JP2004259604A - Cell for fuel cell and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cell for fuel cell preventing deterioration caused by combustion gas without enlarging the size, and to provide a fuel cell. <P>SOLUTION: The cell of the fuel cell is constituted such that at least a solid electrolyte 33c and an oxygen side electrode 33d are installed in order in a porous conductive substrate 33a on which a gas passage 34 is installed, and gas discharged from a gas discharge port 34a is burned in the vicinity of the gas discharge port 34a of the porous conductive substrate 33a, and an inorganic component is impregnated in the porous conductive substrate 33a in the periphery of the gas discharge port 34a. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell and a fuel cell, and more particularly to a fuel cell and a fuel cell that burn near a gas outlet of a porous conductive support having a gas flow passage.
[0002]
[Prior art]
2. Description of the Related Art In recent years, various fuel cells in which a stack of fuel cells is housed in a housing container have been proposed as next-generation energy.
[0003]
In a conventional solid oxide fuel cell, a storage container is known in which a plurality of bottomed tubular fuel cells are housed, and an air introduction pipe for supplying air into the fuel cells is inserted. (See Patent Document 1).
[0004]
In this fuel cell, power is generated by introducing air into the fuel cell through an air introduction pipe and supplying hydrogen to the outer periphery of the fuel cell.
[0005]
Then, excess air in the fuel cell and excess hydrogen outside the fuel cell burn in the vicinity of the opening of _the fuel cell, and the combustion gas heats the air introduction pipe, thereby converting the air in the air introduction pipe. Preheat and shorten start-up time.
[0006]
In this fuel cell, a sleeve is externally fitted to prevent reduction of the air electrode formed inside, and the sleeve shields the fuel cell end from combustion gas.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2001-110435
[Problems to be solved by the invention]
However, in Patent Literature 1, since the end of the fuel cell is inserted into the sleeve, the width of the cell device in which the end of the fuel cell is inserted into the sleeve is reduced due to the large diameter of the sleeve. As a result, the number of cells accommodated in a predetermined volume decreases, and a desired power generation amount cannot be obtained.
[0009]
Further, there is a problem that the length of the fuel cell is increased by the length of the sleeve and the size of the fuel cell is increased.
[0010]
An object of the present invention is to provide a fuel cell and a fuel cell that can prevent deterioration due to combustion gas without increasing the size.
[0011]
[Means for Solving the Problems]
The fuel cell of the present invention is formed by sequentially providing at least a solid electrolyte and an outer electrode on a porous conductive support having a gas flow passage formed therein, and in the vicinity of a gas outlet of the porous conductive support, A fuel cell in which gas discharged from the gas discharge port burns, wherein an inorganic component is impregnated around the gas discharge port in the porous conductive support.
[0012]
In such a fuel cell, the end face exposed to the combustion gas is formed by impregnating a porous conductive support with an inorganic component, so that the porous conductive support having low strength is reinforced with an inorganic component. Thereby, the end of the fuel cell unit exposed to the combustion gas can be strengthened to prevent breakage. In particular, the corners forming the gas flow passages on the end surface of the porous conductive support are easily chipped, so that they can be used effectively. On the other hand, since the porous conductive support is constituted by impregnating an inorganic component, the thermal conductivity is reduced, the heat from the gas combustion part can be cut off, and the electrode can be protected.
[0013]
Further, the fuel cell of the present invention is characterized in that an inner electrode, a solid electrolyte, and an outer electrode are sequentially provided on a porous conductive support. Even in such a fuel cell, the end exposed to the combustion gas can be strengthened to prevent breakage. In the case of this fuel cell, since not only the multi-hard conductive member but also the inner electrode is porous, it is desirable to impregnate the inner electrode with an inorganic component. Thereby, the end face of the fuel cell can be further protected.
[0014]
Further, the fuel cell of the present invention is characterized in that one end on the gas outlet side is a non-power generation portion, and the porous conductive support in the non-power generation portion is impregnated with an inorganic component. In such a fuel cell, the portion where the solid electrolyte is sandwiched between the inner electrode and the outer electrode is the power generation unit, and the portion that is not sandwiched is the non-power generation unit. One end on the gas outlet side is a non-power-generating portion in order to prevent deterioration of the porous outer electrode due to combustion gas, or in a manufacturing process or for holding a fuel cell.
[0015]
By impregnating the porous conductive support in the non-power generation portion of the fuel cell with an inorganic component, the end face can be protected without affecting the power generation performance of the fuel cell. Further, as described above, since the thermal conductivity is reduced, heat from the gas combustion portion can be cut off, and the electrodes can be protected, the non-power generation portion can be shortened, and the fuel cell can be shortened.
[0016]
Further, the fuel cell unit of the present invention is characterized in that the porous conductive support contains Ni and / or NiO.
[0017]
In such a fuel cell, since the porous conductive support contains Ni and / or NiO, the electric conductivity is high. For example, a plate-shaped porous conductive support is produced, and the porous conductive support is produced. When an inner electrode, a solid electrolyte, and an outer electrode are sequentially formed on one main surface of the support and an interconnector is provided on the other main surface of the porous conductive support, the conductivity of the porous conductive support is reduced. Although the power generation performance of the fuel cell can be enhanced due to the high density, the porous conductive support has a thin plate shape and is made of a cermet material containing Ni and / or NiO. Although the strength tends to be low, the strength can be improved by impregnating the inorganic component around the gas outlet of the porous conductive support, and the damage due to the combustion gas can be suppressed.
[0018]
Further, the fuel cell of the present invention is characterized in that the inorganic component is mainly composed of ZrO ₂ . Generally, the thermal expansion coefficient of each member (a porous conductive support, an outer electrode, an inner electrode, etc.) of a fuel cell is controlled to match the thermal expansion coefficient of a solid electrolyte containing ZrO ₂ as a main component. However, since the inorganic component impregnated in the porous conductive support is mainly composed of ZrO ₂ , the coefficient of thermal expansion of the inorganic component can be close to that of the solid electrolyte. Can be suppressed.
[0019]
Further, the fuel cell unit of the present invention is characterized in that a dense solid electrolyte is provided on the outer surface of the porous conductive support in the non-power generation section. In such a fuel cell, leakage of gas in the gas flow passage can be prevented, and when the main component of the solid electrolyte is ZrO ₂ , an inorganic component containing ZrO ₂ as a main component is used as a porous conductive support. By impregnating the fuel cell, damage due to a difference in thermal expansion coefficient at the end of the fuel cell on the combustion side can be suppressed.
[0020]
The fuel cell according to the present invention is obtained by housing a plurality of the above-described fuel cells in a storage container. In such a fuel cell, the breakage of the fuel cell can be suppressed as described above, so that the power generation performance does not deteriorate for a long time and the long-term reliability can be improved.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a cross-sectional perspective view of a fuel cell unit 33 according to the present invention. The fuel cell unit 33 has a flat cross section, an elliptical column shape as a whole, and a plurality of gas flows therein. A passage 34 is formed. In addition, the fuel cell 33 is also made flat by reducing its thickness.
[0022]
This fuel cell 33 contains a rare earth oxide containing at least one element selected from Y, Lu, Yb, Tm, Er, Ho, Dy, Gd, Sm, and Pr, and Ni and / or NiO. A porous fuel-side electrode (inner electrode) 33b is formed on an outer surface of a porous conductive support (hereinafter, also referred to as a support) 33a having a flat cross section and an elliptic column shape as a whole. Solid electrode 33c and an oxygen-side electrode (outer electrode) 33d made of porous conductive ceramics are sequentially laminated, and an intermediate film 33e and a lanthanum-chromium-based oxide are formed on the outer surface of a support 33a opposite to the oxygen-side electrode 33d. An interconnector 33f made of a material and a current collecting film 33g made of a P-type semiconductor material are formed.
[0023]
The support 33a may contain Ni and / or NiO and ZrO ₂ , or may contain spinel and the like.
[0024]
That is, the fuel cell 33 has a cross-sectional shape including an arc-shaped portion m provided at both ends in the width direction and a pair of flat portions n connecting these arc-shaped portions m. It is flat and formed substantially parallel. One of the flat portions n of the fuel cell 33 is formed by forming an intermediate film 33e, an interconnector 33f, and a current collecting film 33g on one main surface of a support 33a, and the other flat portion n A fuel-side electrode 33b, a solid electrolyte 33c, and an oxygen-side electrode 33d are sequentially formed on the other main surface of the support 33a.
[0025]
In other words, the support 33a is porous (having gas permeability) and has a conductive plate shape. The intermediate film 33e, the interconnector 33f, and the collector are provided on one main surface of the plate-like support 33a. An electrode film 33g is sequentially stacked, and a fuel electrode 33b, a solid electrolyte 33c, and an oxygen electrode 33d are sequentially stacked on the other main surface of the plate-shaped support 33a so as to face the interconnector 33f.
[0026]
The fuel-side electrode 33b, the solid electrolyte 33c, and the oxygen-side electrode 33d formed on the other main surface of the plate-shaped support 33a extend to the interconnector 33f formed on one main surface. The joining of the interconnector 33c and the interconnector 33f prevents the gas flowing through the gas flow passage 34 of the fuel cell from leaking outside.
[0027]
The gas flow path 34 of the fuel cell is formed in the axial direction of the support 33a, and one side of the gas flow path 34 is a gas outlet 34a and the other side is a gas inlet. The fuel gas is introduced from the gas inlet of the gas flow passage 34, the fuel gas is discharged from the gas outlet, and mixed with the oxygen-containing gas (air or the like) supplied to the outside of the fuel cell, and the gas outlet is formed. Combustion occurs near 34a.
[0028]
The intermediate film 33e is mainly composed of Ni and / or NiO and ZrO ₂ containing a rare earth element. The Ni conversion amount of the Ni compound in the intermediate film 33e is desirably 35 to 80% by volume, preferably 50 to 70% by volume of the total amount. By setting Ni to 35% by volume or more, the number of conductive paths of Ni increases, the conductivity of the intermediate film 33e improves, and the voltage drop decreases. Further, by setting the Ni content to 80% by volume or less, the difference in thermal expansion coefficient between the support 33a and the interconnector 33f can be reduced, and cracks at the interface between them can be suppressed.
[0029]
In addition, the thickness of the intermediate film 33e is desirably 20 μm or less, and more desirably 10 μm or less, in that the potential drop is reduced.
[0030]
The rare earth element of the support 33a is preferably a medium rare earth element or a heavy rare earth element. The thermal expansion coefficient of the oxide of a medium rare earth element or heavy rare earth element is smaller than that of ZrO ₂ containing Y ₂ O ₃ of the solid electrolyte 33 c, and the support 33 a as a cermet material with Ni is used. Can be made close to the thermal expansion coefficient of the solid electrolyte 33c, and cracking of the solid electrolyte 33c and separation of the solid electrolyte 33c from the fuel-side electrode 33b can be suppressed. By using a heavy rare earth oxide having a small coefficient of thermal expansion, Ni in the support 33a can be increased, and the electrical conductivity of the support 33a can be increased. desirable.
[0031]
Note that the oxides of the light rare earth elements La, Ce, Pr, and Nd are medium rare earth elements and heavy rare earth elements as long as the sum of the thermal expansion coefficients of the rare earth element oxides is less than the thermal expansion coefficient of the solid electrolyte. There is no problem even if it is contained in addition to.
[0032]
Further, by using an inexpensive composite rare earth oxide containing a plurality of rare earth elements in the middle of purification, the raw material cost can be significantly reduced. Also in that case, it is important that the thermal expansion coefficient of the composite rare earth oxide is lower than the thermal expansion coefficient of the solid electrolyte.
[0033]
Further, it is desirable to provide a current collecting film 33g made of a P-type semiconductor, for example, a transition metal perovskite oxide on the surface of the interconnector 33f. When a metal current collecting member is directly disposed on the surface of the interconnector 33f to collect current, non-ohmic contact causes a large potential drop. In order to make ohmic contact and reduce the potential drop, it is necessary to connect a current collecting film 33g made of a P-type semiconductor to the interconnector 33f, and it is preferable to use a transition metal perovskite oxide which is a P-type semiconductor. . The transition metal perovskite oxide is desirably composed of at least one of a lanthanum-manganese-based oxide, a lanthanum-iron-based oxide, and a composite oxide thereof.
[0034]
The fuel-side electrode 33b provided on the outer surface of the support 33a is made of Ni and a solid electrolyte material, for example, ZrO _{2 in} which a rare earth element is dissolved. It is desirable that the thickness of the fuel-side electrode 33b is 1 to 30 μm. By setting the thickness of the fuel-side electrode 33b to 1 μm or more, a three-layer interface as the fuel-side electrode 33b is sufficiently formed. Further, by setting the thickness of the fuel-side electrode 33b to 30 μm or less, interface separation can be prevented due to a difference in thermal expansion with the solid electrolyte 33c.
[0035]
Solid electrolyte 33c provided on the outer surface of the fuel-side electrode 33b is composed of 3 to 15 mol% of Sc, dense ceramics made of partially stabilized or stabilized ZrO ₂ containing a rare earth element such as Y . The solid electrolyte is not limited to this.
[0036]
As the rare earth element, Y or Yb is desirable from the viewpoint of low cost.
[0037]
It is desirable that the thickness of the solid electrolyte 33c is 10 to 100 μm. Gas permeation can be prevented by setting the thickness of the solid electrolyte 33c to 10 μm or more. Further, by setting the thickness of the solid electrolyte 33c to 100 μm or less, an increase in the resistance component can be suppressed.
[0038]
The oxygen-side electrode 33d is made of a transition metal perovskite-type oxide such as a lanthanum-manganese-based oxide, a lanthanum-iron-based oxide, or a composite oxide of at least one kind of porous conductive ceramic. I have. The oxygen-side electrode 33d is desirably made of a (La, Sr) (Fe, Co) O ₃ -based composition because of its high electrical conductivity in a medium temperature range of about 800 ° C. The thickness of the oxygen-side electrode 33d is desirably 30 to 100 μm from the viewpoint of current collection.
[0039]
A part of the outer surface of the support 33a has a portion where the fuel-side electrode 33b, the solid electrolyte 33c, and the oxygen-side electrode 33d are not formed in the axial direction, and the solid-state electrolyte 33c and the oxygen-side electrode 33d An intermediate film 33e, an interconnector 33f made of a lanthanum-chromium-based oxide, and a current collecting film 33g are formed on the exposed outer surface of the support 33a.
[0040]
The interconnector 33f is made dense to prevent leakage of fuel gas and oxygen-containing gas inside and outside the support 33a, and the inside and outside surfaces of the interconnector 33f come into contact with fuel gas and oxygen-containing gas. , Reduction resistance and oxidation resistance.
[0041]
The thickness of the interconnector 33f is desirably 10 to 200 μm from the viewpoint of preventing gas permeation and preventing an increase in the resistance component.
[0042]
Between the end face of the interconnector 33f and the end face of the solid electrolyte 33c, a bonding layer made of, for example, Y ₂ O ₃ may be interposed to improve the sealing property.
[0043]
As shown in FIG. 2, both ends of the fuel cell unit are non-power-generating portions 55 that do not generate power, and a central portion of the fuel cell has a solid electrolyte 33c sandwiched between a fuel electrode 33b and an oxygen electrode 33d. The portion 57 is provided. The non-power-generating portion which burns near the gas outlet 34a of the non-power-generating portion 55 and has a gas inlet is connected to, for example, a fuel gas tank. The non-power generation unit 55 is configured by stacking the fuel-side electrode 33b and the solid electrolyte 33c on the support 33a, and in a state where the solid electrolyte 33c is exposed to the outside. In other words, the solid-state electrolyte 33c has the oxygen-side electrode 33d The portion where is not formed is the non-power generation portion 55.
[0044]
In the fuel cell unit of the present invention, as shown in FIG. 1, the support 33a around the gas outlet 34a is impregnated with an inorganic component. That is, since the support 33a is porous, the inorganic component is impregnated from the gas outlet 34a side, and the pores of the support 33a near the gas outlet 34a are filled with the inorganic component.
[0045]
The inorganic component may be filled in the support 33a in the vicinity of the gas outlet 34a. In particular, the inorganic component needs to be filled only in the non-power-generating portion 55 to prevent the power generation performance from deteriorating. It is sufficient that only the support 33a in the vicinity of the gas outlet 34a, that is, only the surface layer is impregnated, but it is desirable to impregnate the entire non-power generation section 55 from the viewpoint of strength. It is desirable to impregnate not only the support 33a but also the fuel-side electrode 33b with an inorganic component.
[0046]
The inorganic component is mainly composed of ZrO ₂ . The inorganic component may be glass, alumina, silica, or zircon, but a composition similar to that of the solid electrolyte 33c is desirable from the viewpoint of matching the thermal expansion coefficient with other constituent members, and in particular, is the same as the solid electrolyte 33c. Desirably, it is made of a material. The support 33a impregnated with the inorganic component is denser than the portion not impregnated.
[0047]
A method for manufacturing the above fuel cell 33 will be described. First, a rare earth oxide powder excluding La, Ce, Pr, and Nd elements is mixed with Ni and / or NiO powder, and the mixed powder is extruded using a support material in which an organic binder and a solvent are mixed. It is molded to form a flat support molded body, which is dried and degreased.
[0048]
Next, Ni and / or NiO powder, a ZrO ₂ powder in which a rare earth element is dissolved, an organic binder, and a solvent are mixed to prepare a slurry for the fuel-side electrode 33b.
[0049]
Next, a sheet-shaped solid electrolyte molded body is produced using a solid electrolyte material obtained by mixing a ZrO ₂ powder in which a rare earth element is dissolved, an organic binder, and a solvent, and the surface of the sheet-shaped solid electrolyte molded body is The slurry for the fuel-side electrode 33b is applied to form a fuel-side electrode formed body on the surface of the solid electrolyte formed body.
[0050]
The sheet-like solid-electrolyte molded body is formed such that the fuel-side electrode molded body is laminated on the support molded body, and that both ends are spaced apart from each other at predetermined intervals at flat portions of the support molded body. It is wound around a molded support and dried. At this time, degreasing may be performed.
[0051]
Next, a Ni and / or NiO powder, a ZrO ₂ powder in which a rare earth element is dissolved, an organic binder, and a solvent are mixed to prepare a slurry for the intermediate film 33e. It is applied to the surface of a sheet-like interconnector molded body formed by using an interconnector material obtained by mixing a product powder, an organic binder, and a solvent to form an intermediate molded body on the interconnector molded body.
[0052]
The interconnector molded body is laminated on the support molded body exposed from between the solid electrolyte molded body ends.
[0053]
Thus, the fuel-side electrode molded body and the solid electrolyte molded body are sequentially laminated on one main surface of the support molded body, and the intermediate membrane molded body and the interconnector molded body are laminated on the other main surface. A molded body is produced. Each molded article can be produced by sheet molding or printing with a doctor blade, slurry dipping, spraying with a spray, or the like, or may be produced by a combination thereof.
[0054]
Next, the laminated molded body is degreased, and is simultaneously fired at 1300 to 1600 ° C. in an oxygen-containing atmosphere.
[0055]
Next, a transition metal perovskite oxide powder, which is a P-type semiconductor, and a solvent are mixed to prepare a paste, and the laminate is immersed in the paste. The solid electrolyte 33b and the surface of the interconnector 33f are exposed to oxygen. The electrode molded body and the current collecting membrane molded body are formed by dipping or directly spray-coated. At this time, control is performed so that the oxygen-side electrode molded body is not formed so that the non-power generation portions are formed at both ends of the fuel cell. Thereafter, baking is performed at 1000 to 1300 ° C.
[0056]
Next, for example, a fine powder of an inorganic material of the same material as the solid electrolyte 33c and a solvent are mixed to prepare a slurry, and one end of the laminate is immersed in the slurry to form a support in the non-power generation section. 33a, the pores of the fuel-side electrode 33b are filled with an inorganic material, which is dried and cured, or impregnated in a sol of the inorganic material, dried and cured to produce the fuel cell of the present invention. . Since one end of the laminate is immersed in the slurry, the inorganic material is coated not only on the cell end where the gas discharge port 34a is formed, but also on the outer surface of the solid electrolyte 33c of the non-power generation unit 55. However, even in this case, there is no problem because it is the same material as the solid electrolyte material.
[0057]
The filling of the inorganic component into the support may be performed by the above-described method after the laminated molded body is degreased, and may be fired simultaneously with the solid electrolyte or the like. In this case, the manufacturing process can be simplified.
[0058]
Since the Ni component in the support 33a, the fuel-side electrode 33b, and the intermediate film 33e becomes NiO by firing in an oxygen-containing atmosphere, the fuel cell 33 is thereafter reduced from the support 33a side. , And NiO is reduced at 800 to 1000 ° C. This reduction process may be performed at the time of power generation.
[0059]
As shown in FIG. 2, the cell stack is formed by a plurality of fuel cells 33 being aggregated, and between one fuel cell 33 and the other fuel cell 33, a metal felt and / or a metal plate is used. The current collector 43 is interposed, and the support 33a of one fuel cell 33 is connected to the other fuel cell via the interconnector 33f, the current collecting film 33g, and the current collector 43 provided on the support 33a. It is configured to be electrically connected to the 33 oxygen-side electrode 33d.
[0060]
The current collecting member 43 is desirably made of at least one of Pt, Ag, a Ni-based alloy, and an Fe-Cr steel alloy from the viewpoint of heat resistance, oxidation resistance, and electric conductivity. Reference numeral 42 denotes a conductive member for connecting fuel cells in series.
[0061]
The fuel cell of the present invention is configured by storing the cell stack of FIG. 2 in a storage container. The storage container is provided with an introduction pipe for introducing a fuel gas such as hydrogen and an oxygen-containing gas such as air into the fuel cell 33 from the outside, and the fuel cell 33 is heated to a predetermined temperature to generate power. The used fuel gas and oxygen-containing gas are discharged out of the storage container.
[0062]
Note that the present invention is not limited to the above-described embodiment, and various changes can be made without changing the gist of the present invention. For example, a cylindrical fuel cell may be manufactured using the cylindrical support 33a, and any shape may be used as long as the fuel cell 33 uses the support 33a.
[0063]
Further, a reaction prevention layer may be formed between the oxygen-side electrode 33d and the solid electrolyte 33c.
[0064]
Furthermore, the fuel cell in which the inner electrode is provided on the support 33a has been described. However, the present invention is not limited to the above-described example, and has no support, that is, the case where the inner electrode is the support as it is. The present invention can also be used effectively.
[0065]
Further, although the support 33a is configured to contain the rare earth oxide and Ni and / or NiO, the support 33a may be a support containing Ni and / or NiO, spinel, or the like. From the viewpoint of preventing the element from diffusing, and matching the thermal expansion coefficient with the solid electrolyte, it is preferable to include the rare earth oxide and Ni and / or NiO.
[0066]
【The invention's effect】
In the fuel cell of the present invention, the end face exposed to the combustion gas is constituted by impregnating the porous conductive support with the inorganic component, and thus the porous conductive support having low strength is reinforced with the inorganic component. It is possible to strengthen the end of the fuel cell exposed to the combustion gas, thereby preventing breakage, and in particular, since the corner forming the gas flow path on the end face of the porous conductive support is easily chipped, It can be used effectively.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a fuel cell unit of the present invention.
FIG. 2A is a side view of a fuel cell according to the present invention, and FIG. 2B is a side view of a support.
FIG. 3 is a cross-sectional view showing a cell stack of the present invention.
[Explanation of symbols]
33: fuel cell 33a: porous conductive support 33b: fuel-side electrode (inner electrode)
33c: solid electrolyte 33d: oxygen side electrode (outer electrode)
34 gas flow passage 34a gas outlet 55 non-power generation part

Claims (7)

At least a solid electrolyte and an outer electrode are sequentially provided on the porous conductive support in which the gas flow passage is formed, and the gas is discharged from the gas discharge port in the vicinity of the gas discharge port of the porous conductive support. A fuel cell in which gas is burned, wherein a porous conductive support around the gas outlet is impregnated with an inorganic component. 2. The fuel cell according to claim 1, wherein an inner electrode, a solid electrolyte, and an outer electrode are sequentially provided on the porous conductive support. 3. The fuel cell according to claim 1, wherein one end on the gas outlet side is a non-power generation portion, and the porous conductive support in the non-power generation portion is impregnated with an inorganic component. The fuel cell according to any one of claims 1 to 3, wherein the porous conductive support contains Ni and / or NiO. Fuel cell according to any one of claims 1 to 4 inorganic component is characterized by a main component ZrO _2. The fuel cell according to any one of claims 1 to 5, wherein a dense solid electrolyte is provided on an outer surface of the porous conductive support in the non-power generation portion. A fuel cell comprising a plurality of the fuel cells according to any one of claims 1 to 6 stored in a storage container.

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