JP6599696B2 - Cell stack device, module and module housing device - Google Patents

Description

  The present invention relates to a cell stack device, a module, and a module housing device.

  In recent years, as a next-generation energy, a fuel cell stack in which a plurality of fuel cells which are one type of cells capable of obtaining electric power using a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air) are arranged. Various fuel cell modules in which the device is housed in a storage container and fuel cell devices in which the fuel cell module is housed in an outer case have been proposed (see, for example, Patent Document 1).

  Moreover, in the fuel cell stack apparatus of patent document 1, the one end part of a some fuel cell is joined to the support body with the sealing material. One end of the support is joined to the gas tank.

JP 2013-157191 A

  However, in the fuel cell stack device described in Patent Document 1, cracks or the like are generated in the sealing material, which may cause gas leaks, and it has been required to suppress the gas leaks.

  Therefore, an object of the present invention is to provide a cell stack device that can suppress the occurrence of cracks in the sealing material and has improved long-term reliability, a module including the cell stack device, and a module housing device.

The cell stack apparatus of the present invention includes a cell stack in which a plurality of cells are arranged, a support having one or a plurality of insertion ports into which one ends of the plurality of cells are inserted, and the plurality of the plurality of cells. A first sealing material joining one end of the cell and the inner wall of the insertion port, and an opening for supplying a reaction gas to the plurality of cells through the insertion port, A gas tank having a concave groove provided around the opening, and one end of the support is joined to the gas tank by a second sealing material filled in the concave groove of the gas tank, The second sealing material has a first region having a lower porosity than the other part around one end of the support, and the second sealing material includes a pore- forming material. The content of the pore former in the region is less than the other parts Or a surface layer side of the second sealing member in the other part, smaller porosity than the bottom side of the groove, and wherein the porosity of the bottom side is 8% or more.

  The module of the present invention is characterized in that the cell stack device described above is housed in a housing container.

  Furthermore, the module housing apparatus of the present invention is characterized in that the module described above and an auxiliary machine for operating the module are housed in an exterior case.

  The cell stack device of the present invention can suppress the occurrence of cracks in the sealing material, and can be a cell stack device with improved long-term reliability.

  In addition, the module of the present invention can be a module with improved long-term reliability since the cell stack device is stored in a storage container.

  Furthermore, since the module housing apparatus of the present invention houses the above-described module and an auxiliary machine for operating the module, the module housing apparatus can be improved in long-term reliability.

An example of the cell of this embodiment is shown, (a) is a cross-sectional view, (b) is a side view. (A) is a perspective view which shows an example of the cell stack apparatus of this embodiment, (b) is sectional drawing by the side of (a). (A) is a schematic perspective view of the cell stack apparatus shown in FIG. 2, and (b) is an enlarged sectional view of the vicinity of one end of the cell stack. It is an expanded sectional view near the junction part of a cell stack and a support. (A)-(c) is an expanded sectional view for demonstrating a 2nd sealing material. It is an external appearance perspective view which shows the module provided with an example of the cell stack apparatus of this embodiment. It is a disassembled perspective view which shows roughly an example of the module accommodating apparatus of this embodiment. (A) is a top view which shows the other example of the support body of this embodiment, (b) is an expanded sectional view by the side of the cell stack apparatus provided with the support body shown to (a). It is a perspective view which shows the other example of the cell stack apparatus of this embodiment. It is a perspective view which shows the other example of the cell stack apparatus of this embodiment.

  A cell, a cell stack device, a module, and a module housing device will be described with reference to FIGS.

(cell)
Hereinafter, an example of a solid oxide fuel cell will be described as a cell constituting the cell stack.

  FIG. 1 shows an example of an embodiment of a cell, where (a) is a cross-sectional view and (b) is a side view. In addition, in this drawing, a part of each structure of the cell 1 is expanded and shown.

  In the example shown in FIG. 1, the cell 1 is a hollow plate type and has an elongated plate shape. As shown in FIG.1 (b), the shape which looked at the whole cell 1 from the side surface is 5-50 cm in the length of the side of the length direction L, for example, and the width direction W orthogonal to this length direction is It is a rectangle with a length of 1 to 10 cm. The total thickness of the cell 1 is 1 to 5 mm.

  As shown in FIG. 1, the cell 1 is formed on one flat surface n1 of a columnar conductive support substrate 2 (hereinafter sometimes abbreviated as support substrate 2) having a pair of opposed flat surfaces n1 and n2. It has a columnar shape (hollow flat plate shape or the like) formed by laminating element portions each including a fuel electrode 3, a solid electrolyte layer 4, and an air electrode 5.

  In the example shown in FIG. 1, an interconnector 6 is provided on the other flat surface n <b> 2 of the cell 1.

  Hereinafter, each structural member which comprises the cell 1 is demonstrated.

  The support substrate 2 is provided with a gas flow path 2a through which gas flows, and FIG. 1 shows an example in which six gas flow paths 2a are provided. The support substrate 2 is required to be gas permeable in order to allow the fuel gas to pass to the fuel electrode 3 and further to be conductive in order to collect current through the interconnector 6. The support substrate 2 is made of, for example, an iron group metal component and an inorganic oxide. For example, the iron group metal component is Ni and / or NiO, and the inorganic oxide is a specific rare earth element oxide.

As the fuel electrode 3, generally known ones can be used, and porous conductive ceramics such as ZrO ₂ in which a rare earth element oxide is dissolved (referred to as stabilized zirconia, including partial stabilization). And Ni and / or NiO. For example, Y ₂ O ₃ is used as the rare earth oxide.

The solid electrolyte layer 4 has a function as an electrolyte for bridging ions between the fuel electrode 3 and the air electrode 5 and at the same time has a gas barrier property to prevent leakage of the fuel gas and the oxygen-containing gas. And is formed from ZrO ₂ in which 3 to 15 mol% of a rare earth element oxide is dissolved. For example, Y ₂ O ₃ is used as the rare earth element oxide. In addition, as long as it has the said characteristic, you may form using another material etc.

The air electrode 5 is not particularly limited as long as it is generally used. For example, the air electrode 5 can be formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. For example, a composite oxide in which Sr and La coexist on the A site is preferable. Examples _include such _{La x Sr 1-x Co y} Fe 1-y O 3, La x Sr 1-x MnO 3, La x Sr 1-x FeO 3, La x Sr 1-x CoO 3 and the like. Note that x is 0 <x <1, and y is 0 <y <1. The air electrode 5 is required to have gas permeability, and the open porosity is preferably 20% or more, particularly preferably in the range of 30 to 50%.

For the interconnector 6, a lanthanum chromite-based perovskite oxide (LaCrO ₃ -based oxide) or a lanthanum strontium titanium-based perovskite oxide (LaSrTiO ₃ -based oxide) is preferably used. These materials have conductivity and are neither reduced nor oxidized even when they come into contact with a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air or the like). Further, the interconnector 6 must be dense to prevent leakage of the fuel gas flowing through the gas flow path 2a formed in the support substrate 2 and the oxygen-containing gas flowing outside the support substrate 2, It is preferable to have a relative density of 93% or more, particularly 95% or more.

(Cell stack device)
Next, the cell stack apparatus according to the present embodiment using the above-described cell will be described with reference to FIGS.

  FIG. 2A is a perspective view illustrating an example of the cell stack device of the present embodiment, and FIG. 2B is a cross-sectional view of the side surface of FIG. FIG. 3A is a schematic perspective view of the cell stack apparatus shown in FIG. 2, and FIG. 3B is an enlarged cross-sectional view of the vicinity of one end of the cell stack. FIG. 4 is an enlarged cross-sectional view of the vicinity of the joint between the cell stack and the support. FIGS. 5A to 5C are enlarged cross-sectional views for explaining the second sealing material.

  The cell stack apparatus 10 includes a cell stack 18 having a plurality of cells 1 arranged and a manifold 7.

As shown in FIGS. 2 and 3, the manifold 7 includes a support 7a and a gas tank 7b.

  The support 7a has one or a plurality of insertion ports 17 into which one ends of the plurality of cells 1 are inserted. One end of the plurality of cells 1 and the inner wall of the insertion port 17 are joined by a first sealing material 8a.

  The gas tank 7b has an opening for supplying reaction gas to the plurality of cells 1 through the insertion port 17, and has a concave groove 71 provided around the opening. One end of the support 7a is joined to the gas tank 7b by a second sealing material 8b filled in the concave groove 71 of the gas tank 7b.

  In the example shown in FIGS. 2 and 3, fuel gas is stored in an internal space formed by the support 7a and the gas tank 7b. The gas tank 7 b is provided with a gas flow pipe 12, and fuel gas generated by a reformer 13 described later is supplied to the manifold 7 through the gas flow pipe 12, and then the inside of the cell 1 is supplied from the manifold 7. To the gas flow path 2a.

  Each cell 1 protrudes from the manifold 7 side along the longitudinal direction of the cell 1 and one end in the longitudinal direction of each cell 1 is a first sealing material 8a and a support 7a so that the plurality of cells 1 are aligned in a stack. It is fixed to.

  In the example shown in FIGS. 2 and 3, a plurality of cells 1 are provided in two rows, and each row is fixed to a support 7a. In this case, two through holes are provided on the upper surface of the gas tank 7b. Each support body 7a is provided so that the insertion hole 17 is aligned with each of the through holes. As a result, an internal space is formed by one gas tank 7b and two supports 7a.

  The shape of the insertion hole 17 is, for example, an ellipse when viewed from above. For example, the insertion hole 17 may be longer than the distance between the two end conductive members 9b in the cell 1 arrangement direction. Moreover, the width of this insertion hole should just be longer than the length of the width direction W of the cell 1, for example.

  As shown in FIGS. 2 and 3, there are gaps between the inner wall of the insertion hole 17 and the outer surface of the cell 1, and between the cells 1.

  As shown in FIGS. 2 and 3, the solidified first sealing material 8 a is filled in the gap at the joint between the insertion hole 17 and one end of the cell 1. Thereby, the insertion hole 17 and the one end of the some cell 1 are joined and fixed, respectively. One end of the gas flow path 2 a of each cell 1 communicates with the internal space of the manifold 7.

The first sealing material 8a and the second sealing material 8b may be made of amorphous glass, metal brazing material, or the like, but is preferably made of crystallized glass. As the crystallized glass, for example, a SiO ₂ —B ₂ O ₃ system, a SiO ₂ —CaO system, or a MgO—B ₂ O ₃ system can be adopted, but a SiO ₂ —MgO system is most preferable. In this specification, crystallized glass means that the ratio (crystallinity) of “volume occupied by crystal phase” to the total volume is 60% or more, and “volume occupied by amorphous phase and impurities relative to the total volume”. "Refers to glass (ceramics) having a ratio of less than 40%. The crystallinity of the crystallized glass is specifically determined by, for example, “the crystal phase and the composition after the crystal phase is identified by using XRD or the like and crystallized by using SEM and EDS or SEM and EPMA. The volume ratio of the crystal phase region is calculated based on the result of observing the distribution.

In addition, as in the example shown in FIG. 2B, between adjacent cells 1 between adjacent cells 1 (
More specifically, a conductive member 9a for electrically connecting the fuel electrode 3 of one cell 1 and the air electrode 5) of the other cell 1 in series is interposed. 2A and 3, illustration of the conductive member 9a is omitted.

  Further, as in the example illustrated in FIG. 2B, the end conductive member 9 b is connected to the cell 1 positioned on the outermost side in the arrangement direction of the plurality of cells 1. The end conductive member 9 b has a conductive portion 11 that protrudes outside the cell stack 5. The conductive portion 11 has a function of collecting the electricity generated by the power generation of the cell 1 and drawing it out. In FIG. 2A and FIG. 3, the end conductive member 9b is not shown.

  As described above, when the cell stack apparatus 10 of the fuel cell described above is operated, a high-temperature (for example, 600 to 800 ° C.) fuel gas (such as hydrogen) and “gas containing oxygen (such as air)” are circulated. The fuel gas is introduced into the internal space of the manifold 7 and then introduced into the gas flow paths 2 a of the plurality of cells 1 through the insertion holes 17. The fuel gas that has passed through each gas flow path 2a is then discharged to the outside from the other end (free end) of each gas flow path 2a. Air flows along the longitudinal direction of the cell 1 along the gap between the adjacent cells 1.

(Suppression of gas leak in the first seal material)
In the cell stack device 10 shown in FIGS. 2 and 3, when operated in a severe environment due to thermal stress, the heat of the support 7 a and the second sealing material 8 b covering one end of the support 7 a. There was a possibility that the second sealing material 8b would crack due to the expansion difference. Thereby, the support body 7a comes to move with thermal expansion. Therefore, when the cell stack device is generated for a long period of time, the first sealing material 8a that joins the support 7a and the cell stack 18 is repeatedly stressed to cause cracks and gas leaks.

  Therefore, in the cell stack device 10 of the present embodiment, as shown in FIG. 4, the second sealing material 8 b is disposed around the one end portion of the support 7 a in the first region 81 having a lower porosity than the other portion 82. have.

  According to this configuration, even when a difference in thermal expansion occurs between the support 7a and the second seal material 8b, the strength of the surrounding second seal material 8b covering one end of the support 7a is high. For this reason, it is possible to suppress the occurrence of cracks in the second sealing material 8b, and it is possible to improve long-term reliability. Therefore, it is possible to suppress the support 7a from moving together with the thermal expansion, and it is possible to strengthen the fixing by the second sealing material 8b at one end of the support 7a. In addition, since it is possible to suppress the movement of the support 7a, when the cell stack device 10 generates power for a long period of time, the first sealing material 8a that joins the support 7a and the cell stack 18 is repeatedly stressed. Since this can be suppressed, it is possible to suppress the occurrence of a gas leak due to a crack in the first sealing material 8a.

  Below, the 1st field 81 is defined using Drawing 5 (a). First, a line is drawn from the point A2 100 μm away from the point A1 on one side surface of one end of the support 7a toward the bottom surface of the groove 71. This line is a line along the length direction of one end of the support 7a. A similar line is also drawn on the other side surface of the one end portion of the support 7a. It is sandwiched between the line on one side of one end of the support 7a, the line on the other side of the one end of the support 7a, the bottom of the groove 71, and the surface of the second sealing material 8b. This area is referred to as a first area 81.

  The other portion 82 is a region other than the first region 81 in the cross section of the second sealing material 8b.

In the other portion 82, the surface layer side 82 a of the second sealing material 8 b may have a lower porosity than the bottom surface side 82 b of the concave groove 71. When the cell stack device 10 generates power for a long period of time, stress is applied between the support 7a and the inner wall of the concave groove 71 due to thermal expansion deformation of the support 7a, but this stress tends to be relatively large. 2 is the surface layer side 82a of the sealing material 8b. Accordingly, in the other portion 82, the surface layer side 82a of the second sealant 8b has a smaller porosity than the bottom surface side 82b of the concave groove 71, so that the strength of the portion where stress is likely to concentrate can be improved. The occurrence of cracks in the two-seal material 8b can be suppressed.

  Moreover, in the other part 82, it is good for the porosity to become small gradually from the bottom face side 82b of the ditch | groove 71 toward the surface layer side 82a of the 2nd sealing material 8b. According to this configuration, the strength can be gradually increased toward the surface layer side 82a where the stress tends to increase between the support 7a and the inner wall of the concave groove 71. Therefore, the generation of cracks can be suppressed in the region from the bottom surface side 82b to the surface layer side 82a.

  Further, in the cross-sectional view, the pores on the bottom surface side of the groove 71 in the other portion 82 are elliptical, and the long axis may not be directed to one end of the support 7a. This means that the extended line of the major axis of the elliptical pore does not overlap with one end of the support 7a. According to this configuration, even if a crack is generated due to a difference in thermal expansion between the support 7a and the second sealing material 8b, the crack does not face one end of the support 7a.

  Further, the porosity of the first region 81 is preferably 5% or less. According to this structure, since the intensity | strength of the surrounding 2nd sealing material 8b which covers the one end part of the support body 7a becomes high, it can further suppress that a crack arises in the 2nd sealing material 8b.

The porosity of the surface layer side 8 2 a of the second seal member 8b in the other portion 82 may is 6% or less. According to this configuration, since the strength of the surface layer side 8 2 a is increased, it can be further suppressed from cracking in the second seal member 8b.

(Measuring method)
The porosity of the first region 81 and the other portion 82 is measured by the following method in each region. First, the second sealing material 8b is cut together with the support 7a and the gas tank 7b so as to obtain a cross section as shown in FIG. This section is mechanically polished. The microstructure of the second sealing material 8b in this cross section is observed using a scanning electron microscope using a backscattered electron detector, and image processing is performed on the obtained image. In the image, since the second sealant 8b is gray and the pores are white, by calculating the area of each color, the “total area (the sum of the area of the pore portion and the area of the non-pore portion)” The ratio of the “area of the part” is defined as the porosity.

  A method for confirming that “in the other portion 82, the surface layer side 82a of the second sealant 8b has a lower porosity than the bottom surface side 82b of the groove 71” will be described below.

  First, a description will be given with reference to FIG. First, the contact A1 between the surface of the second sealing material 8b and one end of the support 7a is taken out. A line is drawn horizontally from the point A1 toward the inner wall of the groove 71. Let A2 be the intersection of this line and the boundary of the first region 81. The intersection of this line and the inner wall of the groove 71 is A3. Next, let the lowest end part of the one end part of the support body 7a be B1. Then, B2 and B3 are determined in the same manner as A2 and A3. Next, three points are set at equal intervals along line A2-A3, and the porosity of a 10 μm square region is calculated by the same image processing method as described above so as to include each point, and an average value is obtained. Next, the average value of the porosity is similarly obtained along the line B2-B3.

  As a result of the above measurement, if the average value of the porosity of the line A2-A3 is smaller than the average value of the porosity of the line B2-B3, “in the other portion 82, the surface layer of the second sealing material 8b. The side 82a has a lower porosity than the bottom surface side 82b of the groove 71 ".

  Next, a description will be given with reference to FIGS. 5B and 5C. 5 (b) and 5 (c), the surface of the second sealing material 8b is inclined, but as in FIG. 5 (a), the point A1 is supported by the surface of the second sealing material 8b. It is a contact point with one end of the body 7a. Moreover, in FIG.5 (b) and FIG.5 (c), the front-end | tip of the one end part of the support body 71 is sharp. Also in this case, similarly to the case of FIG. 5A, the lowermost end portion of one end portion of the support 7a is set to B1. Except for these, the same method as that shown in FIG.

  A confirmation method of “the porosity of the other portion 82 gradually decreases from the bottom surface side 82b of the concave groove 71 toward the surface layer side 82a of the second sealing material 8b” is shown in FIG. It demonstrates below using (c). First, similarly to the above, the average value of the porosity of the line A2-A3 and the average value of the porosity of the line B2-B3 are calculated. Next, an intermediate point C1 between the points A2 and B2 is determined. Next, an intermediate point C2 between the points A3 and B3 is determined. Next, along the line C1-C2, the average value of the porosity is obtained in the same manner as the lines A2-A3 and B2-B3.

  If the average value of the porosity of the line C1-C2 is an intermediate value between the average value of the porosity of the line A2-A3 and the average value of the porosity of the line B2-B3, “the other portion 82”. , The porosity gradually decreases from the bottom surface side 82b of the concave groove 71 toward the surface layer side 82a of the second sealing material 8b.

The calculation method of “the porosity of the surface layer side 8 2 a of the second sealing material 8b in the other portion 82” is the same as the calculation method of the average value of the porosity along the line A2-A3 described above.

(Production method)
An example of a method for manufacturing the cell stack device 10 of the present embodiment described above will be described. However, various conditions such as materials and temperatures described below can be changed as appropriate.

  The cell stack apparatus 10 is assembled by the following procedure, for example. First, the required number of completed cells 1 and the support 7a are prepared. Next, a plurality of cells 1 are aligned and fixed in a stack using a predetermined jig or the like. Next, one end of each of the plurality of cells 1 is inserted into the insertion hole 17 of the support 7a at a time while maintaining this state. Next, a paste for the first sealing material 8a (typically an amorphous material (amorphous glass) paste) is filled in the gaps between the insertion holes 17 and one end of the plurality of cells 1. To do.

  Next, heat treatment (crystallization treatment) is performed on the paste for the first sealing material 8a filled as described above. When the temperature of the amorphous material reaches its crystallization temperature by this heat treatment, a crystal phase is generated inside the material at the crystallization temperature, and crystallization proceeds. As a result, the amorphous material is solidified and ceramicized to become crystallized glass. Thereby, one end of the plurality of cells 1 is joined and fixed to the insertion hole 17 via the first sealing material 8 a made of crystallized glass. In other words, one end of each cell 1 is joined and supported by the support 7a using the first sealing material 8a. Thereafter, the predetermined jig is removed from the plurality of cells 1.

Next, the support body 7a is joined to the gas tank 7b. In this step, first, the concave groove 71 of the gas tank 7b is filled with the paste for the second sealing material 8b. When filling, a partition plate is provided in the groove 71. For example, the partition plate is divided into a central side and an outer region in the groove 71. The central region is filled with a paste containing almost no pore former, and the outer region is filled with a paste containing more pore former than the central side. Next, one end of the support 7a is inserted into a paste that hardly contains a pore former. Then, the partition plate may be removed and crystallized by heat treatment in the same manner as the first sealing material 8a. In the cell stack device 10 thus obtained, the second sealing material 8b has a first region 81 having a lower porosity than the other portion 82 around one end of the support 7a.

  Moreover, in order to produce the 2nd sealing material 8b "in the other part 82, the surface layer side 82a of the 2nd sealing material 8b has a porosity smaller than the bottom face side 82b of the ditch | groove 71", a partition plate is used. First, a paste containing a large amount of a pore former may be injected into the outer region, and then a paste having a relatively small amount of the pore former may be injected.

(module)
Next, a module according to an embodiment of the present invention using the above-described cell stack device will be described with reference to FIG. FIG. 6 is an external perspective view showing a module including an example of the cell stack device of the present embodiment.

  As shown in FIG. 6, the module 20 stores the cell stack device 10 in a storage container 14. A reformer 13 for generating fuel gas to be supplied to the cell 1 is disposed above the cell stack device 10.

  Further, in the reformer 13 shown in FIG. 6, raw gas such as natural gas and kerosene supplied through the raw fuel supply pipe 16 is reformed to generate fuel gas. The reformer 13 preferably has a structure capable of performing steam reforming, which is an efficient reforming reaction, and a reformer 13a for vaporizing water and reforming raw fuel into fuel gas. And a reforming section 13b in which a reforming catalyst (not shown) for performing the above is disposed. The fuel gas generated by the reformer 13 is supplied to the manifold 7 via the gas flow pipe 12 and is supplied from the manifold 7 to the gas flow path provided inside the cell 1.

  Further, FIG. 6 shows a state in which a part (front and rear surfaces) of the storage container 14 is removed and the fuel cell stack device 10 stored inside is taken out rearward.

  Moreover, in the module 20 of the above-mentioned structure, the temperature in the module 20 becomes about 500-1000 degreeC with the said combustion and the power generation of the cell 1 at the time of normal power generation.

  In such a module 20, as described above, the module 20 with improved long-term reliability can be obtained by housing the cell stack device 10 with improved long-term reliability.

(Module housing device)
FIG. 7 is an exploded perspective view showing an example of the module housing apparatus of the present embodiment in which the module 20 shown in FIG. 6 and an auxiliary machine (not shown) for operating the module 20 are housed in the outer case. FIG. In FIG. 7, a part of the configuration is omitted.

  The module housing apparatus 40 shown in FIG. 7 divides the inside of the exterior case composed of the columns 41 and the exterior plate 42 by a partition plate 43, and the upper side thereof serves as a module storage chamber 44 that houses the module 20 described above. The lower side is configured as an auxiliary machine storage chamber 45 for storing an auxiliary machine for operating the module 20. In addition, the auxiliary machine stored in the auxiliary machine storage chamber 45 is not shown.

  In addition, the partition plate 43 is provided with an air circulation port 46 for allowing the air in the auxiliary machine storage chamber 45 to flow toward the module storage chamber 44, and a part of the exterior plate 42 constituting the module storage chamber 44, An exhaust port 47 for exhausting air in the module storage chamber 44 is provided.

In such a module storage device 40, as described above, the module 20 with improved long-term reliability is stored in the module storage chamber 44, and an auxiliary machine for operating the module 20 is stored in the auxiliary machine storage chamber 45. Thus, the module accommodating device 40 with improved long-term reliability can be obtained.

  Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the scope of the present invention.

  In the present embodiment, a so-called “vertical stripe type” configuration in which only one power generation element portion including an inner electrode, a solid electrolyte layer, and an outer electrode is provided on the surface of the support substrate is employed. A so-called “horizontal stripe type” cell may be employed in which the power generation element portions are provided at a plurality of locations separated from each other, and between adjacent power generation element portions are electrically connected.

  In the cell of the above embodiment, the fuel electrode and the air electrode may be interchanged so that the inner electrode is an air electrode and the outer electrode is a fuel electrode. In this case, a gas flow in which fuel gas and air are exchanged is employed.

  The support substrate may also serve as a fuel electrode, and a cell may be configured by sequentially laminating a solid electrolyte layer and an air electrode on the surface thereof.

  Moreover, in the said embodiment, as shown to FIG. 2, FIG. 3, although the end of all the cells 1 of one row is inserted in the insertion hole 17 formed only in the support body 7a, it shows in FIG. Thus, one cell 1 may be inserted into each of the plurality of insertion holes 17 formed in the support 7a.

  In the above embodiment, a cell stack device in which a plurality of cells are arranged in two rows as shown in FIG. 2 is shown. However, as shown in FIG. 9, a plurality of cells are arranged in one row. Alternatively, the cell stack apparatus 100 may be used.

  In the above embodiment, the fuel cell, the fuel cell stack device, the fuel cell module, and the fuel cell device are shown as examples of the “cell”, “cell stack device”, “module”, and “module housing device”. Other examples may be an electrolytic cell, an electrolytic cell stack device, an electrolytic module, and an electrolytic device, respectively.

  FIG. 10 shows an example of the electrolytic cell stack apparatus 110. The other end (upper end) of the cell 1 is fixed to the manifold by the first sealing material 8a, and the first manifold 71 serves as a supply unit for supplying high-temperature steam, and the second manifold 72 is generated. It becomes a recovery unit for recovering hydrogen. In the example shown in FIG. 10, the gas flow pipe 12 supplies water vapor, and the gas flow pipe 16 collects hydrogen.

(Sample preparation)
About the cell stack apparatus (refer FIG. 3) mentioned above, the several sample from which the porosity of a 2nd sealing material differs based on the above-mentioned manufacturing method was produced. Specifically, as shown in Table 1, nine samples (N = 9) were produced.

Each sample of the cell stack apparatus includes 30 cells. The shape of the cell used in each sample was the same plate shape as in FIG. The manufacturing method of the cell and cell stack device was the same as described above. The length in the longitudinal direction of the cell was 20 cm, the length in the width direction of the cell was 20 mm, and the thickness was 2 mm. As the shape of the opening of the support insertion hole, one elliptical shape was adopted as in FIGS. The first sealing material and the second sealing material are SiO ₂ —MgO—B ₂ O
_{A 5-} Al ₂ O ₃ system was used. Stainless steel was used as the material for the support (manifold).

(Measurement of porosity)
Next, the porosity of the 2nd sealing material of the cell stack apparatus produced as mentioned above was measured. The results are shown in Table 1.

  The measurement was performed after the test described later. As described above, after the mechanical polishing of the cross section of the second sealing material as described above, the microstructure of the cross section was observed with a scanning electron microscope using a backscattered electron detector, and the area ratio was calculated by image processing. .

(An endurance test)
For each of the above samples, a thermal cycle test that repeats 10 times “a pattern in which the ambient temperature is raised from room temperature to 750 ° C. in 1 hour and then lowered from 750 ° C. to room temperature in 2 hours while fuel gas is circulated in the gas tank”. Went.

  After this test, helium gas was flowed into the gas tank. Then, in order to investigate whether or not helium gas leak occurred, a handy type leak detector was brought close to each cell, and it was confirmed whether or not a gas leak occurred at the junction with the sealing material in each cell. The number of cells in which gas leak occurred in each sample stack was counted. The results are shown in Table 1. S, A, B, C, and D mean that the number of cells in which a gas leak has occurred is 0, 1-2, 3-4, 5-6, and 7-8, respectively.

  Further, after the gas leak was confirmed, the number of cracks in the second sealing material was confirmed. The confirmation was performed by observing the microstructure of the cross section with a scanning electron microscope using a backscattered electron detector after mechanical polishing of the cross section of the second sealing material as described above. A crack that reached a length of 1 μm was counted as a crack. The results are shown in Table 1. In addition, the crack which generate | occur | produced by the cutting | disconnection and grinding | polishing for taking out the cross section of a 2nd sealing material was excluded by detecting with a well-known analysis means, and only the crack which arose by the said heat cycle test was made into the count object.

(Endurance test results)
As is clear from Table 1, sample No. In 1, the number of cells in which gas leak occurred was large, and the number of cracks in the second sealing material was also large. This is because the second sealing material did not have the first region having a lower porosity than the other portions around the one end of the support.

  Sample No. In sample 2, sample no. Compared to 1, the number of cells in which gas leak occurred was small, and the number of cracks in the second sealing material was also small. This is because the second sealing material has a first region having a lower porosity than the other part around one end of the support.

  Sample No. 3 sample No. 3 Compared with 2, the number of cells in which gas leak occurred was small, and the number of cracks in the second sealing material was also small. This is because the porosity of the first region was 5% or less.

  Sample No. 4, sample no. Compared with 3, the number of cells in which a gas leak occurred was small, and the number of cracks in the second sealing material was also small. This is because, in other parts, the surface layer side of the second sealing material has a lower porosity than the bottom surface side of the groove.

  Sample No. 5-9, sample no. Compared with 4, the number of cells in which a gas leak occurred was small, and the number of cracks in the second sealing material was also small. This is because the porosity on the surface layer side of the second sealing material in the other portions was 6% or less.

It was confirmed that the same test results as described above were obtained when the SiO ₂ —MgO—B ₂ O ₅ —ZnO system was used as the sealing material.

1: cell 2: support substrate 2a: gas flow path 3: fuel electrode 4: solid electrolyte layer 5: air electrode 6: interconnector 7: manifold 7a: support 7b: gas tank 8a: first sealing material 8b: second seal Material 81: First region 82: Other portion 82a: Surface layer side 82b: Bottom surface side 9a: Conductive member 9b: End conductive member 10, 100, 110: Cell stack device 11: Conductive unit 12: Gas flow pipe 13: Modified Quality device 14: Storage container 15: Air introduction member 16: Raw fuel supply pipe 20: Module 40: Module storage device

Claims (7)

A cell stack in which a plurality of cells are arranged;
A support having one or more insertion ports into which one ends of the plurality of cells are inserted;
A first sealing material joining one end of the plurality of cells and the inner wall of the insertion port;
A gas tank having an opening for supplying a reaction gas to the plurality of cells through the insertion port, and having a concave groove provided around the opening;
One end of the support is joined to the gas tank by a second sealing material filled in the concave groove of the gas tank,
The second sealing material has a first region having a lower porosity than other portions around one end of the support ,
The cell stack device, wherein the second sealing material includes a pore former, and the content of the pore former in the first region is smaller than that of the other portions . The cell stack device according to claim 1, wherein in the other portion, the surface layer side of the second sealing material has a lower porosity than the bottom surface side of the concave groove. 3. The cell stack device according to claim 2, wherein, in a cross-sectional view, the pores on the bottom surface side of the concave groove in the other portion have an elliptical shape, and the long axis does not face one end of the support. The cell stack device according to any one of claims 1 to 3, wherein the porosity of the first region is 5% or less. A cell stack in which a plurality of cells are arranged;
A support having one or more insertion ports into which one ends of the plurality of cells are inserted;
A first sealing material joining one end of the plurality of cells and the inner wall of the insertion port;
A gas tank having an opening for supplying a reaction gas to the plurality of cells through the insertion port, and having a concave groove provided around the opening;
One end of the support is joined to the gas tank by a second sealing material filled in the concave groove of the gas tank,
The second sealing material is a first material having a lower porosity than the other part around one end of the support.
Having an area,
Surface side of the second sealing member in the other part, smaller porosity than the bottom side of the groove, the porosity of the bottom side is Ru der least 8%
Se Rusutakku apparatus.   A module comprising the cell stack device according to any one of claims 1 to 5 stored in a storage container.   A module housing device comprising the module according to claim 6 and an auxiliary machine for operating the module in an outer case.

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