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

Abstract

This electrochemical cell comprises a first electrode layer, a second electrode layer, a solid electrolyte layer, and an intermediate layer. The solid electrolyte layer is positioned between the first electrode layer and the second electrode layer. The intermediate layer is positioned between the solid electrolyte layer and the first electrode layer, and contains Ce. Moreover, the electrochemical cell contains Al in a boundary portion provided between the solid electrolyte layer and the intermediate layer.

Description

[Technical Field]

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

[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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-147030 Summary of the Invention

[0004] An electrochemical cell according to one aspect of the embodiment includes a first electrode layer, a second electrode layer, a solid electrolyte layer, and an intermediate layer. The solid electrolyte layer is located between the first electrode layer and the second electrode layer. The intermediate layer is located between the solid electrolyte layer and the first electrode layer and contains Ce. The electrochemical cell contains Al at the boundary between the solid electrolyte layer and the intermediate layer.

[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. [Brief explanation of the drawings]

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

[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] [First embodiment] <Electrochemical cell configuration> First, with reference to Figures 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 an example of an electrochemical cell according to the first embodiment, viewed from the air 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. 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, 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 section 3, and an interconnector 4. The support substrate 2 is columnar, 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.

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

[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 is gas permeable, allowing 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 (scandium), Y (yttrium), La (lanthanum), Nd (neodymium), Sm (samarium), Gd (gadolinium), Dy (dysprosium), and Yb (ytterbium).

[0022] The anode 5 may be made of a generally known material. The anode 5 may be made of porous conductive ceramics, such as ceramics containing calcium oxide, magnesium oxide, or ZrO2 solid-solubilized with rare earth element oxides, and Ni and / or NiO. The rare earth element oxides may contain, for example, multiple rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. Calcium oxide, magnesium oxide, or ZrO2 solid-solubilized with rare earth element oxides may also be referred to as stabilized zirconia. Stabilized zirconia may also include 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 may be, for example, ZrO2 with 3 mol % to 15 mol % of a rare earth element oxide dissolved therein. 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 contain, for example, ZrO2 with Yb, Sc, or Gd dissolved therein, or BaZrO3 with Sc or Yb dissolved therein.

[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, thereby making it difficult for a resistive layer of SrZrO to form on the solid electrolyte layer 6.

[0026] The intermediate layer 7 contains Ce (cerium). The material of the intermediate layer 7 includes, for example, cerium oxide (CeO2) in which rare earth elements other than Ce (cerium) are dissolved. Such rare earth elements may 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 restrictions on the material of the air electrode 8 as long as it is one that is generally used for air electrodes. The material of the air electrode 8 may be, for example, a conductive ceramic such as a so-called ABO3-type 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 O3, La x Sr 1-x MnO3, La x Sr 1-x FeO3, La x Sr 1-xCoO3, etc. Note that x is 0 <x<1、yは0<y<1である。

[0030] Furthermore, the interconnector 4 is dense and makes it difficult for leakage of the fuel gas flowing through the gas flow channel 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] Lanthanum chromite-based perovskite oxides (LaCrO3-based oxides), lanthanum strontium titanium-based perovskite oxides (LaSrTiO3-based oxides), etc. may be used as the material for the interconnector 4. These materials are conductive and are resistant to reduction and oxidation even when in contact with fuel gases such as hydrogen-containing gases and oxygen-containing gases such as air.

[0032] <Configuration of electrochemical cell device> Next, an electrochemical cell device according to this embodiment using the above-described cell 1 will be described with reference to Figs. 2A to 2C. 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 XX shown in Fig. 2A. 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 a 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 a 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 in the joints between the inner walls of the insertion holes 15a and the lower ends of the cells 1. This bonds and fixes the inner walls of the insertion holes 15a to the lower ends of the multiple cells 1, respectively, 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] 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 materials may 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 adjacent 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 adjacent cell 1.

[0045] 2B, an end current collecting member 17 is electrically 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 that protrudes to the outside of the cell stack 11. The conductive part 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 electrode 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 electrode side end current collecting member 17 of the cell stack 11A. The negative electrode 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 electrode 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 and the end current collecting member 17 on the positive electrode side of the cell stack 11B.

[0049] <Details of the element> Next, details of the element section 3 of the electrochemical cell according to the first embodiment will be described with reference to Fig. 3. Fig. 3 is an enlarged cross-sectional view of region R1 shown in Fig. 1A.

[0050] As shown in Fig. 3, the cell 1 contains Al in a boundary 41 between the solid electrolyte layer 6 and the intermediate layer 7. The boundary 41 is a region that includes a boundary 40 between the solid electrolyte layer 6 and the intermediate layer 7 and is a region that is 100 nm or less away from the boundary 40 in the thickness direction intersecting the boundary 40. At the boundary 40, the detected amounts (atomic %) of Zr and Ce are equal in amount in elemental analysis. The boundary 41 may contain, for example, Al2O3.

[0051] By including Al in the boundary 41 between the solid electrolyte layer 6 and the intermediate layer 7, the Zr component contained in the solid electrolyte layer 6 and the Ce component contained in the intermediate layer 7 are less likely to diffuse into each other, for example, during the manufacture of the element section 3 or at high temperatures. This makes it less likely that an insulating composition containing Zr and Ce will be formed inside the solid electrolyte layer 6 and / or the intermediate layer 7, thereby improving the power generation performance of the cell 1. The content of Al contained in the boundary 41 may be equal to or greater than the detection limit. The composition of the boundary 41 can be measured, for example, by using a cross section of the element section 3 with a scanning electron microscope (SEM) or a transmission electron microscope (TEM) and an energy dispersive X-ray analyzer (EDX).

[0052] For example, a sample of this embodiment containing Al at boundary 41 and another sample not containing Al at boundary 41 were prepared, and linear analysis of elements was performed across boundary 41 using TEM and EDX. In the sample of this embodiment, Al was detected at a maximum of 4 atomic % at boundary 41, and the thickness of the portion containing 10 atomic % or more of both Ce and Zr was approximately 100 nm. On the other hand, in the other sample, Al was not detected at boundary 41, and the thickness of the portion containing 10 atomic % or more of both Ce and Zr was approximately 300 nm. The portion containing 10 atomic % or more of both Ce and Zr can be considered to be an insulating composition containing approximately Zr and Ce.

[0053] Boundary 41 may contain Al uniformly throughout the entire boundary 41, or may have a portion where Al is not present. Furthermore, solid electrolyte layer 6 and / or intermediate layer 7 other than boundary 41 may contain Al.

[0054] The boundary portion 41 may have a solid solution portion 42 containing Al. The solid solution portion 42 may have, for example, a solid solution of Al2O3 and ZrO2, or a solid solution of Al2O3 and CeO2. The solid solution portion 42 may have a solid solution of Al2O3, ZrO2, and CeO2.

[0055] In this way, the structure containing Al in boundary portion 41 between solid electrolyte layer 6 and intermediate layer 7 can be formed, for example, by sandwiching an Al component such as Al2O3 between the material of solid electrolyte layer 6 and the material of intermediate layer 7, and sintering the resulting material. However, there are no limitations on the method for producing boundary portion 41 and solid solution portion 42, and they may be produced by any method.

[0056] <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 part 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.

[0057] 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.

[0058] 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 also 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.

[0059] The fuel gas produced in the reformer 102 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 support member 14.

[0060] Furthermore, in the module 100 having the above-described configuration, the temperature inside the module 100 during normal power generation becomes approximately 500°C to 1000°C due to the combustion of gas and the power generation of the cells 1.

[0061] 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.

[0062] <Module storage device> Fig. 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 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.

[0063] 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 accessory accommodating chamber 116 that accommodates accessory equipment for operating the module 100. Note that in Fig. 5, the accessory equipment accommodated in the accessory accommodating chamber 116 is omitted.

[0064] 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.

[0065] In such a module accommodating device 110, as described above, by accommodating 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.

[0066] 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.

[0067] [Second embodiment] Next, an electrochemical cell and an electrochemical cell device according to a second embodiment will be described with reference to FIGS.

[0068] 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 fuel electrode, a solid electrolyte layer, and an air 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.

[0069] Fig. 6 is a cross-sectional view showing an example of an electrochemical cell device according to a second embodiment. Fig. 7 is a transverse cross-sectional view showing an electrochemical cell according to a second embodiment. Fig. 8 is an enlarged view of a region R2 shown in Fig. 7.

[0070] figure 6 As shown in FIG. 1, the cell stack device 10A has a plurality of cells 1A extending in a longitudinal direction L from a pipe 22a that circulates fuel gas. Each cell 1A has a plurality of element parts 3 on a support substrate 2. A gas flow path 2a through which the fuel gas flows from the pipe 22a is provided inside the support substrate 2.

[0071] Moreover, 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 respective cells 1A, and connect the adjacent cells 1A.

[0072] 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.

[0073] 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.

[0074] As shown in Fig. 8, Al is contained in a boundary 41 between the solid electrolyte layer 6 and the intermediate layer 7. The boundary 41 includes a boundary 40 between the solid electrolyte layer 6 and the intermediate layer 7, and is a region that is 100 nm or less away from the boundary 40 in the thickness direction intersecting the boundary 40. The boundary 41 may contain, for example, Al2O3. The boundary 41 may also have a solid solution portion 42 containing Al.

[0075] By including Al in the boundary 41 between the solid electrolyte layer 6 and the intermediate layer 7, the Zr component contained in the solid electrolyte layer 6 and the Ce component contained in the intermediate layer 7 are less likely to diffuse into each other, for example, during the manufacture of the element portion 3 or at high temperatures. This makes it less likely that an insulating composition containing Zr and Ce will be produced inside the solid electrolyte layer 6 and / or the intermediate layer 7, thereby improving the power generation performance of the cell 1A.

[0076] [Third embodiment] Fig. 9 is a perspective view showing an example of an electrochemical cell according to the third embodiment, and Fig. 10 is a partial cross-sectional view of the electrochemical cell shown in Fig. 9.

[0077] 9 and 10, cell 1B has an element section 3B in which an anode 5, a solid electrolyte layer 6, an intermediate layer 7, and an air electrode 8 are stacked, and conductive members 91 and 92. In an electrochemical cell device in which a plurality of flat-type 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 anode 5 or the air electrode 8.

[0078] 10, cell 1B has a sealing material that airtightly 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 for the cell, and has 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.

[0079] 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.

[0080] Either the bonding material 93 or 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.

[0081] Fig. 11 is an enlarged cross-sectional view of region R3 shown in Fig. 10. As shown in Fig. 11, cell 1B contains Al in boundary region 41 between solid electrolyte layer 6 and intermediate layer 7. Boundary region 41 includes boundary 40 between solid electrolyte layer 6 and intermediate layer 7, and is a region that is 100 nm or less away from boundary 40 in the thickness direction intersecting boundary 40. Boundary region 41 may contain, for example, Al2O3. Boundary region 41 may also have a solid solution portion 42 containing Al.

[0082] By including Al in the boundary 41 between the solid electrolyte layer 6 and the intermediate layer 7, the Zr component contained in the solid electrolyte layer 6 and the Ce component contained in the intermediate layer 7 are less likely to diffuse into each other, for example, during the manufacture of the element portion 3B or at high temperatures. This makes it less likely that an insulating composition containing Zr and Ce will be produced inside the solid electrolyte layer 6 and / or the intermediate layer 7, thereby improving the power generation performance of the cell 1B.

[0083] [Fourth embodiment] Fig. 12A is a cross-sectional view showing an example of an electrochemical cell according to the 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 view of region R4 shown in Fig. 12A. Note that Fig. 13 can also be applied to the examples of Figs. 12B and 12C.

[0084] As shown in FIGS. 12A to 12C, a cell 1C includes an element section 3C in which an anode 5, a solid electrolyte layer 6, an intermediate layer 7, and a cathode 8 are stacked, 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 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.

[0085] 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 the 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 glass or ceramic sealant 9. The sealant 9 covering the side surface of the anode 5 may have electrical insulating properties.

[0086] 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.

[0087] 13 is an enlarged cross-sectional view of region R4 shown in FIG. 12A. As shown in FIG. 13, cell 1C contains Al in boundary region 41 between solid electrolyte layer 6 and intermediate layer 7. Boundary region 41 includes boundary 40 between solid electrolyte layer 6 and intermediate layer 7, and is a region that is 100 nm or less in the thickness direction from boundary 40 to a region that intersects with boundary 40. Boundary region 41 may contain, for example, Al2O3. Boundary region 41 may also have a solid solution portion 42 containing Al.

[0088] By including Al in the boundary 41 between the solid electrolyte layer 6 and the intermediate layer 7, the Zr component contained in the solid electrolyte layer 6 and the Ce component contained in the intermediate layer 7 are less likely to diffuse into each other, for example, during the manufacture of the element portion 3C or at high temperatures. This makes it less likely that an insulating composition containing Zr and Ce will be produced inside the solid electrolyte layer 6 and / or the intermediate layer 7, thereby improving the power generation performance of the cell 1C.

[0089] [Other embodiments] Next, electrochemical cell devices according to other embodiments will be described.

[0090] In the above-described 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 electrolysis cell, an electrolysis cell stack device, an electrolysis module, and an electrolysis device, respectively. The electrolysis cell has a first electrode layer and a second electrode layer, and decomposes water vapor into hydrogen and oxygen, or decomposes carbon dioxide into carbon monoxide and oxygen, when supplied with electric power. Furthermore, in the above-described embodiments, an oxide ion conductor or a hydrogen ion conductor is shown as an example of the electrolyte material of the electrochemical cell, but a hydroxide ion conductor may also be used. Such an electrolysis cell, an electrolysis cell stack device, an electrolysis module, and an electrolysis device can improve electrolysis performance.

[0091] 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 within the scope that does not deviate from the gist of the present disclosure.

[0092] In one embodiment, (1) an electrochemical cell includes a first electrode layer, a second electrode layer, a solid electrolyte layer, and an intermediate layer. The solid electrolyte layer is located between the first electrode layer and the second electrode layer. The intermediate layer is located between the solid electrolyte layer and the first electrode layer and contains Ce. The electrochemical cell contains Al at the boundary between the solid electrolyte layer and the intermediate layer.

[0093] (2) In the electrochemical cell of (1) above, the solid electrolyte layer may contain Zr.

[0094] (3) In the electrochemical cell of (1) or (2), the boundary portion has a solid solution portion containing one or more metal elements contained in the solid electrolyte layer and one or more metal elements contained in the intermediate layer, The solid solution portion may contain Al.

[0095] (4) The electrochemical cell device has a cell stack including any one of the electrochemical cells (1) to (3) above.

[0096] (5) The module includes the electrochemical cell device of (4) above, and a container for housing the electrochemical cell device.

[0097] (6) The module storage device includes the module (5) and Auxiliary equipment for operating the module; and an exterior case that houses the module and the auxiliary equipment.

[0098] 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. [Explanation of symbols]

[0099] 1,1A~1C cell 2 Support substrate 3. Element section 4 Interconnector 5 Fuel electrode 6 Solid electrolyte layer 7. Middle class 8 Air electrode 10 Cell stack device 11 Cell stack 12 Fixing member 13 Fixing material 14 Support member 15 Support 16 Gas Tank 17 End current collecting member 18 Connecting member 41 Boundary 42 Solid solution part 100 modules 110 Module storage device

Claims

1. a first electrode layer; A second electrode layer; a solid electrolyte layer located between the first electrode layer and the second electrode layer; an intermediate layer containing Ce, the intermediate layer being located between the solid electrolyte layer and the first electrode layer; Equipped with The solid electrolyte layer and the intermediate layer contain Al at their boundary portions. Electrochemical cell.

2. The solid electrolyte layer contains Zr.

10. The electrochemical cell of claim 1.

3. the boundary portion has a solid solution portion containing one or more metal elements contained in the solid electrolyte layer and one or more metal elements contained in the intermediate layer, The solid solution portion contains Al.

10. The electrochemical cell of claim 1.

4. A cell stack comprising the electrochemical cell according to any one of claims 1 to 3. Electrochemical cell apparatus.

5. The electrochemical cell device according to claim 4; a container for housing the electrochemical cell device; A module comprising:

6. A module according to claim 5; Auxiliary equipment for operating the module; an exterior case that houses the module and the auxiliary equipment; A module housing device comprising:

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