WO2020196632A1

WO2020196632A1 - Cell stack device, module, and module accommodation device

Info

Publication number: WO2020196632A1
Application number: PCT/JP2020/013364
Authority: WO
Inventors: 和也今仲; 史人古内
Original assignee: 京セラ株式会社
Priority date: 2019-03-27
Filing date: 2020-03-25
Publication date: 2020-10-01
Also published as: JPWO2020196632A1; JP2023126839A; JP7305752B2

Abstract

Provided are: a cell stack device comprising a plurality of cells 1, a support member 7b, and a first joining member 7a that joins the cells 1 and the support member 7b; a module; and a module accommodation device. The support member 7b comprises a cracked layer 7b2 that includes a crack 7bc between a support member main body 7b1 and the first joining member 7a. The first joining member 7a comprises a first end section that is in contact with a first gas and a second end section that is in contact with a second gas that differs from the first gas. If the direction perpendicular to the interface between the support member 7b and the joining member 7a is a first direction x and the direction from the first end section toward the second end section of the first joining member 7a is a second direction y, in the second direction y, the maximum length of the crack 7bc is less than the length of the first joining member 7a.

Description

Cell stack device, module and module housing device

The present disclosure relates to cell stack devices, modules and module accommodating devices.

In recent years, as a next-generation energy, a fuel cell device in which a cell stack device is housed in a storage container has been proposed. The cell stack device includes a plurality of fuel cell cells, a current collector that electrically connects the plurality of fuel cell cells to each other, and a gas tank. The lower ends of the fuel cell cells and the current collector members arranged in an upright state are fixed to the gas tank.

For example, in the fuel cell stacking device of Patent Document 1, one end of a plurality of fuel cell cells is joined to a support member with a fixing material.

Japanese Unexamined Patent Publication No. 2013-157191

The cell stack device of the present disclosure includes a plurality of cells, a support member, and a joining member for joining the cell and the support member. The support member has a support member main body and a crack-containing layer located between the support member main body and the joint member and containing a crack. The joining member has a first end portion in contact with the first gas and a second end portion in contact with a second gas different from the first gas. When the direction perpendicular to the interface between the support member and the joining member is the first direction and the direction from the first end to the second end of the joining member is the second direction, the second direction. The maximum length of the crack is smaller than the length of the joining member.

The module of the present disclosure includes a storage container and the above-mentioned cell stack device housed in the storage container.

The module accommodating device of the present disclosure includes an outer case, the above-mentioned module housed in the outer case, and an auxiliary machine for operating the module.

It is a cross-sectional view which shows one of the examples of a cell. It is a bottom view of the cell of FIG. It is a top view of the cell of FIG. It is a perspective view which shows one of the examples of a cell stack apparatus. It is a cross-sectional view taken along the line vv of FIG. FIG. 5 is a cross-sectional view taken along the line Vi-vi of FIG. It is an enlarged view of the area A of FIG. It is an enlarged view of the area A in one of the examples of a cell stack device. It is an enlarged view of the area A in one of the examples of a cell stack device. It is an external perspective view which shows one of the examples of a module. It is a perspective view which shows one of the example of a module accommodating device schematically. It is a perspective view which shows one of the examples of a flat plate type cell. It is sectional drawing which shows one of the examples of a flat plate type cell stack. It is an enlarged view of the vicinity of the first joining member of FIG.

(cell)
A solid oxide fuel cell will be described as one of the examples of cells constituting the cell stack. 1 is a cross-sectional view showing one of the cell examples, FIG. 2 is a bottom view of FIG. 1, and FIG. 3 is a top view of FIG. In these drawings, the thickness of a part of the members of the cell 1 is shown enlarged from the actual thickness.

Cell 1 shown in FIG. 1 is a hollow flat plate type and has an elongated plate shape. As shown in FIG. 2, the shape of the entire cell 1 viewed from the lower side of FIG. 1 is, for example, a side length of 5 cm or more and 50 cm or less in the length direction L, which is orthogonal to the length direction L. It is a rectangle having a length W in the width direction of 1 cm or more and 10 cm or less. The thickness of the entire cell 1 in the thickness direction T is 1 mm or more and 5 mm or less. Hereinafter, unless otherwise specified, the terms "upper and lower" of cell 1 mean upper and lower in the length direction of FIGS. 2 and 3.

As shown in FIG. 1, the cell 1 has a conductive support substrate 2, an element portion, and an interconnector 6. Hereinafter, the conductive support substrate 2 may be referred to as a support substrate 2. The support substrate 2 is a columnar structure having a pair of flat first surfaces n1 and second surfaces n2 facing each other, and a pair of arcuate side surfaces m connecting the first surface n1 and the second surface n2. The cell 1 includes an element portion on the first surface n1 of the support substrate 2. The element unit has a fuel electrode 3, a solid electrolyte layer 4, and an air electrode 5. The cell 1 includes an interconnector 6 on the second surface n2.

As shown in FIG. 2, the cell 1 has a portion where the solid electrolyte layer 4 is exposed on the surface between the lower end of the air electrode 5 and the lower end of the cell 1. As shown in FIG. 3, the interconnector 6 extends to the lower end of the cell 1. The surface of the pair of arcuate side surfaces m of the cell 1 is the solid electrolyte layer 4. That is, the surface of the lower end of the cell 1 is the interconnector 6 or the solid electrolyte layer 4.

The support substrate 2 includes a gas flow path 2a through which gas flows. One of the examples of the support substrate 2 shown in FIG. 1 includes six gas flow paths 2a. The support substrate 2 has gas permeability and conductivity. Since the support substrate 2 has gas permeability, the fuel gas flowing through the gas flow path 2a can be permeated to the fuel electrode 3. Since the support substrate 2 has conductivity, the electricity generated by the element unit can be collected via the interconnector 6. The material of the support substrate 2 may be, for example, a composite material of an iron group metal component and an inorganic oxide. For example, the iron group metal component may be Ni and / or NiO. For example, the inorganic oxide may be a specific rare earth element oxide. Rare earth elements include Y.

As the fuel electrode 3, generally known ones may be used. The material of the fuel electrode 3 may be a composite material of porous conductive ceramics such as stabilized zirconia and Ni and / or NiO. The stabilized zirconia is ZrO ₂ calcium, magnesium or rare earth oxide, is dissolved, including partially stabilized zirconia. Rare earth oxide may be, for example, Y ₂ O ₃ or the like.

The solid electrolyte layer 4 has ionic conductivity and gas blocking property. The solid electrolyte layer 4 is an electrolyte having ionic conductivity, and bridges ions between the fuel electrode 3 and the air electrode 5. Since the solid electrolyte layer 4 has a gas blocking property, leakage between the fuel gas and the oxygen-containing gas is less likely to occur. The material of the solid electrolyte layer 4 may be, for example, ZrO ₂ in which a rare earth element oxide of 3 mol% or more and 15 mol% or less is solid-solved. Rare earth oxide may be, for example, Y ₂ O ₃ or the like. The material of the solid electrolyte layer 4 may be another material as long as it has ionic conductivity and gas blocking property.

The material of the air electrode 5 is not particularly limited as long as it is generally used. The material of the air electrode 5 may be, for example, conductive ceramics of a so-called ABO ₃ type perovskite type oxide. The perovskite-type oxide may be, for example, a composite oxide in which Sr and La coexist at the A site. Examples of the perovskite type _{_{_{_{oxide, La x Sr 1-x Co}}}} y Fe 1-y O 3, La x Sr 1-x MnO 3, La x Sr 1-x FeO 3, and _La x _Sr 1-x CoO _3rd grade can be mentioned. Note that x is 0 <x <1 and y is 0 <y <1. The air electrode 5 has gas permeability. The air electrode 5 may have an open porosity in the range of 20% or more, particularly 30% or more and 50% or less.

The interconnector 6 has conductivity and is dense. The material of the interconnector 6 may be, for example, a lanthank chromite-based perovskite-type oxide (LaCrO _3- based oxide) or a lanthantium strontium titanium-based perovskite-type oxide (LaSrTiO _3- based oxide). These materials are conductive and are neither reduced nor oxidized when they come into contact with a fuel gas such as a hydrogen-containing gas and an oxygen-containing gas such as air. The interconnector 6 may have a relative density of 93% or more, particularly 95% or more. Since the interconnector 6 is so dense, leakage of fuel gas flowing through the gas flow path 2a of the support substrate 2 and oxygen-containing gas flowing outside the support substrate 2 is less likely to occur.

(Cell stack device)
FIG. 4 is a perspective view showing one of the examples of the cell stack device. FIG. 5 is a sectional view taken along line vv of FIG. The cell stack device 10 includes a cell stack 11, a fixing member 7, and a gas tank 8. The cell stack 11 includes a plurality of cells 1 arranged or stacked in the thickness direction T of the cells 1, a conductive member 9a for electrically connecting adjacent cells 1 in series, and the cell 1 arrangement direction, that is, the thickness direction T. It is provided with a pair of end conductive members 9b arranged at both ends of the above. The fixing member 7 has a first joining member 7a and a support member 7b.

As shown in FIG. 5, the support member 7b has an insertion hole 12 into which the lower ends of the plurality of cells 1 are inserted, and a tank joint portion to be joined to the gas tank 8. The lower ends of the plurality of cells 1 and the inner walls of the insertion holes 12 are joined by a first joining member 7a. In FIG. 5, the support member 7b has one insertion hole 12, and all the lower ends of the plurality of cells 1 arranged in a row are inserted into the one insertion hole 12. The support member 7b may have a plurality of insertion holes 12, and the lower end portion of one cell 1 may be inserted into each of the plurality of insertion holes 12.

The gas tank 8 has one or more openings and a concave groove 8b provided around the openings and filled with the second joining member 8a. The gas tank 8 supplies fuel gas to the plurality of cells 1. The tank joint portion of the support member 7b is joined to the gas tank 8 by a second joining member 8a filled in the concave groove 8b of the gas tank 8. The support member 7b and the gas tank 8 may be made of metal, for example.

In the cell stack device 10 shown in FIG. 4, fuel gas is stored in the internal space formed by the support member 7b and the gas tank 8. This internal space may be simply referred to as the internal space of the gas tank 8. On the other hand, oxygen-containing gas such as air exists in the external space. A gas flow pipe 13 is connected to the gas tank 8. The fuel gas generated by the reformer described later is supplied to the gas tank 8 through the gas flow pipe 13 and further supplied to the gas flow path 2a inside the cell 1.

Hydrogen-rich fuel gas is produced, for example, by steam reforming raw fuel. The fuel gas produced by steam reforming contains steam.

The first joining member 7a and the second joining member 8a are each one of the components of the internal space in which the fuel gas is stored. Both the first joining member 7a and the second joining member 8a have a first end portion in contact with the internal space and a second end portion in contact with the external space. In other words, the first end portion of the first joining member 7a and the second joining member 8a is a portion in contact with the fuel gas in the internal space, and the second end portion of the first joining member 7a and the second joining member 8a is This is the part that comes into contact with the oxygen-containing gas in the external space. In this case, the fuel gas is the first gas in contact with the first end, and the oxygen-containing gas is the second gas in contact with the second end, which is different from the first gas.

The cell stack device shown in FIG. 4 includes two rows of a plurality of cells 1 arranged in the thickness direction T. Each row of the plurality of cells 1 is fixed to the support member 7b. In FIG. 4, the gas tank 8 has two openings on the upper surface, and one support member 7b is arranged in each of the openings. That is, in FIG. 4, the internal space in which the fuel gas is stored is formed by one gas tank 8 and two support members 7b.

The shape of the insertion hole 12 is, for example, an oval shape when viewed from above. The length of the insertion holes 12 in the arrangement direction of the cells 1, that is, the thickness direction T, is longer than, for example, the distance between the pair of end conductive members 9b located at both ends of the cell stack 11. Further, the width of the insertion hole 12 in the width direction W of the cell 1 is longer than, for example, the length of the cell 1 in the width direction W.

As shown in FIG. 4, a solidified first joining member 7a is filled between the insertion hole 12 and the lower end portion of the cell 1. The lower ends of the plurality of cells 1 are joined and fixed to the insertion holes 12 by the first joining member 7a, and the lower ends of the adjacent cells 1 are joined to each other. The lower end of the gas flow path 2a of each cell 1 communicates with the internal space of the gas tank 8.

The first joining member 7a and the second joining member 8a may have an insulating property. The material of the first joining member 7a and the second joining member 8a may be, for example, amorphous glass or crystallized glass. Crystallized glass, for _example, SiO 2 -CaO-based, _MgO-B 2 _{O 3} _{_{_{_{based, La 2 O 3 -B 2 O}}}} 3 -MgO _{_{_{_{based, La 2 O 3 -B 2 O}}}} 3 -ZnO system, SiO ₂ - CaO—ZnO-based crystallized glass may be used.

As shown in FIG. 5, the cell stack device 10 includes a conductive member 9a that electrically connects adjacent cells 1 among a plurality of cells 1 arranged in the thickness direction T in series. The conductive member 9a electrically connects the fuel electrode 3 of one cell 1 of the adjacent cells 1 and the air electrode 5 of the other cell 1 in series. In FIG. 4, the conductive member 9a is not shown.

Further, as shown in FIG. 5, the cell stack device 10 includes a pair of end conductive members 9b on the outside of a plurality of cells 1 arranged in the thickness direction T. The end conductive member 9b is electrically connected to each of the pair of cells 1 located on the outermost side of the plurality of cells 1 arranged in the thickness direction T. The end conductive member 9b has a drawer portion 9c that projects outward in the thickness direction T. The drawing unit 9c collects the electricity generated by the cell 1 and draws it to the outside.

FIG. 6 is a cross-sectional view of the vi-vi of FIG. FIG. 7 is an enlarged view of the A region shown by the broken line in FIG.

In FIGS. 6 and 7, the first joining member 7a exists between the portion of the support member 7b facing the insertion hole 12 and the lower end portion of the cell 1. In an arbitrary cross section along the height direction of the first joining member 7a including the support member 7b, the first joining member 7a, and the cell 1, the direction perpendicular to the interface between the support member 7b and the first joining member 7a is defined as the first. One direction is defined, and the height direction of the first joining member 7a is defined as the second direction y.

The second direction y is a direction from the first end portion of the first joining member 7a in contact with the fuel gas, that is, the first gas, toward the second end portion in contact with the oxygen-containing gas, that is, the second gas. In other words, the second direction y is the direction connecting the first end portion and the second end portion at the shortest distance. The height of the first joining member 7a may be referred to as the length of the first joining member 7a in the second direction y.

In FIG. 6, the first direction x roughly coincides with the width direction W of the cell 1, and the second direction y coincides with the length direction L of the cell 1. In FIG. 5, the first direction x roughly coincides with the thickness direction T of the cell 1, and the second direction y coincides with the length direction L of the cell 1. Hereinafter, the cross section along the height direction of the first joining member 7a may be referred to as a vertical cross section.

As shown in FIG. 7, the solid electrolyte layer 4 of the cell 1 is in contact with the first bonding member 7a. The cell 1 has a porous and conductive fuel electrode 3 and a support substrate 2 inside the solid electrolyte layer 4. The solid electrolyte layer 4 may have a cell reinforcing layer between the solid electrolyte layer 4 and the first joining member 7a. The material of the cell reinforcing layer may be, for example, a material containing ZrO ₂ as a main component, which is a solid solution of Y ₂ O _{3 of} 3 mol% or more and 5 mol% or less.

As shown in FIG. 7, the support member 7b has a crack-containing layer 7b2 containing a crack 7bc between the support member main body 7b1 and the first joining member 7a. The maximum length of the crack 7bc in the second direction y is smaller than the height of the first joining member 7a in the second direction y.

In many cases, the first joint member 7a, which is glass, and the support member body 7b1, which is metal, have different coefficients of thermal expansion. Therefore, stress is generated in the vicinity of the boundary between the first joining member 7a and the support member main body 7b1 due to the temperature rise and fall accompanying the operation and stop of the cell 1. Due to this stress, cracks are likely to occur in the first joining member 7a. When a crack occurs in the first joining member 7a, there is a concern that fuel gas leaks from the crack and the durability of the cell stack device deteriorates.

When the crack-containing layer 7b2 exists between the support member main body 7b1 and the first joining member 7a, the stress generated between the first joining member 7a and the support member main body 7b1 is included in the crack-containing layer 7b2. This is alleviated, and cracks are less likely to occur in the first joining member 7a. As a result, the durability of the cell stack device 10 can be improved. The maximum length of the crack 7bc itself is smaller than the height of the first joined member, and the internal space of the gas tank 8 and the outside are not communicated with each other. The stress can be relaxed by arranging the crack-containing layer 7b2 at least in a part near the boundary between the support member 7b and the first joining member 7a. The crack-containing layer 7b2 may be dispersedly arranged in the entire vicinity of the boundary between the support member 7b and the first joining member 7a. The crack-containing layer 7b2 may be provided only in a specific portion of the support member 7b where cracks are likely to occur, particularly in the first joining member 7a. Note that FIG. 7 shows only a part of the crack 7bc contained in the crack-containing layer 7b2.

In an arbitrary vertical cross section, the height of the first joining member 7a in the second direction y is h, and the maximum length of the crack 7bc contained in the crack-containing layer 7b2 in the second direction y is l. l may be 2/3 or less of h. When l is 2/3 or less of h, the stress generated between the first joining member 7a and the support member 7b can be relaxed. Further, even if the crack 7bc contained in the crack-containing layer 7b2 grows due to stress, since l is 2/3 or less of h, it becomes difficult to communicate between the internal space of the gas tank 8 and the outside, and the crack Leakage of fuel gas or oxygen-containing gas is less likely to occur in the content layer 7b2.

A part of the crack 7bc contained in the crack-containing layer 7b2 may have a bonding material contained in the first bonding member 7a inside the crack 7bc. In other words, as shown in FIG. 8, the crack-containing layer 7b2 may have a crack 7b3 having a bonding material inside. Since some of the cracks 7bc are cracks 7b3 having a bonding material inside, leakage of fuel gas or oxygen-containing gas is less likely to occur in the crack-containing layer 7b2.

The crack 7b3 having the bonding material inside may be located in the vicinity of the portion of the crack-containing layer 7b2 in contact with the first bonding member 7a. By having the crack 7b3 having the bonding material inside in the vicinity of the portion of the crack-containing layer 7b2 in contact with the first bonding member 7a, the first bonding member 7a, the crack-containing layer 7b2, and the support member main body 7b1 are further formed. Strongly joined. As a result, the first joining member 7a, the crack-containing layer 7b2, and the support member main body 7b1 are less likely to come off. The crack-containing layer 7b2 may have cracks 7b3 containing a material different from the bonding material contained in the first bonding member 7a.

As shown in FIG. 9, the support member 7b has a first portion in which the support member main body 7b1 and the first joint member 7a are in direct contact with a part thereof in the height direction of the first joint member 7a, that is, in the second direction y. It may have site 7b4. That is, the support member main body 7b1 may be in direct contact with the first joining member 7a at the first portion 7b4 without interposing the crack-containing layer 7b2. The first portion 7b4 may be arranged at the upper end or the lower end of the portion where the support member 7b faces the first joining member 7a, or may be arranged between the upper end and the lower end. The first portion 7b4 in which the support member main body 7b1 and the first joining member 7a are in direct contact with each other is arranged in a part thereof in the second direction y of the portion where the support member 7b faces the first joining member 7a. The cracks 7bc contained in the crack-containing layer 7b2 are less likely to communicate with each other between the internal space of the gas tank 8 and the outside, and the fuel gas is less likely to leak.

The first portion 7b4 may be located at at least one end of the first joining member 7a in the second direction y which is the height direction of the first joining member 7a. The cell stack 11 becomes hot during operation, and a temperature difference occurs between the upper part and the lower part of the fixing member 7. When the crack-containing layers 7b2 are arranged at both ends of the portion where the support member 7b faces the first joining member 7a in the second direction y, the cracks located at both ends are caused by the thermal stress caused by the temperature difference between both ends. There is a concern that 7bc will develop and communicate between the internal space of the gas tank 8 and the outside. By arranging the first portion 7b4 at at least one end of the surface of the support member 7b facing the first joining member 7a and not arranging the cracks 7bc at both ends, leakage of fuel gas is less likely to occur. The first portion 7b4 may be arranged at the upper end portion in the second direction y. The crack 7bc is likely to grow due to thermal stress especially at the upper end portion in the second direction y, but by arranging the first portion 7b4 at the upper end portion in the second direction y, the crack 7bc is less likely to grow.

The material of the crack-containing layer 7b2 may be, for example, an inorganic oxide. That is, the material of the crack-containing layer 7b2 may be different from both the first glass joining member 7a and the metal supporting member 7b. Inorganic oxides include, for example, aluminum oxide (alumina), magnesium oxide (magnesia), silicon oxide (silica), zirconium oxide (zirconia), chromium oxide (chromia), titanium oxide (titania) and composite oxides thereof. Good. The zirconia may be the above-mentioned stabilized zirconia. The composite oxide may be selected from, for example, forsterite and cordierite. The material of the crack-containing layer 7b2 may be a material having low conductivity or an insulating material. Since the material of the crack-containing layer 7b2 is a material having low conductivity or an insulating material, the cell stack device 10 having a high withstand voltage and a high insulation resistance can be obtained.

In particular, alumina and forsterite have a small difference in the coefficient of thermal expansion of the support member main body 7b1 from the metal material, so that the thermal stress generated by the temperature difference is small. Therefore, the crack-containing layer 7b2 can be firmly bonded to the support member 7b, and the crack-containing layer 7b2 is less likely to be peeled off from the support member main body 7b1.

In the support member 7b, the arithmetic mean roughness of the surface having the crack-containing layer 7b2 and the arithmetic mean roughness of the surface of the support member main body 7b1 not having the crack-containing layer 7b2 may be different. The surface having the crack-containing layer 7b2 is the surface of the crack-containing layer 7b2 or the interface between the crack-containing layer 7b2 and the support member main body 7b1 at the portion having the crack-containing layer 7b2. Further, in the support member 7b, the arithmetic mean roughness of the surface of the crack-containing layer 7b2 on the surface having the crack-containing layer 7b2 and the arithmetic mean roughness of the interface between the crack-containing layer 7b2 and the support member main body 7b1 may be different. ..

Let R0 be the arithmetic mean roughness of the surface of the support member body 7b1 that does not have the crack-containing layer 7b2. Let R1 be the arithmetic mean roughness of the surface of the support member main body 7b1 of the portion having the crack-containing layer 7b2, and let R2 be the arithmetic mean roughness of the surface of the crack-containing layer 7b2.

R1 may be larger than R0. By arranging the crack-containing layer 7b2 on the surface of the support member main body 7b1 having a larger arithmetic mean roughness, that is, the surface having R1, the crack-containing layer 7b2 can be more firmly bonded to the support member main body 7b1.

R2 may be larger than R0. The surface of the crack-containing layer 7b2 having R2, that is, the surface of the support member main body 7b1 having a larger arithmetic mean roughness than the surface having R0, and the first joining member 7a are joined to crack the first joining member 7a. The containing layer 7b2 can be bonded more firmly.

The thickness of the crack-containing layer 7b2 in the first direction x may be, for example, about 20 μm or more and 250 μm or less. The width or length of the crack 7bc in the first direction x may be, for example, 250 μm or less. The thickness of the crack-containing layer 7b2 in the first direction x may be the same from the upper end to the lower end of the interface with the first joining member 7a, or may have portions having different thicknesses. For example, the thickness of the upper end portion of the crack-containing layer 7b2 may be thicker than the thickness of the lower end portion, or vice versa.

(Evaluation method)
The presence or absence of the crack-containing layer 7b2 and the crack 7bc includes, for example, the first joining member 7a and the support member 7b of the fixing member 7, and the cross section along the second direction y, that is, the vertical cross section of the fixing member 7 is scanned by a scanning electron microscope. It can be confirmed by observing with (SEM). The vertical cross section of the fixing member 7 may be a cross section along the first direction x and the second direction y. If the fixing member 7 has a crack 7bc near the boundary between the first joining member 7a and the support member 7b, it is determined that the support member 7b has the crack-containing layer 7b2. The vicinity of the boundary between the first joining member 7a and the support member 7b is a region where the distance from the boundary between the support member main body 7b1 and the first joining member 7a is approximately 100 μm or less, and further 50 μm or less. The height h of the first joining member 7a in the second direction y and the maximum length l of the crack 7bc are h and the maximum crack in each image using, for example, images of 10 vertical sections of the fixing member 7. The length of the second direction y of 7 bc may be measured, and the average value of h and the maximum length l of the crack 7 bc may be calculated.

(Manufacturing method)
The support member 7b having the crack-containing layer 7b2 can be produced by the following method. An inorganic oxide film is formed on a portion of the support member main body 7b1 to be joined to the first joining member 7a by, for example, a thermal spraying method, a vapor deposition method, an electrodeposition method, or a sputtering method. In particular, in the thermal spraying method, since the temperature change during film formation is steep, microcracks are likely to be formed in the inorganic oxide film. The microcrack is a crack having a width of 10 μm or less. Here, the width of the crack is the distance between the inner surfaces of the cracks facing each other across the crack. The microcracks may be formed, for example, by the stress generated from the difference between the linear thermal expansion coefficient of the support member main body 7b1 and the linear thermal expansion coefficient of the inorganic oxide film.

Alternatively, a slurry may be prepared using the nano-sized fine powder of the above-mentioned material, applied to the support member main body 7b1, and fired. By using the nano-sized fine powder, the crack-containing layer 7b2 having the crack 7bc can be formed.

The cell stack device 10 can be manufactured by the following method. A plurality of cells 1 are arranged and fixed in a stack shape using a predetermined jig or the like. Next, while maintaining this state, one end of the plurality of cells 1 is inserted into the insertion hole 12 of the support member 7b. Next, a paste such as amorphous glass is filled in the gap between the insertion hole 12 and one end of the plurality of cells 1.

Next, heat treatment is performed on the paste filled as described above. When the temperature of the amorphous material reaches the crystallization temperature by this heat treatment, a crystal phase is generated inside the material under the crystallization temperature, and crystallization proceeds. After the heat treatment, the jig is removed from the plurality of cells 1.

Finally, the support member 7b is joined to the gas tank 8. In this step, first, the recessed groove 8b of the gas tank 8 is filled with the paste for the second joining member 8a. Then, it may be heat-treated to crystallize. In this way, the cell stack device 10 can be manufactured.

(module)
FIG. 10 is an external perspective view showing one of the examples of the module including the cell stack device.

The module 20 includes a storage container 21 and a cell stack device 10 housed in the storage container 21. A reformer 22 is arranged above the cell stack device 10.

The reformer 22 reforms raw fuels such as natural gas and kerosene to generate fuel gas and supplies it to cell 1. The raw material fuel is supplied to the reformer 22 through the raw material fuel supply pipe 23. The reformer 22 may include a vaporizing unit 22a for vaporizing water and a reforming unit 22b. The reforming unit 22b includes a reforming catalyst (not shown), and reforms the raw material fuel into a fuel gas. Such a reformer 22 can perform steam reforming, which is a highly efficient reforming reaction.

The fuel gas generated by the reformer 22 is supplied to the gas flow path 2a of the cell 1 through the gas flow pipe 13, the gas tank 8, and the support member 7b.

FIG. 10 shows a state in which the front surface portion and the rear surface portion, which are a part of the storage container 21, are removed, and the cell stack device 10 housed inside the storage container 21 is taken out rearward.

In the above-mentioned module 20, the temperature inside the module 20 at the time of normal power generation becomes about 500 ° C. or higher and 1000 ° C. or lower due to the combustion of gas and the power generation of the cell 1.

By using the cell stack device 10 having the crack-containing layer 7b2 in the fixing member 7 as the cell stack device 10 of the module 20, cracks are less likely to occur in the first joining member 7a, and the module has high durability. It can be 20.

(Module storage device)
FIG. 11 is an exploded perspective view showing one of the examples of the module accommodating device. In FIG. 11, some configurations are omitted. The module accommodating device includes an outer case, a module housed in the outer case, and an auxiliary machine for operating the module.

The exterior case of the module accommodating device 30 shown in FIG. 11 has a support column 31 and an exterior plate 32. The partition plate 33 vertically partitions the inside of the outer case. The space above the partition plate 33 in the outer case is the module storage chamber 34 for accommodating the module 20, and the space below the partition plate 33 in the outer case is the supplement for accommodating the auxiliary machine for operating the module 20. The aircraft accommodation room 35. The description of the auxiliary equipment accommodated in the auxiliary equipment accommodation chamber 35 is omitted.

The partition plate 33 has an air flow port 36 for flowing the air of the auxiliary machine accommodating chamber 35 to the module accommodating chamber 34 side. A part of the exterior plate 32 forming the module accommodating chamber 34 has an exhaust port 37 for exhausting the air in the module accommodating chamber 34.

By accommodating the module 20 having the above-mentioned high durability in the module accommodating chamber 34 of such a module accommodating device 30, the module accommodating device 30 having high durability can be obtained.

Although the present disclosure has been described in detail above, the present disclosure is not limited to the above-described embodiment. The cell stack device, module, and module accommodating device of the present disclosure can be variously modified, improved, and the like without departing from the gist of the present disclosure.

Further, the present disclosure is not limited to the so-called "vertical stripe type" in which only one power generation element unit having a fuel electrode, a solid electrolyte layer and an air electrode is provided on the surface of the above-mentioned support substrate. In the cell stack device of the present disclosure, so-called "horizontal stripe type" cells are provided in which power generation element portions are provided at a plurality of positions on the surface of the support substrate and are electrically connected between adjacent power generation element portions. It can be applied to a laminated horizontal stripe type cell stack device. The present disclosure can also be applied to cell stacking devices for "cylindrical" cells. Further, the cell stack device of the present disclosure can also be applied to a flat cell stack device in which so-called "flat plate type" cells are stacked in the thickness direction.

As shown in FIG. 12, for example, the flat plate type cell has an element portion in which a fuel electrode layer 3, a solid electrolyte layer 4, and an air electrode layer 5 are laminated. In the flat cell stack, for example, a plurality of flat cells are electrically connected by a metal layer 6. The metal layer 6 electrically connects adjacent flat cells to each other and forms a gas flow path for supplying gas to the fuel electrode layer 3 or the air electrode layer 5. As shown in FIG. 13, the flat plate type cell stack device has a sealing material that airtightly seals the gas flow path of the fuel gas of the flat plate type cell stack and the gas flow path of the oxygen-containing gas. The sealing material is a cell fixing member 7, and has a first joining member 7a and

support members

7b and 7c which are frames. The first joining member 7a may be glass or a metal material such as silver brazing.

The support member 7b may be a so-called separator that separates the fuel gas flow path and the oxygen gas flow path. The materials of the

support members

7b and 7c may be, for example, a conductive metal or an insulating ceramic. When the first joining member 7a is an insulating material such as glass, both the supporting

members

7b and 7c may be made of metal, or one of them may be made of an insulating material. When the first joining member 7a is a conductive metal, the

support members

7b and 7c may be made of an insulating material. When the

support members

7b and 7c are made of metal, the

support members

7b and 7c may be integrated with the metal layer 6.

Any one of the first joining member 7a, the

support member

7b, and 7c is insulating, and the two metal layers 6 sandwiching the flat cell are electrically insulated from each other.

FIG. 14 is an enlarged view of the B region shown by the broken line in FIG. In the case of the flat plate type cell stack device, as in the case of the vertical stripe type cell stack device described above, as shown in FIG. 14, the support member 7b has a crack 7bc between the support member main body 7b1 and the first joining member 7a. By having the crack-containing layer 7b2 containing the above, it is possible to make it difficult for cracks to occur in the first joining member 7a, and it is possible to make it difficult for fuel gas and oxygen-containing gas to leak. In FIG. 14, the first direction x is the direction perpendicular to the interface between the support member 7b and the first joining member 7a, and the second direction y is the horizontal direction of FIG. 1, that is, the fuel gas of the first joining member 7a. The direction from the first end in contact to the second end in contact with the oxygen-containing gas, in other words, the direction in which the first end and the second end are connected at the shortest.

Further, in the above embodiment, the fuel cell, the fuel cell stack device, the fuel cell module, and the fuel cell device are used as one of the examples of the "cell", the "cell stack device", the "module", and the "module accommodating device". Although shown, other examples may be an electrolytic cell, an electrolytic cell stack device, an electrolytic module, and an electrolytic device, respectively.

1: Cell 2: Support substrate 2a: Gas flow path 3: Fuel pole 4: Solid electrolyte layer 5: Air pole 6: Interconnector, metal layer 7: Fixing member 7a: First joining

member

7b, 7c: Support member 7b1: Support member body 7b2: Crack-containing layer 7bc: Crack-containing layer crack 7b3: Crack containing bonding material inside 7b4: Interface without crack, 1st part 8: Gas tank 8a: 2nd bonding member 8b: Concave groove 10: Cell stack device 11: Cell stack 12: Insert hole 13: Gas flow pipe 20: Module 21: Storage container 30: Module storage device

Claims

A plurality of cells, a support member, and a joining member for joining the cell and the support member are provided.
The support member has a support member main body and a crack-containing layer located between the support member main body and the joint member and containing a crack.
The joining member has a first end portion in contact with the first gas and a second end portion in contact with a second gas different from the first gas.
When the direction perpendicular to the interface between the support member and the joining member is the first direction and the direction from the first end portion to the second end portion of the joining member is the second direction, the second direction. A cell stack device in which the maximum length of the crack is smaller than the length of the joining member.
The cell stack device according to claim 1, wherein the maximum length of the crack is 2/3 or less of the length of the joining member in the second direction in the cross section along the first direction and the second direction.
The cell stack device according to claim 1 or 2, wherein the crack-containing layer has the crack containing the joining material contained in the joining member inside.
The cell stack device according to any one of claims 1 to 3, wherein the support member main body has a first portion that is in direct contact with the joining member in a part of the second direction.
The cell stack device according to claim 4, wherein the first portion is located at at least one end of two ends of the support member main body in the second direction.
The cell stack device according to any one of claims 1 to 5, wherein the crack-containing layer contains an inorganic oxide.
The cell stack device according to any one of claims 1 to 6, wherein the arithmetic mean roughness of the surface of the support member having the crack-containing layer is larger than the arithmetic mean roughness of the surface having no crack-containing layer.
A module comprising a storage container and the cell stack device according to any one of claims 1 to 7 housed in the storage container.
A module accommodating device including an outer case, the module according to claim 8 and an auxiliary machine for operating the module, which are housed in the outer case.