Electrochemical cells, electrochemical cell apparatus, modules, and module housings

Abstract

A composite member comprises a polycrystalline first member, a second member, and a boundary part. The first member contains a first material. The second member contains a second material different from the first material. The boundary part is positioned between the first member and the second member and contains the first material and the second material. The boundary part has a first portion and a second portion. The second portion is thicker than the first portion.

Description

[Technical Field]

[0001] This disclosure , electric This relates to gaseous chemical cells, electrochemical cell systems, modules, and module housing systems. [Background technology]

[0002] In recent years, various fuel cell cell stack devices, which are equipped with multiple fuel cell cells, have been proposed as a next-generation energy source. 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] Japanese Patent Publication No. 2016-81718 [Patent Document 2] Japanese Patent Publication No. 2013-41809 [Patent Document 3] Japanese Patent Publication No. 2012-23017 [Overview of the project]

[0004] A composite member according to one embodiment comprises a polycrystalline first member, a second member, and a boundary portion. The first member contains a first material. The second member contains a second material different from the first material. The boundary portion is located between the first member and the second member and contains the first material and the second material. The boundary portion has a first portion and a second portion. The second portion is thicker than the first portion.

[0005] Furthermore, the electrochemical cell of this disclosure comprises the composite member described above and a first electrode layer and a second electrode layer facing each other with the composite member in between.

[0006] Furthermore, the electrochemical cell apparatus of this disclosure has a cell stack comprising the electrochemical cells described above.

[0007] Furthermore, the module of this disclosure comprises the electrochemical cell apparatus described above and a housing container for housing the electrochemical cell apparatus.

[0008] 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]

[0009] [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, viewed from the air pole layer side. [Figure 1C] Figure 1C is a side view of an example of an electrochemical cell according to the first embodiment, as seen from the interconnector side. [Figure 2A] Figure 2A is a perspective view showing an example of an electrochemical cell apparatus according to the first embodiment. [Figure 2B] Figure 2B is a cross-sectional view of the XX line shown in Figure 2A. [Figure 2C] Figure 2C is a top view showing an example of an electrochemical cell apparatus according to the first embodiment. [Figure 3] Figure 3 is a cross-sectional view showing an example of the vicinity of the boundary shown in Figure 1A. [Figure 4A] Figure 4A is a plan view showing an example of the boundary shown in Figure 3. [Figure 4B] Figure 4B is a plan view showing another example of the boundary shown in Figure 3. [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 example of an electrochemical cell apparatus according to the second embodiment. [Figure 7B]FIG. 7B is a cross-sectional view showing an electrochemical cell according to the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing an example of the vicinity of the boundary portion shown in FIG. 7B. [Figure 9] FIG. 9 is a perspective view showing an example of an electrochemical cell according to the third embodiment. [Figure 10] FIG. 10 is a partial cross-sectional view of the electrochemical cell shown in FIG. 9. [Figure 11] FIG. 11 is a cross-sectional view showing an example of the vicinity of the boundary portion shown in FIG. 10. [Figure 12A] FIG. 12A is a cross-sectional view showing an example of an electrochemical cell according to the fourth embodiment. [Figure 12B] FIG. 12B is a cross-sectional view showing another example of an electrochemical cell according to the fourth embodiment. [Figure 12C] FIG. 12C is a cross-sectional view showing another example of an electrochemical cell according to the fourth embodiment. [Figure 13] FIG. 13 is a cross-sectional view showing an example of the vicinity of the boundary portion shown in FIG. 12A.

MODE FOR CARRYING OUT THE INVENTION

[0010] In the above fuel cell stack device, for example, there is room for improvement in terms of improving durability.

[0011] Therefore, it is possible to improve durability Electric There is an expectation for the provision of an electrochemical cell, an electrochemical cell device, a module, and a module housing device.

[0012] Hereinafter, embodiments of the electrochemical cell, the electrochemical cell device, the module, and the module housing device disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that this disclosure is not limited by the embodiments shown below. Electric

[0013] 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.

[0014] [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.

[0015] 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. 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.

[0016] 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, for example, 1 cm to 10 cm. The overall thickness T of cell 1 is, for example, 1 mm to 5 mm.

[0017] 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, a first surface n1 and a second surface n2, and a pair of arc-shaped side surfaces m connecting the first surface n1 and the second surface n2.

[0018] The element portion 3 is located on the first surface n1 of the support substrate 2. This element portion 3 includes a fuel electrode layer 5, a solid electrolyte layer 6, an intermediate layer 7, and an air electrode layer 8.

[0019] Furthermore, as shown in Figure 1B, the air electrode layer 8 does not extend to the bottom end of cell 1. At the bottom end of cell 1, only the solid electrolyte layer 6 is exposed on the surface of the first surface n1. Also, as shown in Figure 1C, the interconnector 4 may extend to the bottom end of cell 1. At the bottom 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 bottom end of cell 1.

[0020] The following describes each component that makes up Cell 1.

[0021] The support substrate 2 has gas channels 2a 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 layer 5. The support substrate 2 may also be conductive. A conductive support substrate 2 collects the electricity generated in the element section 3 and sends it to the interconnector 4.

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

[0023] The fuel electrode layer 5 can be made of materials that are generally known. The fuel electrode layer 5 may be made of 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 multiple rare earth elements selected from, for example, 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. The stabilized zirconia may include partially stabilized zirconia. The fuel electrode layer 5 is an example of a first electrode layer.

[0024] The solid electrolyte layer 6 is an electrolyte that facilitates the transfer of 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, making it difficult for leaks between the fuel gas and the oxygen-containing gas to occur.

[0025] The solid electrolyte layer 6 contains Zr (zirconium) as the first material. 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, or it may contain BaZrO3 in which Sc or Yb are dissolved. The solid electrolyte layer 6 is an example of the first component.

[0026] The intermediate layer 7 functions as a diffusion-inhibiting layer. The intermediate layer 7 makes it difficult for Sr (strontium) contained in the air electrode layer 8 to diffuse into the solid electrolyte layer 6, thereby making it difficult for a SrZrO3 resistance layer to form in the solid electrolyte layer 6.

[0027] The intermediate layer 7 contains Ce (cerium) as the second material. The material of the intermediate layer 7 includes, for example, cerium oxide (CeO2) in which rare earth elements other than Ce (cerium) are solid-dissolved. Such rare earth elements may include Gd (gadolinium), Sm (samarium), etc. The intermediate layer 7 is an example of the second member.

[0028] The air electrode layer 8 has gas permeability. The open porosity of the air electrode layer 8 may be, for example, 20% or more, particularly in the range of 30% to 50%.

[0029] The material of the air electrode layer 8 is not particularly limited as long as it is generally used for air electrodes. The material of the air electrode layer 8 may be, for example, a conductive ceramic such as a so-called ABO3-type perovskite oxide.

[0030] The material of the air electrode layer 8 may be, for example, a composite oxide in which Sr (strontium) and La (lanthanum) coexist at the A site. Examples of such composite oxides include La x Sr 1-x Co y Fe 1-y O3, La x Sr 1-x MnO3, La x Sr 1-x FeO3, La x Sr 1-x CoO3, etc. Here, x is 0 < x < 1 and y is 0 < y < 1. The air electrode layer 8 is an example of the second electrode layer.

[0031] Further, the interconnector 4 is dense and is less likely to cause leakage of the fuel gas flowing through the gas flow path 2a located 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.

[0032] The interconnector 4 may be made of materials such as lanthanum chromite-based perovskite oxides (LaCrO3-based oxides) or lanthanum strontium titanium-based perovskite oxides (LaSrTiO3-based oxides). These materials are electrically conductive and are resistant to reduction and oxidation even when in contact with fuel gases such as hydrogen-containing gases and oxygen-containing gases such as air.

[0033] Furthermore, the element portion 3 includes a boundary portion 9 located between the solid electrolyte layer 6 and the intermediate layer 7. Details of the boundary portion 9 will be described later.

[0034] <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 taken along line XX shown in Figure 2A. Figure 2C is a top view showing an example of the electrochemical cell apparatus according to the first embodiment.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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).

[0043] 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 a fixing material 13 and solidified. This joins and fixes the inner wall of the insertion hole 15a to the lower ends of the 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.

[0044] 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.

[0045] 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.

[0046] Furthermore, as shown in Figure 2B, a connecting member 18 is interposed between adjacent cells 1 among the multiple cells 1. The connecting member 18 electrically connects the fuel electrode layer 5 of one adjacent cell 1 and the air electrode layer 8 of the other cell 1 in series. More specifically, the connecting member 18 connects the interconnector 4, which is electrically connected to the fuel electrode layer 5 of one adjacent cell 1, to the air electrode layer 8 of the other cell 1.

[0047] 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.

[0048] Furthermore, as shown in Figure 2C, the cell stack device 10 may be a single battery in which two cell stacks 11A and 11B are connected in series. In this case, 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.

[0049] 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.

[0050] 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.

[0051] <Details of the area near the boundary> Next, the details of the boundary 9 and the solid electrolyte layer 6 and intermediate layer 7 located near it according to the first embodiment will be described with reference to Figure 3. Figure 3 is a cross-sectional view showing an example of the vicinity of the boundary shown in Figure 1A.

[0052] As shown in Figure 3, cell 1 has a boundary portion 9 located between a solid electrolyte layer 6 as a first component and an intermediate layer 7 as a second component. Such a structure may be configured as a composite member 90 having a solid electrolyte layer 6 as a first component, an intermediate layer 7 as a second component, and a boundary portion 9. Such a composite member 90 may have a fuel electrode layer 5 or an air electrode layer 8.

[0053] The solid electrolyte layer 6 contains a first material 6a. The solid electrolyte layer 6 is polycrystalline and has a plurality of crystalline grains 61. The plurality of crystalline grains 61 are separated by grain boundaries 60. In Figure 3, only the crystalline grains 61 located along the boundary 9, i.e., in contact with the boundary, are shown, but the solid electrolyte layer 6 may have a plurality of crystalline grains 61 in the thickness direction.

[0054] The boundary portion 9 contains the first material 6a and the second material 7a. The boundary portion 9 may contain, for example, ZrO2 and CeO2, or a solid solution of ZrO2 and CeO2.

[0055] The boundary portion 9 is the part in which the ratio of the first material 6a to the sum of the first material 6a and the second material 7a is in the range of 20% to 80%.

[0056] Furthermore, the boundary portion 9 has a first portion 9a and a second portion 9b. The second portion 9b is thicker than the first portion 9a.

[0057] For example, the region where the thickness of the boundary portion 9 is 0.2 μm or less may be defined as the first portion 9a, and the remaining region as the second portion 9b. Alternatively, the portion where the thickness of the boundary portion 9 is 0.4 μm or more may be defined as the second portion 9b, and the remaining portion as the first portion 9a. The first portion 9a does not need to have substantially any thickness. That is, the first portion 9a may be the interface between the solid electrolyte layer 6 and the intermediate layer.

[0058] The performance of cell 1 is improved by having a boundary portion 9 located between the solid electrolyte layer 6 and the intermediate layer 7, which has a first portion 9a and a second portion 9b with different thicknesses. For example, in the first portion 9a, which is thinner, conductivity between the solid electrolyte layer 6 and the intermediate layer 7 is ensured through the thin boundary portion 9, improving power generation performance. On the other hand, in the second portion 9b, which is thicker than the first portion 9a, for example, the bonding strength between the solid electrolyte layer 6 and the intermediate layer 7 is ensured through the thick boundary portion 9, improving durability. Figure 3 shows the case where the second portion 9b has thickness on both the solid electrolyte layer 6 side and the intermediate layer 7 side, but the second portion 9b may have thickness that is biased towards either the solid electrolyte layer 6 side or the intermediate layer 7 side.

[0059] The thickness of the boundary portion 9 having the first material 6a and the second material 7a can be measured, for example, by measuring the cross-section of the element portion 3 including the solid electrolyte layer 6 and the intermediate layer 7 using an SEM (scanning electron microscope) or TEM (transmission electron microscope) and an EDX (energy dispersive X-ray analyzer). Specifically, for example, the cross-section of the element portion 3 or composite member 90 in the stacking direction is mirror-polished, and the Zr contained in the first material 6a and the Ce contained in the second material 7a are semi-quantitatively analyzed in a predetermined area including the solid electrolyte layer 6 and the intermediate layer 7. Using the obtained analysis results, the content per unit area can be converted to atomic percent, thereby identifying the first portion 9a and the second portion 9b of the boundary portion 9.

[0060] Next, the distribution of the first portion 9a and the second portion 9b of the boundary 9 will be explained using Figures 4A and 4B. Figure 4A is a plan view showing an example of the boundary shown in Figure 3. Figure 4B is a plan view showing another example of the boundary shown in Figure 3.

[0061] As shown in Figure 4A, the second portion 9b of the boundary 9 may be positioned in a network-like manner, overlapping in a plan view with the grain boundaries 60 that are in contact with the boundary 9, among the grain boundaries 60 that demarcate the plurality of crystal grains 61. The second portion 9b may also be positioned so as to overlap in a plan view with defects 62, such as oxygen vacancies in the crystal grains 61.

[0062] The first portion 9a is located in a region where the second portion 9b is not located in a plan view. The first portion 9a may be located in an island-like manner, overlapping in a plan view with at least one of the multiple crystal grains 61 that are in contact with the boundary portion 9.

[0063] Furthermore, as shown in Figure 4B, the second portion 9b of the boundary 9 may be located in an island-like shape that overlaps with the triple point 63 in a plan view among the grain boundaries 60 that demarcate the multiple crystal grains 61. The shape of the second portion 9b in a plan view is not limited to those exemplified in Figures 4A and 4B, but may be any shape such as arc-shaped, linear, Y-shaped, cross-shaped, star-shaped, or dendritic, and these shapes may be mixed. Also, the shape of the second portion 9b in a plan view may be a broken network.

[0064] In this way, by distributing the first portion 9a and the second portion 9b, which have different thicknesses, at the boundary 9 that contacts the solid electrolyte layer 6 and the intermediate layer 7, the desired conductivity and bonding strength are ensured, and the performance is improved.

[0065] A composite member 90 in which the first portion 9a and the second portion 9b are distributed at the boundary 9 in contact with the solid electrolyte layer 6 and the intermediate layer 7, as described above, can be obtained, for example, by coating the surface of the solid electrolyte layer 6 with a sintering aid such as cobalt oxide or copper oxide, drying it, then positioning the intermediate layer material and sintering it. The sintering aid may be coated to a thickness of, for example, 10 nm or less. The sintering aid coated on the surface of the solid electrolyte layer 6 makes it easier for the first material 6a and the second material 7a to solid-solve. Since the magnitude of this effect by the sintering aid differs on the crystal grains 61 and on the grain boundaries 60, a boundary 9 having the first portion 9a and the second portion 9b can be obtained. Alternatively, such a structure of the composite member may be formed by positioning the intermediate layer 7 on the surface of the solid electrolyte layer 6 by epitaxial growth. However, there are no restrictions on the method of manufacturing the composite member 90, and it may be manufactured by any method. Also, the intermediate layer 7 may be polycrystalline, like the solid electrolyte layer 6. In such a case, the intermediate layer 7 may have a crystal structure corresponding to the solid electrolyte layer 6 facing the boundary 9. In other words, among the multiple crystal particles and grain boundaries constituting the intermediate layer 7, the crystal particles and grain boundaries in contact with the boundary 9 may be positioned so as to overlap in a plan view with the multiple crystal particles 61 and grain boundaries 60 of the solid electrolyte layer 6 that are in contact with the boundary 9. The intermediate layer 7 may have pores. The intermediate layer 7 may have a porosity greater than that of the solid electrolyte layer 6 and the boundary 9.

[0066] <module> Next, a module according to the embodiment of this disclosure using the electrochemical cell apparatus described above will be explained with reference to Figure 5. Figure 5 is an external perspective view showing the module according to the first embodiment. In Figure 5, the front and rear surfaces, which are part of the housing container 101, have been removed, and the fuel cell cell stack device 10 housed inside has been taken out to the rear.

[0067] As shown in Figure 5, module 100 comprises a storage container 101 and a cell stack device 10 housed within the storage container. A reformer 102 is positioned above the cell stack device 10.

[0068] 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.

[0069] 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.

[0070] Furthermore, in the module 100 with the above configuration, the temperature inside the module 100 during normal power generation is approximately 500°C to 1000°C due to the combustion of gas and the power generation of cell 1.

[0071] In such a module 100, as described above, the module 100 can be configured to house a cell stack device 10 with improved performance, thereby improving its performance.

[0072] <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.

[0073] 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.

[0074] 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.

[0075] In such a module housing device 110, as described above, by providing the module housing chamber 115 with the module 100 whose performance is improved, the module housing device 110 can be made to have improved performance.

[0076] In the above embodiment, a case using a hollow flat support substrate was illustrated, but it can also be applied to an electrochemical cell apparatus using a cylindrical support substrate.

[0077] [Second Embodiment] Next, the electrochemical cell and electrochemical cell apparatus according to the second embodiment will be described with reference to Figures 7A to 8.

[0078] 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 electrochemical cell apparatus in which a so-called "horizontal stripe type" electrochemical 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.

[0079] Figure 7A is a cross-sectional view showing an example of an electrochemical cell apparatus according to the second embodiment, Figure 7B is a cross-sectional view showing an electrochemical cell according to the second embodiment, and Figure 8 is a cross-sectional view showing an example of the vicinity of the boundary shown in Figure 7B.

[0080] As shown in Figure 7A, the cell stack device 10A has multiple cells 1A extending in the longitudinal direction L from a pipe 22a through which fuel gas flows. Each cell 1A has multiple element sections 3 on a support substrate 2. Inside the support substrate 2, there is a gas passage 2a through which the fuel gas from the pipe 22a flows.

[0081] Furthermore, each cell 1A is electrically connected to one another via a connecting member 31. The connecting member 31 is located between the element portions 3 of each cell 1A and connects adjacent cells 1A.

[0082] Furthermore, as shown in Figure 7B, the cell 1A according to the second embodiment comprises a support substrate 2, a pair of element portions 3, and a sealing portion 30. The support substrate 2 is columnar in shape and has a pair of opposing flat surfaces, a first surface n1 and a second surface n2, and a pair of arc-shaped side surfaces m connecting the first surface n1 and the second surface n2.

[0083] The pair of element portions 3 are positioned on the first surface n1 and the second surface n2 of the support substrate 2, facing each other. The sealing portion 30 is positioned to cover the side surface m of the support substrate 2.

[0084] As shown in Figure 8, cell 1A has a boundary portion 9 located between a solid electrolyte layer 6 as a first component and an intermediate layer 7 as a second component. Such a structure may be configured as a composite member 90 having a solid electrolyte layer 6, an intermediate layer 7, and a boundary portion 9.

[0085] The solid electrolyte layer 6 contains a first material 6a. The solid electrolyte layer 6 is polycrystalline and has a plurality of crystalline grains 61. The plurality of crystalline grains 61 are separated by grain boundaries 60.

[0086] The boundary portion 9 contains the first material 6a and the second material 7a. The boundary portion 9 may contain, for example, ZrO2 and CeO2, or a solid solution of ZrO2 and CeO2.

[0087] The boundary portion 9 has a first portion 9a and a second portion 9b. The second portion 9b is thicker than the first portion 9a.

[0088] In this way, the performance of cell 1A is improved by having a boundary portion 9 located between the solid electrolyte layer 6 and the intermediate layer 7 having a first portion 9a and a second portion 9b with different thicknesses. For example, in the first portion 9a, conductivity between the solid electrolyte layer 6 and the intermediate layer 7 is ensured through the thin boundary portion 9, improving power generation performance. On the other hand, in the second portion 9b, which is thicker than the first portion 9a, for example, the bonding strength between the solid electrolyte layer 6 and the intermediate layer 7 is ensured through the thick boundary portion 9, improving durability.

[0089] [Third Embodiment] Figure 9 is a perspective view showing an example of an electrochemical cell according to the third embodiment. Figure 10 is a partial cross-sectional view of the electrochemical cell shown in Figure 9.

[0090] As shown in Figures 9 and 10, cell 1B has an element section 3B in which a fuel electrode layer 5, a solid electrolyte layer 6, an intermediate layer 7, and an air electrode layer 8 are stacked, and conductive members 91 and 92. A boundary section 9 is located between the solid electrolyte layer 6 and the intermediate layer 7. In an electrochemical cell device in which multiple planar cells are stacked, for example, multiple cells 1B are electrically connected by conductive members 91 and 92, which are adjacent metal layers. The conductive members 91 and 92 electrically connect adjacent cells 1B and also have gas channels for supplying gas to the fuel electrode layer 5 or the air electrode layer 8.

[0091] As shown in Figure 10, cell 1B has a sealing material that hermetically seals the fuel gas flow path and the oxygen-containing gas flow path of the flat-plate cell stack. The sealing material is a cell fixing member 96 and has a joining member 93 and support members 94 and 95 which are frames. The joining member 93 may be glass or a metal material such as silver solder.

[0092] The support member 94 may be a so-called separator that divides the fuel gas flow path from the oxygen-containing gas flow path. The material of the support members 94 and 95 may be, for example, a conductive metal or an insulating ceramic. If the support member 94 is made of metal, it may be integrated with the conductive member 92. If the support member 95 is made of metal, it may be integrated with the conductive member 91.

[0093] One of the bonding material 93 and the support members 94 and 95 is insulating, electrically insulating the two conductive members 91 and 92 that sandwich the flat cell from each other.

[0094] Figure 11 is a cross-sectional view showing an example of the vicinity of the boundary shown in Figure 10. As shown in Figure 11, cell 1B has a boundary 9 located between the solid electrolyte layer 6 as a first member and the intermediate layer 7 as a second member. Such a structure may be configured as a composite member 90 having the solid electrolyte layer 6, the intermediate layer 7 and the boundary 9.

[0095] The solid electrolyte layer 6 contains a first material 6a. The solid electrolyte layer 6 is polycrystalline and has a plurality of crystalline grains 61. The plurality of crystalline grains 61 are separated by grain boundaries 60.

[0096] The boundary portion 9 contains the first material 6a and the second material 7a. The boundary portion 9 may contain, for example, ZrO2 and CeO2, or a solid solution of ZrO2 and CeO2.

[0097] The boundary portion 9 has a first portion 9a and a second portion 9b. The second portion 9b is thicker than the first portion 9a.

[0098] Thus, the performance of cell 1B is improved by having a boundary portion 9 located between the solid electrolyte layer 6 and the intermediate layer 7 having a first portion 9a and a second portion 9b with different thicknesses. For example, in the first portion 9a, conductivity between the solid electrolyte layer 6 and the intermediate layer 7 is ensured through the thin boundary portion 9, improving power generation performance. On the other hand, in the second portion 9b, which is thicker than the first portion 9a, for example, the bonding strength between the solid electrolyte layer 6 and the intermediate layer 7 via the boundary portion 9 is ensured, improving durability.

[0099] [Fourth Embodiment] Figure 12A is a cross-sectional view showing an example of an electrochemical cell according to the fourth embodiment. Figures 12B and 12C are cross-sectional views showing other examples of an electrochemical cell according to the fourth embodiment. Figure 13 is a cross-sectional view showing an example near the boundary shown in Figure 12A. Note that Figure 13 can also be applied to the examples in Figures 12B and 12C.

[0100] As shown in Figures 12A to 12C, cell 1C has an element section 3C in which a fuel electrode layer 5, a solid electrolyte layer 6, an intermediate layer 7, and an air electrode layer 8 are laminated, and a support substrate 2. A boundary section 9 is located between the solid electrolyte layer 6 and the intermediate layer 7. The support substrate 2 has through holes or pores in the portion in contact with the element section 3, 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 electrically connects adjacent cells 1C to each other. 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.

[0101] In the example shown in Figure 12A, the sides of the fuel electrode layer 5 are covered with a solid electrolyte layer 6, hermetically sealing the gas passage 2a through which the fuel gas flows. As shown in Figure 12B, the sides of the fuel electrode layer 5 may also be covered and sealed with a dense glass or ceramic sealant 40. The sealant 40 covering the sides of the fuel electrode layer 5 may have electrical insulating properties.

[0102] Furthermore, the gas flow path 2a of the support substrate 2 may be formed by a member 120 having irregularities, as shown in Figure 12C.

[0103] As shown in Figure 13, cell 1C has a boundary portion 9 located between a solid electrolyte layer 6 as a first component and an intermediate layer 7 as a second component. Such a structure may be configured as a composite member 90 having a solid electrolyte layer 6, an intermediate layer 7, and a boundary portion 9.

[0104] The solid electrolyte layer 6 contains a first material 6a. The solid electrolyte layer 6 is polycrystalline and has a plurality of crystalline grains 61. The plurality of crystalline grains 61 are separated by grain boundaries 60.

[0105] The boundary portion 9 contains the first material 6a and the second material 7a. The boundary portion 9 may contain, for example, ZrO2 and CeO2, or a solid solution of ZrO2 and CeO2.

[0106] The boundary portion 9 has a first portion 9a and a second portion 9b. The second portion 9b is thicker than the first portion 9a.

[0107] In this way, the performance of cell 1C is improved by having a boundary portion 9 located between the solid electrolyte layer 6 and the intermediate layer 7 having a first portion 9a and a second portion 9b with different thicknesses. For example, in the first portion 9a, conductivity between the solid electrolyte layer 6 and the intermediate layer 7 is ensured through the thin boundary portion 9, improving power generation performance. On the other hand, in the second portion 9b, which is thicker than the first portion 9a, for example, the bonding strength between the solid electrolyte layer 6 and the intermediate layer 7 is ensured through the thick boundary portion 9, improving durability.

[0108] [Other embodiments] Next, an electrochemical cell apparatus according to another embodiment will be described.

[0109] In the embodiments described above, a fuel cell cell, fuel cell stack device, 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 device, electrolytic module, and 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, by supplying electricity. In addition, in each embodiment described above, an oxide ion conductor or a hydrogen ion conductor was shown as an example of the electrolyte material of the electrochemical cell, but a hydroxide ion conductor may also be used. Such electrolytic cells, electrolytic cell stack devices, electrolytic modules, and electrolytic devices can improve electrolytic performance and durability.

[0110] 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.

[0111] In one embodiment, (1) the composite member is A polycrystalline first component containing the first material, A second member comprising a second material different from the first material, A boundary portion located between the first member and the second member, containing the first material and the second material. Equipped with, The boundary portion has a first portion and a second portion that is thicker than the first portion.

[0112] (2) In the composite member described in (1) above, the first portion may be positioned so as to overlap in a plan view with at least one of the plurality of crystal grains of the first member that is in contact with the boundary portion.

[0113] (3) In the composite member described in (1) or (2) above, the second portion may be positioned so as to overlap in a plan view with at least a portion of the grain boundaries located between the plurality of crystal grains of the first member that are in contact with the boundary portion.

[0114] (4) In any one of the composite members described in (1) to (3) above, the boundary portion may contain a solid solution of the first material and the second material.

[0115] (5) In any one of the composite members described in (1) to (4) above, the second member may have a crystal structure corresponding to the first material facing the boundary portion.

[0116] (6) The electrochemical cell comprises one of the composite members described in (1) to (5) above, The first electrode layer and the second electrode layer facing each other with the composite member in between. It is equipped with.

[0117] (7) The electrochemical cell apparatus has a cell stack comprising the electrochemical cells described in (6) above.

[0118] (8) The module is the electrochemical cell apparatus described in (7) above, The system includes a storage container for housing the aforementioned electrochemical cell apparatus.

[0119] (9) The module housing device includes the module described in (8) above, Auxiliary equipment for operating the aforementioned module, The system comprises the module and an outer case housing the auxiliary equipment.

[0120] The embodiments disclosed herein should be considered in all respects to be 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]

[0121] Cells 1,1A~1C 2. Support substrate 3,3B,3C element part 4 interconnects 5 Fuel electrode layer 6 Solid electrolyte layer 6a 1st material 7. Middle Class 7a 2nd material 8. Polar air layer 9. Boundary 9a Part 1 9b Part 2 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 Connecting Members 100 modules 110 Module housing device

Claims

1. A composite member and The composite member is flanked by a first electrode layer and a second electrode layer through which an oxygen-containing gas flows. Equipped with, The composite member is A polycrystalline first component which is a solid electrolyte containing Zr, A second member containing Ce is located between the first member and the second electrode layer, A boundary portion located between the first member and the second member, containing the Zr and the Ce Equipped with, The boundary portion has a first portion and a second portion that is thicker than the first portion. The second portion is positioned such that, in a plan view, it overlaps with at least a portion of the grain boundaries located between the plurality of crystal grains of the first member that are in contact with the boundary portion. Electrochemical cell.

2. The first portion is positioned such that, in a plan view, it overlaps with at least one of the plurality of crystal grains of the first member that is in contact with the boundary. The electrochemical cell according to claim 1.

3. The boundary portion contains a solid solution comprising Zr and Ce. The electrochemical cell according to claim 1.

4. The second member has a crystal structure corresponding to the first member that faces it across the boundary. The electrochemical cell according to claim 1.

5. A cell stack comprising an electrochemical cell according to any one of claims 1 to 4 Electrochemical cell apparatus.

6. The electrochemical cell apparatus according to claim 5, A storage container for housing the electrochemical cell apparatus and A module equipped with the following features.

7. The module according to claim 6, Auxiliary equipment for operating the aforementioned module, An outer case housing the module and the auxiliary equipment A module housing device equipped with the following features.

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