Electrochemical cell, electrochemical cell device, module, and module accommodating device

Abstract

This electrochemical cell comprises a first electrode, a second electrode, a solid electrolytic layer, and an intermediate layer. The solid electrolytic layer is located between the first electrode and the second electrode. The intermediate layer is located between the solid electrolytic layer and the second electrode. The intermediate layer contains at least one of Cu, Na, and V as a first element, and contains Ce as a second element.

Description

Electrochemical cell, electrochemical cell device, module, and module housing device

[0001] The present disclosure relates to electrochemical cells, electrochemical cell devices, modules and module housing devices.

[0002] In recent years, various fuel cell stack devices including multiple fuel cell units have been proposed as next-generation energy sources. A fuel cell unit is a type of cell that can generate electricity using a fuel gas such as a hydrogen-containing gas and an oxygen-containing gas such as air.

[0003] JP 2017-147030 A

[0004] An electrochemical cell according to one aspect of the present invention includes a first electrode, a second electrode, a solid electrolyte layer, and an intermediate layer. The solid electrolyte layer is located between the first electrode and the second electrode. The intermediate layer is located between the solid electrolyte layer and the second electrode. The intermediate layer contains at least one of Cu, Na, and V as a first element and Ce as a second element.

[0005] The electrochemical cell device of the present disclosure also includes a cell stack including the electrochemical cell described above.

[0006] The module of the present disclosure includes the electrochemical cell device described above and a container that houses the electrochemical cell device.

[0007] The module housing device of the present disclosure includes the module described above, an auxiliary device for operating the module, and an exterior case for housing the module and the auxiliary device.

[0008] FIG. 1A is a cross-sectional view showing an example of an electrochemical cell according to the first embodiment. FIG. 1B is a side view of an example of an electrochemical cell according to the first embodiment, viewed from the second electrode side. FIG. 1C is a side view of an example of an electrochemical cell according to the first embodiment, viewed from the interconnector side. FIG. 2A is a perspective view showing an example of an electrochemical cell device according to the first embodiment. FIG. 2B is a cross-sectional view taken along line X-X shown in FIG. 2A. FIG. 2C is a top view showing an example of an electrochemical cell device according to the first embodiment. FIG. 3 is an enlarged cross-sectional view of a region R1 shown in FIG. 1A. FIG. 4 is an external perspective view showing an example of a module according to the first embodiment. FIG. 5 is an exploded perspective view schematically showing an example of a module housing device according to the first embodiment. FIG. 6 is a cross-sectional view showing an example of an electrochemical cell device according to the second embodiment. FIG. 7 is a cross-sectional view showing an electrochemical cell according to the second embodiment. FIG. 8 is an enlarged cross-sectional view of a region R2 shown in FIG. 7. FIG. 9 is a perspective view showing an example of an electrochemical cell according to a third embodiment. FIG. 10 is a partial cross-sectional view of the electrochemical cell shown in FIG. 9. Fig. 11 is an enlarged cross-sectional view of region R3 shown in Fig. 10. Fig. 12A is a cross-sectional view showing an example of an electrochemical cell according to the fourth embodiment. Fig. 12B is a cross-sectional view showing another example of an electrochemical cell according to the fourth embodiment. Fig. 12C is a cross-sectional view showing another example of an electrochemical cell according to the fourth embodiment. Fig. 13 is an enlarged cross-sectional view of region R4 shown in Fig. 12A.

[0009] The above-described fuel cell stack device has room for improvement in terms of power generation performance.

[0010] Therefore, it is desired to provide an electrochemical cell, an electrochemical cell device, a module, and a module housing device that can improve performance.

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

[0012] It should also be noted that the drawings are schematic and that the dimensional relationships and ratios of elements may differ from reality. Furthermore, the drawings may contain parts whose dimensional relationships and ratios differ from one another.

[0013] 1A to 1C, an electrochemical cell according to a first embodiment will be described using an example of a solid oxide fuel cell. 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 will be simply referred to as a cell stack device.

[0014] Fig. 1A is a cross-sectional view showing an example of an electrochemical cell according to the first embodiment, Fig. 1B is a side view of the example of the electrochemical cell according to the first embodiment as seen from the second electrode side, and Fig. 1C is a side view of the example of the electrochemical cell according to the first embodiment as seen from the interconnector side. Note that Figs. 1A to 1C show enlarged views of parts of each component of the electrochemical cell. Hereinafter, the electrochemical cell may also be simply referred to as a cell.

[0015] 1A to 1C, the cell 1 is a hollow, flat, elongated plate. As shown in Fig. 1B, the shape of the entire cell 1 as viewed from the side is, for example, a rectangle with a side length in the length direction L of 5 cm to 50 cm and a length in the width direction W perpendicular to the length direction L of 1 cm to 10 cm. The thickness of the entire cell 1 in the thickness direction T is, for example, 1 mm to 5 mm.

[0016] 1A, the cell 1 includes a conductive support substrate 2, an element portion 3, and an interconnector 4. The support substrate 2 is columnar and has a pair of opposing flat surfaces, a first surface n1 and a second surface n2, and a pair of arc-shaped side surfaces m connecting the first surface n1 and the second surface n2.

[0017] The element section 3 is located on a first surface n1 of the support substrate 2. The element section 3 has a fuel electrode 5 as a first electrode, a solid electrolyte layer 6, an intermediate layer 7, and a cathode 8 as a second electrode.

[0018] 1B, the air electrode 8 does not extend to the lower end of the cell 1. At the lower end of the cell 1, only the solid electrolyte layer 6 is exposed on the surface of the first face n1. As shown in FIG. 1C, the interconnector 4 may extend to the lower end of the cell 1. At the lower end of the cell 1, the interconnector 4 and the solid electrolyte layer 6 are exposed on the surface. As shown in FIG. 1A, the solid electrolyte layer 6 is exposed on the surface of a pair of arc-shaped side faces m of the cell 1. The interconnector 4 does not have to extend to the lower end of the cell 1.

[0019] Each of the components constituting the cell 1 will be described below.

[0020] The support substrate 2 has gas flow channels 2a therein through which gas flows. The example of the support substrate 2 shown in FIG. 1A has six gas flow channels 2a. The support substrate 2 has gas permeability, and allows the fuel gas flowing in the gas flow channels 2a to permeate to the anode 5. The support substrate 2 may be conductive. The conductive support substrate 2 collects electricity generated in the element section 3 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.

[0022] A generally known material can be used for the fuel electrode 5. The fuel electrode 5 is made of a porous conductive ceramic, such as calcium oxide, magnesium oxide, or ZrO in which a rare earth element oxide is solid-solved. ２ and Ni and / or NiO may be used. The rare earth element oxide may contain, for example, a plurality of rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. Calcium oxide, magnesium oxide, or ZrO in which a rare earth element oxide is solid-solved may be used. ２ This is sometimes called stabilized zirconia. Stabilized zirconia also includes partially stabilized zirconia.

[0023] The solid electrolyte layer 6 is an electrolyte and transfers ions between the fuel electrode 5 and the air electrode 8. At the same time, the solid electrolyte layer 6 has gas barrier properties and makes it difficult for leakage of fuel gas and oxygen-containing gas to occur.

[0024] The material of the solid electrolyte layer 6 is, for example, ZrO in which 3 mol % to 15 mol % of rare earth element oxide is dissolved. ２ 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 solid electrolyte layer 6 may be, for example, ZrO in which Yb, Sc, or Gd is solid-solved. ２ and CeO in which La, Nd or Yb is solid-solved. ２ and BaZrO in which Sc or Yb is solid-solved. ３ and BaCeO in which Sc or Yb is solid-solved. ３ may include:

[0025] The intermediate layer 7 functions as a diffusion suppression layer. The intermediate layer 7 makes it difficult for Sr (strontium) contained in the air electrode 8 (described later) to diffuse into the solid electrolyte layer 6, particularly into the solid electrolyte layer 6 containing Zr, thereby preventing the solid electrolyte layer 6 from being filled with SrZrO ３ This makes it difficult for a resistive layer to form.

[0026] The material of the intermediate layer 7 is not particularly limited as long as it generally prevents diffusion of elements between the air electrode 8 and the solid electrolyte layer 6. The material of the intermediate layer 7 is, for example, cerium oxide (CeO) in which rare earth elements other than Ce (cerium) are dissolved. ２ Such rare earth elements include Gd (gadolinium) and Sm (samarium).

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

[0028] There are no particular limitations on the material of the air electrode 8 as long as it is a material that is generally used for air electrodes. ３The oxide may be a conductive ceramic such as a perovskite oxide.

[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. Examples of such composite oxides include La ｘ Sr １－ｘ Co ｙ Fe １－ｙ O ３ , La ｘ Sr １－ｘ MnO ３ , La ｘ Sr １－ｘ FeO ３ , La ｘ Sr １－ｘ CoO ３ Here, x is 0<x<1, and y is 0<y<1.

[0030] Furthermore, the interconnector 4 is dense and makes it difficult for leakage of the fuel gas flowing through the gas flow passage 2a located inside the support substrate 2 and the oxygen-containing gas flowing outside the support substrate 2 to occur. The interconnector 4 may have a relative density of 93% or more, particularly 95% or more.

[0031] The material of the interconnector 4 is a lanthanum chromite-based perovskite oxide (LaCrO ３ -based oxides), lanthanum strontium titanium-based perovskite-type oxides (LaSrTiO ３ These materials are electrically conductive and are not easily reduced or oxidized even when in contact with fuel gases such as hydrogen-containing gases and oxygen-containing gases such as air.

[0032] 2A to 2C, an electrochemical cell device according to this embodiment using the above-described cell 1 will be described. Fig. 2A is a perspective view showing an example of the electrochemical cell device according to the first embodiment, Fig. 2B is a cross-sectional view taken along line X-X shown in Fig. 2A, and Fig. 2C is a top view showing an example of the electrochemical cell device according to the first embodiment.

[0033] As shown in FIG. 2A, the cell stack device 10 includes a cell stack 11 having a plurality of cells 1 arranged (stacked) in the thickness direction T of the cells 1 (see FIG. 1A), and a fixing member 12.

[0034] The fixing member 12 has 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 has a support 15 and a gas tank 16. The support 15 and the gas tank 16, which are the support member 14, are made of, for example, metal.

[0035] 2B, the support body 15 has insertion holes 15a into which the lower ends of the plurality of cells 1 are inserted. The lower ends of the plurality of cells 1 and the inner wall of the insertion holes 15a are joined with fixing material 13.

[0036] The gas tank 16 has an opening for supplying a reaction gas to the cells 1 through the insertion holes 15a, and a recessed groove 16a located around the opening. The outer peripheral edge of the support 15 is joined to the gas tank 16 by a bonding material 21 filled in the recessed groove 16a of the gas tank 16.

[0037] In the example shown in Fig. 2A, fuel gas is stored in an internal space 22 formed by a support 15, which is the support 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 102 (see Fig. 4), which will be described later.

[0038] The hydrogen-rich fuel gas can be produced by steam reforming the raw fuel, etc. When the fuel gas is produced by steam reforming, the fuel gas contains water vapor.

[0039] The example shown in Fig. 2A includes two rows of cell stacks 11, two supports 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 a respective support 15. The gas tank 16 has two through-holes on its top surface. A respective support 15 is disposed in each through-hole. An internal space 22 is formed by one gas tank 16 and two supports 15.

[0040] 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. For example, the width of the insertion hole 15a is greater than the length of the cell 1 in the width direction W (see FIG. 1A ).

[0041] 2B , a fixing material 13 is filled and solidified at the joint between the inner wall of the insertion hole 15a and the lower end of the cell 1. This bonds and fixes the inner wall of the insertion hole 15a to the lower end of each of the multiple cells 1, and also bonds and fixes the lower ends of the cells 1 to each other. The gas flow path 2a of each cell 1 communicates with the internal space 22 of the support member 14 at its lower end.

[0042] A material with low conductivity, such as glass, can be used for the fixing material 13 and the bonding material 21. Specific materials for the fixing material 13 and the bonding material 21 include amorphous glass, and in particular, crystallized glass.

[0043] Examples of the crystallized glass include SiO ２ -CaO system, MgO-B ２ O ３ System, La ２ O ３ -B ２ O ３ -MgO-based, La ２ O ３ -B ２ O ３ -ZnO-based, SiO ２ -CaO-ZnO system materials, etc., may be used, and in particular SiO ２ - MgO-based materials may also be used.

[0044] 2B , a connecting member 18 is interposed between adjacent cells 1 among the plurality of cells 1. The connecting member 18 electrically connects the anode 5 of one adjacent cell 1 to the cathode 8 of the other cell 1 in series. More specifically, the connecting member 18 connects the interconnector 4 electrically connected to the anode 5 of one adjacent cell 1 to the cathode 8 of the other cell 1.

[0045] 2B, an end current collecting member 17 is electrically connected to the cell 1 positioned outermost in the arrangement direction of the multiple cells 1. The end current collecting member 17 is connected to a conductive portion 19 that protrudes outside the cell stack 11. The conductive portion 19 collects electricity generated by power generation in the cells 1 and extracts it to the outside. Note that the end current collecting member 17 is not shown in FIG. 2A.

[0046] 2C, the cell stack device 10 may be a single battery in which two cell stacks 11A and 11B are connected in series. In such a case, 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.

[0047] The positive terminal 19A is a positive electrode when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the positive-side end current collecting member 17 of the cell stack 11A. The negative terminal 19B is a negative electrode when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the negative-side end current collecting member 17 of the cell stack 11B.

[0048] The connection terminal 19C electrically connects the end current collecting member 17 on the negative electrode side of the cell stack 11A to the end current collecting member 17 on the positive electrode side of the cell stack 11B.

[0049] <Details of Intermediate Layer> Next, details of the intermediate layer 7 according to the first embodiment will be described with reference to Fig. 3. Fig. 3 is an enlarged cross-sectional view of a region R1 shown in Fig. 1A.

[0050] The intermediate layer 7 contains one or more elements (first elements) selected from Cu, Na, and V, and Ce (second element). The material of the intermediate layer 7 may be a compound containing Ce as the second element. The material of the intermediate layer 7 may be, for example, CeO ２ For example, a ceria-based compound containing La, Sm, or Gd as a solid solution may be used. ２ The material of the intermediate layer 7 may be, for example, BaCeO in which rare earth elements such as Sc, Y, La, Nd, Sm, Gd, Dy, and Yb are dissolved. ３ , SrCeO ３ The compound may be a perovskite compound such as

[0051] The intermediate layer 7 may contain one or more first elements in simple substance. For example, the intermediate layer 7 may contain 0.1 atomic % or more of the first elements relative to all the constituent elements. For example, the intermediate layer 7 may contain 5 atomic % or less of the first elements relative to all the constituent elements.

[0052] By including one or more first elements in the intermediate layer 7, the material of the intermediate layer 7 is more likely to be densified. This makes it even more difficult for Sr (strontium) contained in the air electrode 8 to diffuse into the solid electrolyte layer 6. For this reason, when SrZrO is included in the solid electrolyte layer 6, ３ This makes it difficult for a resistive layer to be formed, and the power generation performance of the cell 1 can be improved.

[0053] 3, the intermediate layer 7 may have a first portion 7A and a second portion 7B. The first portion 7A is located on the solid electrolyte layer 6. The second portion 7B is located between the air electrode 8 and the first portion 7A. Alternatively, the second portion 7B may be located on the solid electrolyte layer 6, and the first portion 7A may be located between the air electrode 8 and the second portion 7B.

[0054] The first portion 7A is denser than the second portion 7B. The first portion 7A may have a relative density of, for example, 93% or more, particularly 95% or more. This makes it even more difficult for Sr (strontium) contained in the air electrode 8 to diffuse into the solid electrolyte layer 6. For this reason, when SrZrO is contained in the solid electrolyte layer 6, ３This makes it difficult for a resistive layer to be formed, thereby improving the power generation performance of the cell 1. The second portion 7B may have a higher porosity than the first portion 7A.

[0055] The first portion 7A may have a higher content of the first element than the second portion 7B. When the content of the first element in the first portion 7A is higher than that in the second portion 7b, the first portion 7A is more likely to be densified. That is, the porosity of the first portion 7A is lower than that of the second portion 7B. This makes it difficult for a resistive layer to form in the solid electrolyte layer 6, thereby improving the power generation performance of the cell 1. The first portion 7A may contain, for example, 0.1 atomic % or more of the first element relative to the second element, particularly 0.1 atomic % to 5 atomic %. If the content of the first element relative to the second element exceeds 5 atomic %, the conductivity of the first portion 7A may decrease, which may not lead to improved power generation performance.

[0056] The second portion 7B may have a higher content of the second element than the first portion 7A. The contents of the first and second elements can be confirmed by elemental analysis using, for example, EPMA, EDS, or the like. Specifically, for example, a cross section of the element portion 3 in the stacking direction is mirror-polished, the intermediate layer 7 is divided into two equal parts in the thickness direction, and the porosity is calculated, for example, by image analysis. The side with the lower porosity of the intermediate layer 7 is designated as the first portion 7A, and the side with the higher porosity is designated as the second portion 7B. By semi-quantitatively analyzing the first and second elements in a predetermined area of ​​the cross section of the first portion 7A, the respective contents per unit area can be calculated. The area to be subjected to elemental analysis may be, for example, the area of ​​a rectangle whose sides are equal to or shorter than the thickness of the first portion 7A. The content of the first element here refers to the mass of the first element (e.g., Cu) relative to the total mass of elements detected in the measurement region. The ratio of the contents of the first element and the second element converted into the number of atoms or the number of moles is defined as the content of the first element relative to the second element.

[0057] Furthermore, the first portion 7A and the second portion 7B may be distinguished by, for example, determining by elemental analysis using EPMA that a portion having a higher content of the first element than other portions as the first portion 7A, and determining the other portions, i.e., portions other than the first portion 7A, as the second portion 7B. Specifically, for example, a cross section of the element portion 3 in the stacking direction is mirror-polished, and each element is subjected to area analysis or line analysis in the stacking direction using EPMA to obtain a concentration map or concentration profile of each element. From the obtained concentration map results or concentration profile results of each element, a region in the intermediate layer 7 having a higher content of the first element than other portions can be determined as the first portion 7A, and the remaining regions can be determined as the second portion 7B.

[0058] Furthermore, the thickness of the first portion 7A may be smaller than the thickness of the second portion 7B. This makes it difficult for the conductivity of the entire intermediate layer 7 including the second portion 7B to decrease, even when the intermediate layer 7 has the first portion 7A, and therefore makes it difficult for the power generation performance to decrease.

[0059] <Module> Next, a module according to an embodiment of the present disclosure using the electrochemical cell device described above will be described with reference to Fig. 4. Fig. 4 is an external perspective view showing the module according to the first embodiment. Fig. 4 shows a state in which the front and rear surfaces, which are parts of the storage container 101, have been removed and the cell stack device 10 of the fuel cell stored inside has been pulled out to the rear.

[0060] 4, the module 100 includes a storage container 101 and a cell stack device 10 housed in the storage container. A reformer 102 is disposed above the cell stack device 10.

[0061] The reformer 102 reforms raw fuel such as natural gas or kerosene to generate fuel gas, which is then supplied to the cell 1. The raw fuel is supplied to the reformer 102 through a raw fuel supply pipe 103. The reformer 102 may include a vaporizer 102a that vaporizes water, and a reformer 102b. The reformer 102b includes a reforming catalyst (not shown) and reforms the raw fuel into fuel gas. Such a reformer 102 can perform steam reforming, a highly efficient reforming reaction.

[0062] The fuel gas produced in the reformer 102 is supplied to the gas flow channel 2 a of the cell 1 (see FIG. 1A) through the gas distribution pipe 20 , the gas tank 16 , and the support member 14 .

[0063] Furthermore, in the module 100 having the above-described configuration, the temperature inside the module 100 during normal power generation reaches approximately 500°C to 1000°C due to the combustion of gas and the power generation of the cells 1.

[0064] In such a module 100, as described above, by accommodating the cell stack device 10 that improves power generation performance, the module 100 can be made to have improved power generation performance.

[0065] <Module Enclosure Device> Fig. 5 is an exploded perspective view showing an example of a module enclosure device according to the first embodiment. The module enclosure device 110 according to this embodiment includes an outer case 111, the module 100 shown in Fig. 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 Fig. 5.

[0066] An exterior case 111 of a module accommodating device 110 shown in Fig. 5 has support columns 112 and an exterior plate 113. A partition plate 114 divides the interior of the exterior case 111 into upper and lower sections. The space above the partition plate 114 in the exterior case 111 is a module accommodating chamber 115 that accommodates the module 100, and the space below the partition plate 114 in the exterior case 111 is an auxiliary equipment accommodating chamber 116 that accommodates auxiliary equipment for operating the module 100. Note that in Fig. 5, the auxiliary equipment accommodated in the auxiliary equipment accommodating chamber 116 is omitted from the illustration.

[0067] The partition plate 114 also has an air flow port 117 for allowing air from the auxiliary equipment housing chamber 116 to flow toward the module housing chamber 115. The exterior plate 113 that constitutes the module housing chamber 115 has an exhaust port 118 for exhausting air from within the module housing chamber 115.

[0068] In such a module accommodating device 110, as described above, by providing the module 100 with improved power generation performance in the module accommodating chamber 115, the module accommodating device 110 can be made to have improved power generation performance.

[0069] In the above embodiment, a case where a hollow flat plate-type support substrate is used is exemplified, but the present invention can also be applied to a cell stack device that uses a cylindrical support substrate.

[0070] Second Embodiment Next, an electrochemical cell and an electrochemical cell device according to a second embodiment will be described with reference to FIGS.

[0071] In the above-described embodiment, a so-called "vertical stripe type" electrochemical cell device has been exemplified, in which only one element unit including a first electrode, a solid electrolyte layer, and a second electrode is provided on the surface of a support substrate. However, the present invention can also be applied to a horizontal stripe type electrochemical cell device in which so-called "horizontal stripe type" electrochemical cells are arranged, in which element units are provided at multiple locations spaced apart from each other on the surface of a support substrate and adjacent element units are electrically connected.

[0072] FIG. 6 is a cross-sectional view showing an example of an electrochemical cell device according to the second embodiment, FIG. 7 is a transverse cross-sectional view showing an electrochemical cell according to the second embodiment, and FIG. 8 is an enlarged cross-sectional view of region R2 shown in FIG. 7.

[0073] 6, in the cell stack device 10A, 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 units 3 on a support substrate 2. A gas flow path 2a through which fuel gas flows from the pipe 22a is provided inside the support substrate 2.

[0074] The cells 1A are electrically connected to one another via connection members 31. The connection members 31 are located between the element portions 3 of the cells 1A, and connect the adjacent cells 1A to one another.

[0075] 7, the cell 1A according to the second embodiment includes a support substrate 2, a pair of element units 3, and a sealing unit 30. The support substrate 2 is columnar and has a pair of opposing flat surfaces, that is, 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.

[0076] The pair of element portions 3 are located opposite each other on the first surface n1 and the second surface n2 of the support substrate 2. The sealing portion 30 is located so as to cover the side surface m of the support substrate 2.

[0077] The intermediate layer 7 contains one or more elements (first elements) selected from Cu, Na, and V, and Ce (second element). The intermediate layer 7 may contain one or more first elements alone.

[0078] When intermediate layer 7 contains one or more first elements, the material of intermediate layer 7 is more likely to be densified. This makes it less likely that a resistance layer will be formed in solid electrolyte layer 6, thereby improving the power generation performance of cell 1A.

[0079] 8, the intermediate layer 7 may have a first portion 7A and a second portion 7B. The first portion 7A is located on the solid electrolyte layer 6. The second portion 7B is located between the air electrode 8 and the first portion 7A. Alternatively, the second portion 7B may be located on the solid electrolyte layer 6, and the first portion 7A may be located between the air electrode 8 and the second portion 7B.

[0080] The first portion 7A is denser than the second portion 7B. This makes it even more difficult for Sr (strontium) contained in the air electrode 8 to diffuse into the solid electrolyte layer 6. For this reason, the solid electrolyte layer 6 is made of SrZrO ３ This makes it difficult for a resistive layer to be formed, thereby improving the power generation performance of the cell 1A.

[0081] [Third Embodiment] Fig. 9 is a perspective view showing an example of an electrochemical cell according to a third embodiment, and Fig. 10 is a partial cross-sectional view of the electrochemical cell shown in Fig. 9 .

[0082] 9 and 10 , cell 1B includes an element portion 3B in which a fuel electrode 5 as a first electrode, a solid electrolyte layer 6, an intermediate layer 7, and a cathode 8 as a second electrode are stacked, and conductive members 91 and 92. In an electrochemical cell device in which a plurality of flat cells are stacked, for example, the plurality of cells 1B are electrically connected by conductive members 91 and 92, which are adjacent metal layers. The conductive members 91 and 92 electrically connect adjacent cells 1B to each other and have gas flow paths for supplying gas to the fuel electrode 5 or the cathode 8.

[0083] 10 , cell 1B has a sealing material that hermetically seals the fuel gas flow path and the oxygen-containing gas flow path of the flat cell stack. The sealing material is a fixing member 96 that fixes the element portion 3B of cell 1B, and includes a bonding material 93 and support members 94 and 95 that serve as a frame. The bonding material 93 may be glass or a metal material such as silver solder.

[0084] The support member 94 may be a so-called separator that separates the fuel gas flow path from the oxygen-containing gas flow path. The material of the support members 94, 95 may be, for example, a conductive metal or an insulating ceramic. Either or both of the support members 94, 95 may be made of an insulating material. If the support member 94 is made of metal, the support member 94 may be integrated with the conductive member 92. If the support member 95 is made of metal, the support member 95 may be integrated with the conductive member 91.

[0085] One of the support members 94 and 95 is insulating, and electrically insulates the two conductive members 91 and 92 that sandwich the flat cell from each other.

[0086] The intermediate layer 7 contains one or more elements (first elements) selected from Cu, Na, and V, and Ce (second element). The intermediate layer 7 may contain one or more first elements alone.

[0087] When intermediate layer 7 contains one or more first elements, the material of intermediate layer 7 is more likely to be densified. As a result, a resistance layer is less likely to be formed in solid electrolyte layer 6, and the power generation performance of cell 1B can be improved.

[0088] Fig. 11 is an enlarged cross-sectional view of region R3 shown in Fig. 10. As shown in Fig. 11, intermediate layer 7 may have a first portion 7A and a second portion 7B. First portion 7A is located on solid electrolyte layer 6. Second portion 7B is located between air electrode 8 and first portion 7A. Alternatively, second portion 7B may be located on solid electrolyte layer 6, and first portion 7A may be located between air electrode 8 and second portion 7B.

[0089] The first portion 7A is denser than the second portion 7B. This makes it even more difficult for Sr (strontium) contained in the air electrode 8 to diffuse into the solid electrolyte layer 6. For this reason, the solid electrolyte layer 6 is made of SrZrO ３ This makes it difficult for a resistive layer to be formed, thereby improving the power generation performance of the cell 1B.

[0090] [Fourth Embodiment] Fig. 12A is a cross-sectional view showing an example of an electrochemical cell according to a fourth embodiment. Figs. 12B and 12C are cross-sectional views showing another example of an electrochemical cell according to the fourth embodiment. Fig. 13 is an enlarged cross-sectional view of region R4 shown in Fig. 12A. Note that Fig. 13 can also be applied to the examples of Figs. 12B and 12C.

[0091] As shown in FIGS. 12A to 12C , the cell 1C includes an element section 3C, which is composed of a stack of an anode 5 as a first electrode, a solid electrolyte layer 6, an intermediate layer 7, and a cathode 8 as a second electrode, and a support substrate 2. The support substrate 2 has through-holes or pores in a portion in contact with the element section 3, and also includes a member 120 located outside the gas flow path 2a. The support substrate 2 allows gas to flow between the gas flow path 2a and the element section 3C. The support substrate 2 may be composed of, for example, one or more metal plates. The material of the metal plate may contain chromium. The metal plate may have a conductive coating layer. The support substrate 2 electrically connects adjacent cells 1C. The element section 3C may be formed directly on the support substrate 2, or may be bonded to the support substrate 2 with a bonding material.

[0092] In the example shown in Fig. 12A, the side surface of the anode 5 is covered with a solid electrolyte layer 6, which airtightly seals a gas flow channel 2a through which the fuel gas flows. As shown in Fig. 12B, the side surface of the anode 5 may be covered and sealed with a dense sealant 9 containing glass or ceramic. The sealant 9 covering the side surface of the anode 5 may have electrical insulating properties.

[0093] Furthermore, the gas flow path 2a of the support substrate 2 may be formed by a member 120 having projections and recesses as shown in FIG. 12C.

[0094] In the fourth embodiment, the intermediate layer 7 also contains one or more elements (first elements) selected from Cu, Na, and V, and Ce (second element). The intermediate layer 7 may contain one or more first elements alone.

[0095] When intermediate layer 7 contains one or more first elements, the material of intermediate layer 7 is more likely to be densified. As a result, a resistive layer is less likely to be formed in solid electrolyte layer 6, and the power generation performance of cell 1C can be improved.

[0096] 13 , the intermediate layer 7 may have a first portion 7A and a second portion 7B. The first portion 7A is located on the solid electrolyte layer 6. The second portion 7B is located between the air electrode 8 and the first portion 7A. Alternatively, the second portion 7B may be located on the solid electrolyte layer 6, and the first portion 7A may be located between the air electrode 8 and the second portion 7b.

[0097] The first portion 7A is denser than the second portion 7B. This makes it even more difficult for Sr (strontium) contained in the air electrode 8 to diffuse into the solid electrolyte layer 6. For this reason, the solid electrolyte layer 6 is made of SrZrO ３ This makes it difficult for a resistive layer to be formed, thereby improving the power generation performance of the cell 1B.

[0098] [Other Embodiments] Next, other embodiments will be described.

[0099] 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 an "electrochemical cell," "electrochemical cell device," "module," and "module housing device." However, other examples may be an electrolytic cell, an electrolytic cell stack device, an electrolysis module, and an electrolysis device, respectively. The electrolytic cell has a first electrode and a second electrode, and decomposes water vapor into hydrogen and oxygen, or carbon dioxide into carbon monoxide and oxygen, when supplied with electric power. Such an electrolytic cell, electrolytic cell stack device, electrolysis module, and electrolysis device can improve electrolysis performance.

[0100] As described above, the electrochemical cell (cell 1) according to this embodiment includes a first electrode (fuel electrode 5), a second electrode (air electrode 8), a solid electrolyte layer 6, and an intermediate layer 7. The solid electrolyte layer 6 is located between the first electrode (fuel electrode 5) and the second electrode (air electrode 8). The intermediate layer 7 is located between the solid electrolyte layer 6 and the second electrode (air electrode 8). The intermediate layer 7 contains at least one of Cu, Na, and V as a first element and Ce as a second element, thereby improving performance.

[0101] Furthermore, the electrochemical cell device (cell stack device 10) according to the embodiment has a cell stack 11 including the electrochemical cell (cell 1) described above. This allows the electrochemical cell device (cell stack device 10) to have improved performance.

[0102] Moreover, the module 100 according to the embodiment includes the electrochemical cell device (cell stack device 10) described above and a storage container 101 that stores the electrochemical cell device (cell stack device 10). This allows the module 100 to have improved performance.

[0103] Furthermore, the module housing device 110 according to the embodiment includes the above-described module 100, accessories for operating the module 100, and an exterior case for housing the module 100 and the accessories. This allows the module housing device 110 to have improved performance.

[0104] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0105] REFERENCE SIGNS LIST 1, 1A to 1C Cell 2 Support substrate 3 Element portion 4 Interconnector 5 Anode 6 Solid electrolyte layer 7 Intermediate layer 8 Cathode 10 Cell stack device 11 Cell stack 12 Fixing member 13 Fixing material 14 Support member 15 Support body 16 Gas tank 17 End current collecting member 18 Connection member 100 Module 110 Module accommodating device

Claims

1. A first electrode; A second electrode; a solid electrolyte layer located between the first electrode and the second electrode; an intermediate layer located between the solid electrolyte layer and the second electrode; Equipped with The intermediate layer contains at least one of Cu, Na, and V as a first element, and Ce as a second element. Electrochemical cell.

2. The solid electrolyte layer contains Zr, The second electrode contains Sr.

10. The electrochemical cell of claim 1.

3. The intermediate layer has a first portion and a second portion having a porosity greater than that of the first portion.

10. The electrochemical cell of claim 1.

4. The first portion has a higher content of the first element than the second portion.

4. The electrochemical cell of claim 3.

5. the first portion is located on the solid electrolyte layer, The second portion is located between the second electrode and the first portion.

4. The electrochemical cell of claim 3.

6. The first portion contains the first element at 0.1 atomic % or more relative to the second element.

4. The electrochemical cell of claim 3.

7. The first portion contains the first element at 5 atomic % or less with respect to the second element.

4. The electrochemical cell of claim 3.

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

9. The electrochemical cell device according to claim 8 ; A container for housing the electrochemical cell device; A module comprising:

10. A module according to claim 9; Auxiliary equipment for operating the module; an exterior case that houses the module and the auxiliary equipment; A module housing device comprising: