JP5895112B1 - Fuel cell - Google Patents

Abstract

The present invention provides a “horizontal stripe type” fuel cell in which cracks are unlikely to occur in the vicinity of the outer edge of a reaction preventing film on the outer surface of an “intermediate fired body”. A fuel electrode 20 of a corresponding power generation element portion A is embedded in each first recess 12 formed on the main surface of a support substrate 10. The “seal part” that prevents the fuel gas and the air from being mixed includes the interconnector 30, the solid electrolyte membrane 40, and the reaction prevention membrane 50. A second recess is formed in “a portion including each region corresponding to each power generation element portion A” on the outer surface of the solid electrolyte membrane 40. The reaction preventing film 50 is embedded in the second recess. The second recess has a bottom wall 41 made of the material of the solid electrolyte membrane 40 and side walls 42 and 43 closed in the circumferential direction made of the material of the solid electrolyte membrane 40 over the entire circumference. [Selection] Figure 3

Description

  The present invention relates to a fuel cell.

  Conventionally, “a support substrate having a longitudinal direction and a gas flow path formed therein along the longitudinal direction” and “a plurality of locations separated from each other on the main surface of the support substrate, respectively” A plurality of power generating element portions provided with at least a fuel electrode, a solid electrolyte membrane made of a dense material, a reaction preventing film made of a dense material containing ceria containing a rare earth element, and an air electrode in this order. '' , “One or more electrical connection portions that electrically connect one fuel electrode and the other air electrode of the adjacent power generation element portions” and “is provided so as to cover the main surface of the support substrate. And a seal part made of a dense material that prevents mixing of the gas supplied to the fuel electrode through the gas flow path and the gas supplied to the air electrode. A fuel cell is widely known (example If, refer to Patent Document 1). Such a configuration is also called a “horizontal stripe type”.

  In the fuel cell described in the above document, each of the electrical connection portions includes a first portion (interconnector) made of a dense material and a second portion (air) connected to the first portion and made of a porous material. Electrode current collector film). The first part is connected to one fuel electrode of the adjacent power generation element part and the second part. The second part is connected to the other air electrode of the adjacent power generation element part and the first part.

  A first recess having a bottom wall made of the material of the support substrate and a side wall closed in the circumferential direction made of the material of the support substrate over the entire circumference at the plurality of locations on the main surface of the support substrate. Each is formed. The fuel electrode of the corresponding power generation element portion is embedded in each first recess.

  The seal portion includes “the first portions of the respective electrical connection portions” and “the respective solid electrolyte membranes included in the respective power generation element portions and continuously from the respective solid electrolyte membranes. A first seal film made of the same dense material as the solid electrolyte extended, and “including each of the reaction prevention films included in each of the power generation element portions and continuously from each of the reaction prevention films. A second sealing film made of the same dense material as the extended reaction preventing film ”.

  In the fuel cell described in the above-mentioned document, usually, a molded body of the support substrate, a molded body of the fuel electrode, and a seal portion (the first portion of each electrical connection portion, the first seal film, and the second The laminated body (green body) is fired at the stage where the molded body (including the sealing film) is laminated. Thereafter, the fired body (hereinafter referred to as “intermediate fired body”) is laminated with a molded body of the air electrode and a molded body of each second part of each electrical connection portion, and this new laminated body ( The green body) is fired at a temperature lower than that at the time of firing described above. Thereby, the fuel cell which is a sintered body is completed.

  By the way, in the fuel cell described in the above document, the first seal film is related to the first seal film (including the solid electrolyte film) and the second seal film (including the reaction preventing film) which are part of the seal portion. A second seal film is laminated on the outer side surface (flat surface). As a result, there is a step corresponding to the thickness of the second seal film at the outer edge of the second seal film on the outer surface of the “intermediate fired body”.

  Here, when the “intermediate fired body” is fired, there is a problem that cracks are likely to occur in the vicinity of the outer edge of the second seal film on the outer surface of the “intermediate fired body”. This is because the height of the step is large, and excessive stress is locally generated in the vicinity of the outer edge of the second seal film on the outer surface of the “intermediate fired body” during firing. It is thought that it is based on what is easy to do.

Japanese Patent No. 4828663

  The present invention is to cope with the above problems, and is a “horizontal stripe type” fuel cell in which cracks are generated in the vicinity of the outer edge of the second seal film on the outer surface of the “intermediate fired body”. The purpose is to provide something difficult to do.

  The fuel cell according to the present invention includes the “support substrate”, the “plurality of power generation element portions”, and the “plurality of electrical connection portions”, as in the fuel cell described in the “Background Art” section. A “horizontal stripe type” fuel cell comprising the “seal portion”.

  The fuel cell according to the present invention is characterized in that a portion of the outer surface of the first seal film including a region corresponding to each power generation element portion includes a bottom wall made of the material of the first seal film, A second recess having a side wall made of a material of the first seal film and closed in the circumferential direction is formed, and the second seal film is embedded in the second recess. As a result, the outer surface of the first portion of each of the electrical connection portions, the portion other than the second recess on the outer surface of the first seal film, and the second seal embedded in the second recess An outer surface of the membrane, and the outer surface of the seal portion is configured.

  According to the above feature of the present invention, for example, when the whole area in the thickness direction of the second seal film is embedded in the second recess, a step is formed at the outer edge of the second seal film on the outer surface of the “intermediate fired body”. Is not formed. In addition, when only a part of the second seal film in the thickness direction is embedded in the second recess (that is, the inner part of the second seal film in the thickness direction is embedded in the second recess, and the second seal film Even in the case where the outer portion in the thickness direction in FIG. 3 protrudes in the thickness direction with respect to the outer surface of the first seal film), the structure of the fuel cell described in the above-described document (that is, the thickness in the second seal film) Compared to the case where the entire area in the vertical direction protrudes in the thickness direction with respect to the outer surface of the first seal film), the level difference formed at the outer edge of the second seal film on the outer surface of the “intermediate fired body” The height becomes smaller.

  Thus, in any case, according to the above-described feature of the present invention, it is formed at the outer edge of the second seal film on the outer surface of the “intermediate fired body” as compared with the configuration of the fuel cell described in the above-mentioned document. The height of the step is reduced. As a result, excessive stress is unlikely to occur locally in the vicinity of the outer edge of the second seal film, and cracks are unlikely to occur in the vicinity of the outer edge.

  In this case, the outer surface of the first portion of each of the electrical connection portions, the portion other than the second recess portion on the outer surface of the first seal film, and the second seal embedded in the second recess portion. It is preferable that the outer surface of the membrane constitutes a continuous outer surface of the seal portion. According to this, there is no “step” in the entire outer surface of the “intermediate fired body”. Accordingly, it is difficult to generate excessive stress due to the presence of “steps” in the entire outer surface of the “intermediate fired body” during firing. As a result, cracks due to the presence of “steps” are less likely to occur across the entire outer surface of the “intermediate fired body”.

  In the fuel cell according to the present invention, the second recess includes a bottom wall made of the material of the first seal film, and a side wall closed in the circumferential direction made of the material of the first seal film over the entire circumference. It is preferable to have

  In the fuel cell according to the present invention, the inner region of the seal portion defined by the seal portion is a reducing atmosphere, and the outer region of the seal portion defined by the seal portion is an oxidizing atmosphere. Here, the second seal film is made of a “ceria-containing material” (for example, gadolinium-doped ceria (GDC)) constituting the reaction preventing film. In general, a “material containing ceria” tends to expand when exposed to a reducing atmosphere. Therefore, when the second seal film is exposed to a reducing atmosphere, the second seal film is likely to be peeled off and warped due to its expansion. In this regard, according to the above configuration, the entire circumference of the side surface of the second seal film can be reliably covered with the frame body formed of the first seal film. Therefore, the second seal film is not easily exposed to the atmosphere (that is, the reducing atmosphere) in the inner region of the seal portion (first seal film). As a result, the above-mentioned “peeling of the second seal film, warping, etc.” is less likely to occur.

  Moreover, in the fuel cell according to the present invention, the seal portion is connected to the first portion of each electrical connection portion and the first seal film, and is denser than the first and second seal films. It is preferable that a plurality of third seal portions made of a material are provided so that the first seal film and the first portions of the respective electrical connection portions are not in contact with each other. In this case, the outer surface of the first portion of each of the electrical connection portions, the portion other than the second recess portion on the outer surface of the first seal film, and the second seal embedded in the second recess portion. The outer surface of the seal portion may be constituted by the outer surface of the membrane and the outer surface of each of the third seal portions.

  In general, the first portion (interconnector) of the electrical connection portion is made of lanthanum chromite, and the first seal membrane (ie, the solid electrolyte membrane) can be made of yttria-stabilized zirconia. Here, when lanthanum chromite comes into contact with zirconia, the sinterability of lanthanum chromite is lowered, and the denseness of lanthanum chromite is easily lost. In this regard, according to the above configuration, the introduction of the third seal portion prevents the first seal film from contacting the first portion of each electrical connection portion. As a result, the problem that the denseness of the first portion of the electrical connection portion is lost due to the contact between the first portion of the electrical connection portion and the first seal film is less likely to occur.

1 is a perspective view showing an embodiment of a fuel cell according to the present invention. FIG. 2 is a cross-sectional view corresponding to line 2-2 of the fuel cell shown in FIG. It is the figure which expanded and showed a part of sectional drawing shown in FIG. 4 is a cross-sectional view corresponding to line 4-4 of the fuel cell shown in FIGS. 1 and 2. FIG. It is the top view which showed the state of the fuel electrode and interconnector which were embed | buried under the recessed part of the support substrate shown in FIG. It is a top view which shows the whole seal part in the fuel cell shown in FIG. It is a figure for demonstrating the operation state of the fuel cell shown in FIG. FIG. 3 is a view corresponding to FIG. 2 for explaining the flow of current in the operating state of the fuel cell shown in FIG. 1. FIG. 4 is a view corresponding to FIG. 3 for explaining the flow of current in the operating state of the fuel cell shown in FIG. 1. It is a perspective view which shows the support substrate shown in FIG. FIG. 4 is a cross-sectional view corresponding to FIG. 3 in a first stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 4 is a cross-sectional view corresponding to FIG. 3 in a second stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 4 is a cross-sectional view corresponding to FIG. 3 in a third stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 4 is a cross-sectional view corresponding to FIG. 3 in a fourth stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 4 is a cross-sectional view corresponding to FIG. 3 in a fifth stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 4 is a cross-sectional view corresponding to FIG. 3 in a sixth stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 6 is a cross-sectional view corresponding to FIG. 3 in a seventh stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 4 is a cross-sectional view corresponding to FIG. 3 in an eighth stage in the manufacturing process of the fuel cell shown in FIG. 1. It is a figure corresponding to FIG. 2 of the modification of embodiment of the fuel cell which concerns on this invention. It is a figure corresponding to FIG. 3 of the modification shown in FIG. It is a figure corresponding to FIG. 5 of the modification shown in FIG. It is a figure corresponding to FIG. 6 of the modification shown in FIG.

(Configuration of the embodiment)
FIG. 1 shows an embodiment (this embodiment) of a solid oxide fuel cell (SOFC) according to the present invention. The SOFC 100 includes a plurality of (this example) electrically connected in series to upper and lower surfaces (main surfaces (planes) on both sides parallel to each other) of the flat support substrate 10 having a longitudinal direction (x-axis direction). In this case, the four power generation element portions A having the same shape are arranged at predetermined intervals in the longitudinal direction, so-called “horizontal stripe type”.

  The shape of the entire SOFC 100 as viewed from above is, for example, a rectangle having a side length in the longitudinal direction of 5 to 50 cm and a length in the width direction (y-axis direction) perpendicular to the longitudinal direction of 1 to 10 cm. The total thickness of the SOFC 100 is 1 to 5 mm. The entire SOFC 100 has a vertically symmetrical shape with respect to a plane that passes through the center in the thickness direction and is parallel to the main surface of the support substrate 10. Hereinafter, the details of the SOFC 100 will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, the support substrate 10 is a flat plate-like fired body made of a porous material having no electron conductivity. As shown in FIG. 10, which will be described later, the support substrate 10 has a main part 10A having a longitudinal direction (x-axis direction) and both ends of the main part 10A in the width direction (y-axis direction). It is comprised from a pair of side edge part 10B and 10B connected to 10A.

  The side end portion 10B has a semicylindrical shape extending in the longitudinal direction (x-axis direction). The curvature radius of the curved surface (a part of the cylindrical surface) protruding in the width direction of the side end portion 10B is 0.3 to 5 mm. At the boundary between the main portion 10A and the pair of side end portions 10B and 10B, the side end portion 10B protrudes in the thickness direction (z-axis direction) with respect to the main portion 10A, and the side end portion 10B is in the longitudinal direction. A pair of steps ST and ST are formed so as to extend in the (x-axis direction).

  Inside the main portion 10A of the support substrate 10, a plurality (six in this example) of fuel gas passages 11 (through holes) extending in the longitudinal direction (x-axis direction) are spaced at a predetermined interval in the width direction. Is formed. Further, in each of the upper and lower surfaces (both main surfaces) of the main portion 10A of the support substrate 10, recesses 12 (corresponding to the “first recesses”) are formed at locations corresponding to the respective power generation element portions A. . In this example, each recess 12 includes a bottom wall made of the material of the support substrate 10 and side walls closed in the circumferential direction made of the material of the support substrate 10 over the entire circumference (two side walls along the longitudinal direction and the width direction). A rectangular parallelepiped depression defined by two side walls).

The support substrate 10 can be made of, for example, CSZ (calcia stabilized zirconia). Alternatively, it may be composed of NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia), NiO (nickel oxide) and Y ₂ O ₃ (yttria), or MgO. (Magnesium oxide) and MgAl ₂ O ₄ (magnesia alumina spinel) may be used.

  The support substrate 10 may be configured to include “transition metal oxide or transition metal” and insulating ceramics. As the “transition metal oxide or transition metal”, NiO (nickel oxide) or Ni (nickel) is suitable. The transition metal can function as a catalyst for promoting a reforming reaction of the fuel gas (hydrocarbon-based gas reforming catalyst).

Further, as the insulating ceramic, MgO (magnesium oxide) or “mixture of MgAl ₂ O ₄ (magnesia alumina spinel) and MgO (magnesium oxide)” is preferable. Further, CSZ (calcia stabilized zirconia), YSZ (8YSZ) (yttria stabilized zirconia), Y ₂ O ₃ (yttria) may be used as the insulating ceramic.

  As described above, since the support substrate 10 contains “transition metal oxide or transition metal”, the gas containing the residual gas component before the reforming is supplied to the fuel through the numerous pores inside the porous support substrate 10. In the process of being supplied from the gas flow path 11 to the fuel electrode, the catalytic action can promote the reforming of the residual gas component before the reforming. In addition, the insulating property of the support substrate 10 can be ensured by the support substrate 10 containing insulating ceramics. As a result, insulation between adjacent fuel electrodes can be ensured. The thickness of the support substrate 10 is 1 to 5 mm.

  As shown in FIGS. 2 to 5, the entire fuel electrode current collector 21 is embedded (filled) in each recess 12 formed on the upper and lower surfaces (both main surfaces) of the support substrate 10. Therefore, each fuel electrode current collector 21 has a rectangular parallelepiped shape. As shown in FIGS. 3 and 5, a recess 21 a is formed on the surface (outer surface) of each fuel electrode current collector 21. Each recess 21a has a rectangular parallelepiped shape defined by a bottom wall made of the material of the fuel electrode current collector 21 and side walls closed in the circumferential direction (two side walls along the longitudinal direction and two side walls along the width direction). It is a depression. The “side wall closed in the circumferential direction” is made of the material of the fuel electrode current collector 21 over the entire circumference.

  In each recess 21a, the entire fuel electrode active portion 22 (the entire region in the thickness direction (z-axis direction)) is embedded (filled). Accordingly, each fuel electrode active portion 22 has a rectangular parallelepiped shape. A fuel electrode 20 is configured by the fuel electrode current collector 21 and the fuel electrode active unit 22. The fuel electrode 20 (fuel electrode current collector 21 + fuel electrode active part 22) is a fired body made of a porous material having electron conductivity. The entire circumference and bottom surface of the “side wall closed in the circumferential direction” of each anode active portion 22 are in contact with the anode current collecting portion 21 in the recess 21a.

  As shown in FIGS. 3 and 5, a recess 21 b is formed in the surface (outer surface) of each fuel electrode current collector 21 except for the recess 21 a. Each recess 21b has a rectangular parallelepiped shape defined by a bottom wall made of the material of the fuel electrode current collector 21 and side walls closed in the circumferential direction (two side walls along the longitudinal direction and two side walls along the width direction). It is a depression. The “side wall closed in the circumferential direction” is made of the material of the fuel electrode current collector 21 over the entire circumference.

  A part of the rectangular parallelepiped interconnector 30 (the inner portion in the thickness direction (z-axis direction)) is embedded (filled) in each recess 21b. The interconnector 30 is a fired body made of a dense material having electronic conductivity. The entire circumference of the inner side portion in the thickness direction of the side wall of each interconnector 30 and the bottom surface of each interconnector 30 are in contact with the fuel electrode current collector 21 in the recess 21b.

As shown in FIGS. 2 to 5, the surface (outer surface) of the fuel electrode current collector 21, the surface (outer surface) of the fuel electrode active portion 22, and the main surface of the main portion 10 </ b> A of the support substrate 10, One plane (the same plane as the main surface of the main portion 10A of the support substrate 10 when the concave portion 12 is not formed) is configured. That is, no step is formed between the surface of the fuel electrode current collector 21, the surface of the fuel electrode active part 22, and the main surface of the main part 10 </ b> A of the support substrate 10. A part of the interconnector 30 (the outer portion in the thickness direction (z-axis direction)) protrudes from the “one plane”.
In FIG. 5, the fuel electrode 20 (current collector 21 + active part 22) and the interconnector 30 are embedded in each recess 12 of the support substrate 10, and a solid electrolyte membrane 40, a reaction prevention membrane 50, and the like described later are provided. It is a top view of the support substrate 10 in the state which is not provided.

The fuel electrode active part 22 may be composed of, for example, NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia). Or you may comprise from NiO (nickel oxide) and GDC (gadolinium dope ceria). The fuel electrode current collector 21 can be composed of, for example, NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia). Alternatively, it may be composed of NiO (nickel oxide) and Y ₂ O ₃ (yttria), or may be composed of NiO (nickel oxide) and CSZ (calcia stabilized zirconia). The thickness of the anode active portion 22 is 5 to 30 μm, and the thickness of the anode current collecting portion 21 (that is, the depth of the recess 12) is 50 to 500 μm.

  As described above, the fuel electrode current collector 21 includes a substance having electronic conductivity. The fuel electrode active part 22 includes a substance having electron conductivity and a substance having oxygen ion conductivity. The “volume ratio of the substance having oxygen ion conductivity with respect to the entire volume excluding the pore portion” in the anode active portion 22 is “having oxygen ion conductivity with respect to the entire volume excluding the pore portion” in the anode current collecting portion 21. It is larger than the “volume ratio of the substance”.

The interconnector 30 can be composed of, for example, LaCrO ₃ (lanthanum chromite). Alternatively, it may be composed of (Sr, La) TiO ₃ (strontium titanate). The thickness of the interconnector 30 is 10 to 100 μm.

As shown in FIGS. 2 to 5, except for a portion where a plurality of interconnectors 30 are formed on the main surface of the main portion 10 </ b> A of the support substrate 10 in a state where the fuel electrode 20 and the interconnector 30 are embedded in the recess 12. The entire surface is covered with a solid electrolyte membrane 40. That is, the solid electrolyte membrane 40 covers the main surface of the main portion 10A of the support substrate 10 and contacts the entire side surfaces of the steps ST and ST (see FIG. 10) of the support substrate 10 and The power generation element part A extends from the inside of the power generation element part A so as to contact the entire circumference of the side surface of each interconnector 30. Here, the entire solid electrolyte membrane 40 (corresponding to the first solid electrolyte membrane and the second solid electrolyte membrane) corresponds to the “first seal membrane”.
In other words, the entire solid electrolyte membrane 40 includes a solid electrolyte membrane 40 (first solid electrolyte membrane) included in the power generation element portion A and a solid electrolyte membrane 40 (second solid state) outside the power generation element portion A. Electrolyte membrane).

The solid electrolyte membrane (first seal membrane) 40 is a fired body made of a dense material having oxygen ion conductivity. The solid electrolyte membrane 40 can be made of, for example, YSZ (8YSZ) (yttria stabilized zirconia). That is, the solid electrolyte membrane 40 contains zirconia (ZrO ₂ ). The thickness of the solid electrolyte membrane (first seal membrane) 40 is 3 to 50 μm.

  As shown in FIG. 4, the surface of the edge located near the step ST in the solid electrolyte membrane (first seal film) 40 and the surface of the portion located near the step ST in the side end portion 10 </ b> B of the support substrate 10. Thus, a continuous surface is formed. That is, no step is formed between the surface of the edge located in the vicinity of the step ST in the solid electrolyte membrane 40 and the surface of the portion located in the vicinity of the step ST in the side end portion 10B of the support substrate 10. .

  As shown in FIGS. 1 and 4, the entire surface of the pair of side end portions 10 </ b> B and 10 </ b> B of the support substrate 10 is covered with side end seal portions 80 and 80. The edge part located in the vicinity of the step ST in the side end seal part 80 covers the surface of the edge part located in the vicinity of the step ST in the solid electrolyte membrane (first seal film) 40. In other words, the side end seal portion 80 is connected to the solid electrolyte membrane 40 so that the edge of the side end seal portion 80 and the edge of the solid electrolyte membrane 40 overlap in the thickness direction (so as to overlap). It is connected.

The side end seal portion 80 is made of a dense material having the same or different composition as the solid electrolyte membrane (first seal membrane) 40. The dense material having a composition different from that of the solid electrolyte membrane 40 may be, for example, another solid electrolyte material such as 10Sc1CeZrO ₂ , or may be a material other than the solid electrolyte such as glass or ZrO _2. Good. Or the side edge part seal | sticker part 80 may be comprised with the dense material which has the same main component (same composition) as the support substrate 10. FIG. The thickness of the side end seal portion 80 is 3 to 100 μm.

  As shown in FIGS. 1 to 4 and 6, the surface (outer surface) of the solid electrolyte membrane (first seal film) 40 covering the main surface of the main portion 10 </ b> A of the support substrate 10 (outer edge portion, and One continuous concave portion (corresponding to the “second concave portion”) is formed in all regions except for a portion surrounding the entire outer periphery of each interconnector 30. Thereby, it can be said that this recessed part is formed in "the part containing each area | region corresponding to each electric power generation element part A" in the outer surface of the solid electrolyte membrane 40. FIG.

  As can be understood from FIG. 1 to FIG. 4 and FIG. 6, this recess has an outer edge of the solid electrolyte membrane 40 that covers the bottom wall 41 made of the material of the solid electrolyte membrane 40 and the main surface of the main portion 10 </ b> A of the support substrate 10. And a side wall 42 made of a material of the solid electrolyte membrane 40 and a side wall 43 made of a material of the solid electrolyte membrane 40 and located in a portion surrounding the entire outer periphery of each interconnector 30. It is. When the main surface of the main portion 10A of the support substrate 10 is viewed from the outside (in the z-axis direction), as can be understood from FIG. 6 in particular, this concave portion excludes the region occupied by each interconnector 30. It has a large rectangular shape surrounded by a frame. In FIG. 6, the main surface of the main portion 10 </ b> A of the support substrate 10 is provided with a solid electrolyte film 40 and a reaction preventing film 50 described later, and an air electrode 60 and an air electrode current collecting film 70 described later. It is a top view of the support substrate 10 in the state which is not.

  In the concave portion formed on the surface (outer surface) of the solid electrolyte membrane (first seal membrane) 40, the entire reaction prevention membrane 50 (the entire region in the thickness direction (z-axis direction)) is embedded (filled). Yes. The reaction preventing film 50 is a fired body made of a dense material. The entire circumference of the side wall of the reaction preventing film 50 and the entire surface of the bottom wall are in contact with the solid electrolyte film 40 in the recess.

The reaction preventing film 50 includes, for example, ceria containing rare earth elements such as GDC = (Ce, Gd) O ₂ (gadolinium-doped ceria) and SDC = (Ce, Sm) O ₂ (samarium-doped ceria). Can be constructed. The thickness of the reaction preventing film 50 (that is, the depth of the concave portion) is 3 to 50 μm. The reaction preventing film 50 is disposed on the bottom wall 41 of the recess and extends from the inside of the power generation element portion A to the outside of the power generation element portion A so as to contact the side walls 42 and 43 of the recess. The entire reaction preventing film 50 (corresponding to the first reaction preventing film and the second reaction preventing film) corresponds to the “second seal film”.
In other words, the entire reaction preventing film 50 includes the reaction preventing film 50 (first reaction preventing film) included in the power generating element part A and the reaction preventing film 50 (second reaction) outside the power generating element part A. Prevention film).

  As shown in FIGS. 2 to 4, the surface (outer surface) of each interconnector 30, the surface (outer surface) of the solid electrolyte membrane (first seal film) 40, and the reaction preventing film (second seal film) 50. A continuous plane is constituted by the surface (outer surface). That is, no step is formed between the surface of each interconnector 30, the surface of the solid electrolyte membrane 40, and the surface of the reaction preventing film 50.

  As described above, the main surfaces on the front and back of the main portion 10A of the support substrate 10 are “continuous consisting of the interconnector 30, the solid electrolyte membrane (first seal membrane) 40, and the reaction prevention membrane (second seal membrane) 50. It is covered by a “dense film”. This continuous dense film corresponds to the “seal part”. The surface of each interconnector 30, the surface of the solid electrolyte membrane (first seal membrane) 40, and the surface of the reaction preventing membrane (second seal membrane) 50 constitute the outer surface of the “seal portion”. .

  In addition, the surfaces of the pair of side end portions 10B and 10B of the support substrate 10 are covered with a dense film called side end seal films 80 and 80. Due to the dense film formed by the “seal part” and the side end seal films 80, 80, the fuel gas flowing in the space inside the dense film and the air flowing in the space outside the dense film And mixing can be prevented. In order to exhibit this gas sealing function, the porosity of this dense membrane (interconnector 30, solid electrolyte membrane 40, reaction preventing membrane 50, and side end seal membrane 80) is 10% or less.

  An air electrode 60 is formed on the upper surface of “a portion corresponding to the fuel electrode active portion 22 when the main surface of the main portion 10 </ b> A of the support substrate 10 is viewed from the outside” in the reaction preventing film (second seal film) 50. Yes. The air electrode 60 is a fired body made of a porous material having electronic conductivity. The shape of the air electrode 60 viewed from above is substantially the same rectangle as the fuel electrode active part 22.

The air electrode 60 can be made of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, from LSF = (La, Sr) FeO ₃ (lanthanum strontium ferrite), LNF = La (Ni, Fe) O ₃ (lanthanum nickel ferrite), LSC = (La, Sr) CoO ₃ (lanthanum strontium cobaltite), etc. It may be configured. Further, the air electrode 60 may be configured by two layers of a first layer (inner layer) made of LSCF and a second layer (outer layer) made of LSC. The thickness of the air electrode 60 is 10 to 100 μm.

Note that the reaction preventing film 50 is interposed between the solid electrolyte membrane 40 and the air electrode 60 because the YSZ in the solid electrolyte membrane 40 and the Sr in the air electrode 60 in the SOFC being manufactured or in operation. This is to suppress the occurrence of a phenomenon in which a reaction layer (SrZrO ₃ ) having a large electric resistance is formed at the interface between the solid electrolyte membrane 40 and the air electrode 60 due to the reaction.

  Here, the anode active portion 22 of the anode 20 and the “part corresponding to the anode active portion 22 when the main surface of the main portion 10A of the support substrate 10 is viewed from the outside (first solid electrolyte) in the solid electrolyte membrane 40”. "Corresponding to the membrane)" and "the portion corresponding to the fuel electrode active portion 22 when the main surface of the main portion 10A of the support substrate 10 is viewed from the outside (corresponding to the first reaction preventing film)" in the reaction preventing film 50, A stacked body in which the air electrode 60 is stacked corresponds to the “power generation element portion A” (see FIGS. 2 and 3). That is, a plurality (four in this example) of power generation element portions A are arranged at predetermined intervals in the longitudinal direction on each of the upper and lower surfaces of the main portion 10A of the support substrate 10.

  As shown in FIGS. 2 and 3, the air electrode 60, the reaction preventing film 50, and the solid electrolyte straddle the air electrode 60 of the power generation element part A and the interconnector 30 adjacent to the power generation element part A. An air electrode current collecting film 70 is formed on the surface of the film 40 and the interconnector 30 (outer surface). The air electrode current collector film 70 is a fired body made of a porous material having electron conductivity. The shape of the air electrode current collector film 70 viewed from the outside is a rectangle.

The air electrode current collector film 70 can be made of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, LSC = (La, Sr) CoO ₃ (lanthanum strontium cobaltite) may be used. Or you may comprise from Ag (silver) and Ag-Pd (silver palladium alloy). Alternatively, it may be composed of La (Ni, Fe, Cu) O ₃ . That is, the air electrode current collector film 70 contains strontium (Sr) or lanthanum (La). The thickness of the air electrode current collector film 70 is 50 to 500 μm.

  By forming each air electrode current collecting film 70 in this way, the air electrode 60 of one power generation element part A and the fuel of the other power generation element part A are obtained for each pair of adjacent power generation element parts A and A. The electrode 20 (in particular, the fuel electrode current collector 21) is electrically connected via the “air electrode current collector film 70 and the interconnector 30” having electronic conductivity. As a result, a plurality (four in this example) of power generation element portions A disposed on the upper and lower surfaces of the main portion 10A of the support substrate 10 are electrically connected in series. Here, the “air electrode current collector film 70 and the interconnector 30” having electronic conductivity correspond to the “electrical connection part”.

  The interconnector 30 corresponds to the “first portion made of a dense material” in the “electrical connection portion” and has a porosity of 10% or less. The air electrode current collecting film 70 corresponds to the “second portion made of a porous material” in the “electrical connection portion”, and has a porosity of 20 to 60%.

As described above, as shown in FIG. 7, the fuel gas (hydrogen gas or the like) flows through the fuel gas flow path 11 of the support substrate 10 and the upper and lower surfaces of the support substrate 10 ( In particular, by exposing each air electrode current collector film 70) to “a gas containing oxygen” (air or the like) (or flowing a gas containing oxygen along the upper and lower surfaces of the support substrate 10), the solid electrolyte membrane 40 An electromotive force is generated by a difference in oxygen partial pressure generated between the two side surfaces. Further, when this SOFC 100 is connected to an external load, chemical reactions shown in the following formulas (1) and (2) occur, and current flows (power generation state).
(1/2) · O ₂ + 2e− → O ²⁻ (where: air electrode 60) (1)
H ₂ + O ²⁻ → H ₂ O + 2e ⁻ (in the fuel electrode 20) (2)

  In the power generation state, as shown in FIGS. 8 and 9, a current flows as indicated by an arrow in each pair of adjacent power generation element portions A and A. As a result, as shown in FIG. 7, from the entire SOFC 100 (specifically, via the interconnector 30 of the power generating element part A on the frontmost side in FIG. 7 and the air electrode 60 of the power generating element part A on the innermost side in FIG. Power) is taken out.

(Manufacturing method of this embodiment)
Next, an example of a method for manufacturing the SOFC 100 shown in FIG. 1 will be briefly described with reference to FIGS. 10 to 18, “g” at the end of the reference numeral of each member indicates that the member is “before firing”.

  First, a support substrate molded body 10g having the shape shown in FIG. 10 is produced. The molded body 10g of the support substrate is manufactured by using a method such as extrusion molding or cutting using a slurry obtained by adding a binder or the like to the material of the support substrate 10 (for example, CSZ). obtain. Hereinafter, the description will be continued with reference to FIGS. 11 to 18 showing partial cross sections corresponding to the line 11-11 shown in FIG.

  As shown in FIG. 11, when the support substrate molded body 10g is manufactured, next, as shown in FIG. 12, in each recess 12 formed on the upper and lower surfaces of the support substrate molded body 10g, the fuel electrode assembly is formed. The molded part 21g of the electric part is embedded and formed respectively. Next, as shown in FIG. 13, the entire molded body 22g of the fuel electrode active portion is embedded and formed in each recess formed on the outer surface of the molded body 21g of each fuel electrode current collector. The molded body 21g of each fuel electrode current collector and each of the fuel electrode active parts 22g use, for example, a slurry obtained by adding a binder or the like to the powder of the material of the fuel electrode 20 (for example, Ni and YSZ), It is embedded and formed using printing methods.

Subsequently, as shown in FIG. 14, in each recess formed in “the portion excluding the portion where the molded body 22 g of the fuel electrode active portion is embedded” on the outer surface of the molded body 21 g of each fuel electrode current collector. A part (inner half) of the interconnector molded body 30g is embedded and formed. The molded body 30g of each interconnector is embedded and formed by using a slurry obtained by adding a binder or the like to the material of the interconnector 30 (for example, LaCrO ₃ ), using a printing method or the like. .

  Next, as shown in FIG. 15, the main portion 10A of the main body 10A of the support substrate molded body 10g in which a plurality of molded fuel electrode bodies (21g + 22g) and a plurality of interconnector molded bodies 30g are embedded and formed, respectively. A solid electrolyte membrane molded body 40g is formed on the entire surface excluding the respective portions where the plurality of interconnector molded bodies 30g are formed on the surface (that is, the upper and lower main surfaces). The solid electrolyte membrane molded body 40g is formed by using a slurry obtained by adding a binder or the like to the powder of the material of the solid electrolyte membrane 40 (for example, YSZ), using a printing method, a dipping method, or the like. The

  In addition, a molded body of the side end seal portion is formed on the entire surface of the pair of side end portions 10B and 10B of the molded body 10g of the support substrate. At this time, in the vicinity of the step ST of the molded body 10g of the support substrate, the edge of the molded body of the side end seal portion and the edge of the molded body 40g of the solid electrolyte membrane overlap in the thickness direction (over). A molded body of the side end seal portion is formed. The formed film of the side end seal portion is also formed by using a printing method, a dipping method, or the like, using a slurry obtained by adding a binder or the like to the material of the solid electrolyte film 40 (for example, YSZ). Is done.

  Next, as shown in FIG. 16, reaction prevention molded bodies 50 g are formed in the recesses formed in the outer surface of the solid electrolyte membrane molded body 40 g. The molded body 50g of each reaction preventing film is formed using a slurry obtained by adding a binder or the like to the powder of the material (for example, GDC) of the reaction preventing film 50, using a printing method or the like.

  Then, 10 g of the support substrate molded body in which various molded bodies are formed in this manner is fired in air at 1500 ° C. for 3 hours. Thereby, a structure (corresponding to the “intermediate fired body” described above) in which the air electrode 60 and the air electrode current collector film 70 are not formed in the SOFC shown in FIG. 1 is obtained.

  Next, as shown in FIG. 17, an air electrode molded body 60 g is formed on the outer surface of the reaction preventing film 50 in the “intermediate fired body”. The molded body 60g of each air electrode is formed, for example, using a slurry obtained by adding a binder or the like to the powder of the material of the air electrode 60 (for example, LSCF) using a printing method or the like.

Next, as shown in FIG. 18, for each pair of adjacent power generation element portions, air is formed so as to straddle the air electrode forming film 60 g of one power generation element portion and the interconnector 30 of the other power generation element portion. On the outer surface of the electrode forming film 60 g, the reaction preventing film 50, the solid electrolyte film 40, and the interconnector 30, the air electrode current collecting film forming film 70 g is formed. The molded film 70g of each air electrode current collector film is, for example, a slurry obtained by adding a binder or the like to the powder of the material of the air electrode current collector film 70 (for example, LSCF, La (Ni, Fe, Cu) O ₃ ). Is formed using a printing method or the like.

  Then, the support substrate 10 in which the molded films 60g and 70g are thus formed is baked in air at 1050 ° C. for 3 hours. Thereby, the SOFC 100 shown in FIG. 1 is obtained. In the above, an example of the manufacturing method of SOFC shown in FIG. 1 was demonstrated.

  At this time, the Ni component in the support substrate 10 and the fuel electrode 20 is NiO by firing in an oxygen-containing atmosphere. Therefore, in order to acquire the conductivity of the fuel electrode 20, thereafter, reducing fuel gas is flowed from the support substrate 10 side, and NiO is reduced at 800 to 1000 ° C. for 1 to 10 hours. This reduction process may be performed during power generation.

(Operation and effect of this embodiment)
As described above, in the present embodiment, the reaction preventing film (the second concave portion) is formed in the concave portion (the “second concave portion”) formed on the surface (outer surface) of the solid electrolyte membrane (first sealing film) 40. The entire seal film 50 (the entire region in the thickness direction (z-axis direction)) is embedded. In other words, no step is formed at the outer edge of the reaction preventing film (second seal film) 50 on the outer surface of the “intermediate fired body”. Accordingly, the structure of the fuel cell described in the literature taken up in the above-mentioned “Background Art” section (that is, the entire region in the thickness direction of the reaction preventing film protrudes in the thickness direction with respect to the outer surface of the solid electrolyte membrane). The height of the step formed on the outer edge of the reaction preventing film 50 on the outer side surface of the “intermediate fired body” is smaller than that of the “composed structure”. As a result, excessive stress is unlikely to occur locally in the vicinity of the outer edge of the reaction preventing film 50, and cracks are unlikely to occur in the vicinity of the outer edge.

  When only a part of the reaction preventing film 50 in the thickness direction is embedded in the “second recess” (that is, the inner portion of the reaction preventing film 50 in the thickness direction is embedded in the “second recess”. In the case where the outer portion in the thickness direction of the reaction preventing film 50 protrudes in the thickness direction with respect to the outer surface of the solid electrolyte membrane 40), compared with the configuration of the fuel cell described in the above-mentioned literature, The height of the step formed at the outer edge of the reaction preventing film 50 on the outer surface of the “intermediate fired body” is reduced. Therefore, even in this case, excessive stress is locally generated in the vicinity of the outer edge of the reaction preventing film 50 as compared with the configuration of the fuel cell described in the above-mentioned document, as in the present embodiment. It becomes difficult to generate cracks in the vicinity of the outer edge.

  In the present embodiment, the “second recess” includes the bottom wall 41 made of the material of the solid electrolyte membrane 40, the side wall 42 made of the material of the solid electrolyte membrane 40, and the side wall 42 closed in the circumferential direction. And a side wall 43. In other words, the entire circumference of the side surface of the reaction preventing film 50 embedded in the “second recess” is reliably covered with the frame body constituted by the solid electrolyte film 40.

  In the present embodiment, the inner area defined by the “seal part” is a reducing atmosphere, and the outer area defined by the ““ seal part ”is an oxidizing atmosphere. Here, the reaction preventing film 50 is composed of a “material containing ceria” (for example, gadolinium-doped ceria (GDC)). In general, a “material containing ceria” tends to expand when exposed to a reducing atmosphere. Therefore, when the reaction preventing film 50 is exposed to a reducing atmosphere, the reaction preventing film 50 is likely to be peeled off and warped due to its expansion. In this regard, in the present embodiment, as described above, the entire circumference of the side surface of the reaction preventing film 50 is reliably covered with the frame configured by the solid electrolyte film 40. Therefore, the reaction preventing film 50 is not easily exposed to the atmosphere (that is, the reducing atmosphere) in the inner region of the “sealing portion” (more specifically, the solid electrolyte membrane 40). As a result, the above-described “peeling and warping of the reaction preventing film 50” is less likely to occur.

  Further, the front and back boundary portions of the main portion 10A of the support substrate 10 and the pair of side end portions 10B and 10B respectively extend in the longitudinal direction in which the side end portion 10B side protrudes in the thickness direction with respect to the main portion 10A side. A pair of steps ST and ST are formed (see FIG. 10). In addition, in the vicinity of the step ST of the support substrate 10, the edge of the side end seal portion 80 and the edge of the solid electrolyte membrane (first seal film) 40 overlap (overlap) in the thickness direction. As described above, the side end seal portion 80 is connected to the solid electrolyte membrane 40.

  As a result, compared to the conventional configuration in which “the solid electrolyte membrane and the side end seal portion are seamlessly connected”, in the vicinity of the connection portion between the solid electrolyte membrane 40 and the side end seal portion 80. It was found that cracks are less likely to occur. Although this is not clear in detail, in the present embodiment, as compared with the above-described conventional configuration, locally excessive thermal stress is generated around the connection portion between the solid electrolyte membrane 40 and the side end seal portion 80. This is thought to be due to the fact that it is difficult for the

  The present invention is not limited to the above-described embodiment, and various modifications can be employed within the scope of the present invention. For example, in the present embodiment, the solid electrolyte membrane (first seal membrane) 40 and the interconnector 30 are in direct contact (see FIGS. 2, 3, 5, and 6). 19, FIG. 20, FIG. 21, and FIG. 22 corresponding to FIG. 3, FIG. 5, and FIG. 6, respectively, the solid electrolyte membrane (first seal membrane) 40 and the interconnector 30 are “A solid electrolyte membrane (first seal membrane) 40, a reaction prevention membrane (second seal membrane) 50, and a dense material different from the interconnector 30 formed over the entire circumference of the peripheral portion of the interconnector 30. It may be connected via a seal portion 35 ”(corresponding to the“ third seal portion ”). In this case, the solid electrolyte membrane (first seal membrane) 40 and the interconnector 30 do not contact each other. In this example as well, as in the present embodiment, the “second concave portion” includes the bottom wall 41 made of the material of the solid electrolyte membrane 40 and the circumferential direction made of the material of the solid electrolyte membrane 40 over the entire circumference. A closed side wall 42 and a side wall 43.

  In the example shown in FIGS. 19, 20, 21, and 22, the “seal portion” includes “each interconnector 30, each seal portion (third seal portion) 35, and solid electrolyte membrane (first This corresponds to a continuous dense film composed of a sealing film 40 and a reaction preventing film (second sealing film) 50. In this case, the surface of each interconnector 30, the surface of each seal portion 35, the surface of the solid electrolyte membrane (first seal membrane) 40, and the surface of the reaction prevention membrane (second seal membrane) 50, The outer surface of the “seal part” is configured.

  In this example, the surface (outer surface) of each interconnector 30, the surface (outer surface) of each seal portion 35, the surface (outer surface) of the solid electrolyte membrane (first seal membrane) 40, and the reaction preventing membrane ( The surface (outer surface) of the second sealing film 50 forms one continuous plane. That is, no step is formed between the surface of each interconnector 30, the surface of each seal portion 35, the surface of the solid electrolyte membrane 40, and the surface of the reaction preventing film 50.

  In general, the interconnector 30 can be made of lanthanum chromite, and the solid electrolyte membrane 40 can be made of yttria-stabilized zirconia. Here, when lanthanum chromite comes into contact with zirconia, the lanthanum chromite becomes brittle and the denseness of the lanthanum chromite is easily lost. In this regard, in the example shown in FIGS. 19, 20, 21, and 22, the solid electrolyte membrane 40 and the interconnector 30 do not come into contact with each other due to the introduction of the seal portion 35. As a result, the problem that the denseness of the interconnector 30 is lost due to the contact between the interconnector 30 and the solid electrolyte membrane 30 is less likely to occur.

  In the present embodiment, the “second recess” includes the bottom wall 41 made of the material of the solid electrolyte membrane 40, the side wall 42 made of the material of the solid electrolyte membrane 40, and the side wall 42 closed in the circumferential direction. And a side wall 43. In other words, the entire circumference of the side surface of the reaction preventing film 50 embedded in the “second recess” is reliably covered with the frame body constituted by the solid electrolyte film 40. On the other hand, the side wall of the “second concave portion” may not be “a side wall closed in the circumferential direction made of the material of the solid electrolyte membrane 40 over the entire circumference”. In other words, the entire circumference of the side surface of the reaction preventing film 50 embedded in the “second recess” may not be covered with the frame formed of the solid electrolyte film 40.

  Further, in the present embodiment, a plurality of recesses 12 are formed on each of the upper and lower surfaces of the flat support substrate 10 and a plurality of power generation element portions A are provided. However, a plurality of recesses 12 are provided only on one side of the support substrate 10. , And a plurality of power generating element portions A may be provided. In this case, the support substrate may be cylindrical. When the support substrate is cylindrical, the internal space of the cylindrical support substrate may correspond to the “gas flow path”.

  DESCRIPTION OF SYMBOLS 10 ... Support substrate, 10A ... Main part, 10B ... Side edge part, 11 ... Fuel gas flow path, 12 ... Recessed part, 20 ... Fuel electrode, 21 ... Fuel electrode current collection part, 21a, 21b ... Recessed part, 22 ... Fuel electrode Active part 30 ... interconnector 35 ... seal part (third seal part), 40 ... solid electrolyte membrane (first seal film), 50 ... reaction prevention film (second seal film), 60 ... air electrode, 70 ... Air current collector film, 80 ... side end seal part, A ... power generation element part, ST ... step

Claims (9)

A support substrate having a longitudinal direction, wherein the gas flow path is formed inside along the longitudinal direction;
Provided respectively at a plurality of locations separated from each other on the main surface of the support substrate, at least a fuel electrode, a solid electrolyte film made of a dense material, a reaction preventing film made of a dense material containing ceria containing a rare earth element, and A plurality of power generation element units in which air electrodes are stacked in this order;
One or a plurality of electrical connection portions that electrically connect one fuel electrode and the other air electrode of the adjacent power generation element portions;
It is provided so as to cover the main surface of the support substrate, and is made of a dense material that prevents mixing of the gas supplied to the fuel electrode via the gas flow path and the gas supplied to the air electrode. A seal part;
A fuel cell comprising a fired body, comprising:
Each of the electrical connection portions includes a first portion made of a dense material and a second portion connected to the first portion and made of a porous material, and the first portion is the adjacent power generation element. Connected to one fuel electrode of the part and the second part, the second part is connected to the other air electrode of the adjacent power generation element part and the first part,
A first recess having a bottom wall made of the material of the support substrate and a side wall closed in the circumferential direction made of the material of the support substrate over the entire circumference at the plurality of locations on the main surface of the support substrate. Each formed,
In each of the first recesses, the corresponding fuel electrode of the power generation element unit is embedded,
The seal portion includes a first portion of each electrical connection portion and each solid electrolyte membrane included in each power generation element portion, and extends continuously from each solid electrolyte membrane. In addition, the first seal film made of the same dense material as the solid electrolyte and the respective reaction prevention films included in each of the power generation element portions, and continuously extending from the respective reaction prevention films A second sealing film made of the same dense material as the reaction preventing film,
A portion of the outer surface of the first seal film including a region corresponding to each power generating element portion includes a bottom wall made of the material of the first seal film, and a side wall made of the material of the first seal film. A second recess having
The second sealing film is embedded in the second recess,
The outer surface of the first portion of each electrical connection portion, the portion other than the second recess on the outer surface of the first seal film, and the outside of the second seal film embedded in the second recess. A side surface, and an outer surface of the seal portion is configured,
The second recess has a bottom wall made of the material of the first seal film and a side wall closed in the circumferential direction made of the material of the first seal film over the entire circumference.
Fuel cell. The outer surface of the first portion of each electrical connection portion, the portion other than the second recess on the outer surface of the first seal film, and the outside of the second seal film embedded in the second recess. A side surface and a continuous outer surface of the seal portion are configured.
The fuel cell according to claim 1. The seal part includes a plurality of third seal parts made of a dense material that is connected to the first part of each electrical connection part and the first seal film and is different from the first and second seal films,
The first seal film and the first portion of each electrical connection portion are configured not to contact each other,
The outer surface of the first portion of each electrical connection portion, the portion other than the second recess on the outer surface of the first seal film, and the outside of the second seal film embedded in the second recess. The outer surface of the seal portion is configured by the side surface and the outer surface of each of the third seal portions.
The fuel cell according to claim 1. The outer surface of the first portion of each electrical connection portion, the portion other than the second recess on the outer surface of the first seal film, and the outside of the second seal film embedded in the second recess. A continuous outer surface of the seal portion is constituted by the side surface and the outer surface of each of the third seal portions.
The fuel cell according to claim 3. A support substrate having a gas flow path formed therein along the longitudinal direction;
A plurality of power generation element portions provided on the main surface of the support substrate at intervals in the longitudinal direction, wherein a fuel electrode, a first solid electrolyte membrane, a first reaction preventing film, and an air electrode are stacked in this order; ,
An electrical connection part that electrically connects one fuel electrode and the other air electrode of the adjacent power generation element part;
In order to prevent mixing of the gas supplied from the gas flow path to the fuel electrode and the gas supplied to the air electrode, a seal portion provided on the main surface of the support substrate;
With
The support substrate has a first recess in which the fuel electrode is disposed,
Each of the electrical connection portions includes a first portion connected to one fuel electrode of the adjacent power generation element portion and a second portion connected to the other air electrode of the adjacent power generation element portion. And
The seal portion is
The first portion of each electrical connection;
A first seal membrane including the first solid electrolyte membrane and a second solid electrolyte membrane extending continuously from the first solid electrolyte membrane, and a second recess having a side wall closed in the circumferential direction is formed on an outer surface; ,
The first reaction preventing film, and a second seal film including the second reaction preventing film continuously extending from the first reaction preventing film and disposed in the second recess,
The outer surface of the seal portion is
An outer surface of the first portion in each electrical connection;
A portion of the outer surface of the first sealing film excluding the second recess;
The outer surface of the second seal film,
Fuel cell. The first seal film and the second seal film are disposed between the fuel electrode and the air electrode.
The fuel cell according to claim 5. The outer surface of the first portion in each electrical connection portion, the portion of the outer surface of the first seal film excluding the second recess, and the outer surface of the second seal film are configured continuously. Being
The fuel cell according to claim 5 or 6. The seal portion is disposed between the first portion of each electrical connection portion and the first seal film, and is connected to the first portion and the first seal membrane of each electrical connection portion. 3 seals further,
The outer surface of the seal portion is
An outer surface of the first portion in each electrical connection;
A portion of the outer surface of the first sealing film excluding the second recess;
An outer surface of the second sealing film;
The outer surface of the third seal portion is configured,
The fuel cell according to claim 5 or 6. The outer surface of the first portion in each of the electrical connection portions, the portion of the outer surface of the first seal film except the second recess, the outer surface of the second seal film, and the third seal portion The outer surface of the is configured continuously,
The fuel cell according to claim 8.

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