has a first base material layer 41 and a second base material layer 42. Each part constituting the conductive member 92 can be made of a material such as the conductive member 18 described above.

[0093] The coating layer 43 is located between the substrate 40 and the element portion 3B (air electrode 8). The coating layer 43 has a conductive oxide. The coating layer 43 may have, for example, a composite oxide having a spinel structure. The coating layer 43 also has a first oxide which is an oxide of a first element whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium. The coating layer 43 contains, for example, one or more of these first elements.

[0094] Thus, because the coating layer 43 has the specific oxides described above, the second substrate layer 42 is less likely to grow, and the conductive member 18 is less likely to experience an increase in internal resistance. As a result, the battery performance of cell 1B is less likely to deteriorate, and the degradation of the battery performance of the electrochemical cell device can be reduced.

[0095] [Fourth Embodiment] Figure 9A is a cross-sectional view showing an example of an electrochemical cell according to the fourth embodiment. Figures 9B and 9C are cross-sectional views showing other examples of an electrochemical cell according to the fourth embodiment. Figure 9D is an enlarged view of region C shown in Figure 9A. Note that Figure 9D can also be applied to the examples in Figures 9B and 9C.

[0096] As shown in Figures 9A to 9C, cell 1C has an element section 3C in which a fuel electrode 5, a solid electrolyte layer 6, and an air electrode 8 are laminated, and a support substrate 2. The support substrate 2 has through holes or pores in the portion of the element section 3 that is in contact with the fuel electrode 5, and also has 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 be composed of, for example, one or more metal plates. The material of the metal plates may contain chromium. The metal plates may have a conductive coating layer. The support substrate 2 is a conductive member that electrically connects adjacent cells 1C. The element section 3C may be formed directly on the support substrate 2, or it may be joined to the support substrate 2 by a bonding material.

[0097] In the example shown in Figure 9A, the side surface of the fuel electrode 5 is covered with a solid electrolyte layer 6, hermetically sealing the gas passage 2a through which the fuel gas flows. As shown in Figure 9B, the side surface of the fuel electrode 5 may also be covered and sealed with a sealing material 9 made of dense glass or ceramic. The sealing material 9 covering the side surface of the fuel electrode 5 may have electrical insulating properties.

[0098] Furthermore, the gas flow path 2a of the support substrate 2 may be formed by a member 120 having irregularities, as shown in Figure 9C.

[0099] In the fourth embodiment, member 120 is joined to the air electrode 8 of another adjacent cell 1C via other conductive members such as an inter-cell connecting member 60 and a bonding material 50. Alternatively, member 120 may be in direct contact with the air electrode 8 of another cell 1C without the need for other conductive members.

[0100] As shown in Figure 9D, member 120 has a base material 40 and a coating layer 43. The base material 40 also has a first base material layer 41 and a second base material layer 42. Each part constituting member 120 can be made of a material such as the conductive member 18 described above. Although a detailed explanation with illustrations is omitted, the inter-cell connecting member 60 may also be a conductive member 18 having a base material 40 and a coating layer 43.

[0101] The coating layer 43 is located between the substrate 40 and the air electrode 8 of another adjacent cell 1C. The coating layer 43 has a conductive oxide. The coating layer 43 may have, for example, a composite oxide having a spinel structure. Alternatively, the coating layer 43 may have a first oxide which is an oxide of a first element whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium. The coating layer 43 may contain, for example, one or more such first elements.

[0102] Thus, because the coating layer 43 has the specific oxides described above, the second base layer 42 is less likely to grow, and the internal resistance of the component 120 is less likely to increase. As a result, the battery performance of cell 1C is less likely to deteriorate, and the deterioration of the battery performance of the electrochemical cell device can be reduced.

[0103] <Other variations> Next, other modifications of the embodiment will be described.

[0104] In the above embodiment, a fuel cell cell, fuel cell cell stack, fuel cell module, and fuel cell device were shown as examples of "electrochemical cell," "electrochemical cell device," "module," and "module housing device," but other examples may be an electrolytic cell, electrolytic cell stack, electrolytic module, and electrolytic device, respectively.

[0105] Furthermore, conductive materials having the specific oxides described above can also be used for other applications.

[0106] Figure 10 is a schematic diagram showing an example of a conductive powder material according to the embodiment. As shown in Figure 10, the conductive powder material 200 has oxide particles 45 and first oxide particles 46.

[0107] The oxide particles 45 have a conductive oxide. The oxide particles 45 may have an oxide containing, for example, Mn (manganese) and Co (cobalt). The oxide particles 45 may also contain elements other than Mn and Co, such as Zn (zinc), Fe (iron), and Al (aluminum). The oxide particles 45 may have a composite oxide having a spinel structure. Examples of composite oxides having such a structure include ZnMnCoO4 and other Zn(Co x Mn 1-x )2O4(0 <x<1)、Mn 1.5 Co 1.5 O4, MnCo2O4, CoMn2O4, etc. may also be used. In such composite oxides, for example, the ratio of Fe to the total metal elements contained in the composite oxide may be 60 atomic percent or less.

[0108] Furthermore, the first oxide particles 46 have an oxide of a first element whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium. Examples of such first oxides are Y2O3, CeO2, EuO, and PrO2. The conductive powder material 200 contains, for example, one or more of the first oxides. The first oxide may also contain elements other than the first element, such as Gd (gadolinium), Sm (samarium), Yb (ytterbium), etc. The first oxide may be substituted with Gd, Sm, or Yb in a proportion of 30 atomic percent or less of the first element.

[0109] Thus, the conductive powder material 200 having the specific oxide and the first oxide as described above can be used, for example, as a conductive raw material when forming a conductive layer or wiring by printing, immersion, thermal spraying, electrodeposition, etc.

[0110] Figure 11 is a schematic diagram showing an example of a slurry according to the embodiment.

[0111] As shown in Figure 11, the slurry 300 comprises oxide particles 45, first oxide particles 46, anionic resin 47, and dispersion medium 48.

[0112] The oxide particles 45 have a conductive oxide. The oxide particles 45 may have an oxide containing, for example, Mn (manganese) and Co (cobalt). The oxide particles 45 may also contain elements other than Mn and Co, such as Zn (zinc), Fe (iron), and Al (aluminum). The oxide particles 45 may have a composite oxide having a spinel structure. Examples of composite oxides having such a structure include ZnMnCoO4 and other Zn(Co x Mn 1-x )2O4(0 <x<1)、Mn 1.5 Co 1.5 O4, MnCo2O4, CoMn2O4, etc. may also be used. In such composite oxides, for example, the ratio of Fe to the total metal elements contained in the composite oxide may be 60 atomic percent or less.

[0113] Furthermore, the first oxide particles 46 have an oxide of a first element whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium. Examples of such first oxides are Y2O3, CeO2, EuO, and PrO2. The slurry 300 contains, for example, one or more of these first oxides.

[0114] Furthermore, the anionic resin 47 may be, for example, a dispersion aid that assists in the uniform dispersion of oxide particles 45 and first oxide particles 46. Such anionic resin 47 is removed together with the dispersion medium 48 by firing at a predetermined temperature or higher. Note that the slurry 300 does not necessarily have to contain the anionic resin 47.

[0115] Furthermore, the dispersion medium 48 is fluid and disperses the solid components of the slurry 300. The dispersion medium 48 may be, for example, a volatile organic solvent or an alcohol. The dispersion medium 48 may also contain, for example, water. In addition, the dispersion medium 48 may dissolve at least a portion of the solid components of the slurry 300.

[0116] Thus, the slurry 300 having the specific oxide and primary oxide described above can be used, for example, as a slurry when forming a conductive layer by electrodeposition.

[0117] <Method for manufacturing conductive materials> Figure 12 is a flowchart illustrating an example of a method for manufacturing a conductive member according to the embodiment.

[0118] First, a slurry is prepared containing a conductive oxide, a primary oxide which is an oxide of a first element whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium, and an anionic resin (step S11).

[0119] Next, a coating film is formed on the surface of the chromium-containing substrate (step S12). The coating film comprises the main component of the slurry prepared in step S11, namely a conductive oxide, a first oxide which is an oxide of a first element whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium, and an anionic resin. Such a coating film may be formed, for example, by electrodeposition.

[0120] Next, the substrate on which the coating film has been formed is fired to remove the anionic resin (step S13). Furthermore, the fired substrate is sintered to form a coating layer that covers the substrate (step S14). Steps S13 and S14 may be performed continuously as a series of processes.

[0121] Although the present disclosure has been described in detail above, this disclosure is not limited to the embodiments described above, and various modifications and improvements are possible without departing from the gist of this disclosure.

[0122] As described above, the conductive member 18 according to this embodiment comprises a chromium-containing substrate 40 and a coating layer 43 covering the substrate 40. The coating layer 43 contains a conductive oxide and a first oxide which is an oxide of a first element whose absolute values ​​of first ionization energy and free formation energy of the oxide are smaller than those of chromium. This makes it possible to create a conductive member 18 that reduces the decrease in battery performance due to an increase in internal resistance.

[0123] Furthermore, the electrochemical cell device according to the embodiment (for example, the cell stack device 10) comprises two or more electrochemical cells (for example, cell 1) having element parts 3, and the conductive member 18 described above. This makes it possible to provide an electrochemical cell device that reduces the decrease in battery performance due to the increase in internal resistance.

[0124] Furthermore, the module 100 according to the embodiment comprises the electrochemical cell device described above (for example, the cell stack device 10) and a housing container 101 for housing the electrochemical cell device. This makes it possible to create a module 100 that reduces the decrease in battery performance due to the increase in internal resistance.

[0125] Furthermore, the module housing device 110 according to the embodiment comprises the module 100 described above, auxiliary equipment for operating the module 100, and an outer case for housing the module 100 and the auxiliary equipment. This makes it possible to create a module housing device 110 that reduces the decrease in battery performance due to the increase in internal resistance.

[0126] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0127] Cells 1,1A,1B 3,3A,3B element part 5 Fuel electrode 6 Solid electrolyte layer 7. Middle Class 8. Air pole 10-cell stack device 11-cell stack 12 Fixing member 13 Fixing material 14 Support Member 15 Support 16 gas tanks 17 End current collector 18 Conductive members 100 modules 110 Module housing device

Claims

1. A chromium-containing metal substrate; a coating layer covering the substrate; Equipped with The coating layer includes conductive oxide particles and first oxide particles that are an oxide of a first element having a first ionization energy and an absolute value of a free energy of formation of an oxide that are smaller than those of chromium. Conductive material.

2. The coating layer is a sintered body containing the oxide particles and the first oxide particles. The conductive member according to claim 1 .

3. The coating layer contains 5 volume % or more and 50 volume % or less of the first oxide particles. The conductive member according to claim 2 .

4. The first oxide particles have an average particle size of 0.1 μm or more and 5 μm or less. The conductive member according to claim 2 .

5. The conductive oxide includes a composite oxide having a perovskite structure. The conductive member according to claim 1 .

6. Two or more electrochemical cells each having an element portion; The conductive member according to any one of claims 1 to 5. An electrochemical cell device comprising:

7. The electrochemical cell device according to claim 6 ; A container for housing the electrochemical cell device; A module comprising:

8. A module according to claim 7; Auxiliary equipment for operating the module; an exterior case that houses the module and the auxiliary equipment; A module housing device comprising:

9. Conductive oxide particles; a first oxide particle which is an oxide of a first element having a first ionization energy and an absolute value of a free energy of formation of an oxide smaller than those of chromium; It is a sintered body containing Conductive materials.

10. The conductive oxide includes a composite oxide having a perovskite structure. The conductive material according to claim 9.

11. The composite oxide is a composite oxide containing Sr (strontium) and La (lanthanum) in the A site, or a lanthanum chromite-based composite oxide. The conductive material according to claim 10.

12. A conductive oxide particle containing Zn or La, a first oxide particle containing a first oxide which is an oxide of a first element having a first ionization energy and an absolute value of a free energy of formation of an oxide smaller than those of chromium; A conductive powder material having

13. The conductive oxide includes a composite oxide having a perovskite structure.

13. The conductive powder material of claim 12.

14. The composite oxide is a composite oxide containing Sr (strontium) and La (lanthanum) in the A site, or a lanthanum chromite-based composite oxide.

14. The conductive powder material of claim 13.

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