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

Abstract

The present invention provides electrochemical cells, electrochemical cell apparatuses, modules, and module housings that can improve durability. [Solution] The electrochemical cell comprises a metal member, an element portion, and a sealing member. The metal member has a first surface. The element portion faces the first surface. The sealing member overlaps with the contour of the element portion in a plan view. The contour has edges and corners. The sealing member has a first portion that overlaps with the corners and a second portion that overlaps with the edges of the contour of the element portion in a plan view. The first portion has a greater thickness in the first direction perpendicular to the first surface than the second portion.

Description

[Technical Field]

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

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

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-35417 [Overview of the project] [Problems that the invention aims to solve]

[0004] Conventional fuel cell cell stack devices had room for improvement in terms of durability.

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

[0006] An electrochemical cell according to one embodiment comprises a metal member, an element portion, and a sealing member. The metal member has a first surface. The element portion faces the first surface. The sealing member overlaps the contour of the element portion in plan view. The contour has edges and corners. The sealing member has a first portion that overlaps with the corners and a second portion that overlaps with the edges of the contour of the element portion in plan view. The first portion has a greater thickness in a first direction perpendicular to the first surface than the second portion.

[0007] Furthermore, an electrochemical cell apparatus according to one embodiment has a cell stack including the electrochemical cell described above.

[0008] Furthermore, the module of this disclosure comprises the electrochemical cell apparatus described above and a housing container for housing the electrochemical cell apparatus.

[0009] Furthermore, the module housing device of this disclosure comprises the module described above, auxiliary equipment for operating the module, and an outer case for housing the module and the auxiliary equipment. [Effects of the Invention]

[0010] According to one embodiment, an electrochemical cell, an electrochemical cell apparatus, a module, and a module housing apparatus can be provided that can improve durability. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a cross-sectional view showing an example of an electrochemical cell according to the embodiment. [Figure 2] Figure 2 is a plan view showing an example of an electrochemical cell according to the embodiment, viewed from the element side. [Figure 3] Figure 3 is a cross-sectional view showing another example of an electrochemical cell according to the embodiment. [Figure 4] Figure 4 is a cross-sectional view of line AA shown in Figure 2. [Figure 5] Figure 5 is a cross-sectional view showing an enlarged example of the second portion of the sealing member of the electrochemical cell shown in Figure 4. [Figure 6] Figure 6 is a cross-sectional view showing an enlarged example of the first portion of the sealing member of the electrochemical cell shown in Figure 4. [Figure 7A] Figure 7A is a perspective view showing an example of an electrochemical cell apparatus according to the embodiment. [Figure 7B] Figure 7B is a cross-sectional view of the XX line shown in Figure 7A. [Figure 7C]FIG. 7C is a top view showing an example of an electrochemical cell device according to an embodiment. [Figure 8] FIG. 8 is an external perspective view showing an example of a module according to an embodiment. [Figure 9] FIG. 9 is an exploded perspective view schematically showing an example of a module housing device according to an embodiment. MODE FOR CARRYING OUT THE INVENTION

[0012] Hereinafter, embodiments of the electrochemical cell, electrochemical cell device, module, and module housing device disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present disclosure is not limited by the embodiments shown below.

[0013] Also, note that the drawings are schematic, and it is necessary to be aware that the dimensional relationships between elements, the ratios of each element, etc. may differ from reality. Furthermore, there may be parts where the dimensional relationships and ratios between the drawings are different from each other.

[0014] [Embodiment] [Configuration of Electrochemical Cell] First, with reference to FIGS. 1 and 2, the electrochemical cell according to the 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 is simply referred to as a cell stack device.

[0015] FIG. 1 is a cross-sectional view showing an example of an electrochemical cell according to the embodiment. FIG. 2 is a plan view showing an example of the electrochemical cell as viewed from the element unit side. In FIGS. 1 and 2, a part of each configuration of the electrochemical cell is enlarged and shown. Hereinafter, the electrochemical cell may also be simply referred to as a cell.

[0016] For the sake of clarity, Figures 1 and 2 illustrate a three-dimensional Cartesian coordinate system including a Z-axis, where the vertically upward direction is positive and the vertically downward direction is negative. This Cartesian coordinate system may also be shown in other diagrams used in later explanations. Furthermore, components with the same reference numerals as those in the electrochemical cell shown in Figures 1 and 2 are used, and their explanations are omitted or simplified.

[0017] As shown in Figures 1 and 2, the cell 1 according to this embodiment comprises a metal plate 32, an element portion 3, and a sealing member 9.

[0018] The metal plate 32 has a first surface 321 and a second surface 322 located at both ends in the thickness direction (Y-axis direction).

[0019] The metal plate 32 is electrically conductive. The metal plate 32 may also be a metal component containing, for example, chromium. The metal plate 32 may also be stainless steel, such as heat-resistant ferritic stainless steel or austenitic stainless steel. The metal plate 32 may also be a nickel-chromium alloy or an iron-chromium alloy. The metal plate 32 may also contain, for example, a metal oxide. Furthermore, the metal plate 32 may have a coating covering its surface. The metal plate 32 does not necessarily have a coating on its surface.

[0020] Furthermore, the metal plate 32 may have an opening 32a. The opening 32a is a through hole that penetrates between the first surface 321 and the second surface 322. The fuel gas flowing through the flow path 33, which will be described later, is supplied to the fuel electrode 5 of the element section 3, which will be described later, through the opening 32a. The diameter of the opening 32a may be, for example, 0.1 mm to 0.5 mm, and particularly 0.3 mm to 0.4 mm. The opening ratio in the region where the opening 32a is formed in the metal plate 32 viewed in plan along the Y-axis direction may be, for example, 10% or more. The metal plate 32 may have a coating that covers the wall surface of the opening 32a. The metal plate 32 does not have to have a coating on the wall surface of the opening 32a.

[0021] The metal plate 32 may, for example, be gas permeable. In such a case, the metal plate 32 does not need to have an opening 32a.

[0022] The element portion 3 is positioned facing the first surface 321 of the metal plate 32. The element portion 3 includes a fuel electrode 5, a solid electrolyte layer 6, and an air electrode 8. In Figure 2, the individual components of the element portion 3, such as the air electrode 8, are not shown, and only the outline 30 of the element portion 3 viewed from the air electrode 8 side is illustrated.

[0023] The fuel electrode 5 is the first electrode in contact with the fuel gas, which is a reducing gas. The fuel electrode 5 is gas permeable. The open porosity of the fuel electrode 5 may be in the range of, for example, 30% to 50%, and particularly 35% to 45%. The open porosity of the fuel electrode 5 is sometimes referred to as the porosity or void ratio of the fuel electrode 5.

[0024] The fuel electrode 5 can be made from materials that are generally known. The fuel electrode 5 may be made from porous conductive ceramics, such as ceramics containing calcium oxide, magnesium oxide, or ZrO2 in which rare earth element oxides are in solid solution, and Ni and / or NiO. These rare earth element oxides may include multiple rare earth elements selected from, for example, Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. The ZrO2 in which calcium oxide, magnesium oxide, or rare earth element oxides are in solid solution is sometimes referred to as stabilized zirconia. The stabilized zirconia may include partially stabilized zirconia. The fuel electrode 5 may also contain CeO2 in which La, Nd, or Yb are in solid solution.

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

[0026] The material of the solid electrolyte layer 6 may be, for example, ZrO2 in which 3 mol% to 15 mol% of rare earth element oxides are dissolved. The rare earth element oxides may contain, for example, one or more rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb. The solid electrolyte layer 6 may contain, for example, ZrO2 in which Yb, Sc, or Gd is dissolved, may contain CeO2 in which La, Nd, or Yb is dissolved, may contain BaZrO3 in which Sc or Yb is dissolved, or may contain BaCeO3 in which Sc or Yb is dissolved.

[0027] The air electrode 8 is a second electrode that contacts 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 void fraction of the air electrode 8.

[0028] The material of the air electrode 8 is not particularly limited as long as it is generally used for an air electrode. The material of the air electrode 8 may be, for example, a conductive ceramic such as a so-called ABO3-type perovskite oxide.

[0029] The material of the air electrode 8 may be, for example, a composite oxide in which Sr (strontium) and La (lanthanum) coexist at the A site. Examples of such composite oxides include La x Sr 1-x Co y Fe 1-y O3, La x Sr 1-x MnO3, La x Sr 1-x FeO3, La x Sr 1-x CoO3, etc. Here, x is 0 < x < 1, and y is 0 < y < 1.

[0030] Furthermore, the element 3 may have a diffusion-suppressing layer (not shown) located between the solid electrolyte layer 6 and the air electrode 8. Certain elements, such as Sr (strontium), contained in the air electrode 8 are easily diffused into the solid electrolyte layer 6. For example, if Sr (strontium) contained in the air electrode 8 diffuses into the solid electrolyte layer 6, a resistive layer of SrZrO3 may be formed in the solid electrolyte layer 6. The diffusion-suppressing layer makes it difficult for elements such as Sr to diffuse, thereby making it difficult for a resistive layer of SrZrO3 to form.

[0031] The material of the diffusion-suppressing layer is generally not limited as long as it makes it difficult for specific elements such as Sr to diffuse. The material of the diffusion-suppressing layer may, for example, contain cerium oxide (CeO2) in which rare earth elements other than Ce (cerium) are dissolved. Such rare earth elements may include, for example, Gd (gadolinium) and Sm (samarium).

[0032] Cell 1 may further have an intermediate layer 40. The intermediate layer 40 may be located between the first surface 321 of the metal plate 32 and the element portion 3. The intermediate layer 40 joins the element portion 3 and the metal plate 32, fixing the element portion 3 to the metal plate 32.

[0033] The intermediate layer 40 may be conductive. The intermediate layer 40 may contain, for example, conductive particles such as Ni and inorganic oxides such as TiO2, rare earth element oxides (Y2O3, CeO2, etc.), and transition metal oxides (Fe2O3, CuO, etc.).

[0034] The intermediate layer 40 may be gas permeable. The intermediate layer 40 may be positioned to cover the opening 32a of the metal plate 32.

[0035] The intermediate layer 40 may be a single layer made of a single material, or it may be a laminate made by stacking multiple materials.

[0036] Cell 1 may also have a diffusion layer, not shown. The diffusion layer may be located between the fuel electrode 5 and the intermediate layer 4. The diffusion layer is gas permeable and allows the fuel gas flowing through the channel 24 (see Figure 1) to permeate to the fuel electrode 5. The open porosity of the diffusion layer may be, for example, in the range of 30% to 50%, particularly 35% to 45%.

[0037] The material of the diffusion layer may be a porous conductive ceramic, such as a ceramic containing calcium oxide, magnesium oxide, or stabilized or partially stabilized zirconia in which a rare earth element oxide is in solid solution, and Ni and / or NiO. This rare earth element oxide may contain, for example, multiple rare earth elements selected from Sc, Y, La, Nd, Sm, Gd, Dy, and Yb.

[0038] The material of the diffusion layer reduces, for example, the shrinkage of the fuel electrode 5 during firing. This makes it possible to bring the degree of shrinkage of the fuel electrode 5 and the solid electrolyte layer 6 closer together during firing, so that the cell 1 having the diffusion layer exhibits less warping or deformation of the element portion 3.

[0039] Furthermore, the diffusion layer material is similar to that of the fuel electrode 5, and the temperature at which the diffusion layer material begins to shrink is close to that of the fuel electrode 5 material, while the rare earth element oxides inhibit the densification of the diffusion layer. As a result, the diffusion layer has appropriate gas permeability while making it less likely for the element part 3 to deform. Therefore, the cell 1 having the diffusion layer has improved adhesion between the element part 3 and the intermediate layer 40, and thus improved durability.

[0040] Furthermore, cell 1 may have a restraining layer (not shown). The restraining layer may be located between the element portion 3 and the metal plate 32. The restraining layer works in cooperation with the solid electrolyte layer 6 to prevent warping or bending of the element portion 3.

[0041] The material of the constraining layer exhibits a shrinkage rate similar to that of the solid electrolyte layer 6 during firing. The material of the constraining layer may be the same as that of the solid electrolyte layer 6. The element 3 obtained by sandwiching the fuel electrode 5 material of the element 3 between the solid electrolyte layer 6 material and the constraining layer material and firing it will have less warping or deformation.

[0042] The restraining layer may or may not be gas permeable. If the restraining layer has gas barrier properties similar to those of the solid electrolyte layer 6, the restraining layer can be partially positioned so as not to obstruct the flow of fuel gas to the fuel electrode 5.

[0043] Furthermore, as shown in Figure 2, the contour 30 of the element portion 3 has sides 3a to 3d and corners 3e to 3h. Side 3a is located at one end of the element portion 3 on the negative X-axis side and extends along the Z-axis direction intersecting the X-axis. Side 3c is located at the other end of the element portion 3 on the positive X-axis side and extends along the Z-axis direction. Side 3b is located at one end of the element portion 3 on the negative Z-axis side and extends along the X-axis direction intersecting the Z-axis. Side 3d is located at the other end of the element portion 3 on the positive Z-axis side and extends along the X-axis direction.

[0044] Corner 3e is located between sides 3a and 3b. Corner 3f is located between sides 3b and 3c. Corner 3g is located between sides 3c and 3d. Corner 3h is located between sides 3d and 3a.

[0045] The sealing member 9 is positioned so as to overlap the contour 30 of the element portion 3 in a plan view. The sealing member 9 may also be located on the side surfaces of the element portion 3 and the intermediate layer 40. The material of the sealing member 9 may be dense glass or ceramic. The material of the sealing member 9 may be, for example, amorphous glass or crystallized glass. As for the crystallized glass, any of the following materials may be used, for example, SiO2-CaO system, MgO-B2O3 system, La2O3-B2O3-MgO system, La2O3-B2O3-ZnO system, or SiO2-CaO-ZnO system, and in particular, SiO2-MgO system material may be used. The sealing member 9 may have electrical insulating properties. The sealing member 9 may be spaced apart from the air electrode 8 or may be in contact with the air electrode 8. Details of the sealing member 9 will be described later.

[0046] Cell 1 may further include a flow path member 34 and a current collector member 36. The flow path member 34 is located on the second surface 322 side of the metal plate 32. The flow path member 34 is electrically joined, for example, by welding at the contact portion with the second surface 322. The flow path member 34 may also be fixed to the metal plate 32 with a conductive sealing material or brazing material and electrically joined. The space located between the metal plate 32 and the flow path member 34 is a flow path 33 through which fuel gas flows. The fuel gas flowing through the flow path 33 is supplied to the fuel electrode 5 by permeating the metal plate 32. The metal plate 32 may have one or more protrusions projecting toward the flow path member 34.

[0047] The flow channel member 34 is further fixed to the current collector member 36 by welding or the like, and electrically joined. The current collector member 36 may be fixed to the flow channel member 34 with a conductive sealing material or brazing material, and electrically joined. The current collector member 36 may be fixed to the air electrode 8 of an adjacent cell 1 via an adhesive (not shown), and electrically joined. The space located between the current collector member 36 and the flow channel member 34 is a flow channel 35 through which oxygen-containing gas flows. The oxygen-containing gas flowing through the flow channel 35 is supplied to the air electrode 8 of the adjacent cell 1 by passing through the adhesive from the slit in the current collector member 36.

[0048] The material of the flow channel member 34 and the current collector member 36 is a dense metal or alloy. The flow channel member 34 reduces leakage of fuel gas flowing through the flow channel 33 and oxygen-containing gas flowing through the flow channel 35. The flow channel member 34 and the current collector member 36 may have a coating layer. For example, the surface of the flow channel member 34 facing the flow channel 33 may have a reduction-resistant coating layer, and the surface of the flow channel member 34 facing the flow channel 35 may have an oxidation-resistant coating layer. These coating layers may be conductive.

[0049] Figure 3 is a cross-sectional view showing another example of an electrochemical cell according to the embodiment. As shown in Figure 3, for example, the flow channel member 34 may be integrated with the current collector member 36 and have a first protrusion that projects toward the adjacent cell 1 along the Y-axis direction and a second protrusion that projects toward the opposite side of the first protrusion.

[0050] <Details of sealing material> Next, the details of the sealing member 9 will be further explained using Figures 2 and 4 to 6. As shown in Figure 2, the sealing member 9 has a first part P1 and a second part P2.

[0051] The first part P1 refers to the portion of the contour 30 of the element part 3 viewed from above that overlaps with the corners 3e to 3h. The first part P1 has a portion 9e that overlaps with corner 3e, a portion 9f that overlaps with corner 3f, a portion 9g that overlaps with corner 3g, and a portion 9h that overlaps with corner 3h in a plan view.

[0052] The second part P2 refers to the portion of the contour 30 of the element part 3 viewed from above that overlaps with the edges 3a to 3d. The second part P2 has a portion 9a that overlaps with edge 3a, a portion 9b that overlaps with edge 3b, a portion 9c that overlaps with edge 3c, and a portion 9d that overlaps with edge 3d in a plan view.

[0053] Figure 4 is a cross-sectional view along line AA shown in Figure 2. As shown in Figure 4, the sealing member 9 has a first surface 91 facing the first surface 321 of the metal plate 32, and a second surface 92 on the opposite side of the first surface 91. In Figure 4, an intermediate layer 40 is located between the first surface 91 and the first surface 321 of the metal plate 32, but the fuel electrode 5, solid electrolyte layer 6, etc. of the element part 3 may also be located between the first surface 91 and the first surface 321 of the metal plate 32. Alternatively, the first surface 91 may be in direct contact with the first surface 321 of the metal plate 32.

[0054] The first portion P1 of the sealing member 9 has a first thickness t01 in a first direction (Y-axis direction) perpendicular to the first surface 321. The second portion P2 has a second thickness t02 in the first direction (Y-axis direction). The first thickness t01 is greater than the second thickness t02. In other words, the first portion P1 has a greater thickness in the first direction perpendicular to the first surface 321 than the second portion P2.

[0055] Thus, by making the thickness of the first portion P1, where stress is more likely to concentrate than in the second portion P2, greater than that of the second portion P2, cracks are less likely to occur in the sealing member 9 even if, for example, the metal plate 32 undergoes thermal deformation. For this reason, the cell 1 according to this embodiment has improved durability.

[0056] Furthermore, because the thickness of the second portion P2 is smaller than that of the first portion P1, heat generated inside the cell 1, for example, is more easily released to the outside. As a result, the cell 1 according to the embodiment has improved durability. In particular, when two cells 1 are stacked and the flow channel member 34 of one cell 1 is placed on the air electrode 8 of the other cell 1, the first portion P1 ensures a gap between the second portion P2 of one cell 1 and the flow channel member 34 of the other cell 1. This gap promotes the airflow between the two cells 1, making it easier for heat generated inside one cell 1 to be quickly released to the outside.

[0057] Furthermore, as shown in Figure 4, the sealing member 9 may have a third portion P3 located between the first portion P1 and the second portion P2. The third portion P3 may have an inclined surface 921 where the distance from the first surface 91 to the second surface 92 decreases from the first portion P1 to the second portion P2. In other words, the thickness of the sealing member 9 may gradually decrease from the first portion P1 to the second portion P2. This makes it less likely for stress concentration to occur in each part of the sealing member 9, improving the durability of the cell 1.

[0058] Here, the first thickness t01 can be, for example, about 300 μm. The second thickness t02 can be, for example, about 150 μm. The length of the third portion P3, located between the first portion P1 and the second portion P2, along the X-axis direction can be, for example, about 1 mm.

[0059] Figure 5 is a cross-sectional view showing an enlarged example of the second portion of the sealing member of the electrochemical cell shown in Figure 4.

[0060] As shown in Figure 5, the second portion P2 of the sealing member 9 is divided into three equal parts in the thickness direction, defining the first region R1 to the third region R3. The first region R1 is the region including the first surface 91, the second region R2 is the region including the second surface 92, and the third region R3 is the region located between the first region R1 and the second region R2. In other words, when the thickness of the sealing member 9 in the first direction (Y-axis direction) is T0, the first region R1 is the range including the first surface 91 and where the distance from the first surface 91 is 1 / 3 × T0 or less. The second region R2 is the range including the second surface 92 and where the distance from the second surface 92 is 1 / 3 × T0 or less.

[0061] The porosity of the first region R1 may be greater than that of the second region R2. This makes it more difficult for the sealing member 9 to peel off from the metal plate 32 and / or the intermediate layer 40, thereby improving the durability of the cell 1.

[0062] Here, the porosity of the first region R1 can be, for example, 5% to 15%. Also, the porosity of the second region R2 can be, for example, 2% or less.

[0063] Furthermore, the average pore diameter of the first region R1 may be larger than the average pore diameter of the second region R2. This makes it more difficult for the sealing member 9 to peel off from the metal plate 32 and / or the intermediate layer 40, thereby improving the durability of the cell 1.

[0064] Here, the average pore size of the first region R1 can be, for example, 10 μm to 15 μm. Similarly, the average pore size of the second region R2 can be, for example, 1 μm to 10 μm.

[0065] Figure 6 is a cross-sectional view showing an enlarged example of the first portion of the sealing member of the electrochemical cell shown in Figure 4.

[0066] As shown in Figure 6, the first portion P1 of the sealing member 9 may have first to third portions 903 with different porosities. The first portion 901 includes the first surface 91 and has a first porosity. The second portion 902 is located further from the first surface 91 than the first portion 901 and has a second porosity that is smaller than the first porosity. The third portion 903 is located further from the first surface 91 than the second portion 902 and has a third porosity that is larger than the second porosity.

[0067] Thus, by having first to third sections 903 with different porosity rates, the second section 902 with low porosity maintains strength and gas sealing properties, while the first and third sections 901 and 903 with high porosity can relieve stress generated between the metal plate 32, the sealing member 9, and the intermediate layer 40, thereby improving the durability of the sealing member 9. For this reason, the cell 1 according to this embodiment has improved durability.

[0068] Furthermore, the first portion P1 may further have a fourth portion 904 located further away from the first surface 91 than the third portion 903 and having a fourth porosity smaller than the third porosity. This further improves the durability of the sealing member 9 and the durability of the cell 1.

[0069] Here, the porosity of the first section 901 can be, for example, 5% to 15%. Also, the porosity of the second section 902 can be, for example, 2% or less. The porosity of the third section 903 can be, for example, 5% to 15%. Also, the porosity of the fourth section 904 can be, for example, 2% or less.

[0070] Here, the arrangement of the first part P1 and the second part P2 of the sealing member 9, the shape of the third part P3, the first thickness t01 and the second thickness t02 shown in Figure 4, and the arrangement of the first to fourth parts 901 to 904 shown in Figure 6 are obtained as follows. For example, a part of the cell 1 including each part of the sealing member 9 and the element part 3 is embedded in resin and polished to obtain a partial cross-section along the thickness direction 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 at, for example, a magnification of 300x. Using the obtained cross-sectional image, the arrangement of the first part P1 and the second part P2 of the sealing member 9, the shape of the third part P3, and the first thickness t01 and the second thickness t02 can be confirmed. The arrangement of the first to fourth parts 904 can be determined, for example, by dividing the first part P1 of the sealing member 9 in the thickness direction into, for example, six equal parts, and calculating the porosity of each part by image analysis. Of the six equal parts obtained by dividing the first part P1, the part containing the first surface 91 is designated as the first part 901. Of the five parts other than the first part 901, the part that has a lower porosity than the first part 901 and is closest to the first part 901 is designated as the second part 902. The part that is further from the first surface 91 than the second part 902 and has a higher porosity than the second part 902 is designated as the third part 903. Furthermore, if the first part P1 has a part that is further from the first surface 91 than the third part 903 and has a lower porosity than the third part 903, that part may be designated as the fourth part 904.

[0071] Furthermore, the porosity and average pore diameter of the first region R1 and the second region R2 shown in Figure 5, and the porosity of the first section 901 to the fourth section 904 shown in Figure 6 are obtained as follows: SEM images of the cross-section including each region or section of cell 1, and including the first surface 91 and the second surface 92, are taken, for example, at a magnification of 300x, and the obtained cross-sectional images are subjected to image analysis. For the porosity of the first region R1 and the second region R2, pores are identified in the cross-sectional image, and the area of ​​each region containing pores in the cross-sectional image (SR1, SR2) and the sum of the areas of pores located in each region (PR1, PR2) are calculated. The ratio of the sum of the areas of pores located in each region (PR1, PR2) to the area of ​​each region (SR1, SR2) can be used as the porosity of each region (PR1 / SR1, PR2 / SR2). For the average pore diameter of each region, the average value of the equivalent circular diameter of the pores located in each region can be calculated by image analysis of the cross-sectional image.

[0072] The porosity of each of the first to fourth parts 901 to 904 can be obtained, for example, as follows: Pores are identified in a cross-sectional image including the first surface 91 and the second surface 92 of the first part P1, and the presence and arrangement of the first to fourth parts 901 to 904 are determined. The area containing pores in each part of the cross-sectional image (SP1, SP2, SP3, SP4) and the sum of the areas of pores located in each part (PP1, PP2, PP3, PP4) are calculated. The ratio of the sum of the areas of pores located in each part (PP1, PP2, PP3, PP4) to the total area of ​​each part (SP1, SP2, SP3, SP4) can be used as the porosity of each part (PP1 / SP1, PP2 / SP2, PP3 / SP3, PP4 / SP4). For image analysis, for example, analysis software (software name: ImageJ, developer: Wayne Rasband) can be used.

[0073] An electrochemical cell according to the embodiment can be manufactured, for example, as follows. For example, prepare sealing tapes containing sealing material powders with different average particle sizes, such as a fine powder-containing tape and a coarse powder-containing tape. Place the fine powder-containing tape so as to overlap the contour 30 of the element portion 3, and then place the coarse powder-containing tape on top of the fine powder-containing tape. At this time, the thickness of the sealing tape that overlaps the corner portion 3e in a plan view is made thicker than the other portions, and by firing, a sealing member 9 having a first portion P1 and a second portion P2 can be obtained. Note that the above-described method for manufacturing the electrochemical cell is merely illustrative, and it may be manufactured by any method.

[0074] <Configuration of an electrochemical cell system> Next, the electrochemical cell apparatus according to this embodiment, using the cell 1 described above, will be explained with reference to Figures 7A to 7C. Figure 7A is a perspective view showing an example of the electrochemical cell apparatus according to the embodiment. Figure 7B is a cross-sectional view taken along line XX shown in Figure 7A. Figure 7C is a top view showing an example of the electrochemical cell apparatus according to the embodiment.

[0075] As shown in Figure 7A, the cell stacking device 10 comprises a cell stack 11 having a plurality of cells 1 arranged (stacked) in the thickness direction of the cells 1 (the Y-axis direction shown in Figure 1), and a fixing member 12.

[0076] The fixing member 12 includes a fixing material 13 and a support member 14. The support member 14 supports the cell 1. The fixing material 13 fixes the cell 1 to the support member 14. The support member 14 also includes a support body 15 and a gas tank 16. The support body 15 and the gas tank 16, which make up the support member 14, are made of metal and are electrically conductive.

[0077] As shown in Figure 7B, the support 15 has an insertion hole 15a into which the lower ends of the multiple cells 1 are inserted. The lower ends of the multiple cells 1 and the inner wall of the insertion hole 15a are joined together by a fixing member 13.

[0078] The gas tank 16 has an opening that supplies reaction gas to multiple cells 1 through an insertion hole 15a, and a groove 16a located around the opening. The outer end of the support 15 is joined to the gas tank 16 by a bonding material 21 that is filled into the groove 16a of the gas tank 16.

[0079] In the example shown in Figure 7A, fuel gas is stored in an internal space 22 (see Figure 7B) formed by the support member 14, which is the support body 15, and the gas tank 16. A gas flow pipe 20 is connected to the gas tank 16. Fuel gas is supplied to the gas tank 16 through this gas flow pipe 20 and then supplied from the gas tank 16 to the internal flow path 33 (see Figure 1) of the cell 1. The fuel gas supplied to the gas tank 16 is generated in a reformer 102 (see Figure 8), which will be described later. The internal space 22 can also be described as a space with a reducing atmosphere containing fuel gas.

[0080] Hydrogen-rich fuel gas can be produced by steam reforming of the raw fuel. When fuel gas is produced by steam reforming, the fuel gas contains water vapor.

[0081] The example shown in Figure 7A comprises two rows of cell stacks 11, two support members 15, and a gas tank 16. Each of the two rows of cell stacks 11 has multiple cells 1. Each cell stack 11 is fixed to each support member 15. The gas tank 16 has two through holes on its top surface. Each support member 15 is positioned in each through hole. The internal space 22 is formed by the one gas tank 16 and the two support members 15.

[0082] The shape of the insertion hole 15a is, for example, an oval shape when viewed from above. The length of the insertion hole 15a is, for example, in the direction of arrangement of the cell 1, i.e., in the thickness direction (Y-axis direction shown in Figure 1), which is greater than the distance between the two end current collector 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 (X-axis direction shown in Figure 1).

[0083] As shown in Figure 7B, the joint between the inner wall of the insertion hole 15a and the lower end of the cell 1 is filled with a fixing material 13 and solidified. This joins and fixes the inner wall of the insertion hole 15a to the lower ends of the multiple cells 1, and also joins and fixes the lower ends of the cells 1 to each other. The gas passage 2a of each cell 1 communicates with the internal space 22 of the support member 14 at its lower end.

[0084] The fixing material 13 and the bonding material 21 can be made of materials with low conductivity, such as glass. Specific materials for the fixing material 13 and the bonding material 21 may include amorphous glass, and in particular, crystallized glass may be used.

[0085] As the crystallized glass, any of the following materials may be used, for example: SiO2-CaO system, MgO-B2O3 system, La2O3-B2O3-MgO system, La2O3-B2O3-ZnO system, SiO2-CaO-ZnO system, and in particular, SiO2-MgO system materials may be used.

[0086] Furthermore, as shown in Figure 7B, a conductive member 18 is interposed between adjacent cells 1 among the multiple cells 1. The conductive member 18 electrically connects one adjacent cell 1 to the other 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. Note that the conductive member 18 may be the flow path member 34 or current collector member 36 shown in Figure 1, or it may be a different member from the flow path member 34 and current collector member 36.

[0087] Furthermore, as shown in Figure 7B, the end current collector 17 is electrically connected to the outermost cell 1 in the arrangement direction of the multiple cells 1. The end current collector 17 is connected to a conductive part 19 that protrudes to the outside of the cell stack 11. The conductive part 19 collects the electricity generated by the cell 1 and draws it out to the outside. Note that the end current collector 17 is not shown in Figure 7A.

[0088] Furthermore, as shown in Figure 7C, the cell stack device 10 consists of two cell stacks 11A and 11B connected in series, functioning as a single battery. Therefore, the conductive part 19 of the cell stack device 10 is distinguished into a positive terminal 19A, a negative terminal 19B, and a connection terminal 19C.

[0089] The positive terminal 19A is the positive terminal when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the positive terminal end current collector 17 of the cell stack 11A. The negative terminal 19B is the negative terminal when the power generated by the cell stack 11 is output to the outside, and is electrically connected to the negative terminal end current collector 17 of the cell stack 11B.

[0090] The connection terminal 19C electrically connects the negative terminal end current collector 17 of the cell stack 11A to the positive terminal end current collector 17 of the cell stack 11B.

[0091] <module> Next, a module according to this embodiment using the cell stack device 10 described above will be explained with reference to Figure 8. Figure 8 is an external perspective view showing an example of a module according to this embodiment. In Figure 8, the front and rear surfaces, which are part of the storage container 101, have been removed, and the cell stack device 10 of the fuel cell housed inside has been taken out to the rear.

[0092] As shown in Figure 8, module 100 comprises a storage container 101 and a cell stack device 10 housed within the storage container 101. A reformer 102 is positioned above the cell stack device 10.

[0093] The reformer 102 reforms raw fuels such as natural gas and kerosene to produce fuel gas, which is then supplied to cell 1. The raw fuels are supplied to the reformer 102 through a raw fuel supply pipe 103. The reformer 102 may also include a vaporization section 102a for vaporizing water and a reforming section 102b. The reforming section 102b is equipped with a reforming catalyst (not shown) and reforms the raw fuels into fuel gas. Such a reformer 102 can perform steam reforming, which is a highly efficient reforming reaction.

[0094] The fuel gas generated in the reformer 102 is then supplied to the flow path 33 of the cell 1 (see Figure 1) through the gas flow pipe 20, the gas tank 16, and the support member 14.

[0095] Furthermore, in the module 100 with the above configuration, the temperature inside the module 100 during normal power generation is approximately 500°C to 1000°C due to the combustion of gas and the power generation of cell 1.

[0096] In such a module 100, as described above, a cell stack device 10 equipped with multiple highly durable cells 1 is housed within it, thereby making the module 100 highly durable.

[0097] <Module housing device> Figure 9 is a schematic exploded perspective view showing an example of a module housing device according to this embodiment. The module housing device 110 according to this embodiment comprises an outer case 111, a module 100 shown in Figure 8, and auxiliary equipment (not shown). The auxiliary equipment operates the module 100. The module 100 and the auxiliary equipment are housed in the outer case 111. Note that some components are omitted in Figure 9.

[0098] The outer casing 111 of the module housing device 110 shown in Figure 9 has support columns 112 and outer panels 113. Partition plates 114 divide the inside of the outer casing 111 into upper and lower sections. The space above the partition plates 114 inside the outer casing 111 is the module housing chamber 115 for housing the module 100, and the space below the partition plates 114 inside the outer casing 111 is the auxiliary equipment housing chamber 116 for housing the auxiliary equipment that operates the module 100. Note that in Figure 9, the auxiliary equipment housed in the auxiliary equipment housing chamber 116 is omitted from the illustration.

[0099] Furthermore, the partition plate 114 has an air circulation port 117 for allowing air from the auxiliary equipment storage room 116 to flow towards the module storage room 115. The outer panel 113 that constitutes the module storage room 115 has an exhaust port 118 for exhausting the air inside the module storage room 115.

[0100] In such a module housing device 110, as described above, a highly durable module housing device 110 can be made possible by providing a highly durable module 100 in the module housing chamber 115.

[0101] [Other embodiments] In the embodiments described above, fuel cell cells, fuel cell stack devices, fuel cell modules, and fuel cell devices were shown as examples of "electrochemical cells," "electrochemical cell devices," "modules," and "module housing devices," but other examples may be electrolytic cells, electrolytic cell stack devices, electrolytic modules, and electrolytic devices, respectively. An electrolytic cell has a first electrode and a second electrode and decomposes water vapor into hydrogen and oxygen, or carbon dioxide into carbon monoxide and oxygen, by supplying electricity. In addition, in each of the embodiments described above, oxide ion conductors or hydrogen ion conductors were shown as examples of electrolyte materials for electrochemical cells, but hydroxide ion conductors may also be used. Such electrolytic cells, electrolytic cell stack devices, electrolytic modules, and electrolytic devices offer improved durability.

[0102] Although the present disclosure has been described in detail above, this disclosure is not limited to the embodiments described above, and various modifications and improvements are possible without departing from the gist of this disclosure.

[0103] In one embodiment, (1) the electrochemical cell comprises a metal member having a first surface, The element portion facing the first surface, A sealing member that overlaps with the contour of the element portion in a plan view. Equipped with, The aforementioned contour has edges and corners, The sealing member has, in plan view, a first portion of the contour of the element portion that overlaps with the corner portion and a second portion that overlaps with the side portion. The first portion has a greater thickness in the first direction perpendicular to the first surface than the second portion.

[0104] (2) In the electrochemical cell described in (1) above, the thickness of the sealing member may gradually decrease from the first portion to the second portion.

[0105] (3) In the electrochemical cell of (1) or (2) above, in the second part, Let T0 be the thickness of the sealing member in the first direction. The first region includes a first surface facing the first surface, and the distance from the first surface is 1 / 3 × T0 or less. When the second region includes the second surface opposite to the first surface, and the distance from the second surface is 1 / 3 × T0 or less, The porosity of the first region may be greater than the porosity of the second region.

[0106] (4) In any one of the electrochemical cells described in (1) to (3) above, in the second part described above, Let T0 be the thickness of the sealing member in the first direction. The first region includes a first surface facing the first surface, and the distance from the first surface is 1 / 3 × T0 or less. When the second region includes the second surface opposite to the first surface, and the distance from the second surface is 1 / 3 × T0 or less, The average pore diameter of the first region may be greater than the average pore diameter of the second region.

[0107] (5) In any one of the electrochemical cells described in (1) to (4) above, the first part is: A first portion having a first porosity and including a first surface facing the first surface, A second portion located further from the first surface than the first portion and having a second porosity smaller than the first porosity, A third portion located further from the first surface than the second portion and having a third porosity greater than the second porosity, It may have.

[0108] (6) In the electrochemical cell described in (5) above, the first portion may further have a fourth portion having a fourth porosity smaller than the third porosity, located at a position further away from the first surface than the third portion.

[0109] In one embodiment, (7) the electrochemical cell apparatus has a cell stack containing any one of the electrochemical cells described in (1) to (6) above.

[0110] In one embodiment, module (8) is the electrochemical cell apparatus of (7) above, The system includes a storage container for housing the aforementioned electrochemical cell apparatus.

[0111] In one embodiment, (9) the module housing device includes the module described in (8) above, Auxiliary equipment for operating the aforementioned module, The system comprises the module and an outer case housing the auxiliary equipment.

[0112] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of Symbols]

[0113] 1 cell 3 Element section 5 Fuel electrode 6 Solid electrolyte layer 8. Air pole 9. Sealing member 10-cell stack device 30 contours 32 Metal plate 40 Middle Class 91 1st surface 92 Second surface 100 modules 110 Module housing device

Claims

1. A metal member having a first surface, The element portion facing the first surface, A sealing member that overlaps with the contour of the element portion in a plan view. Equipped with, The aforementioned contour has edges and corners, The sealing member has, in plan view, a first portion of the contour of the element portion that overlaps with the corner portion and a second portion that overlaps with the side portion. The first portion has a greater thickness in the first direction perpendicular to the first surface than the second portion. Electrochemical cell.

2. The thickness of the sealing member gradually decreases from the first portion to the second portion. The electrochemical cell according to claim 1.

3. In the second part, Let T0 be the thickness of the sealing member in the first direction. The first region includes a first surface facing the first surface, and the distance from the first surface is 1 / 3 × T0 or less. When the second region includes the second surface opposite to the first surface, and the distance from the second surface is 1 / 3 × T0 or less, The porosity of the first region is greater than the porosity of the second region. The electrochemical cell according to claim 1.

4. In the second part, Let T0 be the thickness of the sealing member in the first direction. The first region includes a first surface facing the first surface, and the distance from the first surface is 1 / 3 × T0 or less. When the second region includes the second surface opposite to the first surface, and the distance from the second surface is 1 / 3 × T0 or less, The average pore diameter of the first region is greater than the average pore diameter of the second region. The electrochemical cell according to claim 1.

5. The first part is, A first portion having a first porosity and including a first surface facing the first surface, A second portion located further from the first surface than the first portion and having a second porosity smaller than the first porosity, A third portion located further from the first surface than the second portion and having a third porosity greater than the second porosity, has The electrochemical cell according to claim 1.

6. The first portion further comprises a fourth portion having a fourth porosity smaller than the third porosity, located at a position further from the first surface than the third portion. The electrochemical cell according to claim 5.

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

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

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

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