JP2016154096A - Solid oxide fuel battery and manufacturing method for solid oxide fuel battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid oxide fuel battery and manufacturing method for the battery that are capable of suppressing oxidation of a fuel electrode and leak current between cells.SOLUTION: A solid oxide fuel battery includes a cell stack 101 comprising: a plurality of fuel battery cells 105, each of which comprises a fuel electrode 109, a solid electrolyte film 111, and an air electrode 113 on a substrate 103; and an interconnector 107 for electrically connecting adjacent fuel battery cells 105. A gradient of one end of the fuel electrode 109 to the substrate 103's surface is gentler than that of the other end of the fuel electrode 109 to the substrate 103's surface. A surface of the substrate 103's part positioned at the other end's side, of the substrate 103's parts positioned between adjacent fuel electrodes 109, is in contact with a solid electrolyte film 111; a surface of the remaining part of the substrate 103's parts is in contact with an interconnector 107. The minimum film thickness of the solid electrolyte film 111's part at the tip of the other end is larger than the thickness of the solid electrolyte film 111's part positioned on the fuel electrode 109's surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solid oxide fuel cell and a method for manufacturing the same.

As examples of solid oxide fuel cells, cylindrical solid oxide fuel cells and flat plate solid oxide fuel cells are known.
FIG. 3 is a longitudinal sectional view of a cell stack of a cylindrical solid oxide fuel cell disclosed in Patent Document 1. In a cylindrical solid oxide fuel cell, a plurality of cylindrical cell stacks 201 are electrically connected in parallel and accommodated in the fuel cell. In each cell stack 201, a fuel cell 205 in which a fuel electrode 209, a solid electrolyte membrane 211, and an air electrode 213 are stacked on a porous substrate (substrate tube) 203 made of calcium stabilized zirconia (CSZ), for example. Are formed, and adjacent fuel cells 205 are connected by an interconnector 207. Between the adjacent fuel cells 205, the solid electrolyte membrane 211 of one fuel cell 205 is provided in contact with the base 203.

In the cell stack of FIG. 3, insulation between the fuel electrodes 209 of adjacent fuel cells 205 is achieved by a solid electrolyte membrane 211 provided between the fuel cells 205.
For example, in order to increase the amount of power generated in one cell stack, when the distance between cells is reduced to increase the number of cells and the width of the interconnector is further reduced, the base (base tube) is brought into close proximity between the cells. ) May occur, which may cause a short circuit between cells.

  Therefore, as disclosed in Patent Document 2, an attempt has been made to suppress the generation of leakage current when an insulating film is provided between cells and the cells are close to each other.

JP 2014-116100 A JP, 2014-110164, A

  FIG. 3 shows a structure in which the fuel electrode 209 of the adjacent fuel cell 205 exists through the solid electrolyte membrane 211. When the fuel cell is operated using the cell stack 201, an oxide film is generated at the contact portion with the base 203 and the contact portion with the solid electrolyte membrane 211 so as to surround the end portion of the fuel electrode, It turned out that it might be damaged. In this oxide film, oxygen ions generated at the air electrode 213 at the operating temperature leak to the fuel electrode 209 of the adjacent cell 205 through the solid electrolyte membrane 211 and the substrate 203 between the cells 205, and the metal ( Specifically, it is thought to be generated by reacting with Ni).

  If an insulating film is provided as in Patent Document 2, it is possible to block the leakage of oxygen ions via the solid electrolyte membrane located between the cells and suppress the oxidation of the fuel electrode. However, by newly providing a layer that does not contribute to power generation, there is a problem that the non-power generation area increases and the manufacturing process increases.

  An object of the present invention is to provide a solid oxide fuel cell capable of suppressing oxidation of a fuel electrode and leakage current between cells, and a manufacturing method thereof.

  A first aspect of the present invention is a cell comprising a plurality of fuel cells provided with a fuel electrode, a solid electrolyte membrane, and an air electrode on a substrate, and an interconnector that electrically connects the adjacent fuel cells. A solid oxide fuel cell having a stack, wherein a slope of one end of the fuel electrode with respect to the surface of the substrate is gentler than a slope of the other end of the fuel electrode with respect to the surface of the substrate. The surface of the substrate located on the other end side of the substrate positioned between the fuel electrodes is in contact with the solid electrolyte membrane, and the remaining surface of the substrate is in contact with the interconnector. In the solid oxide fuel cell, the minimum thickness of the solid electrolyte membrane at the tip of the other end is thicker than the thickness of the solid electrolyte membrane located on the surface of the fuel electrode.

  In the first aspect, the thickness of the solid electrolyte membrane located on the surface of the fuel electrode is preferably in the range of 10 μm to 100 μm, and the minimum thickness is preferably 100 μm or more.

  According to a second aspect of the present invention, there is provided a cell having a plurality of fuel cells provided with a fuel electrode, a solid electrolyte membrane, and an air electrode on a substrate, and an interconnector for electrically connecting the adjacent fuel cells. A method of manufacturing a solid oxide fuel cell including a stack, wherein a gradient of one end of the fuel electrode with respect to the substrate surface is gentler than a gradient of the other end with respect to the substrate surface. A step of forming a fuel electrode; a step of forming the solid electrolyte membrane on the fuel electrode; and on the substrate on the other end side between the adjacent fuel cells, and the adjacent A step of forming the interconnector between the fuel cells on the fuel electrode, on the solid electrolyte membrane, and on the base on the one end side. Among the substrates located between the two, the other end side of the substrate contacts the solid electrolyte membrane, and the remaining substrate contacts the one end side of the interconnector. A solid electrolyte membrane and the interconnector are formed, and the minimum thickness of the solid electrolyte membrane at the tip of the other end is larger than the thickness of the solid electrolyte membrane located on the surface of the fuel electrode A method for manufacturing a solid oxide fuel cell in which the solid electrolyte membrane is formed.

  In the second aspect, the solid electrolyte membrane is formed so that the solid electrolyte membrane located on the surface of the fuel electrode is in the range of 10 μm or more and 100 μm or less, and the minimum film thickness is 100 μm or more. Is preferred.

  In the present invention, the shapes of both ends of the fuel electrode are different. Between the fuel cells, the substrate surface located on the fuel extreme part side with a steep gradient is in contact with the solid electrolyte membrane, and the remaining substrate surface is in contact with the interconnector on the fuel extreme part side with a gentle gradient. It is done. The solid electrolyte membrane provides insulation between the cells, and the interconnector prevents oxygen ions from diffusing to the adjacent fuel electrode via the solid electrolyte membrane on the substrate. With the above-described configuration, it is possible to reduce leakage current and to suppress oxidation of the fuel electrode tip due to oxygen ions.

The solid electrolyte membrane is formed on the fuel electrode surface so that the minimum thickness at the tip of the fuel electrode is 100 μm or more while it is in the film thickness range of 10 μm or more and 100 μm or less. By doing so, end portions of a gentle gradient (the inclination angle of the fuel extreme portion with respect to the substrate surface is small) are formed in the solid electrolyte membrane immediately above the substrates between the fuel cells.
In the interconnector formation process, when the fuel electrode and the solid electrolyte membrane have steep edges, the interconnector material cannot enter at the tip of the fuel electrode and the solid electrolyte membrane, creating a space (such as bubbles). It may be easy to do. The interconnector was likely to be damaged starting from this space during the operation of the fuel cell and at the time of starting / stopping. In the present invention, since the solid electrolyte membrane and the fuel electrode have a gentle gradient in the region where the interconnector is formed, the interconnector material can be surely filled at the tip of the fuel electrode and the solid electrolyte membrane. As a result, a dense interconnector can be formed and damage to the interconnector during operation can be prevented.

In the first and second embodiments, the substrate is any one of stabilized zirconia, a mixture of stabilized zirconia and nickel oxide, MgAl ₂ O ₄ , and SrZrO ₃ , and the fuel electrode includes Ni and zirconia. A titanate system in which the solid electrolyte membrane is a zirconia-based electrolyte material, and the interconnector is added in a proportion of 3 mol% or more and 5 mol% or less of Al ₂ O _3. A perovskite type compound is preferred.

Titanate-based perovskite type compounds have stable electrical conductivity in both oxidizing and reducing atmospheres, and have the same thermal expansion coefficient as the base, fuel electrode, and solid electrolyte membrane, making them suitable as interconnector materials It is. On the other hand, a titanate-based perovskite type compound alone is inferior in sinterability compared to a substrate, a fuel electrode and a solid electrolyte membrane. By adding Al ₂ O ₃ to the titanate-based perovskite compound at the above ratio, the shrinkage rate and thermal expansion coefficient can be matched with those of the substrate and the like, and the denseness by sintering can be improved.

In the present invention, insulation between cells is achieved by a solid electrolyte membrane provided in contact with a substrate between cells, and leakage of oxygen ions is prevented by a dense interconnector provided in contact with the substrate between cells. For this reason, oxidation of the fuel electrode and leakage current can be suppressed.
Moreover, in the solid oxide fuel cell and the manufacturing method thereof according to the present invention, particularly when the interconnector is formed between the cells, the interconnector can be disposed between the cells without any gap.

It is the schematic which shows the one aspect | mode of the cell stack of the solid oxide fuel cell of this invention. It is the expansion schematic between the fuel cells of a cell stack. It is the schematic which shows the one aspect | mode of the cell stack of the conventional solid oxide fuel cell.

FIG. 1 is a schematic view showing one embodiment of a cell stack of a cylindrical solid oxide fuel cell. A cylindrical fuel cell is one in which a plurality of cell stacks 101 according to this embodiment are accommodated in a power generation chamber. However, the case where one cell stack 101 is accommodated can also be adopted.
In the present embodiment, the cell stack is described as being cylindrical (the base is cylindrical), but is not limited thereto. For example, the cell stack may be elliptical (the base is an elliptical cylinder).

  The cell stack 101 includes a cylindrical substrate (substrate tube) 103, a plurality of fuel cells 105 formed on the outer peripheral surface of the substrate 103, and an interconnector 107 formed between adjacent fuel cells 105. . The fuel cell 105 is formed by laminating a fuel electrode 109, a solid electrolyte membrane 111, and an air electrode 113. The cell stack 101 is connected to the air electrode 113 of the fuel cell 105 formed at the end in the axial direction of the base body 103 among the plurality of fuel battery cells 105 formed on the outer peripheral surface of the base body 103. The lead film 115 is electrically connected through the via.

According to the present embodiment, the fuel gas and the oxidant gas (for example, air) flow so as to face the inside and the outside of the cell stack 101. The fuel gas is introduced into the inside (inside) of the base 103 from one end of the base 103 and discharged from the other end of the base 103 to the outside. On the other hand, an oxidant gas (for example, air) containing oxygen is supplied to the outside of the substrate 103. The fuel gas supplied through the base 103 is, for example, a gas that is reacted with a mixed gas of methane (CH ₄ ) and water vapor to be reformed into hydrogen (H ₂ ) and carbon monoxide (CO). Further, the fuel electrode 109 has an interface between the solid electrolyte 111 and hydrogen (H ₂ ) and carbon monoxide (CO) obtained by reforming and oxygen ions (O ²⁻ ) supplied via the solid electrolyte 111. It reacts electrochemically in the vicinity to produce water (H ₂ O) and carbon dioxide (CO ₂ ). At this time, the fuel cell 105 generates electric power by electrons emitted from oxygen ions.

The substrate 103 is made of a porous material, for example, CaO stabilized ZrO ₂ (CSZ), a mixture of CSZ and nickel oxide (NiO) (CSZ + NiO), Y ₂ O ₃ stabilized ZrO ₂ (YSZ), MgAl ₂ O. ₄ and SrZrO ₃ as a main component. The base 103 supports the fuel cell 105, the interconnector 107, and the lead film 115, and supplies fuel gas supplied to the inner peripheral surface of the base 103 to the outer peripheral surface of the base 103 through the pores of the base 103. It diffuses in the fuel electrode 109 to be formed.

The fuel electrode 109 is composed of a composite oxide of Ni and a zirconia-based electrolyte material, for example, Ni—YSZ. The thickness of the fuel electrode 109 is 50 to 250 μm.
FIG. 2 is an enlarged schematic view between the fuel cells of the cell stack of this embodiment. In the present embodiment, both end portions of the fuel electrode 109 have different shapes. The gradient of one end 109b of the fuel electrode 109 (the left end of the fuel electrode 109 in FIG. 1) with respect to the surface of the base 103 is the other end 109a of the fuel electrode 109 (the right end of the fuel electrode 109 in FIG. 1). Part) is gentler than the gradient of the surface of the base 103 (the inclination angle of the end 109b with respect to the surface of the base 103 is smaller).

The solid electrolyte membrane 111 is mainly made of YSZ having airtightness that prevents gas from passing and high oxygen ion conductivity at high temperatures. The solid electrolyte membrane 111 moves oxygen ions (O ²⁻ ) generated at the air electrode to the fuel electrode.

The interconnector 107 is composed mainly of a titanate perovskite compound represented by M _1-x L _x TiO ₃ (M is an alkaline earth metal element, L is a lanthanoid element) such as SrTiO ₃ system. And Al ₂ O ₃ is composed of a material to which 3 mol% or more and 5 mol% or less is added. The interconnector 107 is a dense film so that the fuel gas and the oxidant gas are not mixed. Further, the interconnector 107 has stable electrical conductivity in both an oxidizing atmosphere and a reducing atmosphere. The interconnector 107 electrically connects the air electrode 113 of one fuel battery cell 105 and the fuel electrode 109 of the other fuel battery cell 105 in adjacent fuel battery cells 105 so that the adjacent fuel battery cells 105 are connected to each other. Are connected in series.

  As will be described later, the fuel electrode 109, the solid electrolyte membrane 111, and the interconnector 107 formed on the substrate 103 are co-sintered. At this time, in order to suppress breakage of each layer, the material of each layer is selected so that the contraction rate and thermal expansion coefficient of the fuel electrode 109, the solid electrolyte membrane 111, and the interconnector 107 are approximately the same as those of the base body 103. The In particular, it is necessary to prevent the occurrence of cracks in the solid electrolyte membrane 111 and the interconnector 107 from the viewpoint of preventing mixing of the fuel gas and the oxidant gas.

As described above, the substrate 103, the fuel electrode 109, and the solid electrolyte membrane 111 are mainly composed of stabilized zirconia. For this reason, it is easy to match the solid electrolyte membrane 111 so that the shrinkage rate and thermal expansion coefficient are comparable to those of the substrate 103 and the fuel electrode 109. SrZrO ₃ and stabilized zirconia have close thermal expansion coefficients. For this reason, when the substrate 103 is mainly composed of SrZrO ₃ , it is easy to match the thermal expansion coefficient and the contraction rate of the substrate 103, the fuel electrode 109, and the solid electrolyte membrane 111. The thermal expansion coefficient of MgAl ₂ O ₄ varies depending on the amount of MgO added. Therefore, when the base 103 is mainly composed of MgAl ₂ O ₄ , the thermal expansion coefficients of the base 103, the fuel electrode 109, and the solid electrolyte membrane 111 can be matched by adjusting the amount of MgO added.

On the other hand, titanate based perovskite which is the material of the interconnector 107, the substrate 103, but the fuel electrode 109 and the solid electrolyte film 111 showing a thermal expansion coefficient comparable, have poor sinterability, below Al ₂ O The content of ₃ is adjusted.

Table 1 summarizes the shrinkage rate and thermal expansion coefficient of each layer.

As a material for the interconnector 107, a titanate-based perovskite type compound containing Al ₂ O ₃ in the above range has a higher shrinkage rate than the case of not containing Al ₂ O ₃ . That is, by including Al ₂ O ₃ , it is possible to improve the sinterability and form the dense interconnector 107. Also, titanate based perovskite containing _Al 2 _{O 3} is close to the thermal expansion coefficient of the base body (CZS) than when not containing _Al 2 _{O 3.}
By appropriately selecting the material in this way, the shrinkage rate and thermal expansion coefficient of each layer are matched to the substrate.

  In the present embodiment, the solid electrolyte membrane 111 is in contact with the base 103 exposed between the fuel cells 105 on the end 109 a side of the fuel electrode 109. Further, the interconnector 107 contacts the base body 103 exposed between the fuel cells 105 on the end 109 b side of the fuel electrode 109. In other words, of the bases 103 exposed between the adjacent fuel electrodes 109, the surface of the base tube 103 on the end 109 a side contacts the solid electrolyte membrane 111. The remaining surface of the substrate 103 (the surface of the substrate 103 on the end 109b side, that is, the end 111a of the solid electrolyte membrane 111 in contact with the substrate 103 (the end of the solid electrolyte membrane on the end 109a side) and the fuel extreme portion 109b The surface between the contactor 107 and the interconnector 107. Between the adjacent fuel electrodes 109, the solid electrolyte membrane 111 and the interconnector 107 are in contact with the base tube 103 without a gap.

  The thickness (indicated by arrow B in FIG. 2) of the solid electrolyte membrane 111 located on the surface of the fuel electrode 109 (flat portion of the fuel electrode 109) is 10 to 100 μm. On the other hand, the thickness of the solid electrolyte membrane 111 in the vicinity of the end portion of the fuel electrode 109 is thicker than the solid electrolyte membrane 111 formed on the fuel electrode 109. The minimum film thickness (indicated by arrow A in FIG. 2) of the solid electrolyte membrane 111 at the tip of the end 109a of the fuel electrode 109 is 100 μm or more. By doing so, as shown in FIG. 2, the inclination angle of the end portion of the solid electrolyte membrane 111 on the end portion 109a side of the fuel electrode 109 with respect to the surface of the substrate 103 becomes smaller than the inclination angle of the end portion 109a. That is, the gradient of the end portion of the solid electrolyte membrane 111 on the end portion 109a side of the fuel electrode 109 with respect to the surface of the substrate 103 is gentler than the gradient of the end portion 109a.

The air electrode 113 is made of, for example, a LaSrMnO ₃ oxide or a LaCoO ₃ oxide. This air electrode 113 generates oxygen ions (O ²⁻ ) by dissociating oxygen in an oxidizing gas such as air supplied near the interface with the solid electrolyte membrane 111.
The air electrode 113 may have a two-layer structure. In this case, the air electrode layer (air electrode intermediate layer) on the solid electrolyte membrane 111 side is made of a material exhibiting high ionic conductivity such as Sm-doped CeO ₂ and having excellent catalytic activity. The air electrode layer (air electrode conductive layer) on the air electrode intermediate layer is preferably composed of a perovskite oxide (Sr and Ca-doped LaMnO ₃ ) represented by La (Sr, Ca) MnO ₃ . By doing so, the power generation performance can be improved.

  The lead film 115 plays a role of extracting electricity generated in the cell stack 101 to the outside. The lead film 115 is made of the same material as the fuel electrode 109.

The process of forming the cell stack will be described below.
The base 103 is formed by, for example, an extrusion method. The diameter of the base 103 is substantially uniform in the axial direction.

  A fuel electrode 109 of each fuel cell 105 is formed on the base 103 by a screen printing method. For example, the fuel electrode material (Ni + YSZ) mixed powder and an organic vehicle (organic solvent added with a dispersant and a binder) are mixed to prepare a fuel electrode slurry. The slurry for the fuel electrode is applied at a predetermined interval at a predetermined position corresponding to the fuel cell 105 in the circumferential direction on the outer peripheral surface of the substrate 103. The mixing ratio of the powder is appropriately selected depending on the performance required for the fuel electrode 109. The mixing ratio of the mixed powder and the organic vehicle is appropriately selected in consideration of the thickness of the fuel electrode 109, the state of the film after slurry application, and the like.

  The application of the fuel electrode slurry by screen printing is performed a plurality of times until a desired thickness is reached. In order to obtain the end shape illustrated in FIG. 1, the opening position of the screen is shifted for each application, and the upper layer is formed using a screen having an opening area smaller than the opening of the screen used in the lower layer.

  Lead films 115 are formed on the substrate 103 by screen printing at both ends of the cell stack 101. As the slurry for the lead film, the above slurry for fuel electrode can be used. Alternatively, when a material different from the fuel electrode material is used, the lead film material powder and the organic vehicle are mixed to produce a lead film slurry.

  After the fuel electrode 109 is formed, a solid electrolyte membrane is formed on the outer surface of the fuel electrode 109 in each fuel cell 105 and between the adjacent fuel electrodes 109 and the substrate 103 on the end 109a side of the fuel electrode 109. 111 is formed by a screen printing method. For example, the solid electrolyte membrane 111 powder and the organic vehicle are mixed to produce a solid electrolyte membrane slurry. The mixing ratio of the powder and the organic vehicle is appropriately selected in consideration of the thickness of the solid electrolyte membrane 111, the state and thickness of the membrane after slurry application, and the like. In particular, the solid electrolyte membrane slurry is formed so that air bubbles enter between the tip of the fuel extreme portion 109a and the solid electrolyte membrane 111 and there is no portion where the surface of the substrate 103 does not contact the solid electrolyte membrane 111 at the tip of the end portion 109a. It is applied on the substrate 103.

  The application of the slurry for the solid electrolyte membrane by screen printing is performed a plurality of times until a desired thickness is reached. Since the end of the fuel electrode 109 a has a steep gradient, the solid electrolyte membrane slurry applied on the end 109 a of the fuel electrode flows toward the substrate 103. Therefore, the amount of slurry increases at the tip of the end 109 a side of the fuel electrode 109, and the solid electrolyte membrane 111 is formed thick at the tip of the fuel electrode 109. Specifically, when the solid electrolyte membrane slurry is applied so that the solid electrolyte membrane 111 on the surface of the fuel electrode 109 is in the range of 10 μm to 100 μm, the flow of the slurry at the tip of the end 109 a side of the fuel electrode 109. Is 100 μm or more.

  An interconnector layer 107 is formed on the substrate 103 by a screen printing method. For example, the interconnector powder and the organic vehicle are mixed to produce an interconnector slurry. The interconnector slurry is located at a position corresponding to between adjacent fuel cells 105 from the end portion 109a of the fuel electrode 109 of one fuel cell 105 and the solid electrolyte membrane 111 formed in the upper layer thereof, and is adjacent to the fuel cell. The coating is applied in the circumferential direction of the outer peripheral surface of the base 103 up to the end 109 b of the fuel electrode 109 of the cell 105. The composition of the powder is appropriately selected according to the performance required for the interconnector. The mixing ratio of the powder and the organic vehicle is appropriately selected in consideration of the state of the film after applying the slurry.

  In the region where the interconnector slurry is applied, the gradient of the end 109b of the fuel electrode 109 and the end of the solid electrolyte membrane 111 is gentle. For this reason, the screen can follow the shape of the substrate (cell stack), and the interconnector slurry can be reliably poured into the region between the solid electrolyte membrane 111 and the adjacent fuel electrode 109. In particular, the slurry can be applied to the entire surface of the substrate 103 exposed between the fuel cells 105 without bubbles or the like entering the tips of the fuel electrode 109 and the solid electrolyte membrane 111.

  The substrate 103 on which the fuel electrode 109, the solid electrolyte membrane 111, and the slurry film of the interconnector 107 are formed is co-sintered in the atmosphere. The sintering temperature is specifically 1350 ° C. to 1450 ° C.

An air electrode is formed on the co-sintered substrate 103. For example, the air electrode material powder and the organic vehicle are mixed to produce an air electrode slurry. The air electrode slurry is applied to predetermined positions on the outer surface of the solid electrolyte membrane 111 and the interconnector 107 of each fuel cell 105. The air electrode slurry may be applied by screen printing, or may be applied using a dispenser. Application by the dispenser is performed by discharging droplets of slurry from the dispenser onto the rotating substrate 103. The mixing ratio of the powder and the organic vehicle is appropriately selected in consideration of the thickness of the air electrode, the state of the film after applying the slurry, the film thickness, and the like.
When the air electrode 113 has a two-layer structure, slurries are respectively produced using the powder of the air electrode intermediate layer material and the powder of the air electrode conductive layer material. Each slurry is applied to a predetermined position of the substrate 103 using screen printing or a dispenser.

The substrate 103 on which the air electrode slurry film is formed is sintered in the atmosphere. The sintering temperature is specifically 1100 ° C. to 1250 ° C. The sintering temperature here is lower than the co-sintering temperature after the base body 103 to the interconnector 107 are formed.
Thus, the process for forming the cell stack 101 is completed.

DESCRIPTION OF SYMBOLS 101 Cell stack 103 Base body 105 Fuel cell 107 Interconnector 109 Fuel electrode 109a, 109b End part 111 of a fuel electrode Solid electrolyte film 111a End part of a solid electrolyte film 113 Air electrode 115 Lead film

Claims (6)

A solid oxide fuel cell having a cell stack including a plurality of fuel cells each including a fuel electrode, a solid electrolyte membrane, and an air electrode, and an interconnector that electrically connects the adjacent fuel cells on a substrate. Because
The gradient of one end of the fuel electrode with respect to the surface of the base is gentler than the gradient of the other end of the fuel electrode with respect to the surface of the base;
Of the substrates positioned between adjacent fuel electrodes, the surface of the substrate positioned on the other end side is in contact with the solid electrolyte membrane, and the remaining surfaces of the substrate are in contact with the interconnector. ,
The solid oxide fuel cell, wherein the minimum thickness of the solid electrolyte membrane at the tip of the other end is thicker than the thickness of the solid electrolyte membrane located on the surface of the fuel electrode. The thickness of the solid electrolyte membrane located on the surface of the fuel electrode is in the range of 10 μm to 100 μm,
The solid oxide fuel cell according to claim 1, wherein the minimum film thickness is 100 μm or more. The substrate is any one of stabilized zirconia, a mixture of stabilized zirconia and nickel oxide, MgAl ₂ O ₄ , and SrZrO ₃ ;
The fuel electrode is an oxide of a composite material of Ni and a zirconia-based electrolyte material,
The solid electrolyte membrane is a zirconia-based electrolyte material;
_3. The solid oxide fuel cell according to claim 1, wherein the interconnector is a titanate-based perovskite compound to which Al ₂ O ₃ is added in a proportion of 3 mol% to 5 mol%. A solid oxide fuel cell comprising a plurality of fuel cells having a fuel electrode, a solid electrolyte membrane, and an air electrode on a substrate, and a cell stack having an interconnector for electrically connecting the adjacent fuel cells. A manufacturing method of
Forming the fuel electrode such that a slope of one end of the fuel electrode with respect to the surface of the base is gentler than a slope of the other end with respect to the surface of the base;
Forming the solid electrolyte membrane on the fuel electrode and on the substrate on the other end side between the adjacent fuel cells; and
Forming the interconnector on the fuel electrode, on the solid electrolyte membrane, and on the base on the one end side between the adjacent fuel cells, and
Of the substrates positioned between the adjacent fuel cells, the substrate on the other end side is in contact with the solid electrolyte membrane, and the remaining substrate is connected to the interconnector on the one end side. The solid electrolyte membrane and the interconnector are formed to contact,
Solid oxide on which the solid electrolyte membrane is formed so that the minimum thickness of the solid electrolyte membrane at the tip of the other end is thicker than the thickness of the solid electrolyte membrane located on the surface of the fuel electrode Of manufacturing a fuel cell.   The solid electrolyte membrane according to claim 4, wherein the solid electrolyte membrane is formed such that the solid electrolyte membrane located on the surface of the fuel electrode is in a range of 10 µm or more and 100 µm or less, and the minimum thickness is 100 µm or more. Manufacturing method of oxide fuel cell. The substrate is any one of stabilized zirconia, a mixture of stabilized zirconia and nickel oxide, MgAl ₂ O ₄ , and SrZrO ₃ ;
The fuel electrode is an oxide of a composite material of Ni and a zirconia-based electrolyte material,
The solid electrolyte membrane is a zirconia-based electrolyte material;
6. The method for producing a solid oxide fuel cell according to claim 4, wherein the interconnector is a titanate-based perovskite compound to which Al ₂ O ₃ is added in a proportion of 3 mol% to 5 mol%.

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