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

Abstract

This electrochemical cell has an element part and a sealing material. The element part includes: a solid electrolyte layer that has a first surface; a first electrode that faces the first surface; and a second electrode that is positioned on the opposite side of the first electrode across the solid electrolyte layer. The sealing material has a portion that is located on the first surface, and covers an end surface of the second electrode. The first electrode has a second surface that is positioned on the opposite side from the solid electrolyte layer. When L1 is the length from the first surface to the second surface and L2 is the length from the end of the sealing material located on the first surface side to the first surface in a first direction that is perpendicular to the first surface, the sealing material has a portion where L2 is larger than the average of L1.

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 having multiple fuel cell units have been proposed as next-generation energy sources. A fuel cell unit is a type of electrochemical cell that can generate electric power using a fuel gas such as a hydrogen-containing gas and an oxygen-containing gas such as air.

[0003] Japanese Patent Application Laid-Open No. 2020-113525

[0004] An electrochemical cell according to one aspect of the embodiment includes an element unit and a sealing material. The element unit includes a solid electrolyte layer having a first surface, a first electrode facing the first surface, and a second electrode located on the opposite side of the solid electrolyte layer from the first electrode. The sealing material has a portion located on the first surface and covers an end face of the second electrode. The first electrode has a second surface located on the opposite side of the solid electrolyte layer. In a first direction perpendicular to the first surface, when the length from the first surface to the second surface is defined as L1 and the length from the end of the sealing material located on the first surface side to the first surface is defined as L2, the sealing material has a portion where L2 is greater than the average of L1.

[0005] An electrochemical cell according to one aspect of the embodiment includes an element unit and a sealing material. The element unit includes a solid electrolyte layer having a first surface, a first electrode facing the first surface, and a second electrode located on the opposite side of the solid electrolyte layer from the first electrode. The sealing material has a portion located on the first surface and covers an end face of the second electrode. The sealing material has an end portion located on the first surface side that is located inside the outline of the solid electrolyte layer in a plan view.

[0006] The electrochemical cell device of the present disclosure also includes a cell stack including the electrochemical cell described above.

[0007] The module of the present disclosure includes the electrochemical cell device described above and a container that houses the electrochemical cell device.

[0008] 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.

[0009] FIG. 1A is a cross-sectional view showing an example of an electrochemical cell device according to an embodiment. FIG. 1B is a plan view of an example of an electrochemical cell according to an embodiment, viewed from the air electrode side. FIG. 2A is a cross-sectional view taken along line A-A in FIG. 1B. FIG. 2B is a cross-sectional view taken along line B-B in FIG. 1B. FIG. 3A is a cross-sectional view showing another example of an electrochemical cell according to an embodiment. FIG. 3B is a cross-sectional view showing another example of an electrochemical cell according to an embodiment. FIG. 4A is a perspective view showing an example of an electrochemical cell device according to an embodiment. FIG. 4B is a cross-sectional view taken along line X-X in FIG. 4A. FIG. 4C is a top view showing an example of an electrochemical cell device according to an embodiment. FIG. 5 is an external perspective view showing an example of a module according to an embodiment. FIG. 6 is an exploded perspective view schematically showing an example of a module housing device according to an embodiment.

[0010] The above-described fuel cell stack device has room for improvement in terms of power generation performance.

[0011] Therefore, it is desired to provide an electrochemical cell, an electrochemical cell device, a module, and a module housing device that can improve performance.

[0012] 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.

[0013] 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.

[0014] 1A to 2B, an electrochemical cell according to an 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.

[0015] Fig. 1A is a cross-sectional view showing an example of an electrochemical cell device according to an embodiment. Fig. 1B is a plan view of an example of an electrochemical cell according to an embodiment, viewed from the air electrode side. Note that Figs. 1A and 1B 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.

[0016] 1A and 1B illustrate a three-dimensional Cartesian coordinate system including a Z-axis, with the vertically upward direction being the positive direction and the vertically downward direction being the negative direction. This Cartesian coordinate system may also be shown in other drawings used in the following explanation. Furthermore, components similar to those in the electrochemical cell shown in FIGS. 1A and 1B are denoted by the same reference numerals, and their explanations will be omitted or simplified.

[0017] 1A, the electrochemical cell device according to this embodiment includes a cell 1. The cell 1 includes a support member 2, an element portion 3, a sealing material 9, and a flow path member 30.

[0018] The support member 2 is electrically conductive. The support member 2 may be, for example, a metal plate containing chromium. The support member 2 may be, for example, a stainless steel such as a ferritic stainless steel or an austenitic stainless steel having high heat resistance. The support member 2 may be, for example, a nickel-chromium alloy or an iron-chromium alloy. The support member 2 may contain, for example, a metal oxide. The support member 2 may have a coating covering the surface. The support member 2 does not have to have a coating on the surface.

[0019] The support member 2 may also have openings penetrating in the thickness direction (Y-axis direction). The fuel gas flowing through the flow path 2a is supplied to the fuel electrode 5 of the element section 3 through these openings. The diameter of the openings may be, for example, 0.1 mm to 0.5 mm, particularly 0.3 mm to 0.4 mm. The opening ratio of the support member 2 in the region where the openings are formed may be, for example, 10% or more. The support member 2 may have a coating covering the wall surfaces of the openings. The support member 2 does not need to have a coating on the wall surfaces of the openings.

[0020] The support member 2 may be gas permeable, for example. In such a case, the support member 2 does not need to have an opening penetrating in the thickness direction (Y-axis direction).

[0021] The element section 3 has an anode 5, a solid electrolyte layer 6, and an air electrode 8. The anode 5 is an electrode that comes into contact with a fuel gas, which is a reducing gas. The anode 5 has gas permeability. The open porosity of the anode 5 may be, for example, in the range of 30% to 50%, particularly 35% to 45%. The open porosity of the anode 5 is sometimes referred to as the porosity or void ratio of the anode 5.

[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 The stabilized zirconia may contain partially stabilized zirconia. The anode 5 is made of CeO in which La, Nd, or Yb is solid-solved. ２ may include:

[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 air electrode 8 is an electrode that comes into 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, in the range of 20% to 50%, particularly 30% to 50%. The open porosity of the air electrode 8 may also be referred to as the porosity of the air electrode 8.

[0026] 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. ３ Conductive ceramics such as perovskite oxides may also be used.

[0027] 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.

[0028] 1B , the air electrode 8 has a surface 81 on the positive side of the Y axis. The surface 81 is a second surface located on the opposite side of the solid electrolyte layer 6. The surface 81 has sides 8a and 8c extending along the Z axis direction and sides 8b and 8d extending along the X axis direction.

[0029] The element unit 3 may also have an intermediate layer (not shown) located between the solid electrolyte layer 6 and the air electrode 8. When the element unit 3 has an intermediate layer, the intermediate layer functions, for example, as a diffusion suppression layer. When elements such as Sr (strontium) contained in the air electrode 8 diffuse into the solid electrolyte layer 6, SrZrO ３ The intermediate layer is formed by making it difficult for elements such as Sr to diffuse, and is therefore SrZrO ３ This makes it difficult for compounds such as

[0030] The material of the intermediate layer 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 intermediate layer may be made of, for example, cerium oxide (CeO ２ ) may be included. Examples of such rare earth elements include Gd (gadolinium) and Sm (samarium).

[0031] The sealing material 9 is located on the side surfaces of the fuel electrode 5 and the solid electrolyte layer 6. The sealing material 9 is also in contact with the support member 2. As shown in FIG. 1B , the sealing material 9 is located along the sides 8a to 8d of the surface 81 of the air electrode 8. The portion of the sealing material 9 that extends along the sides 8a and 8c may be referred to as a first portion, and the portion that extends along the sides 8b and 8d may be referred to as a second portion.

[0032] The sealing material 9 may be dense glass or ceramic. The material of the sealing material 9 may be, for example, amorphous glass or crystallized glass. Examples of crystallized glass include SiO ２ -CaO system, MgO-B ２ O ３ System, La ２ O ３ -B ２ O ３ -MgO system, La ２ O３ -B ２ O ３ -ZnO-based, SiO ２ -CaO-ZnO system materials, etc., may be used, and in particular SiO ２ - An MgO-based material may be used. The sealing material 9 may have electrical insulating properties.

[0033] The flow path member 30 is located between the element units 3 of adjacent cells 1. The flow path member 30 is located between the fuel electrode 5 of one element unit 3 and the air electrode 8 of the other element unit 3. The material of the flow path member 30 may be a dense metal or alloy. The flow path member 30 has a surface 31 and a surface 32 located opposite to the surface 31. The flow path member 30 makes it difficult for the fuel gas flowing on the surface 31 side and the oxygen-containing gas flowing on the surface 32 side to leak. The flow path member 30 may have a coating layer. For example, the surface 31 of the flow path member 30 may have a coating layer that is resistant to reduction, and the surface 32 may have a coating layer that is resistant to oxidation. These coating layers may be conductive.

[0034] The flow path member 30 is fixed and electrically joined to the support member 2 by, for example, welding or the like at the contact portion. The flow path member 30 may be fixed and electrically joined to the support member 2 by a conductive sealing material, brazing material, or the like. A flow path 2a through which the fuel gas flows is located between a surface 31 of the flow path member 30 and the support member 2. The fuel gas flowing through the flow path 2a permeates the support member 2 and is supplied to the anode 5.

[0035] The surface 32 is fixed to and electrically joined to the air electrode 8, for example, via a conductive adhesive. A space is located between the flow path member 30 and the air electrode 8, through which an oxygen-containing gas flows.

[0036] The cell 1 may further include a constraining layer (not shown). The constraining layer may be located between the element portion 3 and the support member 2. The constraining layer cooperates with the solid electrolyte layer 6 to make the element portion 3 less likely to warp or bend.

[0037] The material of the constraining layer exhibits a shrinkage rate similar to that of the material of the solid electrolyte layer 6 during firing. The material of the constraining layer may be the same as the material of the solid electrolyte layer 6. The element unit 3 obtained by sandwiching the material of the anode 5 of the element unit 3 between the material of the solid electrolyte layer 6 and the material of the constraining layer and firing the resulting element unit 3 has little warping or deformation.

[0038] The constraining layer may or may not be gas permeable. When the constraining layer has gas barrier properties comparable to those of the solid electrolyte layer 6, the constraining layer can be partially disposed so as not to obstruct the inflow of fuel gas to the anode 5.

[0039] The cell 1 may further include a gas diffusion layer (not shown). The gas diffusion layer is located between the fuel electrode 5 and the support member 2. The gas diffusion layer has gas permeability and allows the fuel gas flowing through a flow path 2a (described later) 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%.

[0040] The material of the gas diffusion layer may be a porous conductive ceramic, such as a ceramic containing calcium oxide, magnesium oxide, or stabilized zirconia or partially stabilized zirconia in which a rare earth element oxide is solid-solved, 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.

[0041] <Details of Main Parts of Electrochemical Cell> Next, the main parts of the cell 1 will be further described with reference to Figures 1A to 1B and Figures 2A to 2B. Figure 2A is a cross-sectional view taken along line AA in Figure 1B. Figure 2B is a cross-sectional view taken along line BB in Figure 1B.

[0042] The cell 1 includes a support member 2, an element unit 3, a sealing material 9, and a flow path member 30. The element unit 3 includes a solid electrolyte layer 6 having a surface 61 as a first surface and a surface 62 opposite to surface 61, a cathode 8 as a first electrode facing surface 61, and a fuel electrode 5 as a second electrode located on the opposite side of the solid electrolyte layer 6 from the cathode 8 and facing surface 62. When the cell 1 has an intermediate layer between the solid electrolyte layer 6 and the cathode 8, surface 61 may be the surface of the solid electrolyte layer 6 that contacts the intermediate layer.

[0043] The sealing material 9 has a portion located on the surface 61, and covers the end surface 5a (see FIG. 2A) and the end surface 5b (see FIG. 2B) of the anode 5. The cathode 8 has a surface 81 as a second surface located on the opposite side of the solid electrolyte layer 6. In a first direction (Y-axis direction) perpendicular to the surface 61, when the length from the surface 61 to the surface 81 is L1 and the length from an end 91 of the sealing material 9 located on the surface 61 side to the surface 61 is L2, the sealing material 9 has a portion where L2 is larger than the average of L1.

[0044] In this way, by positioning the plugging material 9 so that there is a portion where L2 is larger than the average of L1, for example, oxygen-containing gas supplied to the space 50 located between the plugging material 9 and the flow path member 30 is less likely to stagnate and is more likely to flow along the Z-axis direction, thereby improving the power generation performance of the cell 1.

[0045] 2B , when the length in the Y-axis direction from the surface 61 to the surface 81 is L1 and the length from the end 9b of the second portion of the sealing material 9 located on the surface 61 side to the surface 61 is L4, the average of L4 may be smaller than the average of L1 for the sealing material 9. This makes it easier for the oxygen-containing gas supplied to the space 50 located between the sealing material 9 and the flow path member 30 to flow along the Z-axis direction. This improves the power generation performance of the cell 1.

[0046] Furthermore, when the length in the Y-axis direction from the end 9a of the first portion of the sealing material 9 located on the surface 61 side to the surface 61 is defined as L3, and the length from the end 9b of the second portion of the sealing material 9 located on the surface 61 side to the surface 61 is defined as L4, the average of L3 of the sealing material 9 may be greater than the average of L4. This makes it easier for the oxygen-containing gas supplied to the space 50 located between the sealing material 9 and the flow path member 30 to flow along the Z-axis direction. This improves the power generation performance of the cell 1.

[0047] Furthermore, the first portion of the sealing material 9 may have an end portion 9a (see FIG. 2A) that contacts the flow path member 30. This allows the oxygen-containing gas flowing through the space 50 to flow more easily along the Z-axis direction, thereby further improving the power generation performance of the cell 1.

[0048] Furthermore, the first portion of the sealing material 9 may have an end portion 9a separated from the flow path member. This allows a portion of the oxygen-containing gas flowing through the space 50 to be discharged to the outside of the cell 1, facilitating the release of heat generated in the element portion 3. This makes it difficult for the element portion 3 to overheat, thereby improving the durability of the cell 1.

[0049] The cell 1 may further include an adhesive 41. The adhesive 41 may be located between the element portion 3 and the support member 2. The adhesive 41 bonds the element portion 3 and the support member 2 together, and fixes the element portion 3 to the support member 2.

[0050] The adhesive 41 may be conductive. For example, the adhesive 41 may be a mixture of conductive particles such as Ni and TiO ２ , rare earth element oxides (Y ２ O ３ , CeO ２ etc.), transition metal oxides (Fe ２ O ３ The adhesive 41 may contain an inorganic oxide such as SiO 2 or CuO. The adhesive 41 may be gas permeable.

[0051] The flow path member 30 may also have a surface 31 and one or more protrusions 31a. The surface 31 is positioned to face the surface 81 of the air electrode 8. The protrusions 31a protrude from the surface 31 toward the element section 3. The surface 31 may be flat or may have projections and recesses.

[0052] The cell 1 may further have an intermediate portion 42. The intermediate portion 42 may be located between the flow path member 30 and the element portion 3. The intermediate portion 42 may be an adhesive that bonds the protruding portion 31a of the flow path member 30 to the air electrode 8 and fixes the element portion 3 to the flow path member 30. The protruding portion 31a may be in contact with the element portion 3 or may be separated from the element portion 3. The sealing material 9 may include a portion having L2 and L3 that are greater than the lengths from the surface of the intermediate portion 42 that faces the flow path member 30 to the surface 61.

[0053] The intermediate portion 42 may be electrically conductive. The intermediate portion 42 may be gas permeable. The material of the intermediate portion 42 may be the same as or different from the material of the cathode 8.

[0054] The intermediate portion 42 may also include a filler 42a. Examples of materials that can be used for the filler 42a include oxides such as alumina, mullite, silica, and magnesia, and high-melting-point glass.

[0055] Fig. 3A is a cross-sectional view showing another example of an electrochemical cell according to an embodiment. Fig. 3B is a cross-sectional view showing another example of an electrochemical cell according to an embodiment. Fig. 3A is a cross-sectional view corresponding to the AA cross section shown in Fig. 1B. Fig. 3B is a cross-sectional view corresponding to the BB cross section shown in Fig. 1B.

[0056] 3A , the sealing material 9 may have an end 9 a of the first portion of the sealing material 9 located on the surface 61 side that is located inside the outline of the solid electrolyte layer 6 in a plan view. Also, as shown in FIG. 3B , the sealing material 9 may have an end 9 b of the second portion of the sealing material 9 located on the surface 61 side that is located inside the outline of the solid electrolyte layer 6 in a plan view.

[0057] In this way, the sealing material 9 has an end 91 of the sealing material 9 located on the surface 61 side that has a portion located inside the outline of the solid electrolyte layer 6 in a plan view, which makes it easier to impart pressure drop to the oxygen-containing gas flowing through the space 50. This makes it easier for the oxygen-containing gas to flow inside the space 50, further improving the power generation performance of the cell 1.

[0058] Here, L1 to L4 can be measured as follows. For example, a sample in which a part of the cell 1 including the element portion 3 and the sealing material 9 is embedded in resin is polished to obtain a partial cross section of the cell 1. The obtained partial cross section is observed using a scanning electron microscope (SEM) or the like to obtain a cross-sectional image. L1 to L4 can be measured using the obtained cross-sectional image.

[0059] In the case of FIG. 2A , L1, i.e., the length from surface 61 to surface 81, can be measured as follows. Within the range of 100 μm or more and 200 μm or less in the X direction from side 8 a, the surface 61 of the solid electrolyte layer 6 facing the air electrode 8 and the surface 81 of the air electrode 8 located on the opposite side of the solid electrolyte layer 6 are identified. L1 can be measured as the length from surface 61 to surface 81 located in a direction perpendicular to surface 61. If surface 61 is curved, the direction perpendicular to surface 61 (the Y-axis direction) does not need to coincide with the arrangement direction of the cells 1. The average L1 is the average length from surface 61 to surface 81 within the range of 100 μm or more and 200 μm or less in the X direction from side 8 a.

[0060] Furthermore, L2, i.e., the length from the end 91 of the sealing material 9 located on the surface 61 side to the surface 61, can be measured as follows. As shown in FIG. 2A , the sealing material 9 has a portion that does not overlap with the solid electrolyte layer 6 in a planar view. Therefore, a line connecting the position of the surface 61 that overlaps with the side 8a in the Y-axis direction in the cross-sectional image and the position of the surface 61 at the end of the solid electrolyte layer 6 is defined as a virtual plane of the surface 61 of the sealing material 9 at the portion that does not overlap with the solid electrolyte layer 6. The point on the contour of the sealing material 9 where the length from the surface 61 including the virtual plane is maximum in a direction perpendicular to the surface 61 including the virtual plane is defined as the end 91. L2 can be measured as the length from the end 91 to the surface 61. Hereinafter, the surface 61 refers to the surface 61 including the virtual plane.

[0061] Furthermore, L3, i.e., the length from the end 9a of the first part of the sealing material 9 located on the surface 61 side to the surface 61 and the average of L3, and L4, i.e., the length from the end 9b of the second part of the sealing material 9 located on the surface 61 side to the surface 61 and the average of L4, can be measured in the same way as L2 and the average of L2.

[0062] A cell 1 having such a plugging material 9 may be fabricated, for example, as follows. For example, a paste or molded sheet containing the material for the plugging material 9 is prepared. An element unit 3 is prepared, either formed directly on a support member 2 or joined to the support member 2 using an adhesive 41. A paste containing the material for the plugging material 9 is applied or a molded sheet containing the material for the plugging material 9 is placed on the outline of the fuel electrode 5 and solid electrolyte layer 6 of the element unit 3 as viewed in plan from the Y-axis direction, and heat treatment is performed to form the plugging material 9. The air electrode 8 may be formed after the plugging material 9 is formed. The magnitude relationship between L1 to L4 can be achieved by adjusting the thickness of the plugging material 9, for example, by adjusting the properties, application conditions, number of applications, etc. of the paste containing the material for the plugging material 9, or the thickness of the molded sheet containing the material for the plugging material 9.

[0063] <Configuration of Electrochemical Cell Device> Next, an electrochemical cell device according to this embodiment using the above-described electrochemical cell will be described with reference to Figures 4A to 4C. Figure 4A is a perspective view showing an example of an electrochemical cell device according to an embodiment. Figure 4B is a cross-sectional view taken along line XX shown in Figure 4A. Figure 4C is a top view showing an example of an electrochemical cell device according to an embodiment.

[0064] As shown in FIG. 4A, the cell stack device 10 includes a cell stack 11 having a plurality of cells 1 arranged (stacked) in the thickness direction (Y-axis direction) of the cells 1, and a fixing member 12.

[0065] 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 metal and are electrically conductive.

[0066] 4B, 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.

[0067] 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.

[0068] In the example shown in Fig. 4A, 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 flow path 2a (see Fig. 1A) inside the cell 1. The fuel gas supplied to the gas tank 16 is generated in a reformer 104 (see Fig. 5), which will be described later.

[0069] 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.

[0070] The example shown in FIG. 4A 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 corresponding support 15. The gas tank 16 has two through-holes on its top surface. A support 15 is disposed in each through-hole. The internal space 22 is formed by one gas tank 16 and two supports 15. The cell stack device 10 may include only one cell stack 11, or may include three or more cell stacks 11.

[0071] The shape of the insertion hole 15a may be, 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, may be 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 may be greater than the length of the cell 1 in the width direction (X-axis direction: see FIG. 1A ).

[0072] 4B , the joints between the inner walls of the insertion holes 15a and the lower ends of the cells 1 may be filled with and solidified with a fixing material 13. 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 flow paths 2a of each cell 1 communicate with the internal space 22 of the support member 14 at their lower ends.

[0073] 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.

[0074] 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 system, 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.

[0075] 4B , a conductive member 18 may be interposed between adjacent cells 1 among the plurality of cells 1. The conductive member 18 electrically connects one adjacent cell 1 to the other adjacent cell 1 in series. More specifically, the conductive member 18 connects the fuel electrode 5 of one cell 1 to the air electrode 8 of the other cell 1.

[0076] 4B, an end current collecting member 17 may be 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 may be connected to a conductive portion 19 that protrudes to the outside of 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. 4A.

[0077] 4C, the cell stack device 10 may be a single battery in which two cell stacks 11A, 11B are connected in series. In such a case, the conductive portion 19 of the cell stack device 10 may have a positive terminal 19A, a negative terminal 19B, and a connection terminal 19C.

[0078] The positive electrode terminal 19A may be a positive electrode when the power generated by the cell stack 11 is output to the outside. The positive electrode terminal 19A 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 may be a negative electrode when the power generated by the cell stack 11 is output to the outside. The positive electrode terminal 19A is electrically connected to the end current collecting member 17 on the negative electrode side of the cell stack 11B.

[0079] 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.

[0080] <Module> Next, a module according to an embodiment of the present disclosure using the above-described cell stack device 10 will be described with reference to Fig. 5. Fig. 5 is an external perspective view showing an example of a module according to an embodiment. Fig. 5 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 removed to the rear.

[0081] 5, the module 100 includes a storage container 101 and a cell stack device 10 housed in the storage container 101. A reformer 102 may be disposed above the cell stack device 10.

[0082] 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.

[0083] The fuel gas produced in the reformer 102 is supplied to the flow path 2 a of the cell 1 (see FIG. 1A) through the gas distribution pipe 20 , the gas tank 16 , and the support member 14 .

[0084] 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.

[0085] 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.

[0086] <Module Enclosure Device> Fig. 6 is an exploded perspective view schematically illustrating an example of a module enclosure device according to an embodiment. The module enclosure device 110 according to this embodiment includes an outer case 111, the module 100 shown in Fig. 5, 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. 6.

[0087] An exterior case 111 of a module accommodating device 110 shown in Fig. 6 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. 6, the auxiliary equipment accommodated in the auxiliary equipment accommodating chamber 116 is not shown.

[0088] 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.

[0089] 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.

[0090] Other Embodiments 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 hydrogen electrode as a first electrode and an oxygen electrode as a second electrode, 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] The present disclosure has been described in detail above, but 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 an element portion including a solid electrolyte layer having a first surface, a first electrode facing the first surface, and a second electrode located on the opposite side of the first electrode with the solid electrolyte layer sandwiched therebetween; and a sealing material having a portion located on the first surface and covering an end face of the second electrode, wherein the first electrode has a second surface located on the opposite side of the solid electrolyte layer, and when a length from the first surface to the second surface in a first direction perpendicular to the first surface is defined as L1 and a length from an end of the sealing material located on the first surface side to the first surface is defined as L2, the sealing material has a portion where L2 is larger than the average of L1.

[0093] (2) The electrochemical cell of (1) above may further include a flow path member facing the second surface and having a flow path between the second surface and the second surface, wherein the second surface has a first side and a second side that intersect with each other, and the sealing material has a first portion extending along the first side and a second portion extending along the second side, and when the length from the end of the second portion located on the first surface side to the first surface in the first direction is L4, the average of L4 of the sealing material may be smaller than the average of L1.

[0094] In one embodiment, (3) the electrochemical cell includes an element portion including a solid electrolyte layer having a first surface, a first electrode facing the first surface, and a second electrode located on the opposite side of the solid electrolyte layer from the first electrode, and a sealing material having a portion located on the first surface and covering an end face of the second electrode, wherein the sealing material has an end portion located on the first surface side that is located inside the outline of the solid electrolyte layer in a plan view.

[0095] (4) The electrochemical cell of (1) or (2) above may further include a flow path member facing the second surface and having a flow path between the second surface and the second surface, wherein the second surface has a first side and a second side that intersect with each other, and the sealing material has a first portion extending along the first side and a second portion extending along the second side, and when the length from the end of the first portion located on the first surface side to the first surface in the first direction is L3 and the length from the end of the second portion located on the first surface side to the first surface is L4, the average of L3 of the sealing material may be greater than the average of L4.

[0096] (5) In the electrochemical cell of (4) above, the first portion may have a portion where the end portion contacts the flow path member.

[0097] (6) In the electrochemical cell of (4) or (5) above, the first portion may have a portion where the end is separated from the flow path member.

[0098] (7) The electrochemical cell of any one of (4) to (6) above may have an intermediate portion that contains a filler and is located between the first electrode and the flow path member.

[0099] (8) The electrochemical cell of any one of (1) to (7) above may further include a support member that supports the second electrode, and the sealing material may be in contact with the support member.

[0100] In one embodiment, (9) an electrochemical cell device has a cell stack including any one of the electrochemical cells (1) to (8) above.

[0101] In one embodiment, a module (10) includes the electrochemical cell device (9) described above, and a container for housing the electrochemical cell device.

[0102] In one embodiment, (11) a module housing device includes the module of (10) above, an auxiliary device for operating the module, and an exterior case for housing the module and the auxiliary device.

[0103] 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.

[0104] REFERENCE SIGNS LIST 1 cell 2 support member 3 element section 5 fuel electrode 6 solid electrolyte layer 8 air electrode 9 sealing material 10 cell stack device 30 flow path member 100 module 110 module housing device

Claims

1. An electrochemical cell comprising: an element portion including a solid electrolyte layer having a first surface, a first electrode facing the first surface, and a second electrode located on the opposite side of the first electrode with the solid electrolyte layer between them; and a sealing material having a portion located on the first surface and covering an end face of the second electrode, wherein the first electrode has a second surface located on the opposite side of the solid electrolyte layer, and wherein, in a first direction perpendicular to the first surface, when a length from the first surface to the second surface is L1 and a length from an end of the sealing material located on the first surface side to the first surface is L2, the sealing material has a portion where L2 is larger than the average of L1.

2. The electrochemical cell according to claim 1, further comprising a flow path member facing said second surface and having a flow path between said second surface and said flow path member, wherein said second surface has a first side and a second side intersecting each other, said sealing material has a first portion extending along said first side and a second portion extending along said second side, and when the length from an end of said second portion located on the first surface side to said first surface in said first direction is L4, the average of L4 of said sealing material is smaller than the average of L1.

3. An electrochemical cell comprising: an element portion including a solid electrolyte layer having a first surface, a first electrode facing the first surface, and a second electrode located on the opposite side of the solid electrolyte layer from the first electrode; and a sealing material having a portion located on the first surface and covering an end face of the second electrode, wherein the sealing material has an end portion located on the first surface side that is partly located inside the outline of the solid electrolyte layer in a plan view.

4. An electrochemical cell as described in claim 1 or 2, further comprising a flow path member facing the second surface and having a flow path between the second surface and the second surface, wherein the second surface has a first side and a second side intersecting each other, the sealing material has a first portion extending along the first side and a second portion extending along the second side, and wherein, in the first direction, when the length from an end of the first portion located on the first surface side to the first surface is L3 and the length from the end of the second portion located on the first surface side to the first surface is L4, the average of L3 of the sealing material is greater than the average of L4.

5. The electrochemical cell according to claim 4, wherein the first portion has a portion where the end contacts the flow path member.

6. The electrochemical cell according to claim 4 or 5, wherein the first portion has a portion where the end is spaced apart from the flow path member.

7. The electrochemical cell according to any one of claims 4 to 6, further comprising an intermediate portion which contains a filler and is located between said first electrode and said flow path member.

8. An electrochemical cell according to any one of claims 1 to 7, further comprising a support member that supports the second electrode, and the sealing material is in contact with the support member.

9. An electrochemical cell device comprising a cell stack comprising the electrochemical cell according to any one of claims 1 to 8.

10. A module comprising the electrochemical cell device according to claim 9 and a container for housing the electrochemical cell device.

11. A module housing device comprising: a module according to claim 10; an auxiliary device for operating said module; and an exterior case for housing said module and said auxiliary device.

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