Cell stack device, module, and module housing device

Abstract

To provide a cell stack device, module, and module housing device with improved durability.SOLUTION: The cell stack device includes a cell stack, a holding member, and a positive electrode terminal. The cell stack is composed of a plurality of cells stacked together. The holding member holds the cells. The positive electrode terminal functions as a positive electrode when power generated by the cell stack is output to the outside. Potential of the positive electrode terminal is less than or equal to the potential of the holding member.SELECTED DRAWING: Figure 4A

Description

[Technical field]

[0001] The present disclosure relates to a cell stack device, a module, and a module housing device. [Background technology]

[0002] In recent years, various fuel cell stack devices have been proposed as next-generation energy sources. The fuel cell stack devices are configured by arranging multiple fuel cells, which are a type of cell that can generate electricity using fuel gas (hydrogen-containing gas) and oxygen-containing gas (air).

[0003] In such a fuel cell stack device, for example, the lower ends of a plurality of fuel cells are joined to a holding member by a fastening material (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-157191 A Summary of the Invention

[0005] A cell stack device according to one aspect of an embodiment of the present disclosure includes a cell stack, a holding member, ,of The cell stack is made up of multiple cells. have The holding member holds the cell. .Ma The above Retaining material The potential of cell Electric potential of End It is.

[0006] Moreover, the module of the present disclosure is configured by housing the above-described cell stack device in a housing container.

[0007] Furthermore, the module housing device of the present disclosure is configured by housing the above-described module and auxiliary equipment for operating the module within an exterior case. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 1A is a cross-sectional view showing an example of a cell according to an embodiment. [Figure 1B] FIG. 1B is a side view of an example of a cell according to an embodiment, viewed from the air electrode side. [Figure 1C] FIG. 1C is a side view of an example of a cell according to an embodiment, viewed from the interconnector side. [Figure 2A] FIG. 2A is a perspective view showing an example of a cell stack device according to an embodiment. [Figure 2B] FIG. 2B is a cross-sectional view taken along line XX shown in FIG. 2A. [Figure 2C] FIG. 2C is a top view illustrating an example of a cell stack device according to an embodiment. [Figure 3A] FIG. 3A is a diagram showing an example of a power system including a cell stack device of a reference example. [Figure 3B] FIG. 3B is a diagram showing an example of the magnitude relationship of the potentials of the various parts in the cell stack device of the reference example. [Figure 3C] FIG. 3C is a diagram for explaining a phenomenon that occurs in the cell stack device of the reference example. [Figure 3D] FIG. 3D is a diagram for explaining a phenomenon that occurs in the cell stack device of the reference example. [Figure 3E] FIG. 3E is a perspective view showing another example of the holder. [Figure 3F] FIG. 3F is a perspective view showing another example of a holder. [Figure 3G] FIG. 3G is an enlarged cross-sectional view of a joint between another example of a holder and a cell (corresponding to FIGS. 3C and 3D). [Figure 4A] FIG. 4A is a diagram showing an example of a power system including a cell stack device according to an embodiment. [Figure 4B] FIG. 4B is a diagram showing the magnitude relationship of the potentials of the various parts in the cell stack device according to this embodiment. [Figure 5A] FIG. 5A is a diagram illustrating an example of a power system including a cell stack device according to a first modification of the embodiment. [Figure 5B] FIG. 5B is a diagram showing the magnitude relationship of the potentials of the various parts in the cell stack device according to the first modified example of the embodiment. [Figure 6] FIG. 6 is an external perspective view illustrating an example of a module according to the embodiment. [Figure 7] FIG. 7 is an exploded perspective view illustrating an example of a module housing device according to an embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a cell stack device according to the second modification of the embodiment. [Figure 9] FIG. 9 is an enlarged cross-sectional view showing a structure of a cell according to the second modification of the embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of a power system including a cell stack device according to the second modification of the embodiment. [Figure 11] FIG. 11 is a diagram showing another example of a power system including a cell stack device according to the second modification of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of a cell stack device, a module, and a module housing device disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the disclosure is not limited to the embodiments described below.

[0010] In addition, it should be noted that the drawings are schematic, and that the dimensional relationships, ratios, etc. of each element may differ from the reality. Furthermore, there may be cases where the dimensional relationships, ratios, etc. of each element differ from those of the drawings.

[0011] <Cell configuration> First, with reference to FIGS. 1A to 1C, a description will be given of an example of a solid oxide fuel cell as a cell constituting a cell stack device according to an embodiment.

[0012] Fig. 1A is a cross-sectional view showing an example of a cell 1 according to an embodiment, Fig. 1B is a side view of the example of the cell 1 according to an embodiment as viewed from the air electrode 5 side, and Fig. 1C is a side view of the example of the cell 1 according to an embodiment as viewed from the interconnector 6 side. Figs. 1A to 1C show enlarged views of parts of each component of the cell 1.

[0013] 1A to 1C, cell 1 is a hollow flat plate-like elongated plate. As shown in Fig. 1B, the shape of the entire cell 1 seen from the side is, for example, a rectangle with a side length of 5 cm to 50 cm in the length direction L and a side length of 1 cm to 10 cm in the width direction W perpendicular to the length direction L. The entire thickness (thickness direction T) of this cell 1 is 1 mm to 5 mm.

[0014] 1A, the cell 1 includes a conductive support substrate 2, an element portion, and an interconnector 6. The support substrate 2 is columnar having a pair of opposing first and second flat surfaces n1 and n2, and a pair of arc-shaped side surfaces m connecting the first and second flat surfaces n1 and n2.

[0015] The element portion is provided on a first flat surface n1 of a support substrate 2. The element portion has a fuel electrode 3, a solid electrolyte layer 4, and an air electrode 5. In the example shown in FIG. 1A, an interconnector 6 is provided on a second flat surface n2 of the cell 1.

[0016] As shown in FIG. 1B, the air electrode 5 does not extend to the lower end of the cell 1. At the lower end of the cell 1, only the solid electrolyte layer 4 is exposed on the surface of the first flat surface n1. As shown in FIG. 1C, the interconnector 6 may extend to the lower end of the cell 1. At the lower end of the cell 1, the interconnector 6 and the solid electrolyte layer 4 are exposed on the surface. As shown in FIG. 1A, the solid electrolyte layer 4 is exposed on the surface of a pair of arc-shaped side surfaces m of the cell 1. The interconnector 6 does not have to extend to the lower end of the cell 1.

[0017] Each of the components constituting the cell 1 will be described below.

[0018] The support substrate 2 has therein gas flow channels 2a through which gas flows. FIG. 1A shows an example having six gas flow channels 2a extending along the length direction. The support substrate 2 has gas permeability and allows the fuel gas to pass through to the fuel electrode 3. The support substrate 2 shown in FIG. 1A has electrical conductivity. The support substrate 2 can collect electricity generated in the element portion via the interconnector 6.

[0019] The material of the support substrate 2 includes, for example, 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.

[0020] The material of the fuel electrode 3 may be a generally known material. The fuel electrode 3 may be formed from a porous conductive ceramic, for example, a ceramic containing calcium oxide, magnesium oxide, or ZrO2 in which a rare earth element oxide is solid-dissolved, and Ni and / or NiO. As the rare earth element oxide, for example, Y2O3 or the like is used. Hereinafter, calcium oxide, magnesium oxide, or ZrO2 in which a rare earth element oxide is solid-dissolved is referred to as stabilized zirconia. In the present disclosure, stabilized zirconia also includes partially stabilized zirconia.

[0021] The solid electrolyte layer 4 is an electrolyte and acts as a bridge between ions between the fuel electrode 3 and the air electrode 5. At the same time, the solid electrolyte layer 4 has gas barrier properties and makes it difficult for leakage of fuel gas and oxygen-containing gas to occur.

[0022] The material of the solid electrolyte layer 4 is, for example, ZrO2 in which 3 to 15 mol % of a rare earth element oxide is dissolved. As the rare earth element oxide, for example, Y2O3 or the like is used. Note that other materials may be used for the material of the solid electrolyte layer 4 as long as they have the above characteristics.

[0023] There are no particular limitations on the material of the air electrode 5 as long as it is a material generally used for air electrodes. The material of the air electrode 5 may be, for example, a conductive ceramic such as a so-called ABO3 type perovskite oxide.

[0024] The material of the cathode 5 may be, for example, a composite oxide in which Sr and La 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. Note that x is 0 <x<1、yは0<y<1である。

[0025] The air electrode 5 has gas permeability. The open porosity of the air electrode 5 may be 20% or more, and particularly may be in the range of 30% to 50%.

[0026] Lanthanum chromite-based perovskite oxide (LaCrO3-based oxide), lanthanum strontium titanium-based perovskite oxide (LaSrTiO3-based oxide), etc. may be used as the material of the interconnector 6. These materials are conductive and are not reduced or oxidized even when in contact with a fuel gas such as a hydrogen-containing gas and an oxygen-containing gas such as air.

[0027] Moreover, the interconnector 6 is dense, which makes it difficult for leakage to occur of the fuel gas flowing through the gas flow passage 2a formed in the support substrate 2 and the oxygen-containing gas flowing outside the support substrate 2. The interconnector 6 may have a relative density of 93% or more, particularly 95% or more.

[0028] <Configuration of cell stack device> Next, a cell stack device 10 according to the present embodiment using the above-mentioned cell 1 will be described with reference to Figures 2A to 2C. Figure 2A is a perspective view showing an example of the cell stack device 10 according to the embodiment, Figure 2B is a cross-sectional view taken along line AA shown in Figure 2A, and Figure 2C is a top view showing an example of the cell stack device 10 according to the embodiment.

[0029] As shown in FIG. 2A, the cell stack device 10 includes a cell stack 11 having a plurality of cells 1 arranged (stacked) in a thickness direction T of the cells 1 (see FIG. 1A), and a fixing member 12.

[0030] The fixing member 12 has a fixing material 13 and a holding member 14. The holding member 14 holds the cell 1. The fixing material 13 fixes the cell 1 to the holding member 14. The holding member 14 also has a holder 15 and a gas tank 16. The holder 15 and the gas tank 16, which are the holding member 14, are made of metal and are conductive.

[0031] 2B, the holder 15 has insertion holes 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 holes 15a are joined with a fixing material 13.

[0032] The gas tank 16 has an opening for supplying a reaction gas to the multiple cells 1 through the insertion holes 15a, and a groove 16a provided around the opening. The outer peripheral end of the holder 15 is joined to the gas tank 16 by a bonding material 21 filled in the groove 16a of the gas tank 16.

[0033] In the example shown in Fig. 2A, fuel gas is stored in an internal space formed by a holder 15, which is the holding member 14, and a gas tank 16. A gas circulation pipe 20 is connected to the gas tank 16. The fuel gas is supplied to the gas tank 16 through this gas circulation pipe 20, and is supplied from the gas tank 16 to a gas flow path 2a (see Fig. 1A) inside the cell 1. The fuel gas supplied to the gas tank 16 is generated in a reformer 82 (see Fig. 6), which will be described later.

[0034] The hydrogen-rich fuel gas may be produced, for example, by steam reforming a raw fuel. The fuel gas produced by steam reforming contains water steam.

[0035] The example shown in FIG. 2A includes two rows of cell stacks 11, two holders 15, and a gas tank 16. Each of the two rows of cell stacks 11 has a plurality of cells 1. Each cell stack 11 is fixed to each holder 15. The gas tank 16 has two through holes on the upper surface. A holder 15 is disposed in each through hole. An internal space is formed by the one gas tank 16 and the two holders 15.

[0036] The shape of the insertion hole 15a is, for example, an oval shape when viewed from above. For example, the length of the insertion hole 15a in the arrangement direction of the cells 1, i.e., the thickness direction T, is greater than the distance between the two end current collecting members 17 located at both ends of the cell stack 11. The width of the insertion hole 15a is, for example, greater than the length of the cell 1 in the width direction W (see FIG. 1A).

[0037] 2A, the joints between the inner walls of the insertion holes 15a and the lower ends of the cells 1 are filled with a fixing material 13 and solidified. This bonds and fixes the inner walls of the insertion holes 15a to the lower ends of the cells 1, respectively, and also bonds and fixes the lower ends of the cells 1 to each other. The gas flow paths 2a of each cell 1 communicate with the internal space of the holding member 14 at their lower ends.

[0038] The fixing material 13 and the bonding material 21 have oxide ion conductivity. Note that the fixing material 13 and the bonding material 21 may have even lower electrical conductivity. Specific materials for the fixing material 13 and the bonding material 21 may include amorphous glass, and in particular, crystallized glass.

[0039] As the crystallized glass, for example, any of materials such as SiO2-CaO, MgO-B2O3, La2O3-B2O3-MgO, La2O3-B2O3-ZnO, and SiO2-CaO-ZnO may be used, and in particular, SiO2-MgO-based materials may be used.

[0040] 2B, a conductive member 18 for electrically connecting the adjacent cells 1 in series is interposed between the adjacent cells 1. More specifically, the space between the adjacent cells 1 refers to the space between the fuel electrode 3 of one adjacent cell 1 and the air electrode 5 of the other adjacent cell 1.

[0041] As shown in Fig. 2B, an end current collecting member 17 is connected to the cell 1 located at the outermost position in the arrangement direction of the multiple cells 1. The end current collecting member 17 is connected to a conductive part 19 protruding to the outside of the cell stack 11. The conductive part 19 has the function of collecting electricity generated by power generation of the cells 1 and drawing it out to the outside. Note that the end current collecting member 17 is not shown in Fig. 2A.

[0042] 2C, the cell stack device 10 has two cell stacks 11A and 11B connected in series to function as one battery. Therefore, the conductive portion 19 of the cell stack device 10 is divided into a positive terminal 19A, a negative terminal 19B, and a connection terminal 19C.

[0043] The positive electrode terminal 19A functions as a positive electrode when the electric power generated by the cell stack 11 is output to the outside, and is electrically connected to the end current collecting member 17 on the positive electrode side of the cell stack 11A. The negative electrode terminal 19B functions as a negative electrode when the electric power generated by the cell stack 11 is output to the outside, and is electrically connected to the end current collecting member 17 on the negative electrode side of the cell stack 11B.

[0044] The connection terminal 19C electrically connects the end current collecting member 17 on the negative electrode side in the cell stack 11A and the end current collecting member 17 on the positive electrode side in the cell stack 11B.

[0045] <Reference example> A reference example shown in Fig. 3A to Fig. 3G will be described. Fig. 3A is a diagram showing an example of a power system 100 including a cell stack device 10 of the reference example, and Fig. 3B is a diagram showing an example of the magnitude relationship of the electric potentials of the various parts in the cell stack device 10 of the reference example. Also, Fig. 3C and Fig. 3D are diagrams for explaining phenomena that occur within the cell stack device 10 of the reference example.

[0046] As shown in FIG. 3A, in a power system 100, a cell stack device 10 is connected to a PCS (Power Conditioning Subsystem) 101, and power generated by the cell stack device 10 is supplied to a power grid 102 via the PCS 101.

[0047] Specifically, the PCS 101 converts DC power generated in the cell stack device 10 into AC power, and supplies the AC power to the power grid 102. Therefore, the PCS 101 is connected to both a positive terminal 19A and a negative terminal 19B of the cell stack device 10.

[0048] 3A, when the electromotive force of the cell stack device 10 is 2A (V), the potential of the positive terminal 19A is +A (V) and the potential of the negative terminal 19B is -A (V), as shown in Fig. 3B. The electromotive force of the cell stack device 10 is, in other words, the electromotive force of the cell stack 11.

[0049] The holding member 14, which is made of metal and has electrical conductivity, is grounded to ensure stable operation of the cell stack device 10. The holding member 14 includes a holding body 15 and a gas tank 16. That is, the potential of the holding body 15 (holding member 14) is 0 (V). Note that the potential of the holding body 15 may be a potential that is slightly shifted from the midpoint between the potential of the positive electrode terminal 19A and the potential of the negative electrode terminal 19B.

[0050] Due to this relationship in potential magnitude, as shown in FIG. 3C, a potential difference occurs between cell 1 near positive terminal 19A, which has a potential of approximately +A (V), and holder 15, which has a potential of 0 (V).

[0051] Then, due to this potential difference, as shown in FIG. 3C, oxygen ions (O 2- ) is attracted to the cell 1 side, and the metal ions (M + ) is attracted to the support 15. That is, at the interface between the fixing material 13 and the support 15, a reduction reaction of the oxide film occurs.

[0052] As a result, the oxide film on the surface of the holder 15 at the interface with the fixing material 13 is damaged, and as shown in Fig. 3D, this damage causes a gap C between the fixing material 13 and the holder 15. The phenomenon of the occurrence of this gap C is likely to occur between the cell 1 and the holder 15 in the vicinity of the positive electrode terminal 19A, where there is a large potential difference, and the occurrence of this gap C may reduce the durability of the cell stack device 10.

[0053] The holder 15 may be a flat plate-shaped holder 15 as shown in FIG. 3E. In this case, for example, the gas tank 16 is joined to the lower surface or side surface of the flat plate-shaped holder 15 to form an internal space. The holder 15 may also be a holder 15 having a plurality of insertion holes 15a as shown in FIG. 3F. In this case, one cell 1 may be inserted into each of the plurality of insertion holes 15a of the holder 15, or a plurality of cells 1 may be inserted into each of the plurality of insertion holes 15a of the holder 15. FIG. 3G is a cross-sectional view of the joint between the flat plate-shaped holder 15 and the cell 1. In addition, the holder 15 may be integrally formed with the gas tank 16. In such a holder 15, a gap C is also generated between the fixing material 13 and the holder 15.

[0054] <Embodiment> Next, the cell stack device 10 according to the embodiment will be described with reference to Fig. 4A and Fig. 4B. Fig. 4A is a diagram showing an example of a power system 100 including the cell stack device 10 according to the embodiment, and Fig. 4B is a diagram showing the magnitude relationship of the electric potentials of the various parts in the cell stack device 10 according to the embodiment.

[0055] 4A, in the power system 100 according to the embodiment, the positive terminal 19A of the cell stack device 10 and the PCS 101 are connected to a ground potential 31 via a noise reduction unit 32. That is, in the cell stack device 10 according to the embodiment, the positive terminal 19A is connected to the ground potential 31, thereby grounding the positive terminal 19A.

[0056] 4B, the potential of positive electrode terminal 19A can be set to 0 (V), which is the same as the potential of holder 15 (holding member 14). In this case, the potential of negative electrode terminal 19B becomes -2A (V).

[0057] That is, in the embodiment, since no potential difference occurs between the cell 1 near the positive electrode terminal 19A and the holder 15 as described in the above reference example, it is possible to prevent the reduction reaction at the interface between the fixing material 13 and the holder 15.

[0058] Therefore, according to the embodiment, it is possible to reduce damage to the oxide film on the surface of the holder 15 at the interface with the fixing material 13. As a result, it is possible to make it difficult for the gap C to occur between the fixing material 13 and the holder 15. In other words, according to the embodiment, it is possible to improve the durability of the cell stack device 10.

[0059] In the embodiment, a noise reduction unit 32 may be provided between the positive terminal 19A and the ground potential 31. The noise reduction unit 32 includes, for example, a coil 32a and a resistor 32b connected in series between the positive terminal 19A and the ground potential 31, and a capacitor 32c connected in parallel to the resistor 32b.

[0060] In the embodiment, by providing such a noise reduction unit 32 between the positive electrode terminal 19A and the ground potential 31, it is possible to reduce noise contained in the DC power supplied from the cell stack device 10. Therefore, according to the embodiment, the PCS 101 can stably convert DC power into AC power.

[0061] It should be noted that the circuit configuration of the noise reduction unit 32 shown in FIG. 4A is merely an example, and other circuit configurations may also be adopted.

[0062] <Variation 1> Next, a cell stack device 10 according to a first modified embodiment of the embodiment will be described with reference to Fig. 5A and Fig. 5B. Fig. 5A is a diagram showing an example of a power system 100 including a cell stack device 10 according to a first modified embodiment of the embodiment, and Fig. 5B is a diagram showing the magnitude relationship of the electric potentials of the various parts in the cell stack device 10 according to the first modified embodiment of the embodiment.

[0063] Modification 1 differs from the embodiment in that a separate battery 33 is provided between positive terminal 19A and ground potential 31. The positive electrode of battery 33 is connected to ground potential 31 via noise reduction unit 32. The negative electrode of battery 33 is connected to positive terminal 19A.

[0064] 5B, when the electromotive force of the battery 33 is B (V), the potential of the positive electrode terminal 19A can be set to -B (V) which is lower than the potential 0 (V) of the holder 15 (holding member 14). In this case, the potential of the negative electrode terminal 19B becomes -B-2A (V).

[0065] In other words, in the first modification, since a potential difference opposite to the potential difference described in the above reference example can be generated, an oxidation reaction opposite to the reduction reaction can be generated at the interface between the fixing material 13 and the holder 15.

[0066] As a result, even if an oxide film on the surface of the holder 15 at the interface with the fixing material 13 grows due to an oxidation reaction, it is possible to reduce damage to the oxide film. Therefore, according to the first modification, it is possible to make it difficult for gap C to occur between the fixing material 13 and the holder 15, thereby improving the durability of the cell stack device 10.

[0067] The battery 33 is an example of a negative voltage application unit that applies a negative voltage to the positive terminal 19A. In other words, the negative voltage application unit is not limited to the battery 33, and may have any configuration as long as it can apply a negative voltage to the positive terminal 19A with respect to the ground potential 31.

[0068] In addition, in the first modification, as in the embodiment, a noise reduction unit 32 may be provided between the positive electrode terminal 19A and the ground potential 31. This makes it possible to reduce noise contained in the DC power supplied from the cell stack device 10, thereby enabling the PCS 101 to stably convert the DC power into AC power.

[0069] <module> Next, a module 80 according to an embodiment of the present disclosure using the above-mentioned cell stack device 10 will be described with reference to Fig. 6. Fig. 6 is an external perspective view showing the module 80 according to the embodiment, with the front and rear surfaces, which are part of the storage container 81, removed and the cell stack device 10 of the fuel cell stored inside removed to the rear.

[0070] 6, the module 80 includes a storage container 81 and a cell stack device 10 stored in the storage container 81. Above the cell stack device 10, a reformer 82 is disposed.

[0071] The reformer 82 reforms raw fuel such as natural gas or kerosene to generate fuel gas and supplies it to the cell 1. The raw fuel is supplied to the reformer 82 through a raw fuel supply pipe 83. The reformer 82 may include a vaporizer 82a that vaporizes water, and a reformer 82b. The reformer 82b includes a reforming catalyst (not shown) and reforms the raw fuel into fuel gas. Such a reformer 82 can perform steam reforming, which is a highly efficient reforming reaction.

[0072] The fuel gas generated in the reformer 82 is supplied to the gas flow channel 2a of the cell 1 (see FIG. 1A) through the gas distribution pipe 20, the gas tank 16, and the fixing member 12.

[0073] Furthermore, in the module 80 having the above-mentioned configuration, the temperature inside the module 80 during normal power generation becomes approximately 500 to 1000° C. as the gas is combusted and the cells 1 generate power.

[0074] In such a module 80, as described above, gaps C are unlikely to occur, and by including the highly durable cell stack device 10, the module 80 can be made highly durable.

[0075] <Module storage device> Fig. 7 is an exploded perspective view showing an example of a module housing device 90 according to an embodiment. The module housing device 90 according to the embodiment includes an outer case, the module 80 shown in Fig. 6, and auxiliary equipment (not shown). The auxiliary equipment operates the module 80. The module 80 and the auxiliary equipment are housed in the outer case. Note that some components are omitted in Fig. 7.

[0076] The exterior case of the module accommodating device 90 shown in Fig. 7 has support posts 91 and an exterior plate 92. A partition plate 93 divides the interior of the exterior case into upper and lower sections. The space above the partition plate 93 in the exterior case is a module accommodating chamber 94 that accommodates the module 80, and the space below the partition plate 93 in the exterior case is an auxiliary equipment accommodating chamber 95 that accommodates the auxiliary equipment that operates the module 80. Note that in Fig. 7, the auxiliary equipment accommodated in the auxiliary equipment accommodating chamber 95 is omitted.

[0077] In addition, the partition plate 93 has an air flow port 96 for allowing air from the auxiliary equipment housing chamber 95 to flow toward the module housing chamber 94. The exterior plate 92 constituting the module housing chamber 94 has an exhaust port 97 for exhausting air from within the module housing chamber 94.

[0078] In such a module housing device 90, as described above, the highly durable module 80 is provided in the module housing chamber 94, and thus the module housing device 90 can have high durability.

[0079] Although the present disclosure has been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible without departing from the gist of the present disclosure.

[0080] In the above embodiment, a vertically striped cell stack device is illustrated in which so-called "vertically striped" cells, in which only one power generating element unit consisting of a fuel electrode, a solid electrolyte layer, and an air electrode is provided on the surface of a support substrate, are stacked. The present disclosure can be applied to a horizontally striped cell stack device in which so-called "horizontally striped" cells, in which power generating element units are provided at multiple locations spaced apart from each other on the surface of a support substrate and adjacent power generating element units are electrically connected, are stacked.

[0081] In the above embodiment, a case where a hollow flat support substrate is used is exemplified. The present disclosure can also be applied to a cell stack device using a cylindrical support substrate. The present disclosure can also be applied to a flat cell stack device in which so-called "flat" cells are stacked in the thickness direction.

[0082] In the above embodiment, the fuel electrode is provided on the support substrate, and the air electrode is disposed on the surface of the cell. The present disclosure can also be applied to a cell stack device in which the opposite arrangement is used, that is, the air electrode is provided on the support substrate, and the fuel electrode is disposed on the surface of the cell.

[0083] In addition, in the above embodiments, a fuel cell, a fuel cell stack device, a fuel cell module and a fuel cell device are shown as examples of a "cell," a "cell stack device," a "module" and a "module accommodating device," but other examples may be an electrolytic cell, an electrolytic cell stack device, an electrolytic module and an electrolytic device, respectively.

[0084] Fig. 8 is a cross-sectional view showing a cell stack device 200 according to Modification 2 of the embodiment. As shown in Fig. 8, the cell stack device 200 according to Modification 2 includes a cell stack 210 in which a plurality of plate-shaped cells 201 are stacked. In the cell stack device 200 according to Modification 2, the cell stack 210 is sandwiched between a positive electrode side end current collecting member 220 and a negative electrode side end current collecting member 221.

[0085] The cell 201 of the second modification has an element portion 202 , a separator 203 , an air electrode side frame 204 , a fuel electrode side frame 205 , an air electrode side current collector 206 , a fuel electrode side current collector 207 , and an interconnector 208 .

[0086] Fig. 9 is an enlarged cross-sectional view showing the structure of a cell 201 according to Modification 2 of the embodiment. As shown in Fig. 9, the element section 202 of Modification 2 has an air electrode 202a, a solid electrolyte layer 202b located on the lower surface of the air electrode 202a, and an anode 202c located on the lower surface of the solid electrolyte layer 202b. The air electrode 202a is located on the side of the element section 202 that contacts the air electrode side current collector 206, and the anode 202c is located on the side of the element section 202 that contacts the anode side current collector 207.

[0087] Returning to the explanation of FIG. 8, separator 203 is a frame-shaped member having a through hole penetrating in the vertical direction near the center. Separator 203 may be made of a material such as metal. The periphery of the through hole in separator 203 faces the peripheral edge of the surface of solid electrolyte layer 202b (see FIG. 9) on the side of air electrode 202a (see FIG. 9). Separator 203 is joined to solid electrolyte layer 202b at this facing portion.

[0088] The separator 203 separates an air chamber 264 facing the air electrode 202a from a fuel chamber 265 facing the fuel electrode 202c (see FIG. 9), making it difficult for gas to leak from one electrode side to the other electrode side at the periphery of the element portion 202.

[0089] The air electrode side frame 204 is a frame-shaped member having a through hole penetrating in the vertical direction near the center. The material of the air electrode side frame 204 may be an insulator such as mica. The air electrode side frame 204 contacts the peripheral portion of the surface of the separator 203 opposite to the side facing the solid electrolyte layer 202b and the peripheral portion of the surface of the interconnector 208 facing the air electrode 202a.

[0090] Since the uppermost cell 201 in the cell stack 210 does not have an upper interconnector 208 , the air electrode side frame 204 in this cell 201 comes into contact with the end current collecting member 220 .

[0091] The through-holes in the air electrode side frame 204 form an air chamber 264 facing the air electrode 202a. Furthermore, the air electrode side frame 204 electrically insulates adjacent interconnectors 208 from each other.

[0092] The fuel electrode side frame 205 is a frame-shaped member having a through hole penetrating in the vertical direction near the center. The material of the fuel electrode side frame 205 may be, for example, a metal. The through hole of the fuel electrode side frame 205 constitutes a fuel chamber 265 facing the fuel electrode 202c.

[0093] The fuel electrode side frame 205 contacts the peripheral edge of the surface of the separator 203 facing the solid electrolyte layer 202b, and the peripheral edge of the surface of the interconnector 208 facing the fuel electrode 202c.

[0094] The air electrode side current collector 206 is disposed in the air chamber 264. The air electrode side current collector 206 is composed of a plurality of columnar conductive members arranged at predetermined intervals. The material of the air electrode side current collector 206 may be, for example, stainless steel.

[0095] The air electrode side current collector 206 contacts a surface of the air electrode 202a opposite to the side facing the solid electrolyte layer 202b, and a surface of the interconnector 208 facing the air electrode 202a. Since the uppermost cell 201 in the cell stack 210 does not have an upper interconnector 208, the air electrode side current collector 206 of this cell 201 contacts the end current collecting member 220.

[0096] That is, the air electrode side current collector 206 electrically connects between the air electrode 202a and the interconnector 208, or between the air electrode 202a and the end current collecting member 220. The air electrode side current collector 206 and the interconnector 208 may be formed as an integrated member.

[0097] The fuel electrode side current collector 207 is disposed in the fuel chamber 265. The fuel electrode side current collector 207 may be composed of a plurality of columnar conductive members arranged at a predetermined interval. The material of the fuel electrode side current collector 207 may be, for example, stainless steel. The fuel electrode side current collector 207 may have, for example, an electrode facing portion 207a, an interconnector facing portion 207b, a connection portion 207c, and a spacer 207d, as shown in FIG. 9.

[0098] The electrode facing portion 207a faces the fuel electrode 202c of the element portion 202. The interconnector facing portion 207b faces the interconnector 208 (or the end current collecting member 221). The connection portion 207c connects the electrode facing portion 207a and the interconnector facing portion 207b. The electrode facing portion 207a, the interconnector facing portion 207b, and the connection portion 207c may all be made of metal, and may be made, for example, integrally.

[0099] The spacer 207d is located between the electrode facing portion 207a and the interconnector facing portion 207b. The material of the spacer 207d may be, for example, mica. By disposing the spacer 207d on the fuel electrode side current collector 207, the fuel electrode side current collector 207 can easily follow the deformation of the cell 201 due to temperature cycles, pressure fluctuations of the reactant gas, and the like.

[0100] Therefore, a cell 201 having an anode side current collector 207 as shown in FIG. 9 can maintain good electrical connection between the anode 202c and the interconnector 208 (or end current collecting member 221) via the anode side current collector 207.

[0101] Returning to the description of FIG. 8, the interconnector 208 is a conductive member having a flat plate shape. The material of the interconnector 208 may be, for example, stainless steel. The interconnector 208 ensures electrical connection between adjacent cells 201. In addition, the interconnector 208 makes it difficult for reaction gases to mix between adjacent cells 201, that is, makes it difficult for gas to leak from one cell 201 side to the other cell 201 side. In addition, in the second modification, adjacent cells 201 share one interconnector 208.

[0102] Note that the cells 201 in contact with the end current collecting member 220 or the end current collecting member 221 do not have the interconnector 208 because the end current collecting member 220 or the end current collecting member 221 has the function of the interconnector 208 .

[0103] The positive electrode terminal 222 functions as a positive electrode when the electric power generated by the cell stack 210 is output to the outside, and is electrically connected to the end current collecting member 220 on the positive electrode side of the cell stack 210. The negative electrode terminal 223 functions as a negative electrode when the electric power generated by the cell stack 210 is output to the outside, and is electrically connected to the end current collecting member 221 on the negative electrode side of the cell stack 210.

[0104] The cell stack device 200 has communication holes 261, 262 that communicate between the end current collecting member 220, the cell stack 210, and the end current collecting member 221, and a metal bolt 231 is inserted into the communication holes 261, 262.

[0105] Then, metal nuts 232 are fitted onto bolts 231 exposed to the outside from end current collecting member 220 and end current collecting member 221, and multiple cells 201 are held between end current collecting member 220 and end current collecting member 221. That is, in Modification 2, the bolts 231 and the nuts 232 constitute a holding member 230 that holds multiple cells 201.

[0106] Fixing material 240 is located between end current collecting member 220 and holding member 230, and between end current collecting member 220 and holding member 230. Fixing material 240 in Modification 2 may be made of the same material as fixing material 13 in the embodiment, for example. Fixing material 240 in Modification 2 is not limited to being made of the same material as fixing material 13 in the embodiment, and may be made of an insulating sheet, for example.

[0107] Either the end current collecting member 220 or the end current collecting member 221 may have a screw hole. For example, when the end current collecting member 220 has a screw hole, the bolt 231 may be screwed into the screw hole. The inner wall of the screw hole and the bolt 231 may be in direct contact with each other, or a fixing member 240 may be located between the inner wall of the screw hole and the bolt 231. In this case, the bolt 231 is exposed to the outside from the end current collecting member 221, and a metal nut 232 is fitted onto the exposed bolt 231. The fixing member 240 is located between the end current collecting member 221 and the holding member 230.

[0108] Instead of the bolt 231 and the nut 232, a bolt having a flange portion may be used as the retaining member 230. The bolt having the flange portion is screwed into a screw hole of the end current collecting member 220, and a fixing member 240 is positioned between the flange portion of the retaining member 230 and the end current collecting member 221. The screw hole may pass through the end current collecting member 220, or may not pass through and have a bottom.

[0109] 10 is a diagram showing an example of a power system 100A including a cell stack device 200 according to Modification 2 of the embodiment. As shown in Fig. 10, in the power system 100A according to Modification 2, a connection between a positive electrode terminal 222 of the cell stack device 200 and a PCS 101 is made to a ground potential 31 via a noise reduction unit 32.

[0110] That is, in the cell stack device 200 according to the second modification, the positive terminal 222 is connected to the ground potential 31, and thereby the positive terminal 222 is grounded.

[0111] 4B, the potential of the positive electrode terminal 222 can be set to 0 (V), which is the same as the potential of the holding member 230. The positive electrode terminal 222 and the end current collecting member 220 may be electrically connected to the holding member 230. In this case, the potential of the negative electrode terminal 223 becomes −2 A (V).

[0112] As a result, in the second modification, since no potential difference occurs between the positive electrode terminal 222 and the holding member 230 as in the embodiment, it is possible to prevent a reduction reaction from occurring at the interface between the fixing material 240 and the holding member 230.

[0113] Therefore, according to the second modification, it is possible to reduce damage to the oxide film on the surface of the holding member 230 at the interface with the fixing material 240. As a result, it is possible to make it difficult for gaps to occur between the fixing material 240 and the holding member 230. In other words, according to the second modification, it is possible to improve the durability of the cell stack device 200.

[0114] It should be noted that the power system 100A including the cell stack device 200 according to the second modification is not limited to the example shown in Fig. 10. Fig. 11 is a diagram showing another example of the power system 100A including the cell stack device 200 according to the second modification of the embodiment.

[0115] 11 differs from the example of FIG 10 in that a separate battery 33 is provided between the positive terminal 222 and the ground potential 31. The positive electrode of the battery 33 is connected to the ground potential 31 via the noise reduction unit 32, and the negative electrode of the battery 33 is connected to the positive terminal 222.

[0116] As a result, in the second modification, as in the first modification, an oxidation reaction, which is the opposite of a reduction reaction, can be caused at the interface between the fixing material 240 and the holding member 230. That is, in the example of Fig. 11, although the oxide film on the surface of the holding member 230 at the interface with the fixing material 240 may grow due to an oxidation reaction, damage to the oxide film can be reduced.

[0117] Therefore, according to the example of FIG. 11, gaps can be made less likely to occur between the fixing material 240 and the holding member 230, and the durability of the cell stack device 200 can be improved.

[0118] 10 and 11, as in the embodiment, a noise reduction unit 32 may be provided between the positive electrode terminal 222 and the ground potential 31. This makes it possible to reduce noise contained in the DC power supplied from the cell stack device 200, thereby enabling the PCS 101 to stably convert the DC power into AC power.

[0119] The remaining parts of the cell stack device 200 shown in FIG. 8 will be described below. The communication holes 261 and 262 of the holding member 230 may be simple bolt holes through which bolts for fixing the cells 201 are inserted, for example. The communication hole 261 may function as a gas supply manifold that supplies a reactant gas or an oxygen-containing gas to the multiple cells 201. The communication hole 262 may function as a gas exhaust manifold that exhausts the reactant gas or the oxygen-containing gas from the multiple cells 201. Hereinafter, a case will be described in which the communication hole 261 functions as an oxygen supply manifold that supplies an oxygen-containing gas to the multiple cells 201, and the communication hole 262 functions as an oxygen exhaust manifold that exhausts the oxygen-containing gas from the multiple cells 201, as shown in FIG. 8.

[0120] The oxygen-containing gas flowing through the oxygen supply manifold is supplied to the air chamber 264 from the communication hole 261 through a flow path (not shown) formed in the air electrode side frame 204. In addition, the oxygen-containing gas discharged from the air chamber 264 flows to the communication hole 262 through a flow path (not shown) formed in the air electrode side frame 204.

[0121] A gas passage member 250 is positioned at the entrance of the communication hole 261. The gas passage member 250 has a main body portion 251 and a branch portion 252, and is sandwiched between the end current collecting member 221 and a nut 232.

[0122] A gas passage member 270 is positioned at the outlet of the communication hole 262. The gas passage member 270 has a main body portion 271 and a branch portion 272, and is sandwiched between the end current collecting member 221 and the nut 232.

[0123] 8, the cell stack device 200 may have a communication hole other than the communication hole 261 that supplies an oxygen-containing gas to the multiple cells 201 and the communication hole 262 that discharges the oxygen-containing gas from the multiple cells 201. The cell stack device 200 may have, for example, a communication hole that functions as a fuel supply manifold that supplies fuel gas to the multiple cells 201 or a fuel discharge manifold that discharges fuel gas from the multiple cells 201. The cell stack device 200 may also have a communication hole that does not have the function of supplying or discharging gas.

[0124] Furthermore, the cell stack device 200 may have, in addition to the communication holes through which the bolts 231 are inserted, communication holes through which the bolts 231 are not inserted. The communication holes through which the bolts 231 are not inserted may have the function of a gas supply manifold or a gas exhaust manifold.

[0125] Furthermore, in the above embodiment, an example has been shown in which the cell stacks 11A, 11B in the cell stack device 10 are connected in series, but the cell stacks 11A, 11B may be connected in parallel to form one battery.

[0126] Furthermore, in the above embodiment, an example has been shown in which the holding member 14 is grounded, but the holding member 14 does not necessarily have to be grounded. Even in this case, by making the potential of the positive electrode terminal 19A equal to or lower than the potential of the holding member 14, it is possible to make it difficult for gap C to occur between the fixing material 13 and the holding body 15, thereby improving the durability of the cell stack device 10.

[0127] As described above, the cell stack device 10 (200) according to the embodiment includes the cell stack 11 (210), the holding member 14 (230), and the positive electrode terminal 19A (222). The cell stack 11 (210) is configured by stacking a plurality of cells 1 (201). The holding member 14 (230) holds the cells 1 (201). The positive electrode terminal 19A (222) functions as a positive electrode when the power generated by the cell stack 11 (210) is output to the outside. In addition, the potential of the positive electrode terminal 19A (222) is equal to or lower than the potential of the holding member 14 (230). This can improve the durability of the cell stack device 10 (200).

[0128] Furthermore, in the cell stack device 10 (200) according to this embodiment, the positive terminal 19A (222) and the holding member 14 (230) are at the same potential, which can improve the durability of the cell stack device 10 (200).

[0129] Furthermore, in the cell stack device 10 (200) according to this embodiment, the potential of the positive electrode terminal 19A (222) is lower than the potential of the holding member 14 (230). This makes it possible to improve the durability of the cell stack device 10 (200).

[0130] Moreover, in the cell stack device 10 (200) according to the embodiment, the positive electrode terminal 19A (222) is connected to the ground potential 31. In the cell stack device 10 (200) according to the embodiment, a noise reduction unit 32 that reduces noise is located between the positive electrode terminal 19A (222) and the ground potential 31. This allows the PCS 101 to stably convert DC power to AC power.

[0131] Moreover, the module 80 according to the embodiment is configured by housing the above-described cell stack device 10 (200) in a housing container 81. This makes it possible to provide a module 80 with high durability.

[0132] Moreover, the module housing device 90 according to the embodiment is configured by housing, inside an exterior case, the above-described module 80 and auxiliary equipment for operating the module 80. This allows the module housing device 90 to have high durability.

[0133] The disclosed embodiments should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. In addition, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0134] 1,201 cells 10, 200 Cell stack device 11, 11A, 11B, 210 Cell stack 12 Fixing member 13, 240 Fixing material 14, 230 Retaining member 15 Holder 16 Gas Tank 19A, 222 Positive terminal 19B, 223 negative terminal 31 Ground potential 32 Noise reduction section 33 Batteries 80 Modules 90 Module storage device

Claims

1. A cell stack having a plurality of cells which are fuel cells or electrolysis cells; A holding member for holding the cell; Equipped with A first cell having the highest potential among the plurality of cells is connected to a ground potential; a noise reduction unit that reduces noise is located between the first cell and the ground potential; When the cell is operating, the potential of the holding member is equal to or greater than the potential of the first cell. Cell stack device.

2. The holding member is at the same potential as the first cell. The cell stack device according to claim 1 .

3. The potential of the holding member is higher than the potential of the first cell. The cell stack device according to claim 1 .

4. A module comprising a container housing the cell stack device according to any one of claims 1 to 3.

5. A module housing device configured by housing the module according to claim 4 in an exterior case.

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