JP5646779B2 - Fuel cell - Google Patents

Description

  The present invention relates to a fuel cell.

  Conventionally, “a porous support substrate having a gas flow path formed therein” and “provided at a plurality of locations separated from each other on each of the main surfaces of the support substrate, a fuel electrode, a solid electrolyte, and “A plurality of power generation element portions in which air electrodes are laminated in this order” and “a fuel of one of the adjacent power generation element portions provided between the power generation element portions adjacent to each other on the front and back main surfaces of the support substrate” An electrical connection portion for electrically connecting the electrode and the other air electrode ”,“ a portion excluding a region where the power generation element portion is provided on each of the front and back main surfaces of the support substrate, and the support substrate ” A dense end wall that prevents the mixing of the gas (fuel gas) supplied to the fuel electrode through the gas flow path and the gas (air) supplied to the air electrode. A solid acid provided with a sealing film made of a porous material Things fuel cells (SOFC) are known (e.g., see Patent Document 1). Such a configuration is also called a “horizontal stripe type”.

  In the fuel cell described in the above document, the power generation element portions provided on the front and back surfaces of the support substrate include a side end surface of the support substrate and a portion covering the side end surface of the support substrate in the seal film. They are electrically connected by a connecting member provided therebetween. In other words, the connecting member is positioned on the “region where the fuel gas flows” of the “region where the fuel gas flows” and the “region where the air flows” defined and formed by the seal film. .

  The “region where fuel gas flows” is exposed to a reducing atmosphere (specifically, fuel gas) during operation of the fuel cell. However, under a specific situation such as immediately after the end of the operation of the fuel cell, the “region where the fuel gas flows” can be temporarily exposed to an oxidizing atmosphere (specifically, air).

  On the other hand, the connecting member of the fuel cell described in the above document is made of a conductive material containing Ni. Therefore, every time the atmosphere to which the connecting member is exposed changes between a reducing atmosphere and an oxidizing atmosphere, an oxidation / reduction reaction may occur for Ni contained in the connecting member. Due to this oxidation / reduction reaction, expansion and contraction may occur in the connecting member. As a result, there arises a problem that peeling occurs at the interface between the “member of the sealing film covering the side end surface of the support substrate” and the connection member, and further, a crack occurs in the connection member itself. Obtained. In other words, there is a problem that the reliability of the member that electrically connects the power generating element portions provided on the front and back of the support substrate is low.

JP 2008-59793 A

  The present invention is to cope with the above problems, and is a “horizontal stripe type” fuel cell, in which the reliability of a member that electrically connects power generating element portions provided on the front and back of a support substrate is improved. The purpose is to provide something expensive.

  The fuel cell according to the present invention includes the support substrate, the plurality of power generation element portions, the electrical connection portion, and the seal film, similarly to the fuel cell described in the “Background Art” section. It is a “horizontal stripe type” fuel cell. The electrical connection portion is connected to the air electrode and is made of a porous material, and the second portion is connected to the fuel electrode and is connected to the first portion and made of a dense material. Part.

  A feature of the fuel cell according to the present invention is that the power generating element portions provided on the main surfaces of the front and back surfaces of the support substrate are provided so as to cover the “portion that covers the side end surface of the support substrate in the seal film” It is provided with a front-back connection member made of a conductive ceramic material that is electrically connected.

  According to the said structure, the said front-back connection member is located in the "area | region through which air distribute | circulates" divided and formed by the said sealing film. That is, the atmosphere to which the front-back connection member is exposed can be stably maintained in an oxidizing atmosphere. In other words, the above-described problems such as “crack generation” caused by the change in the atmosphere to which the front-back connecting member is exposed between the reducing atmosphere and the oxidizing atmosphere do not occur. As a result, the reliability of the member that electrically connects the power generating element portions provided on the front and back of the support substrate is increased.

  By the way, the distance of the “electric path (electric path) formed by the front-back connection member” between the power generation element portions provided on the front and back main surfaces of the support substrate is between the adjacent power generation element portions. It becomes longer than the distance of “the electric path (electric path) formed by the electrical connection portion”. Accordingly, the electrical resistance of the front-back connection member becomes relatively large, and the heat (Joule heat) generated from the front-back connection member during energization tends to be relatively large. Due to this, excessive thermal stress is locally generated on the front-back connection member (particularly the portion covering the side end surface of the support substrate), and cracks are likely to occur. From the above, it is desired to reduce the electrical resistance of the front-back connection member.

  For this reason, the characteristic of the 1st aspect of the fuel cell which concerns on this invention exists in the porosity of the said front-back connection member being smaller than the porosity of the 1st part of the said electrical connection part. According to this, the porosity of the said front-back connection member can be made small. As a result, the cross-sectional area of the electrical path inside the front-back connection member can be increased, and the electrical resistance of the front-back connection member can be reduced.

  A feature of the second aspect of the fuel cell according to the present invention resides in that the thickness of the front-back connection member is larger than the thickness of the first portion of the electrical connection portion. More specifically, the minimum value of the thickness of the front-back connection member is larger than the minimum value of the thickness of the first portion of the electrical connection portion. According to this, similarly to the first aspect, the cross-sectional area of the electric path inside the front-back connection member can be increased, and the electrical resistance of the front-back connection member can be reduced.

  A feature of the third aspect of the fuel cell according to the present invention resides in that the conductivity of the front-back connection member is larger than the conductivity of the first portion of the electrical connection portion. According to this, the electrical conductivity of the front-back connection member can be increased. As a result, the electrical resistance of the front-back connection member can be reduced.

In the fuel cell according to the present invention, the seal film may be made of a dense material containing zirconia, and the front-back connection member may be made of a perovskite-type conductive ceramic material containing strontium or lanthanum. The front-back connection member may be a dense film or a porous film. In this case, it is preferable that a reaction preventing film not containing zirconia (ZrO ₂ ) is interposed in a portion where the front-back connection member and the seal film face each other.

The front-back connection member may be made of La (Ni, Fe, Cu) O ₃ (lanthanum nickel ferrite to which copper is added). Alternatively, it can be composed of (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite).

In general, it is widely known that SrZrO ₃ is formed when Sr and ZrO ₂ react. It is widely known that La ₂ Zr ₂ O ₇ is formed when La and ZrO ₂ react. Therefore, in a configuration in which the sealing film made of a dense material containing zirconia and the front-to-back connecting member made of a perovskite-type conductive ceramic material containing strontium or lanthanum are in direct contact, the sealing film is connected to the front and back. A reaction layer of SrZrO ₃ or La ₂ Zr ₂ O ₇ may be formed at the interface with the member at a high temperature such as during production or operation of the fuel cell. When a reaction layer of SrZrO ₃ or La ₂ Zr ₂ O ₇ is formed at the interface, there arises a problem that peeling is likely to occur at the interface. This is considered to be caused by a large difference in thermal expansion coefficient between “SrZrO ₃ or La ₂ Zr ₂ O ₇ ” and “front-back connection member or seal film”. From the above, it is necessary to suppress the occurrence of a situation in which a reaction layer of SrZrO ₃ or La ₂ Zr ₂ O ₇ is formed at the interface.

The above configuration is based on such knowledge. According to the above configuration, the reaction preventing film (not including ZrO ₂ ) is interposed between the front-back connection member (including Sr or La) and the seal film (including ZrO ₂ ). Therefore, the occurrence of a reaction between “Sr or La” and ZrO ₂ can be suppressed by interposing the reaction preventing film. As a result, the formation of a reaction layer of SrZrO ₃ or La ₂ Zr ₂ O ₇ between the front and back connection member and the seal film is suppressed, and peeling occurs at a portion where the front and back connection member and the seal film face each other. Can be suppressed.

  In the fuel cell according to the present invention, each of the sealing films has the same composition as or a different composition from the solid electrolyte extending from the corresponding solid electrolyte film of the power generation element portion so as to cover the main surface and side end surfaces of the support substrate. It can be composed of a dense film made of a material having the same.

  The electrical connection portion includes the first portion and a second portion that is connected to the fuel electrode and connected to the first portion and is formed of a dense material. First recesses 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 are formed at the plurality of locations on the main surface of the support substrate, respectively. The fuel electrode of the power generation element portion corresponding to each first recess is embedded, and the second recess formed on the outer surface of each embedded fuel electrode corresponds to the corresponding electrical connection portion. Each second part may be embedded.

  Each of the second recesses in which the corresponding second portion of the electrical connection portion is embedded includes a bottom wall made of the fuel electrode material and a circumferential direction made of the fuel electrode material over the entire circumference. And have closed sidewalls.

  Moreover, one flat surface may be constituted by the outer surface of the fuel electrode other than the second recess, the outer surface of the second portion of the electrical connection portion, and the main surface of the support substrate.

1 is a perspective view showing 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. FIG. 3 is a cross-sectional view corresponding to line 3-3 of the fuel cell shown in 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 sectional drawing corresponding to line 5-5 of the fuel cell shown in FIG. 6 is a cross-sectional view corresponding to line 6-6 of the fuel cell shown in FIGS. 1 and 5. FIG. It is a figure for demonstrating the operation state of the fuel cell shown in FIG. It is a figure for demonstrating the flow of the electric current in the operating state of the fuel cell shown in FIG. It is a perspective view which shows the support substrate shown in FIG. FIG. 3 is a cross-sectional view corresponding to FIG. 2 in a first stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 3 is a cross-sectional view corresponding to FIG. 2 in a second stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 3 is a cross-sectional view corresponding to FIG. 2 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. 2 in a fourth stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 6 is a cross-sectional view corresponding to FIG. 2 in a fifth stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 7 is a cross-sectional view corresponding to FIG. 2 in a sixth stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 8 is a cross-sectional view corresponding to FIG. 2 in a seventh stage in the manufacturing process of the fuel cell shown in FIG. 1. FIG. 7 is a cross-sectional view corresponding to FIG. 2 in an eighth stage in the manufacturing process of the fuel cell shown in FIG. 1. It is sectional drawing corresponding to FIG. 5 of the 1st modification of the fuel cell which concerns on this invention. It is sectional drawing corresponding to FIG. 6 of the 1st modification of the fuel cell which concerns on this invention.

(Constitution)
FIG. 1 shows a solid oxide fuel cell (SOFC) according to an embodiment of the present invention. This SOFC is electrically connected in series to each of the 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) (this example). 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 as viewed from above is, for example, a rectangle whose length in the longitudinal direction is 5 to 50 cm and whose length in the width direction (y-axis direction) perpendicular to the longitudinal direction is 1 to 10 cm. The total thickness of this SOFC is 1-5 mm. The entire SOFC has a vertically symmetrical shape with respect to a plane passing through the center in the thickness direction and parallel to the main surface of the support substrate 10. Details of the SOFC will be described below with reference to FIGS. FIG. 2 is a partial cross-sectional view showing a configuration (part of) each of a typical pair of adjacent power generation element portions A and A and a configuration between the power generation element portions A and A. The configuration between the other power generation element portions A and A in other sets is the same as the configuration shown in FIG.

  The support substrate 10 is a flat plate-like fired body made of a porous material having no electronic conductivity. As shown in FIG. 9 to be described later, a plurality of (six in this example) fuel gas passages 11 (through holes) extending in the longitudinal direction are provided in the support substrate 10 at predetermined intervals in the width direction. Is formed. In addition, in each of the upper and lower surfaces (both main surfaces) of the support substrate 10, recesses 12 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 4, 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 FIG. 4, a recess 21 a is formed on the upper 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.

  The entire anode active portion 22 is embedded (filled) in each recess 21a. 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 FIG. 4, a recess 21 b is formed on the upper 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.

  An interconnector 30 is embedded (filled) in each recess 21b. Accordingly, each interconnector 30 has a rectangular parallelepiped shape. The interconnector 30 is a fired body made of a dense material having electronic conductivity. The entire circumference and bottom surface of the “circumferentially closed sidewall” of each interconnector 30 are in contact with the fuel electrode current collector 21 in the recess 21b.

  The upper surface (outer surface) of the fuel electrode 20 (the fuel electrode current collector 21 and the fuel electrode active unit 22), the upper surface (outer surface) of the interconnector 30, and the main surface of the support substrate 10 form one plane (recessed portion). The same plane as the main surface of the support substrate 10 when 12 is not formed) is formed. That is, no step is formed between the upper surface of the fuel electrode 20, the upper surface of the interconnector 30, and the main surface of the support substrate 10.

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.

  The entire surface excluding the central portion of each portion where the plurality of interconnectors 30 are formed on the outer peripheral surface extending in the longitudinal direction of the support substrate 10 in a state where the fuel electrode 20 and the interconnector 30 are embedded in the respective recesses 12, The solid electrolyte membrane 40 is covered. That is, the solid electrolyte membrane 40 extends from the inside of the power generation element portion A to the outside of the power generation element portion A so as to cover the surface of the support substrate 10. In other words, the solid electrolyte membrane 40 is a portion excluding the region where the power generating element part A is provided on each of the main surfaces on the front and back sides of the support substrate 10 and the side end surface (width direction (y-axis direction)) of the support substrate 10. Are provided so as to cover the both end faces of the head.

The solid electrolyte membrane 40 is a fired body made of a dense material that has ionic conductivity and no electronic 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 40 is 3 to 50 μm.

  That is, the portions other than the regions where the power generation element portions A are provided on the front and back main surfaces of the support substrate 10 and the side end surfaces of the support substrate 10 are dense films made of the interconnector 30 and the solid electrolyte film 40. Covered by. This dense membrane exhibits a gas seal function that prevents mixing of the fuel gas flowing in the space inside the dense membrane and the air flowing in the space outside the dense membrane. In order to exhibit this gas sealing function, the porosity of this dense membrane (interconnector 30 + solid electrolyte membrane 40) is 10% or less. This dense film corresponds to the “sealing film”. Accordingly, the portion of the “seal membrane” that covers the side end surface of the support substrate 10 is composed of a dense membrane made of a material having the same composition as the solid electrolyte membrane 40 (ie, a material containing zirconia).

  As shown in FIG. 2, in this example, the solid electrolyte membrane 40 includes the upper surface of the fuel electrode 20 (current collector 21 + active portion 22), the central portion of the upper surface of the interconnector 30, and the main surface of the support substrate 10. Covering. Here, as described above, no step is formed between the upper surface of the fuel electrode 20, the upper surface of the interconnector 30, and the main surface of the support substrate 10. Therefore, the solid electrolyte membrane 40 is flattened. As a result, compared with the case where a step is formed in the solid electrolyte membrane 40, the generation of cracks in the solid electrolyte membrane 40 due to stress concentration can be suppressed, and the gas sealing function of the solid electrolyte membrane 40 is reduced. Can be suppressed.

  An air electrode 60 is formed on the upper surface of a portion in contact with each fuel electrode active part 22 in the solid electrolyte membrane 40 via a reaction preventing film 50. The reaction preventing film 50 is a fired body made of a dense material, and the air electrode 60 is a fired body made of a porous material having electron conductivity. The shape of the air electrode 60 viewed from above is substantially the same rectangle as the fuel electrode active part 22.

The reaction preventing film 50 may be composed of ceria containing rare earth elements such as GDC = (Ce, Gd) O ₂ (gadolinium doped ceria) and SDC = (Ce, Sm) O ₂ (samarium doped ceria). . That is, the reaction preventing film 50 does not contain zirconia (ZrO ₂ ). Here, “the reaction preventing film 50 does not contain zirconia (ZrO ₂ )” means that the distance from the interface between the reaction preventing film 50 and the seal film is about the laminate of the reaction preventing film 50 and the seal film. In a region within 2 μm, among zirconium (Zr), yttrium (Y), cerium (Ce), gadolinium (Gd), and oxygen (O), the zirconium concentration is 5 at. % (Atomic fraction, atomic percent) or less (more preferably 1 at.% Or less). The thickness of the reaction preventing film 50 is 3 to 50 μm.

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 laminated body formed by laminating the fuel electrode 20, the solid electrolyte membrane 40, the reaction preventing membrane 50, and the air electrode 60 corresponds to the “power generation element portion A” (see FIG. 2). That is, a plurality (four in this example) of power generation element portions A are arranged on the upper and lower surfaces of the support substrate 10 at predetermined intervals in the longitudinal direction.

  For the adjacent power generation element parts A and A, the air electrode 60 of one power generation element part A (on the left side in FIG. 2) and the interconnector 30 of the other power generation element part A (on the right side in FIG. 2) are connected. An air electrode current collecting film 70 is formed on the upper surfaces of the air electrode 60, the solid electrolyte film 40, and the interconnector 30 so as to straddle. 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 as viewed from above 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.

In this specification, La (Ni, Fe, Cu) O ₃ specifically refers to an oxide represented by a chemical formula of the following formula (1). However, in Formula (1), m and n are 0.95 or more and 1.05 or less, x is 0.03 or more and 0.3 or less, y is 0.05 or more and 0.5 or less, δ Is 0 or more and 0.8 or less.
_{La m (Ni 1-x-} y Fe x Cu y) n O 3-δ ... (1)

  By forming each air electrode current collecting film 70 in this way, for each pair of adjacent power generation element portions A and A, the air electrode 60 of one power generation element portion A (on the left side in FIG. 2), The other fuel electrode 20 (particularly, the fuel electrode current collector 21) of the power generating element part A (on the right side in FIG. 2) passes through the “air electrode current collector film 70 and interconnector 30” having electronic conductivity. Are electrically connected. As a result, a plurality (four in this example) of power generation element portions A disposed on the upper and lower surfaces 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 “second portion made of a dense material” in the “electrical connection portion” and has a porosity of 10% or less. The air electrode current collector film 70 corresponds to the “first portion made of a porous material” in the “electrical connection portion”, and has a porosity of 20 to 60%.

  In the configuration shown in FIG. 2, the reaction preventing film 50 extends from the inside of the power generation element part A (that is, the part between the solid electrolyte film 40 and the air electrode 60) to the sealing film (= the power generation element part in the solid electrolyte film 40). A portion formed outside A) extends outside the power generation element portion A so as to cover the surface (so as to be in contact with the surface). The air electrode current collecting film 70 covers the surface of the reaction preventing film 50 (more specifically, the portion formed outside the power generating element part A in the reaction preventing film 50) (so as to be in contact with the surface). Is formed. The reaction preventing film 50 (more specifically, the part formed outside the power generating element portion A in the reaction preventing film 50) is interposed in all the portions facing the seal film.

  As shown in FIGS. 1, 5, and 6, one end portion in the longitudinal direction of the support substrate 10 (the end portion in the negative x-axis direction) is the one end in the longitudinal direction on the front and back main surfaces of the support substrate 10. A front-back connection member 80 that electrically connects the power generation element portions A provided on the side (x-axis negative direction side) is provided.

The front-back connection member 80 is made of, for example, the same material as the air electrode current collector film 70, that is, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite), LSC = (La, Sr) CoO. ₃ (lanthanum strontium cobaltite) or La (Ni, Fe, Cu) O ₃ or the like. In this case, the front-back connection member 80 is a fired body made of a perovskite-type conductive ceramic containing strontium (Sr) or lanthanum (La). The porosity of the front / back connection member 80 may be the same as or different from the porosity of the air electrode current collector film 70.

  As shown in FIG. 6, which is a cross-sectional view corresponding to line 6-6 in FIG. 5, in this example, the front-back connection member 80 is provided so as to circulate around one end portion in the longitudinal direction of the support substrate 10. ing. Therefore, the front-back connection member 80 is provided so as to cover the surface of “the portion covering the side end surface of the support substrate 10” (that is, the solid electrolyte membrane 40) in the “seal membrane”.

  In this example, the reaction preventing film 50 of the power generation element part A electrically connected by the front-to-back connection member 80 has all of the front-back connection member 80 and the “seal film” (that is, the solid electrolyte film 40) facing each other. It extends to the outside of the power generation element portion A so as to be interposed in the portion. In other words, at one end portion in the longitudinal direction of the support substrate 10, the reaction preventing film is formed so as to cover the surface of the “seal film” (solid electrolyte film 40) formed so as to cover the main surface and side end surfaces of the support substrate 10. 50 is formed, and a front-back connection member 80 is formed so as to cover the surface of the reaction preventing film 50.

  In the example shown in FIGS. 5 and 6, the front-back connection member 80 includes the air electrode 60 of the power generation element portion A formed on one of the upper and lower surfaces of the support substrate 10 (the upper main surface in FIG. 5), and the support substrate. The fuel electrode 20 (more specifically, the interconnector 30 electrically connected to the fuel electrode 20) of the power generation element portion A formed on the other of the upper and lower surfaces (lower main surface in FIG. 5) 10. And are electrically connected. That is, the front-back connection member 80 electrically connects the power generation element portions provided on the upper and lower surfaces of the support substrate 10 in series.

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. Furthermore, when this structure is connected to an external load, chemical reactions shown in the following formulas (2) and (3) occur, and current flows (power generation state).
(1/2) · O ₂ + 2e ⁻ → O ²⁻ (where: air electrode 60) (2)
H ₂ + O ²⁻ → H ₂ O + 2e ⁻ (in the fuel electrode 20) (3)

  In the power generation state, as shown in FIG. 8, 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, the entire SOFC (specifically, the interconnector 30 of the power generating element portion A on the front side in FIG. 7 and the air electrode 60 of the power generating element portion A on the farthest side in FIG. Power).

(Production method)
Next, an example of a method for manufacturing the “horizontal stripe type” SOFC shown in FIG. 1 will be briefly described with reference to FIGS. 9 to 17, “g” at the end of the reference numeral of each member represents that the member is “before firing”.

  First, a support substrate molded body 10g having the shape shown in FIG. 9 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. 10 to 17 showing partial cross sections corresponding to line 10-10 shown in FIG. 9.

  When the support substrate molded body 10g is manufactured as shown in FIG. 10, next, as shown in FIG. 11, fuel electrode current collectors are formed in the recesses formed on the upper and lower surfaces of the support substrate molded body 10g. Each of the molded parts 21g is embedded and formed. Next, as shown in FIG. 12, a molded body 22g of the fuel electrode active portion is embedded and formed in each recess formed in 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. 13, in each recess formed in “a 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. The interconnector molded bodies 30g are respectively 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. 14, the outer periphery extending in the longitudinal direction of the molded body 10g of the support substrate in a state where the molded body (21g + 22g) of the plurality of fuel electrodes and the molded body 30g of the plurality of interconnectors are respectively embedded and formed. A solid electrolyte membrane molding film 40g is formed on the entire surface excluding the central portion of each portion where the plurality of interconnector moldings 30g are formed on the surfaces (ie, the upper and lower main surfaces and the side end surfaces on both sides). Is done. The molded membrane 40g of the solid electrolyte membrane is formed using, for example, a printing method, a dipping method, etc., 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). The

  Next, as shown in FIG. 15, a reaction preventing film forming film 50 g is formed on the entire outer surface of the solid electrolyte film forming body 40 g. The molded film 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 films are thus formed is fired in air at 1500 ° C. for 3 hours. As a result, a structure 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. 16, an air electrode forming film 60 g is formed on the outer surface of each reaction preventing film 50. The molded film 60g of each air electrode is formed 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. 17, 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 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.

In addition, a molded film of the front-back connection member is formed so as to go around the periphery of one end of the support substrate 10 in the longitudinal direction (see FIGS. 5 and 6). For example, the molded film of the front-back connection member is made of 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 ). It is formed using a printing method or the like.

  And the support substrate 10 in the state in which the molded films 60g and 70g and the molded film of the front-back connection member are thus formed is baked in air at 1050 ° C. for 3 hours. Thereby, the SOFC 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.

(Action / Effect)
As described above, in the “horizontal stripe type” SOFC according to the embodiment of the present invention, the “sealing” is performed so as to cover the main surface and the side end surface of the support substrate 10 at one end portion in the longitudinal direction of the support substrate 10. The membrane ”(solid electrolyte membrane 40) is formed, the reaction preventing film 50 is formed so as to cover the surface of the“ seal membrane ”, and the front-back connection member 80 is formed so as to cover the surface of the reaction preventing film 50. ing. Therefore, the front-back connection member 80 is located on the “area where air flows” defined and formed by the “seal film”. That is, the atmosphere to which the front-back connection member 80 is exposed can be stably maintained in an oxidizing atmosphere. Therefore, problems such as “the occurrence of cracks caused by the change in the atmosphere to which the front-to-back connecting member 80 is exposed between the reducing atmosphere and the oxidizing atmosphere” as described in the section “Background Art” occur. do not do. As a result, the reliability of the member that electrically connects the power generation element portions A provided on the front and back of the support substrate 10 is increased.

<Suppression of the frequency of occurrence of cracks due to Joule heat in the connecting member between the front and back>
The distance of the “electric path (electric path) formed by the front-back connection member 80” between the power generation element portions A provided on the front and back main surfaces of the support substrate 10 is “air” between the adjacent power generation element portions A. It becomes longer than the distance of the “electric path (electric path)” formed by the pole current collecting film 70. Therefore, the electrical resistance of the front-to-back connection member 80 is relatively large, and the heat (Joule heat) generated from the front-back connection member 80 during energization tends to be relatively large. As a result, excessive thermal stress is locally generated in the front-back connection member 80 (particularly the portion covering the side end surface of the support substrate 10), and cracks are likely to occur.

<< First Aspect >>
For this reason, in the 1st aspect of the said embodiment, the porosity of the front-back connection member 80 is smaller than the porosity of the air electrode current collection film | membrane 70. FIG. According to the first aspect, the porosity of the front-back connection member 80 can be reduced (typically, the front-back connection member 80 can be formed of a dense material). As a result, the cross-sectional area of the electrical path inside the front-to-back connection member 80 can be increased, and the electrical resistance of the front-back connection member 80 can be reduced.

  Specifically, in the first aspect, for example, the porosity of the air electrode current collector film 70 can be adjusted to 30 to 45%, and the porosity of the front-back connection member 80 can be adjusted to 10 to 30%. The porosity can be adjusted, for example, by adjusting the particle size and amount of the pore-forming agent contained in the slurry.

<< Second aspect >>
Alternatively, in the second aspect of the above embodiment, the thickness of the front-back connection member 80 is greater than the thickness of the air electrode current collector film 70. More specifically, the minimum value of the thickness of the front-back connection member 80 (see T2 in FIG. 5 and FIG. 18 described later) is the minimum value of the thickness of the air electrode current collector film 70 (FIGS. 5 and 5). (See T1 in FIG. 18 described later). According to the second aspect, similarly to the first aspect, the cross-sectional area of the electrical path inside the front-to-back connection member 80 can be increased, and the electrical resistance of the front-back connection member 80 is reduced. be able to.

  Specifically, in the second aspect, for example, the thickness (the minimum value) of the air electrode current collector film 70 is set to 30 to 80 μm, and the thickness (the minimum value) of the front-back connection member 80 is set to be 30 μm. It can be set to 80-200 micrometers. The thickness adjustment can be achieved by adjusting the thickness of the molded film.

<< Third aspect >>
Alternatively, in the third aspect of the above embodiment, the conductivity of the front-back connection member 80 is greater than the conductivity of the air electrode current collector film 70. According to the third aspect, the conductivity of the front-back connection member 80 can be increased. As a result, the electrical resistance of the front-back connection member 80 can be reduced.

In the third aspect, specifically, for example, the conductivity of the air electrode current collector film 70 is set to 200 to 500 S / cm (750 ° C.), and the conductivity of the front-back connection member 80 is set to 500 to 800 S / cm. cm (750 ° C.). For example, when both the front and back connecting member 80 and the air electrode current collector film 70 are made of La (Ni, Fe, Cu) O ₃ (when expressed by the chemical formula of the above formula (1)), the conductivity This adjustment can be achieved by adjusting the Cu content, etc. (the higher the Cu content, the higher the conductivity).

  In the embodiment, only one of the first to third aspects may be provided, or any two may be provided, or all three may be provided. It may be.

  Further, in the above-described embodiment, the reaction preventing film 50 is interposed in all the portions where the front-back connection member 80 and the “seal film” face each other. In addition, the reaction preventing film 50 is interposed in all the portions where the air electrode current collecting film 70 and the “seal film” face each other.

According to the above configuration, the air current collector film 70 (including Sr or La) and the seal film (including ZrO ₂ ), and the front-back connection member 80 (including Sr or La) and the seal film ( (Including ZrO ₂ ) is interposed a reaction preventing film 50 (not including ZrO ₂ ). Accordingly, the interposition of the reaction preventing film 50 causes “Sr or La” and ZrO ₂ between the air electrode current collecting film 70 and the seal film and between the front and back connecting member 80 and the seal film. The occurrence of reaction can be suppressed. As a result, formation of a reaction layer of SrZrO ₃ or La ₂ Zr ₂ O ₇ between the air electrode current collector film 70 and the seal film and between the front-back connection member 80 and the seal film is suppressed, and the air It is possible to suppress a situation in which peeling occurs at a portion where the electrode current collecting film 70 and the seal film face each other and a portion where the front-back connection member 80 and the seal film face each other.

  Further, the circumferential direction in which each of the plurality of recesses 12 embedded in the upper and lower surfaces of the support substrate 10 for embedding the fuel electrode 20 (current collector 21) is made of the material of the support substrate 10 over the entire circumference. Have closed side walls. In other words, the support body 10 is formed with a frame surrounding each recess 12. Therefore, this structure is not easily deformed when the support substrate 10 receives an external force.

  In addition, the support substrate 10 and the embedded member are filled in the recesses 12 of the support substrate 10 such as the fuel electrode 20 (current collector 21 + active portion 22) and the interconnector 30 without any gaps. And are co-sintered. Therefore, a sintered body having high bondability between members and high reliability can be obtained.

  Further, the interconnector 30 is embedded in a recess 21b formed on the outer surface of the fuel electrode current collector 21, and as a result, the four side surfaces and the bottom surface of the rectangular parallelepiped interconnector 30 are connected to the fuel electrode in the recess 21b. It is in contact with the electric part 21. Therefore, the fuel electrode 20 (the current collector 21) and the interconnector 30 are compared to the case where a configuration in which the rectangular parallelepiped interconnector 30 is laminated (contacted) on the outer plane of the fuel electrode current collector 21 is employed. The area of the interface with can be increased. Therefore, the electronic conductivity between the fuel electrode 20 and the interconnector 30 can be increased, and as a result, the power generation output of the fuel cell can be increased.

  Further, in the above-described embodiment, a plurality of power generation element portions A are provided on each of the upper and lower surfaces of the flat support substrate 10. Thereby, compared with the case where a plurality of power generation element portions are provided only on one side surface of the support substrate, the number of power generation element portions in the structure can be increased, and the power generation output of the fuel cell can be increased.

  Further, in the above embodiment, the solid electrolyte membrane 40 includes the outer surface of the fuel electrode 20 (current collector 21 + active portion 22), both end portions in the longitudinal direction of the outer surface of the interconnector 30, and the main surface of the support substrate 10. Covering. Here, no step is formed between the outer surface of the fuel electrode 20, the outer surface of the interconnector 30, and the main surface of the support substrate 10. Therefore, the solid electrolyte membrane 40 is flattened. As a result, compared with the case where a step is formed in the solid electrolyte membrane 40, the generation of cracks in the solid electrolyte membrane 40 due to stress concentration can be suppressed, and the gas sealing function of the solid electrolyte membrane 40 is reduced. Can be suppressed.

  In addition, this invention is not limited to the said embodiment, A various modification can be employ | adopted within the scope of the present invention. For example, in the above-described embodiment, the front-back connection member 80 is formed at one end in the longitudinal direction of the support substrate 10, but may be formed at the center in the longitudinal direction of the support substrate 10. The front-back connection member 80 is provided so as to circulate around the support substrate 10 at one end in the longitudinal direction of the support substrate 10, but between the power generating element portions provided on the upper and lower surfaces of the support substrate 10. As long as the electrical connection is secured, the front-back connection member 80 does not have to go around the support substrate 10.

  Moreover, in the said embodiment, as can be understood from FIG.5 and FIG.6, the power generating element part A in which the front-back connection member 80 was formed in one of the upper and lower surfaces of the support substrate 10 (upper main surface in FIG. 5). The air electrode 60 and the fuel electrode 20 of the power generating element part A formed on the other of the upper and lower surfaces of the support substrate 10 (the lower main surface in FIG. 5) are electrically connected in series. ing.

  On the other hand, as shown in FIGS. 18 and 19 corresponding to FIGS. 5 and 6, the front-back connection member 80 is formed on one of the upper and lower surfaces of the support substrate 10 (upper main surface in FIG. 18). The air electrode 60 of the power generating element part A and the air electrode 60 of the power generating element part A formed on the other of the upper and lower surfaces of the support substrate 10 (the lower main surface in FIG. 18) are electrically connected in parallel. The structure to do may be employ | adopted.

  Moreover, in the said embodiment, as shown in FIG. 9 etc., the planar shape (shape when it sees from the direction perpendicular | vertical to the main surface of the support substrate 10) of the recessed part 12 formed in the support substrate 10 becomes a rectangle. However, it may be, for example, a square, a circle, an ellipse, or a long hole shape.

  In the above embodiment, the entire interconnector 30 is embedded in each recess 12, but only a part of the interconnector 30 is embedded in each recess 12, and the remaining portion of the interconnector 30 is recessed 12. May protrude outside (that is, protrude from the main surface of the support substrate 10).

  Further, in the above embodiment, the fuel electrode 20 is composed of two layers of the fuel electrode current collector 21 and the fuel electrode active portion 22, but the fuel electrode 20 is a single layer corresponding to the fuel electrode active portion 22. It may be configured.

  Further, in the above-described embodiment, “a part inside the power generation element part A” (a part between the fuel electrode active part 22 and the reaction preventing film 50) and “a part outside the power generation element part A” in the solid electrolyte membrane 40. Are composed of the same composition, but may be composed of different compositions. Similarly, the “part on the inner side of the power generation element part A” (the part between the solid electrolyte film 40 and the air electrode 60) and the “part on the outer side of the power generation element part A” in the reaction preventing film 50 are configured with the same composition. However, it may be composed of different compositions.

  DESCRIPTION OF SYMBOLS 10 ... Support substrate, 11 ... Fuel gas flow path, 12 ... Recessed part, 20 ... Fuel electrode, 21 ... Fuel electrode current collecting part, 21a, 21b ... Recessed part, 22 ... Fuel electrode active part, 30 ... Interconnector, 40 ... Solid Electrolyte membrane, 50 ... Reaction prevention membrane, 60 ... Air electrode, 70 ... Air electrode current collector membrane, 80 ... Front-back connecting member, A ... Power generation element part

Claims (8)

A porous support substrate having a flat plate-like electron conductivity, in which a gas flow path is formed;
A plurality of power generating element portions each provided at a plurality of positions separated from each other on the main surfaces of the front and back surfaces of the support substrate, wherein at least a fuel electrode, a solid electrolyte membrane, and an air electrode are laminated in this order;
An electrical connecting portion that is provided between the adjacent power generation element portions on each of the main surfaces of the support substrate, and electrically connects one fuel electrode and the other air electrode of the adjacent power generation element portions; ,
Provided to cover the main surface on the front and back surfaces of the support substrate excluding the region where the power generation element portion is provided and the side end surface of the support substrate, and supply the fuel electrode via the gas flow path A sealing film made of a dense material that prevents mixing of the gas to be supplied and the gas supplied to the air electrode;
A fuel cell comprising:
Constructed of a conductive ceramic material that is provided so as to cover a portion of the seal film that covers the side end surface of the support substrate, and that electrically connects the power generating element portions provided on the main surfaces of the front and back surfaces of the support substrate. Provided with a connected member between the front and back,
The electrical connection portion is connected to the air electrode and is made of a porous material, and the second portion is connected to the fuel electrode and is connected to the first portion and made of a dense material. Part, and
Porosity of the front and rear between the connecting member is smaller than the porosity of the first portion of the electrical connections, the porosity of the front and rear between the connecting member is 10-30%, the first portion of the electrical connection section A fuel cell having a porosity of 30 to 45%. A porous support substrate having a flat plate-like electron conductivity, in which a gas flow path is formed;
A plurality of power generating element portions each provided at a plurality of positions separated from each other on the main surfaces of the front and back surfaces of the support substrate, wherein at least a fuel electrode, a solid electrolyte membrane, and an air electrode are laminated in this order;
An electrical connecting portion that is provided between the adjacent power generation element portions on each of the main surfaces of the support substrate, and electrically connects one fuel electrode and the other air electrode of the adjacent power generation element portions; ,
Provided to cover the main surface on the front and back surfaces of the support substrate excluding the region where the power generation element portion is provided and the side end surface of the support substrate, and supply the fuel electrode via the gas flow path A sealing film made of a dense material that prevents mixing of the gas to be supplied and the gas supplied to the air electrode;
A fuel cell comprising:
Constructed of a conductive ceramic material that is provided so as to cover a portion of the seal film that covers the side end surface of the support substrate, and that electrically connects the power generating element portions provided on the main surfaces of the front and back surfaces of the support substrate. Provided with a connected member between the front and back,
The electrical connection portion is connected to the air electrode and is made of a porous material, and the second portion is connected to the fuel electrode and is connected to the first portion and made of a dense material. Part, and
The conductivity of the front-back connection member is greater than the conductivity of the first portion of the electrical connection portion ,
The fuel cell in which the conductivity of the connecting member between the front and back surfaces is 500 to 800 S / cm at 750 ° C., and the conductivity of the first portion of the electrical connection portion is 200 to 500 S / cm at 750 ° C. A porous support substrate having a flat plate-like electron conductivity, in which a gas flow path is formed;
A plurality of power generating element portions each provided at a plurality of positions separated from each other on the main surfaces of the front and back surfaces of the support substrate, wherein at least a fuel electrode, a solid electrolyte membrane, and an air electrode are laminated in this order;
An electrical connecting portion that is provided between the adjacent power generation element portions on each of the main surfaces of the support substrate, and electrically connects one fuel electrode and the other air electrode of the adjacent power generation element portions; ,
Provided to cover the main surface on the front and back surfaces of the support substrate excluding the region where the power generation element portion is provided and the side end surface of the support substrate, and supply the fuel electrode via the gas flow path A sealing film made of a dense material that prevents mixing of the gas to be supplied and the gas supplied to the air electrode;
A fuel cell comprising:
Constructed of a conductive ceramic material that is provided so as to cover a portion of the seal film that covers the side end surface of the support substrate, and that electrically connects the power generating element portions provided on the main surfaces of the front and back surfaces of the support substrate. Provided with a connected member between the front and back,
The electrical connection portion is connected to the air electrode and is made of a porous material, and the second portion is connected to the fuel electrode and is connected to the first portion and made of a dense material. Part, and
Porosity of the front and rear between the connecting member is smaller than the porosity of the first portion of the electrical connections, the porosity of the front and rear between the connecting member is 10-30%, the first portion of the electrical connection section Has a porosity of 30-45%,
The fuel cell, wherein a thickness of the front-back connection member is larger than a thickness of the first portion of the electrical connection portion . A porous support substrate having a flat plate-like electron conductivity, in which a gas flow path is formed;
A plurality of power generating element portions each provided at a plurality of positions separated from each other on the main surfaces of the front and back surfaces of the support substrate, wherein at least a fuel electrode, a solid electrolyte membrane, and an air electrode are laminated in this order;
An electrical connecting portion that is provided between the adjacent power generation element portions on each of the main surfaces of the support substrate, and electrically connects one fuel electrode and the other air electrode of the adjacent power generation element portions; ,
Provided to cover the main surface on the front and back surfaces of the support substrate excluding the region where the power generation element portion is provided and the side end surface of the support substrate, and supply the fuel electrode via the gas flow path A sealing film made of a dense material that prevents mixing of the gas to be supplied and the gas supplied to the air electrode;
A fuel cell comprising:
Constructed of a conductive ceramic material that is provided so as to cover a portion of the seal film that covers the side end surface of the support substrate, and that electrically connects the power generating element portions provided on the main surfaces of the front and back surfaces of the support substrate. Provided with a connected member between the front and back,
The electrical connection portion is connected to the air electrode and is made of a porous material, and the second portion is connected to the fuel electrode and is connected to the first portion and made of a dense material. Part, and
Porosity of the front and rear between the connecting member is smaller than the porosity of the first portion of the electrical connections, the porosity of the front and rear between the connecting member is 10-30%, the first portion of the electrical connection section Has a porosity of 30-45%,
The electrical conductivity of the front-back connection member is greater than the electrical conductivity of the first portion of the electrical connection portion , and the electrical conductivity of the front-back connection member is 500-800 S / cm at 750 ° C., and the electrical connection The fuel cell whose electrical conductivity of the 1st part of a part is 200-500 S / cm at 750 degreeC. A porous support substrate having a flat plate-like electron conductivity, in which a gas flow path is formed;
A plurality of power generating element portions each provided at a plurality of positions separated from each other on the main surfaces of the front and back surfaces of the support substrate, wherein at least a fuel electrode, a solid electrolyte membrane, and an air electrode are laminated in this order;
An electrical connecting portion that is provided between the adjacent power generation element portions on each of the main surfaces of the support substrate, and electrically connects one fuel electrode and the other air electrode of the adjacent power generation element portions; ,
Provided to cover the main surface on the front and back surfaces of the support substrate excluding the region where the power generation element portion is provided and the side end surface of the support substrate, and supply the fuel electrode via the gas flow path A sealing film made of a dense material that prevents mixing of the gas to be supplied and the gas supplied to the air electrode;
A fuel cell comprising:
Constructed of a conductive ceramic material that is provided so as to cover a portion of the seal film that covers the side end surface of the support substrate, and that electrically connects the power generating element portions provided on the main surfaces of the front and back surfaces of the support substrate. Provided with a connected member between the front and back,
The electrical connection portion is connected to the air electrode and is made of a porous material, and the second portion is connected to the fuel electrode and is connected to the first portion and made of a dense material. Part, and
The thickness of the front-back connection member is greater than the thickness of the first portion of the electrical connection portion ,
The electrical conductivity of the front-back connection member is greater than the electrical conductivity of the first portion of the electrical connection portion , and the electrical conductivity of the front-back connection member is 500-800 S / cm at 750 ° C., and the electrical connection The fuel cell whose electrical conductivity of the 1st part of a part is 200-500 S / cm at 750 degreeC. A porous support substrate having a flat plate-like electron conductivity, in which a gas flow path is formed;
A plurality of power generating element portions each provided at a plurality of positions separated from each other on the main surfaces of the front and back surfaces of the support substrate, wherein at least a fuel electrode, a solid electrolyte membrane, and an air electrode are laminated in this order;
An electrical connecting portion that is provided between the adjacent power generation element portions on each of the main surfaces of the support substrate, and electrically connects one fuel electrode and the other air electrode of the adjacent power generation element portions; ,
Provided to cover the main surface on the front and back surfaces of the support substrate excluding the region where the power generation element portion is provided and the side end surface of the support substrate, and supply the fuel electrode via the gas flow path A sealing film made of a dense material that prevents mixing of the gas to be supplied and the gas supplied to the air electrode;
A fuel cell comprising:
Constructed of a conductive ceramic material that is provided so as to cover a portion of the seal film that covers the side end surface of the support substrate, and that electrically connects the power generating element portions provided on the main surfaces of the front and back surfaces of the support substrate. Provided with a connected member between the front and back,
The electrical connection portion is connected to the air electrode and is made of a porous material, and the second portion is connected to the fuel electrode and is connected to the first portion and made of a dense material. Part, and
Porosity of the front and rear between the connecting member is smaller than the porosity of the first portion of the electrical connections, the porosity of the front and rear between the connecting member is 10-30%, the first portion of the electrical connection section Has a porosity of 30-45%,
The thickness of the front-back connection member is greater than the thickness of the first portion of the electrical connection portion ,
The electrical conductivity of the front-back connection member is greater than the electrical conductivity of the first portion of the electrical connection portion , and the electrical conductivity of the front-back connection member is 500-800 S / cm at 750 ° C., and the electrical connection The fuel cell whose electrical conductivity of the 1st part of a part is 200-500 S / cm at 750 degreeC. The fuel cell according to any one of claims 1 to 6, wherein
The sealing film is made of a material containing zirconia,
The connection member between the front and back is made of a perovskite type conductive ceramic material containing strontium or lanthanum,
A fuel cell in which a reaction preventing film not containing zirconia is interposed in a portion where the front-back connecting member and the seal film face each other. The fuel cell according to any one of claims 1 to 7,
The front and rear inter-connecting member, the formula _{La m (Ni 1-x-} y Fe x Cu y) n O 3-δ ( However, m and n are 0.95 to 1.05, x is 0.03 or more 0 .3 or less, y is 0.05 or more and 0.5 or less, and δ is 0 or more and 0.8 or less.

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