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

Abstract

This electrochemical cell includes a first electrode, a first conductive member, and a second conductive member. The first electrode contains a first material having ionic conductivity in which a first element is solid-solubilized, and a second material having electronic conductivity. A first element is solid-solubilized in the first material. The first conductive member contains a second element different from the first element, and a second material. A second conductive member is located between the first electrode and the first conductive member, and contains a first element, a second element, and a second material. The first element is at least one element selected from among Mg, Ca, and rare earth elements. The second element is at least one element selected from among Mg, Ca, Ti, Al, Si, and rare earth elements.

Description

[Technical Field]

[0001] This disclosure relates to electrochemical cells, electrochemical cell apparatus, modules, and module housing apparatus. [Background technology]

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

[0003] [Patent Document 1] Special Publication No. 2014-524655 [Overview of the Initiative]

[0004] An electrochemical cell according to one embodiment comprises a first electrode, a first conductive member, and a second conductive member. The first electrode contains a first material having ionic conductivity and a second material having electronic conductivity. The first material contains a first element in solid solution. The first conductive member contains a second element different from the first element and the second material. The second conductive member is located between the first electrode and the first conductive member and contains the first element, the second element, and the second material. The first element is one or more elements selected from Mg, Ca, and rare earth elements. The second element is one or more elements selected from Mg, Ca, Ti, Al, Si, and rare earth elements.

[0005] Furthermore, the electrochemical cell apparatus of this disclosure has a cell stack including the electrochemical cell described above.

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

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

[0008] [Figure 1A] Figure 1A is a cross-sectional view showing an example of an electrochemical cell according to the first embodiment. [Figure 1B] Figure 1B is a side view of an example of an electrochemical cell according to the first embodiment, viewed from the air electrode side. [Figure 1C] Figure 1C is a side view of an example of an electrochemical cell according to the first embodiment, as seen from the interconnector side. [Figure 2A] Figure 2A is a perspective view showing an example of an electrochemical cell apparatus according to the first embodiment. [Figure 2B] Figure 2B is a cross-sectional view of the XX line shown in Figure 2A. [Figure 2C] Figure 2C is a top view showing an example of an electrochemical cell apparatus according to the first embodiment. [Figure 3] Figure 3 is an enlarged cross-sectional view of region R1 shown in Figure 1A. [Figure 4] Figure 4 is an external perspective view showing an example of a module according to the first embodiment. [Figure 5] Figure 5 is an exploded perspective view schematically showing an example of a module housing device according to the first embodiment. [Figure 6] Figure 6 is a cross-sectional view of an electrochemical cell apparatus according to the second embodiment. [Figure 7] Figure 7 is a cross-sectional view showing an example of an electrochemical cell according to the second embodiment. [Figure 8] Figure 8 is an enlarged cross-sectional view of region R2 shown in Figure 7. [Figure 9A] Figure 9A is a cross-sectional view showing an example of an electrochemical cell according to the third embodiment. [Figure 9B] Figure 9B is a cross-sectional view showing another example of an electrochemical cell according to the third embodiment. [Figure 9C] FIG. 9C is a cross-sectional view showing another example of an electrochemical cell according to the third embodiment. [Figure 10] FIG. 10 is an enlarged cross-sectional view of the region R3 shown in FIG. 9A.

Embodiments for Carrying Out the Invention

[0009] In the above fuel cell stack device, there was room for improvement in terms of improving durability.

[0010] Therefore, there is an expectation for providing an electrochemical cell, an electrochemical cell device, a module, and a module housing device that can improve durability.

[0011] Hereinafter, embodiments of the electrochemical cell, electrochemical cell device, module, and module housing device disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that this disclosure is not limited by the embodiments shown below.

[0012] Also, the drawings are schematic, and it is necessary to note that the dimensional relationships between elements, the ratios of each element, etc. may be different from reality. Furthermore, there may be portions where the dimensional relationships and ratios between the drawings are different from each other.

[0013] [First Embodiment] <Configuration of Electrochemical Cell> First, an example of a solid oxide type fuel cell as an electrochemical cell constituting an electrochemical cell device according to the first embodiment will be described while referring to FIGS. 1A to 1C. The electrochemical cell device may include a cell stack having a plurality of electrochemical cells. An electrochemical cell device having a plurality of electrochemical cells is simply referred to as a cell stack device.

[0014] Figure 1A is a cross-sectional view showing an example of an electrochemical cell according to the first embodiment. Figure 1B is a side view of an example of an electrochemical cell according to the first embodiment, viewed from the air electrode side. Figure 1C is a side view of an example of an electrochemical cell according to the first embodiment, viewed from the interconnector side. Figures 1A to 1C show enlarged views of some of the components of the electrochemical cell. Hereinafter, the electrochemical cell may simply be referred to as a cell.

[0015] In the examples shown in Figures 1A to 1C, cell 1 is a hollow, flat plate type, elongated in shape. As shown in Figure 1B, the overall shape of cell 1 when viewed from the side is, for example, a rectangle with a length of 5 cm to 50 cm along the length direction L, and a width direction W perpendicular to this length direction L, for example, 1 cm to 10 cm. The overall thickness T of cell 1 is, for example, 1 mm to 5 mm.

[0016] As shown in Figure 1A, cell 1 comprises a conductive support substrate 2, an element section 3, and an interconnector 4. The support substrate 2 is columnar in shape, having a pair of opposing first surfaces n1 and second surfaces n2, and a pair of arc-shaped side surfaces m connecting the first surface n1 and the second surface n2.

[0017] The element unit 3 is provided on the first surface n1 of the support substrate 2. This element unit 3 includes a fuel electrode 5, a solid electrolyte layer 6, and an air electrode 8. In the example shown in Figure 1A, the interconnector 4 is located on the second surface n2 of the cell 1. The cell 1 may also have an intermediate layer 7 between the solid electrolyte layer 6 and the air electrode 8.

[0018] Furthermore, as shown in Figure 1B, the air electrode 8 does not extend to the lower end of cell 1. At the lower end of cell 1, only the solid electrolyte layer 6 is exposed on the surface of the first surface n1. Also, as shown in Figure 1C, the interconnector 4 may extend to the lower end of cell 1. At the lower end of cell 1, the interconnector 4 and the solid electrolyte layer 6 are exposed on the surface. Note that, as shown in Figure 1A, the solid electrolyte layer 6 is exposed on the surface of the pair of arc-shaped side surfaces m of cell 1. The interconnector 4 does not necessarily have to extend to the lower end of cell 1.

[0019] The following describes each component that makes up Cell 1.

[0020] The support substrate 2 has gas passages 2a inside through which gas flows. An example of the support substrate 2 shown in Figure 1A has six gas passages 2a. The support substrate 2 is gas permeable and allows fuel gas flowing through the gas passages 2a to pass through to the fuel electrode 5. The support substrate 2 may also be conductive. A conductive support substrate 2 collects the electricity generated in the element section 3 and sends it to the interconnector 4.

[0021] The material of the support substrate 2 includes, for example, an iron group metal component and an inorganic oxide. The iron group metal component may be, for example, Ni (nickel) and / or NiO. The inorganic oxide may be, for example, a specific rare earth element oxide. The rare earth element oxide may include, for example, one or more rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. Further details of the support substrate 2 will be described later.

[0022] The fuel electrode 5 may be a porous conductive ceramic. As the material for the fuel electrode 5, for example, ceramics containing calcium oxide, magnesium oxide, or ZrO2 in which rare earth element oxides are solid-dissolved, along with Ni and / or NiO, may be used. These rare earth element oxides may include, for example, multiple rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. The calcium oxide, magnesium oxide, or ZrO2 in which rare earth element oxides are solid-dissolved is sometimes referred to as stabilized zirconia. The stabilized zirconia may include partially stabilized zirconia. The fuel electrode 5 is an example of the first electrode.

[0023] Furthermore, the fuel electrode 5 may also contain cerium oxide (CeO2) in which rare earth elements such as La (lanthanum), Gd (gadolinium), and Sm (samarium) are solid-solved. The fuel electrode 5 may also contain perovskite-type compounds such as BaMO3 and SrMO3 (where M is Zr and / or Ce) in which rare earth elements are solid-solved.

[0024] The content of rare earth element oxides in solid solution in the fuel electrode 5, such as ZrO2, CeO2, BaMO3, and SrMO3, may be in the range of 35% to 65% by volume. The content of Ni and / or NiO may also be in the range of 65% to 35% by volume. The porosity of the fuel electrode 5 may be 15% or more, particularly in the range of 20% to 40%. The thickness of the fuel electrode 5 may be 1 μm to 30 μm.

[0025] The solid electrolyte layer 6 is an electrolyte that facilitates the transfer of ions between the fuel electrode 5 and the air electrode 8. At the same time, the solid electrolyte layer 6 has gas barrier properties, making it difficult for leaks between the fuel gas and the oxygen-containing gas to occur.

[0026] The solid electrolyte layer 6 contains Zr. The material of the solid electrolyte layer 6 may be, for example, ZrO2 in which 3 mol% to 15 mol% of rare earth element oxides, calcium oxide, or magnesium oxide are solid-dissolved. The rare earth element oxide may contain, for example, one or more rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. The material of the solid electrolyte layer 6 may be stabilized zirconia containing, for example, Sc, Y, or Yb. The solid electrolyte layer 6 may also contain perovskite-type compounds such as BaZrO3 and SrZrO3 in which rare earth elements such as Sc, Y, La, Nd, Sm, Gd, Dy, and Yb are solid-dissolved.

[0027] The air electrode 8 is gas permeable. The air electrode 8 is an example of a second electrode. The open porosity of the air electrode 8 may be in the range of, for example, 20% to 50%, and particularly 30% to 50%.

[0028] The material for the air electrode 8 is not particularly limited as long as it is a material commonly used for air electrodes. For example, the material for the air electrode 8 may be conductive ceramics such as so-called ABO3 type perovskite oxides.

[0029] The material of the air electrode 8 may be, for example, a composite oxide in which Sr (strontium) and La (lanthanum) coexist at the A site. An example of such a composite oxide is La 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 Examples include SrCoFeO3, LaSrMnO3, LaSrFeO3, LaSrCoO3, etc. Here, 0 < x < 1 and 0 < y < 1.

[0030] Also, when the element part 3 has the intermediate layer 7, the intermediate layer 7 functions as a diffusion suppression layer. When elements such as Sr (strontium) contained in the air electrode 8 diffuse into the solid electrolyte layer 6, a resistance layer such as SrZrO3 is formed in the solid electrolyte layer 6. The intermediate layer 7 makes it difficult for Sr to diffuse, thereby making it difficult for SrZrO3 and other electrically insulating oxides to be formed.

[0031] The material of the intermediate layer 7 is not particularly limited as long as it generally makes it difficult for elements to diffuse between the air electrode 8 and the solid electrolyte layer 6. The material of the intermediate layer 7 may contain, for example, cerium oxide (CeO2) in which rare earth elements excluding Ce (cerium) are solid-dissolved. As such rare earth elements, for example, Gd (gadolinium), Sm (samarium), etc. may be used.

[0032] Also, the interconnector 4 is dense and hardly causes leakage of the fuel gas flowing through the gas flow path 2a located inside the support substrate 2 and the oxygen-containing gas flowing outside the support substrate 2. The interconnector 4 may have a relative density of 93% or more, particularly 95% or more.

[0033] For the material of the interconnector 4, perovskite-type oxides of the lanthanum chromite system (LaCrO3-based oxides), perovskite-type oxides of the lanthanum strontium titanium system (LaSrTiO3-based oxides), etc. may be used. These materials have conductivity and are hardly reduced or oxidized even when they come into contact with fuel gases such as hydrogen-containing gases and oxygen-containing gases such as air. Also, a metal or an alloy may be used as the material of the interconnector 4.

[0034] <Configuration of an electrochemical cell system> Next, the electrochemical cell apparatus according to this embodiment, using the electrochemical cell described above, will be explained with reference to Figures 2A to 2C. Figure 2A is a perspective view showing an example of the electrochemical cell apparatus according to the first embodiment. Figure 2B is a cross-sectional view taken along line XX shown in Figure 2A. Figure 2C is a top view showing an example of the electrochemical cell apparatus according to the first embodiment.

[0035] As shown in Figure 2A, the cell stacking device 10 comprises a cell stack 11 having a plurality of cells 1 arranged (stacked) in the thickness direction T (see Figure 1A) of the cell 1, and a fixing member 12.

[0036] The fixing member 12 includes a fixing material 13 and a support member 14. The support member 14 supports the cell 1. The fixing material 13 fixes the cell 1 to the support member 14. The support member 14 also includes a support body 15 and a gas tank 16. The support body 15 and the gas tank 16, which make up the support member 14, are made of, for example, metal and are electrically conductive.

[0037] As shown in Figure 2B, the support 15 has an insertion hole 15a into which the lower ends of the multiple cells 1 are inserted. The lower ends of the multiple cells 1 and the inner wall of the insertion hole 15a are joined together by a fixing member 13.

[0038] The gas tank 16 has an opening that supplies reaction gas to multiple cells 1 through an insertion hole 15a, and a groove 16a located around the opening. The outer end of the support 15 is joined to the gas tank 16 by a bonding material 21 that is filled into the groove 16a of the gas tank 16.

[0039] In the example shown in Figure 2A, fuel gas is stored in the internal space 22 formed by the support member 14, which is the support body 15, and the gas tank 16. A gas flow pipe 20 is connected to the gas tank 16. Fuel gas is supplied to the gas tank 16 through this gas flow pipe 20 and then supplied from the gas tank 16 to the gas flow path 2a (see Figure 1A) inside the cell 1. The fuel gas supplied to the gas tank 16 is generated in the reformer 102 (see Figure 4), which will be described later.

[0040] Hydrogen-rich fuel gas can be produced by steam reforming of the raw fuel. When fuel gas is produced by steam reforming, the fuel gas contains water vapor.

[0041] In the example shown in Figure 2A, the cell stack device 10 comprises two rows of cell stacks 11, two support members 15, and a gas tank 16. Each of the two rows of cell stacks 11 has multiple cells 1. Each cell stack 11 is fixed to each support member 15. The gas tank 16 has two through holes on its top surface. Each support member 15 is positioned in each through hole. The internal space 22 is formed by one gas tank 16 and two support members 15. Although Figure 2A shows a cell stack device 10 with two rows of cell stacks 11, the cell stack device may have one row of cell stacks 11, or three or more rows of cell stacks 11.

[0042] The shape of the insertion hole 15a is, for example, an oval shape when viewed from above. The length of the insertion hole 15a in the arrangement direction of the cell 1, i.e., the thickness direction T, may be greater than the distance between the two end current collectors 17 located at both ends of the cell stack 11. The width of the insertion hole 15a may be, for example, greater than the length in the width direction W (see Figure 1A) of the cell 1.

[0043] As shown in Figure 2B, the joint between the inner wall of the insertion hole 15a and the lower end of the cell 1 is filled with a fixing material 13 and solidified. This joins and fixes the inner wall of the insertion hole 15a to the lower ends of the multiple cells 1, and also joins and fixes the lower ends of the cells 1 to each other. The gas passage 2a of each cell 1 communicates with the internal space 22 of the support member 14 at its lower end.

[0044] The fixing material 13 and the bonding material 21 can be made of materials with low conductivity, such as glass. Specific materials for the fixing material 13 and the bonding material 21 may include amorphous glass, and in particular, crystallized glass may be used.

[0045] As the crystallized glass, any of the following materials may be used, for example: SiO2-CaO system, MgO-B2O3 system, La2O3-B2O3-MgO system, La2O3-B2O3-ZnO system, SiO2-CaO-ZnO system, and in particular, SiO2-MgO system materials may be used.

[0046] Furthermore, as shown in Figure 2B, a conductive member 18 is interposed between adjacent cells 1 among the multiple cells 1. The conductive member 18 electrically connects the fuel electrode 5 of one adjacent cell 1 and the air electrode 8 of the other cell 1 in series. More specifically, the conductive member 18 connects the interconnector 4, which is electrically connected to the fuel electrode 5 of one adjacent cell 1, to the air electrode 8 of the other cell 1. If the interconnector 4 is made of metal or an alloy, the interconnector 4 and the conductive member 18 may be integrated, or the conductive member 18 may also function as the interconnector 4.

[0047] Furthermore, as shown in Figure 2B, the end current collector 17 is electrically connected to the outermost cell 1 in the arrangement direction of the multiple cells 1. The end current collector 17 is connected to a conductive part 19 that protrudes to the outside of the cell stack 11. The conductive part 19 collects the electricity generated by the cell 1 and draws it out to the outside. Note that the end current collector 17 is not shown in Figure 2A.

[0048] Furthermore, as shown in Figure 2C, the cell stack device 10 consists of two cell stacks 11A and 11B connected in series, functioning as a single battery. Therefore, the conductive part 19 of the cell stack device 10 is distinguished into a positive terminal 19A, a negative terminal 19B, and a connection terminal 19C.

[0049] The positive terminal 19A is the positive terminal when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the positive terminal end current collector 17 of the cell stack 11A. The negative terminal 19B is the negative terminal when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the negative terminal end current collector 17 of the cell stack 11B.

[0050] The connection terminal 19C electrically connects the negative terminal end current collector 17 of the cell stack 11A to the positive terminal end current collector 17 of the cell stack 11B.

[0051] <Details of the electrochemical cell> Next, the details of the electrochemical cell including the support substrate 2 according to the first embodiment will be described with reference to Figure 3. Figure 3 is an enlarged cross-sectional view of the region R1 shown in Figure 1A.

[0052] As shown in Figure 3, cell 1 comprises a solid electrolyte layer 6, a fuel electrode 5 as a first electrode, a support substrate 2 as a first conductive member, and a second conductive member 2b. For example, the performance of the element 3 can be improved by using an ion-conducting material containing a first element for the first electrode, and a material containing a second element different from the first element can be used for the first conductive member. This allows for adjustment of the thermal expansion coefficient between the first electrode and the first conductive member, making it less likely for the first electrode to peel off from the first conductive member.

[0053] The solid electrolyte layer 6 contains a first material containing a first element. The first element may be in solid solution in the first material. The first element is one or more elements selected from Mg, Ca, and rare earth elements. The rare earth elements may include, for example, one or more elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. The first material may contain an oxide-based solid electrolyte material in which an oxide of the first element is in solid solution. The first material may contain, for example, stabilized zirconia containing Sc, Y, or Yb.

[0054] The fuel electrode 5 contains a first material having ionic conductivity and a second material having electronic conductivity. The second material may be, for example, Ni or NiO.

[0055] The support substrate 2 contains a second element and a second material. The second element is one or more elements selected from Mg, Ca, Ti, Al, Si, and rare earth elements, and is different from the first element. The support substrate 2 may also contain an oxide of the second element. For example, the support substrate 2 may contain Sc2O3, Y2O3, or Yb2O3.

[0056] The second conductive member 2b is located between the fuel electrode 5, which serves as the first electrode, and the support substrate 2, which serves as the first conductive member. The second conductive member 2b contains a first element, a second element, and a second material. The second conductive member 2b may also contain an oxide of the first element and an oxide of the second element. Furthermore, the second conductive member 2b may also contain the first material.

[0057] Here, the content of the first element, the second element, the first material, and the second material can be confirmed, for example, by elemental analysis using EPMA. Specifically, for example, the cross-section of the element part 3 in the stacking direction can be mirror-polished, and the content of the first element, the second element, the first material, and the second material can be calculated by performing semi-quantitative analysis on a predetermined area. The content of the first element may be evaluated, for example, as the ratio of the first element to the total of the metal elements constituting the first element, the second element, and the first material.

[0058] Thus, by positioning the second conductive member 2b, which includes the first element present in the fuel electrode 5 and the second element present in the support substrate 2, between the fuel electrode 5 and the support substrate 2, the difference in thermal expansion between the fuel electrode 5 and the support substrate 2 can be mitigated. For this reason, the cell 1 according to this embodiment can improve durability.

[0059] Furthermore, the content of the first element in the fuel electrode 5 may decrease as it approaches the support substrate 2 in the cross-section in the stacking direction of the element portion 3. The content of the first element in the fuel electrode 5 may be distributed such that it decreases as it approaches the boundary between the fuel electrode 5 and the second conductive member 2b. This further improves the durability of the cell 1.

[0060] The fuel electrode 5, the second conductive member 2b, and the support substrate 2 may have portions in the cross-section of the element portion 3 in the stacking direction where the content of the first element takes on a maximum and / or minimum value. A maximum value is a local maximum value, and a minimum value is a local minimum value.

[0061] The boundary between the second conductive member 2b and the fuel electrode 5 is, for example, the region closest to the solid electrolyte layer 6 among the regions where the content of the first element is at its minimum. The content of the first element included in the boundary between the second conductive member 2b and the fuel electrode 5 may be, for example, 1 / 3 or less of the content of the first element in the vicinity of the solid electrolyte layer 6 of the fuel electrode 5.

[0062] The boundary between the second conductive member 2b and the support substrate 2 is, for example, a region where the distance from the solid electrolyte layer 6 is greater than the distance to the boundary between the second conductive member 2b and the fuel electrode 5, and where the content of the first element is equal to the content of the first element at the boundary between the second conductive member 2b and the fuel electrode 5.

[0063] The second conductive member 2b may have a portion between the boundary between the second conductive member 2b and the fuel electrode 5 and the boundary between the second conductive member 2b and the support substrate 2 where the content of the first element is at its maximum.

[0064] The second conductive member 2b may contain a larger amount of the first material containing the first element in the portion closer to the fuel electrode 5 than in the portion further away from the fuel electrode 5. This makes it more difficult for the fuel electrode 5 to detach from the support substrate 2. The second conductive member 2b may contain a larger amount of the oxide of the first element in the portion closer to the support substrate 2 than in the portion further away from the support substrate 2. This makes it more difficult for the fuel electrode 5 to detach from the support substrate 2. The second conductive member 2b may contain a first material containing the second element in the portion closer to the fuel electrode 5.

[0065] The content of the second material in the fuel electrode 5, the support substrate 2, and the second conductive member 2b may be the same or different.

[0066] <module> Next, the module according to this embodiment using the electrochemical cell device described above will be explained with reference to Figure 4. Figure 4 is an external perspective view showing the module according to the first embodiment. In Figure 4, the front and rear surfaces, which are part of the storage container 101, have been removed, and the fuel cell cell stack device 10 housed inside has been taken out to the rear.

[0067] As shown in Figure 4, module 100 comprises a storage container 101 and a cell stack device 10 housed within the storage container 101. A reformer 102 is positioned above the cell stack device 10.

[0068] The reformer 102 reforms raw fuels such as natural gas and kerosene to produce fuel gas, which is then supplied to cell 1. The raw fuels are supplied to the reformer 102 through a raw fuel supply pipe 103. The reformer 102 may also include a vaporization section 102a for vaporizing water and a reforming section 102b. The reforming section 102b is equipped with a reforming catalyst (not shown) and reforms the raw fuels into fuel gas. Such a reformer 102 can perform steam reforming, which is a highly efficient reforming reaction.

[0069] The fuel gas generated in the reformer 102 is then supplied to the gas flow path 2a of cell 1 (see Figure 1A) through the gas flow pipe 20, the gas tank 16, and the support member 14.

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

[0071] As described above, such a module 100 can be made highly durable by housing a highly durable cell stack device 10.

[0072] <Module housing device> Figure 5 is an exploded perspective view showing an example of a module housing device according to the first embodiment. The module housing device 110 according to this embodiment comprises an outer case 111, a module 100 shown in Figure 4, and auxiliary equipment (not shown). The auxiliary equipment operates the module 100. The module 100 and the auxiliary equipment are housed in the outer case 111. Note that some components are omitted in Figure 5.

[0073] The outer casing 111 of the module housing device 110 shown in Figure 5 has support columns 112 and outer panels 113. Partition plates 114 divide the inside of the outer casing 111 into upper and lower sections. The space above the partition plates 114 inside the outer casing 111 is the module housing chamber 115 for housing the module 100, and the space below the partition plates 114 inside the outer casing 111 is the auxiliary equipment housing chamber 116 for housing the auxiliary equipment that operates the module 100. Note that in Figure 5, the auxiliary equipment housed in the auxiliary equipment housing chamber 116 is omitted from the illustration.

[0074] Furthermore, the partition plate 114 has an air circulation port 117 for allowing air from the auxiliary equipment storage room 116 to flow towards the module storage room 115. The outer panel 113 that constitutes the module storage room 115 has an exhaust port 118 for exhausting the air inside the module storage room 115.

[0075] In such a module housing device 110, as described above, a highly durable module housing device 110 can be made possible by providing a highly durable module 100 in the module housing chamber 115.

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

[0077] [Second Embodiment] Next, the electrochemical cell and electrochemical cell apparatus according to the second embodiment will be described with reference to Figures 6 to 8.

[0078] In the above-described embodiment, a so-called "vertical stripe type" was exemplified, in which only one element section including a fuel electrode layer, a solid electrolyte layer, and an air electrode layer is provided on the surface of the support substrate. However, this can be applied to a horizontal stripe type electrochemical cell apparatus in which a so-called "horizontal stripe type" electrochemical cell is arranged, in which element sections are provided at multiple locations on the surface of the support substrate that are far apart from each other, and adjacent element sections are electrically connected.

[0079] Figure 6 is a cross-sectional view of an electrochemical cell apparatus according to the second embodiment. Figure 7 is a cross-sectional view showing an example of an electrochemical cell according to the second embodiment.

[0080] As shown in Figure 6, in the cell stack device 10A according to the second embodiment, a plurality of cells 1A extend in the longitudinal direction L from a pipe 22a through which fuel gas flows. Each cell 1A has a plurality of element parts 3 on a support substrate 2. A gas flow path 2a is provided inside the support substrate 2 through which the fuel gas from the pipe 22a flows.

[0081] Furthermore, each cell 1A is electrically connected to one another via a connecting member 31. The connecting member 31 is located between the element sections 3 of each cell 1A and connects adjacent cells 1A. Specifically, the connecting member 31 electrically connects the air electrode 8 of the element section 3 of one of the adjacent cells 1A to the fuel electrode 5 of the element section 3 of the other cell 1A.

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

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

[0084] Cell 1A may have a shape that is symmetrical with respect to a plane that passes through the center of the thickness direction T and is parallel to the first surface n1 and the second surface n2 of the support substrate 2. The element portion 3 comprises a fuel electrode 5, a solid electrolyte layer 6, and an air electrode 8. The element portion 3 may also have an intermediate layer 7 between the solid electrolyte layer 6 and the air electrode 8.

[0085] Figure 8 is an enlarged cross-sectional view of region R2 shown in Figure 7. As shown in Figure 8, cell 1A comprises a solid electrolyte layer 6, a fuel electrode 5, and an insulating support substrate 2.

[0086] The solid electrolyte layer 6 contains a first material in which a first element is in solid solution. The first element is one or more elements selected from Mg, Ca, and rare earth elements. The first material may include, for example, stabilized zirconia containing Sc, Y, or Yb.

[0087] The fuel electrode 5 includes a fuel electrode functional layer 5a as a first electrode, a fuel electrode current collector layer 5b as a first conductive member, and a second conductive member 5c. The fuel electrode functional layer 5a contains a first material having ionic conductivity and a second material having electronic conductivity.

[0088] The fuel electrode current collector layer 5b is a first conductive member and contains a second element and a second material. The second element is one or more elements selected from Mg, Ca, Ti, Al, Si, and rare earth elements, and is different from the first element. The fuel electrode current collector layer 5b may contain stabilized zirconia containing, for example, Sc, Y, or Yb. The insulating support substrate 2 may or may not contain stabilized zirconia containing, for example, Sc, Y, or Yb.

[0089] The second conductive member 5c is located between the fuel electrode functional layer 5a, which serves as the first electrode, and the fuel electrode current collector layer 5b, which serves as the first conductive member. The second conductive member 5c contains the first element, the second element, and the second material.

[0090] Thus, by positioning the second conductive member 5c, which includes the first element in the fuel electrode functional layer 5a and the second element in the fuel electrode current collector layer 5b, between the fuel electrode functional layer 5a and the fuel electrode current collector layer 5b, the difference in thermal expansion between the fuel electrode functional layer 5a and the fuel electrode current collector layer 5b can be mitigated. For this reason, the cell 1A according to this embodiment can improve durability.

[0091] [Third Embodiment] Figure 9A is a cross-sectional view showing an example of an electrochemical cell according to the third embodiment. Figures 9B and 9C are cross-sectional views showing other examples of an electrochemical cell according to the third embodiment.

[0092] As shown in Figures 9A to 9C, cell 1B has an element section 3B comprising a fuel electrode 5, a solid electrolyte layer 6, and an air electrode 8, and a support substrate 2. The element section 3B may have an intermediate layer 7 between the solid electrolyte layer 6 and the air electrode 8. The support substrate 2 has through holes or pores in the portion in contact with the element section 3B, and also has a member 120 located outside the gas flow path 2a. The support substrate 2 allows gas to flow between the gas flow path 2a and the element section 3B. The support substrate 2 may be composed of, for example, one or more metal plates. The material of the metal plates may contain chromium. The metal plates may have a conductive coating layer. The support substrate 2 electrically connects adjacent cells 1B to each other. The element section 3B is joined to the support substrate 2 by bonding materials 23, 24.

[0093] In the example shown in Figure 9A, the side surface of the fuel electrode 5 is covered with a solid electrolyte layer 6, hermetically sealing the gas passage 2a through which the fuel gas flows. As shown in Figure 9B, the side surface of the fuel electrode 5 may be covered and sealed with a dense sealing material 9 containing glass or ceramic. The sealing material 9 covering the side surface of the fuel electrode 5 may have electrical insulating properties.

[0094] Furthermore, the gas flow path 2a of the support substrate 2 may be formed by a member 120 having irregularities, as shown in Figure 9C.

[0095] Figure 10 is an enlarged cross-sectional view of region R3 shown in Figure 9A. As shown in Figure 10, cell 1B comprises a solid electrolyte layer 6, a fuel electrode 5 as a first electrode, a bonding material 23 as a first conductive member, and a bonding material 24 as a second conductive member. Note that Figure 10 can also be applied to the examples in Figures 9B and 9C.

[0096] The solid electrolyte layer 6 contains a first material in which a first element is in solid solution. The first element is one or more elements selected from Mg, Ca, and rare earth elements.

[0097] The fuel electrode 5 contains a first material having ionic conductivity and a second material having electronic conductivity.

[0098] The bonding material 23 contains a second element and a second material. The second element is one or more elements selected from Mg, Ca, Ti, Al, Si, and rare earth elements, and is different from the first element. The bonding material 23 may also contain an oxide of the second element. The bonding material 23 may include, for example, TiO2, Al2O3, SiO2, etc.

[0099] The bonding material 24, which serves as the second conductive member, is located between the fuel electrode 5, which serves as the first electrode, and the bonding material 23, which serves as the first conductive member. The bonding material 24 contains the first element, the second element, and the second material.

[0100] Thus, by positioning the bonding material 24, which contains a first material comprising the first element present in the fuel electrode 5 and the second element present in the bonding material 23, between the fuel electrode 5 and the bonding material 23, the difference in thermal expansion between the fuel electrode 5 and the bonding material 23 can be mitigated. For this reason, the cell 1B according to this embodiment can improve durability.

[0101] [Other embodiments] Next, an electrochemical cell apparatus according to another embodiment will be described.

[0102] In the embodiments described above, fuel cell cells, fuel cell stack devices, fuel cell modules, and fuel cell devices were shown as examples of "electrochemical cells," "electrochemical cell devices," "modules," and "module housing devices," but other examples may be electrolytic cells, electrolytic cell stack devices, electrolytic modules, and electrolytic devices, respectively. An electrolytic cell has a first electrode layer and a second electrode layer, and decomposes water vapor into hydrogen and oxygen, or carbon dioxide into carbon monoxide and oxygen, when power is supplied. In the embodiments described above, oxide ion conductors or hydrogen ion conductors were shown as examples of electrolyte materials for the electrochemical cell, but hydroxide ion conductors may also be used. Such electrolytic cells, electrolytic cell stack devices, electrolytic modules, and electrolytic devices can improve durability.

[0103] Although the present disclosure has been described in detail above, this disclosure is not limited to the embodiments described above, and various modifications and improvements are possible without departing from the gist of this disclosure.

[0104] In one embodiment, (1) the electrochemical cell comprises a first electrode containing a first material having ionic conductivity in which a first element is solid-solved and a second material having electronic conductivity, A first conductive member containing a second element different from the first element and the second material, A second conductive member is located between the first electrode and the first conductive member and contains the first element, the second element, and the second material. Equipped with, The first element is one or more elements selected from Mg, Ca, and rare earth elements. The second element is one or more elements selected from Mg, Ca, Ti, Al, Si, and rare earth elements.

[0105] (2) In the electrochemical cell described in (1) above, the first conductive member may contain an oxide of the second element.

[0106] (3) In the electrochemical cell described in (1) or (2) above, the second conductive member may contain an oxide of the first element and an oxide of the second element.

[0107] (4) In any one of the electrochemical cells described in (1) to (3) above, the second conductive member may contain the first material.

[0108] (5) In any one of the electrochemical cells described in (1) to (4) above, the second conductive member may have a region between the boundary between the first electrode and the second conductive member and the boundary between the first conductive member and the second conductive member where the content of the first element is maximized.

[0109] In one embodiment, (6) the electrochemical cell apparatus has a cell stack containing any one of the electrochemical cells described in (1) to (5) above.

[0110] In one embodiment, module (7) is the electrochemical cell apparatus of (6) above, The system includes a storage container for housing the aforementioned electrochemical cell apparatus.

[0111] In one embodiment, (8) the module housing device includes the module described in (7) above, Auxiliary equipment for operating the aforementioned module, The system comprises the module and an outer case housing the auxiliary equipment.

[0112] In one embodiment, (9) the electrochemical cell comprises a first electrode containing a first material having ionic conductivity and a second material having electronic conductivity, A first conductive member containing a second element different from the first element and the second material, A second conductive member is located between the first electrode and the first conductive member and contains the first element, the second element, and the second material. Equipped with, The first element is one or more elements selected from Mg, Ca, and rare earth elements. The second element is one or more elements selected from Mg, Ca, Ti, Al, Si, and rare earth elements.

[0113] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of Symbols]

[0114] 1 cell 2. Support substrate 2b Second conductive member 5 Fuel electrode 6 Solid electrolyte layer 10-cell stack device 11-cell stack 12 Fixing member 13 Fixing material 14 Support Member 15 Support 16 gas tanks 17 End current collector 18 Conductive members 100 modules 110 Module housing device

Claims

1. A first electrode containing a first material having ionic conductivity in which a first element is solid-solved, and a second material having electronic conductivity, A first conductive member containing an oxide of a second element different from the first element and the second material, A second conductive member is located between the first electrode and the first conductive member and contains an oxide of the first element, an oxide of the second element, and the second material. Equipped with, The first element is one or more elements selected from Mg, Ca, and rare earth elements. The second element is one or more elements selected from Mg, Ca, Ti, Al, Si, and rare earth elements. Electrochemical cell.

2. The first material contains an oxide of the first element. The electrochemical cell according to claim 1.

3. The second conductive member contains the first material The electrochemical cell according to claim 1.

4. The second conductive member has a region where the content of the first element is maximized, between the boundary between the first electrode and the second conductive member and the boundary between the first conductive member and the second conductive member. The electrochemical cell according to claim 1.

5. A first electrode containing a first material having ionic conductivity and a second material having electronic conductivity, A first conductive member containing an oxide of a second element different from the first element and the second material, A second conductive member is located between the first electrode and the first conductive member and contains an oxide of the first element, an oxide of the second element, and the second material. Equipped with, The first element is one or more elements selected from Mg, Ca, and rare earth elements. The second element is one or more elements selected from Mg, Ca, Ti, Al, Si, and rare earth elements. Electrochemical cell.

6. The first material contains an oxide of the first element The electrochemical cell according to claim 5.

7. A cell stack comprising an electrochemical cell according to any one of claims 1 to 6. Electrochemical cell apparatus.

8. The electrochemical cell apparatus according to claim 7, A storage container for housing the electrochemical cell apparatus and A module equipped with the following features.

9. The module according to claim 8, Auxiliary equipment for operating the aforementioned module, An outer case housing the module and the auxiliary equipment A module housing device equipped with the following features.

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