Electrochemical cell, electrochemical cell device, module, and module storage device

Abstract

To provide an electrochemical cell, an electrochemical cell device, a module, and a module storage device which can increase the performance.SOLUTION: The electrochemical cell includes a solid electrolyte layer, a first electrode, and a second electrode. The solid electrolyte layer has a first surface and a second surface in both ends in a thickness direction. The first electrode faces the first surface. The second electrode faces the second surface. The second surface has irregularities including a plurality of recessed parts arranged at intervals of 0.5 mm at a maximum.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] In recent years, various fuel cell stack devices including a plurality of fuel cells have been proposed as next-generation energy sources. A fuel cell is a type of cell that can generate electric power 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] International Publication No. 2020 / 218334 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional fuel cell stack devices, there is still room for improvement in terms of power generation performance.

[0005] One aspect of the embodiment aims to provide an electrochemical cell, an electrochemical cell device, a module, and a module housing device that can improve performance. [Means for solving the problem]

[0006] An electrochemical cell according to one aspect of the embodiment includes a solid electrolyte layer, a first electrode, and a second electrode. The solid electrolyte layer has a first surface and a second surface at both ends in a thickness direction. The first electrode faces the first surface. The second electrode faces the second surface. The second surface has projections and recesses that are spaced apart by 0.5 mm or less.

[0007] An electrochemical cell according to one aspect of the embodiment includes an element unit, an adjustment layer, and a support. The element unit includes a first electrode, a second electrode, and a solid electrolyte layer located between the first electrode and the second electrode. The adjustment layer is located on the opposite side of the solid electrolyte layer from the first electrode, and has a plurality of first through holes penetrating in a thickness direction. The support is located on the opposite side of the first electrode from the adjustment layer, and has a plurality of second through holes penetrating in the thickness direction. When viewed in a plan view in the thickness direction, a first interval that is an interval between adjacent first through holes is smaller than a second interval that is an interval between adjacent second through holes.

[0008] The electrochemical cell device of the present disclosure also includes a cell stack including the electrochemical cell described above.

[0009] The module of the present disclosure includes the electrochemical cell device described above and a container for housing the electrochemical cell device.

[0010] The module housing device of the present disclosure includes the above-described module, an auxiliary device for operating the module, and an exterior case for housing the module and the auxiliary device. Effect of the Invention

[0011] According to one aspect of the embodiment, it is possible to provide an electrochemical cell, an electrochemical cell device, a module, and a module housing device that can provide improved performance. [Brief description of the drawings]

[0012] [Figure 1A] FIG. 1A is a cross-sectional view illustrating 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, as 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 illustrating an example of the electrochemical cell device according to the first embodiment. [Diagram 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. [Diagram 5] FIG. 5 is an exploded perspective view illustrating an example of a module housing device according to the first embodiment. [Figure 6A] FIG. 6A is a cross-sectional view showing an example of an electrochemical cell device according to a second embodiment. [Figure 6B] FIG. 6B is a cross-sectional view showing an electrochemical cell according to a second embodiment. [Figure 7] FIG. 7 is an enlarged cross-sectional view of a region R2 shown in FIG. 6B. [Figure 8A] FIG. 8A is a cross-sectional view illustrating an example of an electrochemical cell according to a third embodiment. [Figure 8B] FIG. 8B is a cross-sectional view showing another example of the electrochemical cell according to the third embodiment. [Figure 8C] FIG. 8C is a cross-sectional view showing another example of the electrochemical cell according to the third embodiment. [Figure 9] FIG. 9 is an enlarged cross-sectional view of a region R3 shown in FIG. 8A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 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. Note that the disclosure is not limited to the embodiments described below.

[0014] In addition, it should be noted that the drawings are schematic, and that the dimensional relationships, ratios, etc. of each element may differ from the reality. Furthermore, there may be cases where the dimensional relationships, ratios, etc. of each element differ from those of the drawings.

[0015] [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.

[0016] 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 viewed from the air electrode side, and Fig. 1C is a side view of the example of the electrochemical cell according to the first embodiment as viewed from the interconnector side. Figs. 1A to 1C show enlarged views of parts of each component of the electrochemical cell. Hereinafter, the electrochemical cell may be simply referred to as a cell.

[0017] 1A to 1C, cell 1 is a hollow flat plate-like elongated plate. As shown in Fig. 1B, the shape of the entire cell 1 seen from the side is, for example, a rectangle with a side length of 5 cm to 50 cm in the length direction L and a length of 1 cm to 10 cm in the width direction W perpendicular to the length direction L. The thickness of the entire cell 1 in the thickness direction T is, for example, 1 mm to 5 mm.

[0018] 1A, the cell 1 includes a conductive support substrate 2, an element portion 3, and an interconnector 4. The support substrate 2 is columnar having a pair of opposing flat surfaces, a first flat surface n1 and a second flat surface n2, and a pair of arc-shaped side surfaces m connecting the first flat surface n1 and the second flat surface n2.

[0019] The element section 3 is located on a first flat 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.

[0020] As shown in FIG. 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 flat surface 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 surfaces m of the cell 1. The interconnector 4 does not have to extend to the lower end of the cell 1.

[0021] Each of the members constituting the cell 1 will be described below.

[0022] The support substrate 2 has therein gas flow channels 2a 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 through 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.

[0023] 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.

[0024] The fuel electrode 5 is a first electrode that contacts the fuel gas, which is a reducing gas. The material of the fuel electrode 5 may be a generally known material. The fuel electrode 5 may be made of porous conductive ceramics, such as ceramics containing calcium oxide, magnesium oxide, or ZrO2 in which rare earth element oxides are solid-dissolved, and Ni and / or NiO. The rare earth element oxide may contain a plurality of rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. Calcium oxide, magnesium oxide, or ZrO2 in which rare earth element oxides are solid-dissolved may also be called stabilized zirconia. The stabilized zirconia may also include partially stabilized zirconia.

[0025] The solid electrolyte layer 6 has a first surface 6a and a second surface 6b at both ends in the thickness direction T. The first surface 6a is a surface facing the fuel electrode 5. The second surface 6b is a surface facing the air electrode 8 with the intermediate layer 7 interposed therebetween.

[0026] 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 the fuel gas and oxygen-containing gas to occur.

[0027] The material of the solid electrolyte layer 6 may be, for example, ZrO2 with 3 mol % to 15 mol % of rare earth element oxide dissolved therein. 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. The solid electrolyte layer 6 may include, for example, ZrO2 with Yb, Sc, or Gd dissolved therein, or may include BaZrO3 with Sc, Y, or Yb dissolved therein.

[0028] 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, which will be described later, to diffuse into the solid electrolyte layer 6, thereby making it difficult for a resistive layer of SrZrO3 to form on the solid electrolyte layer 6.

[0029] 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 may contain, for example, cerium oxide (CeO2) in which a rare earth element other than Ce (cerium) is dissolved. As such a rare earth element, Gd (gadolinium), Sm (samarium), or the like may be used.

[0030] The air electrode 8 is a second electrode in contact with an oxygen-containing gas. The air electrode 8 has gas permeability. The open porosity of the air electrode 8 may be, for example, 20% or more, and particularly in the range of 30% to 50%. The open porosity of the air electrode 8 may also be referred to as the porosity of the air electrode 8.

[0031] There are no particular limitations on the material of the air electrode 8 as long as it is a material 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.

[0032] 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. x Sr 1-x Co y Fe 1-y O3, La x Sr 1-x MnO3, La x Sr 1-x FeO3, La x Sr 1-x CoO3, etc. Note that x is 0 <x<1、yは0<y<1である。

[0033] Moreover, the interconnector 4 is dense and prevents 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. The interconnector 4 may have a relative density of 93% or more, particularly 95% or more.

[0034] 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 not easily reduced or oxidized even when in contact with a fuel gas such as a hydrogen-containing gas and an oxygen-containing gas such as air.

[0035] <Configuration of electrochemical cell device> Next, an electrochemical cell device according to the present embodiment using the above-mentioned cell 1 will be described with reference to Fig. 2A to Fig. 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, and Fig. 2C is a top view showing an example of the electrochemical cell device according to the first embodiment.

[0036] 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.

[0037] 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 body 15 and a gas tank 16. The support body 15 and the gas tank 16, which are the support member 14, are made of, for example, metal.

[0038] 2B, the support 15 has insertion holes 15a into which the lower ends of the multiple cells 1 are inserted. The lower ends of the multiple cells 1 and the inner wall of the insertion holes 15a are joined with a fixing material 13.

[0039] The gas tank 16 has an opening for supplying a reaction gas to the cells 1 through the insertion holes 15a, and a groove 16a located around the opening. The outer peripheral edge of the support 15 is joined to the gas tank 16 by a joining material 21 filled in the groove 16a of the gas tank 16.

[0040] In the example shown in Fig. 2A, fuel gas is stored in an internal space 22 formed by a support body 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.

[0041] The hydrogen-rich fuel gas can be produced by steam reforming of the raw fuel, etc. When the fuel gas is produced by steam reforming, the fuel gas contains water vapor.

[0042] 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 each of the supports 15. The gas tank 16 has two through holes on the upper surface. Each of the supports 15 is disposed in each of the through holes. An internal space 22 is formed by the one gas tank 16 and the two supports 15.

[0043] The shape of the insertion hole 15a is, for example, an oval shape when viewed from above. For example, the length of the insertion hole 15a in the arrangement direction of the cells 1, i.e., the thickness direction T, is greater than the distance between the two end current collecting members 17 located at both ends of the cell stack 11. The width of the insertion hole 15a is, for example, greater than the length of the cell 1 in the width direction W (see FIG. 1A).

[0044] 2B, the joints between the inner walls of the insertion holes 15a and the lower ends of the cells 1 are filled with a fixing material 13 and solidified. This bonds and fixes the inner walls of the insertion holes 15a to the lower ends of the cells 1, respectively, and also bonds and fixes the lower ends of the cells 1 to each other. The gas flow paths 2a of each cell 1 communicate with the internal space 22 of the support member 14 at their lower ends.

[0045] A material having low electrical 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.

[0046] As the crystallized glass, for example, any of materials such as SiO2-CaO, MgO-B2O3, La2O3-B2O3-MgO, La2O3-B2O3-ZnO, and SiO2-CaO-ZnO may be used, and in particular, SiO2-MgO-based materials may be used.

[0047] 2B, a connection member 18 is interposed between adjacent cells 1 among the multiple cells 1. The connection member 18 electrically connects the fuel electrode 5 of one adjacent cell 1 to the air electrode 8 of the other cell 1 in series. More specifically, the connection member 18 connects the interconnector 4 electrically connected to the fuel electrode 5 of one adjacent cell 1 to the air electrode 8 of the other cell 1.

[0048] As shown in Fig. 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 protruding to the outside of the cell stack 11. The conductive part 19 collects electricity generated by power generation in the cells 1 and draws it out to the outside. Note that the end current collecting member 17 is not shown in Fig. 2A.

[0049] 2C, the cell stack device 10 may be a single battery in which two cell stacks 11A, 11B are connected in series. In this 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.

[0050] The positive electrode terminal 19A is a positive electrode when the electric power generated by the cell stack 11 is output to the outside, and is electrically connected to the end current collecting member 17 on the positive electrode side of the cell stack 11A. The negative electrode terminal 19B is a negative electrode when the electric power generated by the cell stack 11 is output to the outside, and is electrically connected to the end current collecting member 17 on the negative electrode side of the cell stack 11B.

[0051] The connection terminal 19C electrically connects the end current collecting member 17 on the negative electrode side in the cell stack 11A and the end current collecting member 17 on the positive electrode side in the cell stack 11B.

[0052] <Electrochemical cell details> Next, details of the electrochemical cell according to this 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.

[0053] 3, the solid electrolyte layer 6 has a second surface 6b facing the air electrode 8 via the intermediate layer 7. The second surface 6b has projections and recesses including a plurality of recesses 6b1. Here, the recesses 6b1 refer to portions of the second surface 6b that are close to the support substrate 2 in a cross-sectional view.

[0054] The recesses 6b1 are arranged at intervals of 0.5 mm or less. The interval between the recesses 6b1 is the average value of the intervals d1 between adjacent recesses 6b1. The interval between the recesses 6b1 may be, for example, equal to or greater than the thickness of the solid electrolyte layer 6. The interval between the recesses 6b1 may be, for example, equal to or greater than the thickness of the element portion 3 and equal to or less than 0.5 mm.

[0055] In this way, by having the second surface 6b of the solid electrolyte layer 6 have unevenness including a plurality of recesses 6b1, the surface area of ​​the second surface 6b is increased compared to a case where such unevenness is not present, and the power generation performance of the cell 1 is improved. By having the interval between the plurality of recesses 6b1 be equal to or greater than the thickness of the solid electrolyte layer 6, the effect of the unevenness on the thickness of the solid electrolyte layer 6 can be reduced. In other words, the solid electrolyte layer 6 can be easily made to have unevenness even without providing a thin portion of the solid electrolyte layer 6. By arranging the plurality of recesses 6b1 at intervals of 0.5 mm or less, air bubbles are less likely to be present between the intermediate layer 7 and the solid electrolyte layer 6, and between the intermediate layer 7 and the air electrode 8, and the power generation performance of the cell 1 is improved.

[0056] The second surface 6b may have a protrusion 6b2 located between the multiple recesses 6b1. The protrusion 6b2 refers to a portion of the second surface 6b that protrudes away from the support substrate 2 in a cross-sectional view.

[0057] The second surface 6b may have an average height of the irregularities of 5 μm or less. This makes it difficult for air bubbles to be present between the intermediate layer 7 and the solid electrolyte layer 6, and between the intermediate layer 7 and the air electrode 8, improving the power generation performance of the cell 1. Here, the average height of the irregularities is the average value of the height h of the irregularities. The height h of the irregularities can be measured based on the positional relationship between the bottoms of the adjacent recesses 6b1 and the tops of the adjacent protrusions 6b2 on the second surface 6b of the solid electrolyte layer 6 in a cross-sectional view.

[0058] Here, the surface shape and the like of the second surface 6b of the solid electrolyte layer 6 can be calculated, for example, by photographing a cross section of the element portion 3 using a SEM (scanning electron microscope) and performing image analysis on the obtained cross section photograph.

[0059] Not only the second surface 6b but also the first surface 6a may have irregularities. By having the first surface 6a have irregularities, the surface area of ​​the first surface 6a is increased compared to a case where such irregularities are not present, and the power generation performance of the cell 1 is improved. The positions of the irregularities of the first surface 6a may correspond to the positions of the irregularities of the second surface 6b. That is, the positions of the recesses of the first surface 6a may correspond to the positions of the protrusions 6b2 of the second surface 6b, and the positions of the protrusions of the first surface 6a may correspond to the positions of the recesses 6b1 of the second surface 6b. When the positions of the irregularities of the first surface 6a correspond to the positions of the irregularities of the second surface 6b, the variation in the thickness of the solid electrolyte layer 6 is reduced, that is, defects in the solid electrolyte layer 6 can be reduced, and the power generation performance of the cell 1 is improved. It should be noted that, even if only the first surface 6a has irregularities, a predetermined effect can be obtained.

[0060] The solid electrolyte layer 6 having the unevenness on the second surface 6b can be obtained, for example, by placing a tape that will become the fuel electrode 5 and the solid electrolyte layer 6 on the surface of the support substrate 2 having the unevenness, and firing the tape under predetermined conditions. The intermediate layer 7 and the air electrode 8 are further formed on the fired solid electrolyte layer 6, thereby obtaining the cell 1 of this embodiment.

[0061] <module> Next, a module according to an embodiment of the present disclosure using the above-mentioned electrochemical cell device will be described with reference to Fig. 4. Fig. 4 is an external perspective view showing the module according to the first embodiment, with the front and rear surfaces, which are part of the storage container 101, removed and the cell stack device 10 of the fuel cell stored inside removed to the rear.

[0062] 4, the module 100 includes a storage container 101 and a cell stack device 10 housed in the storage container. In addition, above the cell stack device 10, a reformer 102 is disposed.

[0063] The reformer 102 reforms raw fuel such as natural gas or kerosene to generate fuel gas and supplies it to the cell 1. The raw fuel is supplied to the reformer 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, which is a highly efficient reforming reaction.

[0064] The fuel gas generated 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.

[0065] Furthermore, in the module 100 having the above-mentioned configuration, the temperature inside the module 100 during normal power generation becomes approximately 500°C to 1000°C as the gas is combusted and the cells 1 generate power.

[0066] In such a module 100, as described above, by accommodating the cell stack device 10 having the cells 1 whose performance is improved, it is possible to make the module 100 have improved performance.

[0067] <Module storage device> Fig. 5 is an exploded perspective view showing an example of a module housing device according to the first embodiment. A 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.

[0068] 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 that operates the module 100. Note that in Fig. 5, the auxiliary equipment accommodated in the auxiliary equipment accommodating chamber 116 is omitted.

[0069] In addition, the partition plate 114 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 constituting the module housing chamber 115 has an exhaust port 118 for exhausting air from within the module housing chamber 115.

[0070] In such a module housing device 110, as described above, by accommodating the module 100 whose performance is improved in the module housing chamber 115, it is possible to provide a module housing device 110 whose performance is improved.

[0071] In the above embodiment, a case where a hollow flat 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.

[0072] [Second embodiment] Next, an electrochemical cell and an electrochemical cell device according to a second embodiment will be described with reference to FIGS. 6A to 7. FIG.

[0073] In the above-described embodiment, a so-called "vertical stripe type" 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 supporting 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 supporting substrate and adjacent element units are electrically connected.

[0074] Fig. 6A is a cross-sectional view showing an example of an electrochemical cell device according to a second embodiment. Fig. 6B is a transverse cross-sectional view showing an electrochemical cell according to a second embodiment. Fig. 7 is an enlarged view of a region R2 shown in Fig. 6B.

[0075] 6A, in the cell stack device 10A, multiple cells 1A extend in a longitudinal direction L from a pipe 22a through which a fuel gas flows. The cells 1A have multiple element portions 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.

[0076] Moreover, the cells 1A are electrically connected to each other 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.

[0077] 6B, the cell 1A according to this embodiment includes a support substrate 2, a pair of element portions 3, and a sealing portion 30. The support substrate 2 is columnar and has a pair of opposing flat surfaces, that is, a first flat surface n1 and a second flat surface n2, and a pair of arc-shaped side surfaces m connecting the first flat surface n1 and the second flat surface n2.

[0078] The pair of element portions 3 are located opposite each other on the first flat surface n1 and the second flat 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.

[0079] As shown in FIG. 7, the solid electrolyte layer 6 has a second surface 6b facing the air electrode 8 (see FIG. 6B) via the intermediate layer 7. The second surface 6b has projections and recesses including a plurality of recesses 6b1. The recesses 6b1 are arranged at intervals of 0.5 mm or less. The interval between the recesses 6b1 may be, for example, equal to or greater than the thickness of the solid electrolyte layer 6. The interval between the recesses 6b1 may be, for example, equal to or greater than the thickness of the element portion 3 and equal to or less than 0.5 mm.

[0080] In this way, by having the second surface 6b of the solid electrolyte layer 6 have unevenness including a plurality of recesses 6b1, the surface area of ​​the second surface 6b is increased compared to a case without such unevenness, and the power generation performance of the cell 1A is improved. By having the interval between the plurality of recesses 6b1 be equal to or greater than the thickness of the solid electrolyte layer 6, the effect of the unevenness on the thickness of the solid electrolyte layer 6 can be reduced. By arranging the plurality of recesses 6b1 at intervals of 0.5 mm or less, air bubbles are less likely to be present between the intermediate layer 7 and the solid electrolyte layer 6, and between the intermediate layer 7 and the air electrode 8, and the power generation performance of the cell 1A is improved.

[0081] The second surface 6b may have a convex portion 6b2 located between a plurality of concave portions 6b1. The second surface 6b may have an average height of the concave portions of 5 μm or less. This makes it difficult for air bubbles to be located between the intermediate layer 7 and the solid electrolyte layer 6, and between the intermediate layer 7 and the air electrode 8, improving the power generation performance of the cell 1A. In this embodiment, not only the second surface 6b but also the first surface 6a may have concave portions. Even if only the first surface 6a has concave portions, a predetermined effect can be obtained.

[0082] [Third embodiment] Fig. 8A is a cross-sectional view showing an example of an electrochemical cell according to the third embodiment. Fig. 8B and Fig. 8C are cross-sectional views showing another example of an electrochemical cell according to the third embodiment. Fig. 9 is an enlarged view of a region R3 shown in Fig. 8A. Fig. 9 can also be applied to the examples of Figs. 8B and 8C.

[0083] As shown in FIGS. 8A to 8C, the 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 laminated, a support substrate 2 as a support, and an adjustment layer 24. The support substrate 2 has a member 120 located outside the gas flow passage 2a. The support substrate 2 can distribute gas between the gas flow passage 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 plate may contain chromium. The metal plate may have a conductive coating layer. The support substrate 2 electrically connects adjacent cells 1B to each other.

[0084] In the example shown in Fig. 8A, 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. 8B, 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 insulation properties.

[0085] 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. 8C.

[0086] As shown in Fig. 9, the solid electrolyte layer 6 has a second surface 6b facing the air electrode 8 (see Fig. 8A) via the intermediate layer 7. The second surface 6b has projections and recesses including a plurality of recesses 6b1. The recesses 6b1 are arranged at intervals of 0.5 mm or less. The recesses 6b1 may be arranged at intervals of 0.1 mm or more and 0.5 mm or less.

[0087] In this way, by having the second surface 6b of the solid electrolyte layer 6 have unevenness including a plurality of recesses 6b1, the surface area of ​​the second surface 6b is increased compared to a case where such unevenness is not present, and the power generation performance of the cell 1B is improved. The interval between the recesses 6b1 may be, for example, equal to or greater than the thickness of the solid electrolyte layer 6 and equal to or less than 0.5 mm. By arranging the plurality of recesses 6b1 at intervals of 0.5 mm or less, air bubbles are less likely to be present between the intermediate layer 7 and the solid electrolyte layer 6, and between the intermediate layer 7 and the air electrode 8, and the power generation performance of the cell 1B is improved.

[0088] The second surface 6b may have protrusions 6b2 located between the recesses 6b1. The second surface 6b may have an average height of the protrusions and recesses of 5 μm or less. This makes it difficult for air bubbles to form between the intermediate layer 7 and the solid electrolyte layer 6, and between the intermediate layer 7 and the air electrode 8, improving the power generation performance of the cell 1B.

[0089] Moreover, the adjustment layer 24 is located between the support substrate 2 and the solid electrolyte layer 6. In other words, the adjustment layer 24 is located on the opposite side of the fuel electrode 5 from the solid electrolyte layer 6. The adjustment layer 24 cooperates with the solid electrolyte layer 6 to make the element portion 3B less likely to warp or bend.

[0090] The material of adjustment layer 24 exhibits a similar shrinkage rate during firing as the material of solid electrolyte layer 6. The material of adjustment layer 24 may be the same as the material of solid electrolyte layer 6. The element portion 3B obtained by sandwiching the material of fuel electrode 5 between the material of solid electrolyte layer 6 and the material of adjustment layer 24 and firing is less likely to warp or deform.

[0091] Adjustment layer 24 may or may not have gas permeability. When adjustment layer 24 has gas barrier properties (density) similar to that of solid electrolyte layer 6, adjustment layer 24 has a plurality of first through holes 24a penetrating in thickness direction T of cell 1B so as not to impede the inflow of fuel gas to fuel electrode 5. Inside first through holes 24a, adhesive 26 (described later) and / or a part of fuel electrode 5 may be located.

[0092] The support substrate 2 is fixed to the adjustment layer 24 via an adhesive 26. The support substrate 2 is located on the opposite side of the adjustment layer 24 from the fuel electrode 5, and serves as a support that supports the element portion 3B via the adjustment layer 24. The support substrate 2 has a plurality of second through holes 2b that penetrate in the thickness direction T of the cell 1B so as not to impede the inflow of fuel gas to the fuel electrode 5.

[0093] The adhesive 26 may be conductive. The adhesive 26 may include, for example, conductive particles such as Ni, and inorganic oxides such as TiO, rare earth oxides (YO, CeO, etc.), and transition metal oxides (FeO, CuO, etc.).

[0094] The adhesive material 26 may have gas permeability. When the adhesive material 26 has gas permeability, the adhesive material 26 may be positioned so as to cover the first through-hole 24a and the second through-hole 2b.

[0095] Moreover, the cell 1B may further include a gas diffusion layer. The gas diffusion layer is located between the fuel electrode 5 and the adjustment layer 24. The gas diffusion layer has gas permeability and allows the fuel gas to pass through to the fuel electrode 5. The open porosity of the gas diffusion layer may be in the range of, for example, 30% to 50%, particularly 35% to 45%. When the adjustment layer 24 has gas barrier properties, the interval between the recesses 6b1 may be equal to or smaller than the thickness of the fuel electrode 5 or equal to or smaller than the combined thickness of the fuel electrode 5 and the gas diffusion layer.

[0096] The material of the gas diffusion layer may be a porous conductive ceramic, such as calcium oxide, magnesium oxide, or ceramic containing stabilized zirconia or partially stabilized zirconia in which rare earth element oxides are solid-dissolved, and Ni and / or NiO. The rare earth element oxide may contain a plurality of rare earth elements selected from, for example, Sc, Y, La, Nd, Sm, Gd, Dy, and Yb.

[0097] Furthermore, when the cell 1B is viewed in a plan view in the thickness direction T, the first through holes 24a may be positioned to overlap with the recesses 6b1. This makes it easier to expel air bubbles that may be unavoidably generated when fixing the cell 1B to the support substrate 2 to the outside of the cell 1B, improving the power generation performance of the cell 1A.

[0098] Furthermore, when the cell 1B is viewed in plan in the thickness direction T, the interval between adjacent second through holes 2b may be larger than the interval between adjacent first through holes 24a. This makes it easier to allow the gas to flow evenly in the element portion 3B while maintaining the rigidity of the support substrate 2.

[0099] Furthermore, when the cell 1B is viewed in plan in the thickness direction T, the interval between adjacent first through holes 24a may be smaller than the interval between adjacent second through holes 2b. This reduces the gas diffusion distance in the planar direction in the fuel electrode 5 and the diffusion layer, making it possible to reduce variation in the amount of power generation in the element portion 3B.

[0100] The solid electrolyte layer 6 may have unevenness corresponding to the intervals of the first through holes 24a and undulations corresponding to the intervals of the second through holes 2b. The surface area of ​​the second surface 6b can be increased by the solid electrolyte layer 6 having unevenness corresponding to the intervals of the first through holes 24a. The solid electrolyte layer 6 has undulations corresponding to the intervals of the second through holes 2b, so that the solid electrolyte layer 6 is given springiness in the planar direction, and the element portion 3 is less likely to peel off even if the support substrate 2 is deformed. Here, the unevenness corresponding to the intervals of the first through holes 24a means that, when the cell 1B is viewed in a plane in the thickness direction T, a plurality of recesses 6b1 are positioned so as to overlap with the first through holes 24a. The undulations corresponding to the intervals of the second through holes 2b means that, when the cell 1B is viewed in a plane in the thickness direction T, a bulge including unevenness is larger than the recesses 6b1 and is positioned between the second through holes 2b.

[0101] In the above embodiment, the solid electrolyte layer 6 has been described as having irregularities including a plurality of recesses 6b1 arranged on the second surface 6b, but the first surface 6a may also have irregularities. In this case, the first surface 6a may have irregularities positioned to correspond to the irregularities of the second surface 6b.

[0102] [Other embodiments] Next, electrochemical cell devices according to other embodiments will be described.

[0103] In the above-mentioned 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", an "electrochemical cell device", a "module", and a "module housing device", but 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. In addition, in each of the above-mentioned embodiments, an oxide ion conductor or a hydrogen ion conductor is shown as an example of an 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.

[0104] Although the present disclosure has been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible without departing from the gist of the present disclosure.

[0105] In one embodiment, (1) an electrochemical cell includes a solid electrolyte layer having a first surface and a second surface at both ends in a thickness direction; a first electrode facing the first surface; a second electrode facing the second surface; Equipped with The second surface has projections and recesses that are spaced apart from one another at intervals of 0.5 mm or less.

[0106] (2) In the electrochemical cell of (1) above, the average height of the irregularities may be 5 μm or less.

[0107] (3) The electrochemical cell of (1) or (2) above may further include an adjustment layer located on the opposite side of the first electrode from the solid electrolyte layer, the adjustment layer having a plurality of first through holes penetrating in the thickness direction.

[0108] (4) In the electrochemical cell of (3) above, the plurality of first through holes may be positioned to overlap the recess when viewed in a plan view in the thickness direction.

[0109] (5) The electrochemical cell of (3) or (4) above may further include a support located on the opposite side of the adjustment layer from the first electrode and having a plurality of second through holes penetrating in the thickness direction.

[0110] (6) In the electrochemical cell of (5) above, when viewed in a plan view in the thickness direction, a distance between adjacent second through holes may be larger than a distance between adjacent first through holes.

[0111] In one embodiment, (7) the electrochemical cell includes an element portion including a first electrode and a second electrode, and a solid electrolyte layer located between the first electrode and the second electrode; an adjustment layer located on the opposite side of the solid electrolyte layer with respect to the first electrode, the adjustment layer having a plurality of first through holes penetrating in a thickness direction; a support member having a plurality of second through holes penetrating in the thickness direction, the support member being located on the opposite side of the adjustment layer from the first electrode; Equipped with When viewed in a plan view in the thickness direction, the distance between adjacent first through holes is smaller than the distance between adjacent second through holes.

[0112] (8) In the electrochemical cell of (7) above, the solid electrolyte layer may have irregularities corresponding to the spacing between the first through holes and undulations corresponding to the spacing between the second through holes.

[0113] In one embodiment, (9) an electrochemical cell device has a cell stack including any one of the electrochemical cells (1) to (8) above.

[0114] In one embodiment, the module (10) comprises the electrochemical cell device (9) described above, and a container for housing the electrochemical cell device.

[0115] In one embodiment, the module housing device (11) includes the module (10) and Auxiliary equipment for operating the module; and an exterior case that houses the module and the auxiliary equipment.

[0116] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. In addition, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0117] 1,1A,1B Cell 2 Support substrate 3. Element section 4 Interconnector 5 Fuel electrode 6 Solid electrolyte layer 7. Middle Tier 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 Connection parts 24 Adjustment layer 100 Modules 110 Module storage device

Claims

1. a solid electrolyte layer having a first surface and a second surface at both ends in a thickness direction; a first electrode facing the first surface; a second electrode facing the second surface; Equipped with The second surface has projections and recesses arranged at intervals of 0.5 mm or less. Electrochemical cell.

2. The average height of the irregularities is 5 μm or less.

10. The electrochemical cell of claim 1.

3. an adjustment layer located on the opposite side of the solid electrolyte layer with the first electrode therebetween, the adjustment layer having a plurality of first through holes penetrating in the thickness direction; 10. The electrochemical cell of claim 1.

4. When viewed in a plan view in the thickness direction, the plurality of first through holes are positioned so as to overlap with the recess.

4. The electrochemical cell of claim 3.

5. a support member having a plurality of second through holes penetrating in the thickness direction, the support member being located on the opposite side of the adjustment layer from the first electrode; 4. The electrochemical cell of claim 3.

6. When viewed in a plan view in the thickness direction, a distance between adjacent second through holes is greater than a distance between adjacent first through holes.

6. The electrochemical cell of claim 5.

7. an element portion having a first electrode and a second electrode, and a solid electrolyte layer located between the first electrode and the second electrode; an adjustment layer located on the opposite side of the solid electrolyte layer with respect to the first electrode, the adjustment layer having a plurality of first through holes penetrating in a thickness direction; a support member having a plurality of second through holes penetrating in the thickness direction, the support member being located on the opposite side of the adjustment layer from the first electrode; Equipped with When viewed in a plan view in the thickness direction, a distance between adjacent first through holes is smaller than a distance between adjacent second through holes. Electrochemical cell.

8. The solid electrolyte layer has irregularities corresponding to the intervals between the first through holes and undulations corresponding to the intervals between the second through holes.

8. The electrochemical cell of claim 7.

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

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

11. A module according to claim 10; 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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