JP6679652B2 - Fuel cell - Google Patents

Description

  The present invention relates to a fuel cell unit.

  BACKGROUND ART Conventionally, there has been known a fuel cell in which a fuel electrode current collector, a fuel electrode active part, a solid electrolyte, and an air electrode are sequentially stacked. In general, the fuel electrode current collector is arranged so as to cover the fuel electrode active portion arranged on the solid electrolyte for the purpose of expanding the power generation area of the fuel cell (see Patent Document 1).

JP, 2018-37401, A

  By the way, the fuel electrode current collector is made of a material having electron conductivity, while the solid electrolyte is made of a material having oxide ion conductivity but not electron conductivity. Therefore, peeling is likely to occur in the contact region between the fuel electrode current collector made of different materials and the solid electrolyte.

  An object of the present invention is to provide a fuel battery cell capable of suppressing peeling of a solid electrolyte.

  The fuel cell according to the present invention includes a fuel electrode current collector, a fuel electrode active part disposed on the fuel electrode current collector, and a solid electrolyte disposed on the fuel electrode active part. The average Zr concentration of the anode active portion is higher than the average Zr concentration of the anode current collector and lower than the average Zr concentration of the solid electrolyte. The anode active portion has a first portion arranged between the anode current collector and the solid electrolyte, and a second portion exposed from the anode current collector.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell which can suppress peeling of a solid electrolyte can be provided.

The perspective view of the fuel cell concerning an embodiment. Sectional drawing of the fuel cell which concerns on embodiment. The figure which shows the manufacturing method of the fuel cell which concerns on embodiment. The figure which shows the manufacturing method of the fuel cell which concerns on embodiment. The figure which shows the manufacturing method of the fuel cell which concerns on embodiment. The figure which shows the manufacturing method of the fuel cell which concerns on embodiment. The figure which shows the manufacturing method of the fuel cell which concerns on embodiment. The figure which shows the manufacturing method of the fuel cell which concerns on embodiment. The figure which shows the manufacturing method of the fuel cell which concerns on embodiment. Sectional drawing of the fuel cell which concerns on the modification 1. FIG. Sectional drawing of the fuel cell which concerns on the modification 2. FIG.

  Hereinafter, embodiments of the fuel cell 301 will be described with reference to the drawings. FIG. 1 is a perspective view of the fuel cell 301. FIG. 2 is a sectional view taken along line AA of FIG.

  The fuel cell 301 is formed in a plate shape extending in the longitudinal direction (x-axis direction). The fuel cell 301 according to the present embodiment is a so-called horizontal stripe fuel cell. The fuel cell unit 301 includes a plurality of power generation element units 10, a support substrate 20, and a plurality of interconnectors 31.

[Supporting substrate 20]
The support substrate 20 has therein a plurality of gas flow paths 21 extending along the longitudinal direction (x-axis direction) of the support substrate 20. Each gas flow path 21 extends substantially parallel to each other.

  As shown in FIG. 2, the support substrate 20 has a first main surface 22, a plurality of recesses 23, and a second main surface 24. In the fuel cell 301 according to the present embodiment, the first main surface 22 side and the second main surface 24 side of the support substrate 20 are configured in the same manner, and therefore the configuration on the first main surface 22 side will be described below. Mainly explained.

  Each recess 23 is formed in the first major surface 22. The recesses 23 are arranged at intervals in the longitudinal direction of the support substrate 20. The recesses 23 are not formed at both ends of the support substrate 20 in the width direction (y-axis direction).

The support substrate 20 is made of a porous material having no electronic conductivity. The support substrate 20 can be made of, for example, CSZ (calcia-stabilized zirconia). Alternatively, the support substrate 20 may be composed of NiO (nickel oxide) and YSZ (8YSZ) (yttria-stabilized zirconia), or may be composed of MgO (magnesium oxide) and Y ₂ O ₃ (yttria). Alternatively, it may be composed of NiO (nickel oxide) and Y ₂ O ₃ , or may be composed of MgO and MgAl ₂ O ₄ (magnesia alumina spinel). The porosity of the support substrate 20 is, for example, about 20 to 60%.

  The supporting substrate 20 may contain Zr (zirconia) or may not contain Zr. When the support substrate 20 contains Zr, the average Zr concentration in the support substrate 20 may be lower than the average Zr concentration in the solid electrolyte 5 described below, or may be lower than the average Zr concentration in the fuel electrode active part 42. The average Zr concentration in the support substrate 20 is not particularly limited, but can be 0.1% by mass to 70% by mass, for example. The average Zr concentration in the support substrate 20 is obtained by measuring the Zr concentration at four points that divide the inner surface of the gas flow path 21 to the first main surface 22 into 5 equal parts in the cross section shown in FIG. Obtained by taking the arithmetic mean. The Zr concentration is the ratio of the Zr mass to the total cation mass, which is measured using a scanning electron microscope (SU3500 manufactured by Hitachi High-Tech Co., Ltd.) and an energy dispersive X-ray analyzer (EDAX Apollo manufactured by AMETEK).

[Power generation element part 10]
The fuel battery cell 301 includes four power generation element units 10 arranged on the first main surface 22 side of the support substrate 20 and four power generation element units 10 arranged on the second main surface 24 side. In FIG. 2, three power generating element units 10 arranged on the first main surface 22 side of the support substrate 20 and two power generating element units 10 arranged on the second main surface 24 side are illustrated.

  Each power generation element unit 10 is supported by the support substrate 20. The power generation element units 10 are arranged at intervals in the longitudinal direction of the support substrate 20. The power generating element units 10 adjacent to each other in the longitudinal direction are electrically connected to each other by the interconnector 31.

  Each power generation element unit 10 has a fuel electrode 4, a solid electrolyte 5, an air electrode 6, and a reaction prevention film 7. The fuel electrode 4, the solid electrolyte 5, the reaction preventing film 7, and the air electrode 6 are arranged in this order from the support substrate 20 side. Each power generation element unit 10 has the same configuration as each other.

[Fuel electrode 4]
The fuel electrode 4 is a fired body made of a porous material having electronic conductivity. The fuel electrode 4 has a fuel electrode current collector 41 and a fuel electrode active part 42.

[Fuel electrode current collector 41]
The fuel electrode current collector 41 is arranged in the recess 23. Specifically, the fuel electrode current collector 41 is filled in the recess 23 and has the same outer shape as the recess 23. Each fuel electrode current collector 41 has a second main surface 411. In the present embodiment, the second main surface 411 is substantially on the same plane as the first main surface 22 of the support substrate 20. That is, the first main surface 22 of the support substrate 20 and the second main surface 411 of each fuel electrode current collector 41 form one plane. However, the second main surface 411 does not have to be completely on the same plane as the first main surface 22. For example, there may be a step difference of about 20 μm or less between the first main surface 22 and the second main surface 411. The second main surface 411 is a flat surface, and no recess is formed on the second main surface 411.

  The fuel electrode current collector 41 has electronic conductivity. The fuel electrode current collector 41 preferably has higher electron conductivity than the fuel electrode active portion 42. The fuel electrode current collector 41 may or may not have oxide ion (oxygen ion) conductivity.

The fuel electrode current collector 41 can be made of, for example, NiO (nickel oxide) and YSZ (8YSZ) (yttria-stabilized zirconia). Alternatively, the fuel electrode current collector 41 may be made of NiO (nickel oxide) and Y ₂ O ₃ (yttria), or NiO (nickel oxide) and CSZ (calcia-stabilized zirconia). Good. The thickness of the fuel electrode current collector 41 and the depth of the recess 23 are about 50 to 500 μm.

  The fuel electrode current collector 41 may contain Zr or may not contain Zr. When the fuel electrode current collector 41 contains Zr, the average Zr concentration in the fuel electrode current collector 41 is lower than the average Zr concentration in the solid electrolyte 5 and lower than the average Zr concentration in the fuel electrode active part 42. The average Zr concentration in the fuel electrode current collector 41 is not particularly limited, but may be, for example, 10% by mass to 70% by mass. The average Zr concentration in the fuel electrode current collector 41 was obtained by measuring the Zr concentration at four points that divide the fuel electrode current collector 41 into five equal parts in the thickness direction (z-axis direction) in the cross section shown in FIG. It is obtained by arithmetically averaging the Zr concentration. The Zr concentration is the ratio of the Zr mass to the total cation mass, which is measured using a scanning electron microscope (SU3500 manufactured by Hitachi High-Tech Co., Ltd.) and an energy dispersive X-ray analyzer (EDAX Apollo manufactured by AMETEK).

[Fuel electrode active part 42]
The anode active portion 42 is not embedded in the anode current collector 41. The fuel electrode active portion 42 is arranged across the second main surface 411 of the fuel electrode current collector 41 and the first main surface 22 of the support substrate 20. That is, in the longitudinal direction (x-axis direction), one end edge of the fuel electrode active portion 42 extends outside the one end edge of the fuel electrode current collector 41.

  Specifically, the fuel electrode active portion 42 has a first portion 42a arranged between the fuel electrode current collector 41 and the solid electrolyte 5, and a second portion 42b exposed from the fuel electrode current collector 41. .

  The first portion 42 a is a region of the fuel electrode active portion 42 sandwiched between the fuel electrode current collector 41 and the solid electrolyte 5. The first portion 42a contacts the fuel electrode current collector 41 and the solid electrolyte 5, respectively.

  The second portion 42b is a region of the fuel electrode active portion 42 that extends outside the one end edge of the fuel electrode current collector 41. The second portion 42b is arranged between the support substrate 20 and the solid electrolyte 5. The second portion 42b is in contact with each of the support substrate 20 and the solid electrolyte 5 and is not in contact with the fuel electrode current collector 41. By providing such a second portion 42b, the region where the fuel electrode current collector 41 is in contact with the solid electrolyte 5 can be reduced.

  Here, the average Zr concentration in the fuel electrode active portion 42 is lower than the average Zr concentration in the solid electrolyte 5 and higher than the average Zr concentration in the fuel electrode current collector 41. Therefore, the difference in Zr concentration between the anode active portion 42 and the solid electrolyte 5 is smaller than the difference in Zr concentration between the anode current collector 41 and the solid electrolyte 5. Therefore, the anode active portion 42 has a higher affinity with the solid electrolyte 5 in terms of material composition than the anode current collector 41. The average Zr concentration in the fuel electrode active part 42 is not particularly limited, but can be, for example, 10% by mass to 70% by mass. The average Zr concentration in the anode active portion 42 is obtained by measuring the Zr concentration at four points that divide the anode current collector 41 into five equal parts in the thickness direction (z-axis direction) in the cross section shown in FIG. Obtained by arithmetically averaging the concentrations. The Zr concentration is the ratio of the Zr mass to the total cation mass, which is measured using a scanning electron microscope (SU3500 manufactured by Hitachi High-Tech Co., Ltd.) and an energy dispersive X-ray analyzer (EDAX Apollo manufactured by AMETEK).

  Thus, by providing the second portion 42b in the fuel electrode active portion 42 having a high affinity with the solid electrolyte 5, the contact area between the fuel electrode current collector 41 and the solid electrolyte 5 can be reduced, It is possible to suppress peeling from occurring in the contact region between the fuel electrode current collector 41 and the solid electrolyte 5.

[Solid electrolyte 5]
The solid electrolyte 5 is arranged so as to cover the fuel electrode 4. Specifically, the solid electrolyte 5 extends from one interconnector 31 to another interconnector 31 in the longitudinal direction (x-axis direction) of the support substrate 20. A gas barrier layer is configured by the solid electrolytes 5 and the interconnectors 31 that are alternately arranged in the longitudinal direction of the support substrate 20.

  The solid electrolyte 5 is made of a dense material having oxide ion conductivity and electron conductivity. The solid electrolyte 5 can be composed of, for example, YSZ (8YSZ) (yttria-stabilized zirconia). The thickness of the solid electrolyte 5 is, for example, about 3 to 50 μm.

  The average Zr concentration in the solid electrolyte 5 is higher than the average Zr concentration in the anode active portion 42 and higher than the average Zr concentration in the anode current collector 41. The difference in Zr concentration between the anode active portion 42 and the solid electrolyte 5 is smaller than the difference in Zr concentration between the anode current collector 41 and the solid electrolyte 5. Therefore, the solid electrolyte 5 has a higher affinity with the anode active portion 42 in terms of material composition than the anode current collector 41. The average Zr concentration in the solid electrolyte 5 is not particularly limited, but can be, for example, 80% by mass to 95% by mass. For the average Zr concentration in the solid electrolyte 5, the Zr concentration is measured at four points that divide the solid electrolyte 5 into five equal parts in the thickness direction (z-axis direction) in the cross section shown in FIG. 2, and the obtained Zr concentration is arithmetically averaged. Obtained by The Zr concentration is the ratio of the Zr mass to the total cation mass, which is measured using a scanning electron microscope (SU3500 manufactured by Hitachi High-Tech Co., Ltd.) and an energy dispersive X-ray analyzer (EDAX Apollo manufactured by AMETEK).

[Reaction prevention film 7]
The reaction prevention film 7 is made of a dense material. The reaction prevention film 7 is arranged between the solid electrolyte 5 and an air electrode active part 61 described later. The reaction prevention film 7 is provided in order to prevent YSZ in the solid electrolyte 5 and Sr in the air electrode active portion 61 from reacting with each other to form a reaction layer having a large electric resistance. The reaction prevention film 7 can be composed of, for example, GDC = (Ce, Gd) O ₂ (gadolinium-doped ceria). The thickness of the reaction prevention film 7 is, for example, about 3 to 50 μm. In the present embodiment, the reaction prevention film 7 is also disposed between the solid electrolyte 5 and the air electrode current collector 62, which will be described later, but is disposed between the solid electrolyte 5 and the air electrode current collector 62. It does not have to be done.

[Air electrode 6]
The air electrode 6 is made of a porous material having electronic conductivity. The air electrode 6 is arranged on the opposite side of the fuel electrode 4 via the solid electrolyte 5. The air electrode 6 has an air electrode active portion 61 and an air electrode current collecting portion 62.

[Air electrode active part 61]
The air electrode active portion 61 is disposed on the reaction prevention film 7. The air electrode active portion 61 has not only oxide ion conductivity but also electron conductivity. The air electrode active portion 61 has a higher content rate of the substance having oxide ion conductivity than the air electrode current collecting portion 62. Specifically, the volume ratio of the substance having oxide ion conductivity to the total volume excluding the pores in the air electrode active portion 61 is determined by the oxide volume with respect to the total volume excluding the pores in the air electrode collector 62. It is larger than the volume ratio of the substance having ion conductivity.

The air electrode active part 61 may be composed of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, the air electrode active part 61 may be LSF = (La, Sr) FeO ₃ (lanthanum strontium ferrite), LNF = La (Ni, Fe) O ₃ (lanthanum nickel ferrite), or LSC = (La, Sr) CoO. ₃ (lanthanum strontium cobaltite) or the like. The air electrode active portion 61 may be composed of two layers, a first layer (inner layer) made of LSCF and a second layer (outer layer) made of LSC. The thickness of the air electrode active portion 61 is, for example, 10 to 100 μm.

[Air electrode current collector 62]
The air electrode current collector 62 is disposed on the air electrode active portion 61. The air electrode current collector 62 extends from the air electrode active portion 61 toward the adjacent power generation element unit 10. The air electrode current collector 62 is arranged so as to cover the interconnector 31. In the present embodiment, the air electrode current collector 62 is arranged so as to cover the entire interconnector 31, but it may cover only part of the interconnector 31.

  The air electrode current collector 62 is made of a porous material having electronic conductivity. The air electrode current collector 62 preferably has higher electron conductivity than the air electrode active portion 61. The air electrode current collector 62 may or may not have oxide ion conductivity.

The air electrode current collector 62 can be made of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, the air electrode current collector 62 may be made of LSC = (La, Sr) CoO ₃ (lanthanum strontium cobaltite). Alternatively, the air electrode current collector 62 may be made of Ag (silver) or Ag-Pd (silver-palladium alloy). The thickness of the air electrode current collector 62 is, for example, about 50 to 500 μm.

[Interconnector 31]
The interconnector 31 is configured to electrically connect the two power generating element units 10 that are adjacent to each other in the longitudinal direction (x-axis direction) of the support substrate 20. Specifically, the interconnector 31 electrically connects the fuel electrode current collector 41 of one power generating element unit 10 and the air electrode current collector 62 of the other power generating element unit 10.

  The interconnector 31 is arranged on the second main surface 411 of the fuel electrode current collector 41. That is, the interconnector 31 is not embedded in the fuel electrode current collector 41. The interconnector 31 is arranged on the second main surface 411 with a space from the fuel electrode active portion 42.

The interconnector 31 is made of a dense material having electronic conductivity. The interconnector 31 may be made of LaCrO ₃ (lanthanum chromite), for example. Alternatively, the interconnector 31 may be composed of (Sr, La) TiO ₃ (strontium titanate).

  The thickness of the interconnector 31 is not particularly limited, but is 10 to 100 μm, for example. The porosity of the interconnector 31 is, for example, preferably 20% or less, more preferably 10% or less.

[Manufacturing Method of Fuel Cell 301]
Next, a method for manufacturing the fuel cell 301 configured as described above will be described. In FIGS. 3 to 9, “g” at the end of the reference numeral of each member indicates that the member has not been fired yet.

  First, as shown in FIG. 3, a support substrate molded body 20g is manufactured. The molded body 20g of the supporting substrate is formed by using a kneaded material obtained by adding a binder or the like to the powder of the material of the supporting substrate 20 (for example, CSZ), and using a method such as extrusion molding and cutting. Can be made.

  When the molded body 20g of the supporting substrate is produced, next, as shown in FIG. 4, the recesses 23 in the upper and lower surfaces of the molded body 20g of the supporting substrate are filled with the molded body 41g of the fuel electrode current collector. The molded body 41g of the fuel electrode current collector is produced, for example, by a printing method using a slurry obtained by adding a binder or the like to the powder of the material of the fuel electrode current collector 41 described above.

  Next, as shown in FIG. 5, a molded film 42g of the fuel electrode active portion is formed so as to extend over the molded body 41g of the fuel electrode current collector and the molded body 20g of the support substrate. The formed film 42g is formed by, for example, a printing method using a slurry obtained by adding a binder or the like to the powder of the material of the fuel electrode active portion 42 described above.

  Further, a molded film 31g of the interconnector is formed on the molded body 41g of each fuel electrode current collector. The molding film 31g of each interconnector is formed by, for example, a printing method using a slurry obtained by adding a binder or the like to the powder of the material of the interconnector 31 described above.

  Next, as shown in FIG. 6, a molded film 5g of solid electrolyte is formed on the molded film 42g of the fuel electrode active portion. Specifically, the solid electrolyte molded film 5g is formed between the adjacent interconnector molded films 31g. As a result, the molded body 20g of the support substrate in which the molded body 41g of the fuel electrode current collector and the molded film 42g of the active portion of the fuel electrode are formed is the molded film 31g of the interconnector and the molded film 5g of the solid electrolyte. Covered by. The solid electrolyte molded film 5g is formed by, for example, a printing method or a dipping method using a slurry obtained by adding a binder or the like to the powder of the material of the solid electrolyte 5 described above.

  Next, as shown in FIG. 7, the reaction preventive film 7g is formed on the solid electrolyte film 5g. The molded film 7g of each reaction-preventing film is formed by, for example, a printing method using a slurry obtained by adding a binder or the like to the powder of the material of the reaction-preventing film 7 described above.

  Then, the molded body 20g of the supporting substrate on which various molded films are formed is fired in the air at about 1000 to 1500 ° C. for about 1 to 5 hours. As a result, a fuel cell in which the air electrode 6 is not formed is obtained.

  Next, as shown in FIG. 8, a forming film 61g of the air electrode active portion is formed on each reaction preventing film 7. The formed film 61g of each air electrode active portion is formed by a printing method or the like using, for example, a slurry obtained by adding a binder or the like to the powder of the material of the air electrode active portion 61 described above.

  Next, as shown in FIG. 9, a molded film 62g of the air electrode current collector is formed so as to straddle the molded film 61g of the air electrode active part and the interconnector 31 of the adjacent power generating element part. That is, the molded film 62g of the air electrode current collector is formed on the molded film 61g of the air electrode active part, the solid electrolyte 5, and the interconnector 31. The formed film 62g of each air electrode current collector is formed by, for example, a printing method using a slurry obtained by adding a binder or the like to the powder of the material of the air electrode current collector 62 described above.

  Then, the support substrate 20 on which the air electrode molding films 61g and 62g are formed is fired in air at about 800 to 1200 ° C. for about 1 to 5 hours. As a result, the fuel cell 301 is completed.

[Modification]
The embodiments of the present invention have been described above, but the present invention is not limited to these, and various modifications can be made without departing from the spirit of the present invention.

  In the above embodiment, the case where the fuel electrode active portion according to the present invention is applied to the horizontal stripe type fuel battery cell has been described, but the fuel electrode active portion according to the present invention can be applied to various fuel battery cells.

Modification 1
The fuel electrode active part according to the present invention can be applied to an electrolyte-supporting fuel cell 302 as shown in FIG. The fuel cell 302 has a solid electrolyte 100, a fuel electrode active part 101, a fuel electrode current collector 102, and an air electrode 103. The constituent materials and the like of each member are the same as those described in the above embodiment.

  The solid electrolyte 100 has a first main surface 100S and a second main surface 100T. The solid electrolyte 100 is a support substrate for the fuel cell 302. The fuel electrode active part 101 is arranged on the first main surface 100S of the solid electrolyte 100. The fuel electrode current collector 102 is disposed on the fuel electrode active portion 101. The air electrode 103 is arranged on the second main surface 100T of the solid electrolyte 100.

  The anode active portion 101 has a first portion 101 a arranged between the anode current collector 102 and the solid electrolyte 100, and a second portion 101 b exposed from the anode current collector 102. The average Zr concentration in the anode active portion 101 is lower than the average Zr concentration in the solid electrolyte 100 and higher than the average Zr concentration in the anode current collector 102. Thus, by providing the second portion 101b in the fuel electrode active portion 101 having a high affinity with the solid electrolyte 100, it is possible to reduce the contact area between the fuel electrode current collector 102 and the solid electrolyte 100. It is possible to suppress peeling from occurring in the contact region between the fuel electrode current collector 102 and the solid electrolyte 100.

Modification 2
The fuel electrode active part according to the present invention is applicable to a cathode-supported fuel cell 303 as shown in FIG. The fuel cell 303 has an air electrode 104, a solid electrolyte 105, a fuel electrode active section 106, and a fuel electrode current collector 107. The constituent materials and the like of each member are the same as those described in the above embodiment.

  The air electrode 104 has a first main surface 104S and a second main surface 104T. The air electrode 104 is a support substrate for the fuel cell 303. The solid electrolyte 105 is arranged on the first main surface 104S of the air electrode 104. The solid electrolyte 105 is a film formed on the first main surface 104S of the air electrode 104. The solid electrolyte 105 has a main surface 105S. The fuel electrode active portion 106 is arranged on the main surface 105S of the solid electrolyte 105. The fuel electrode current collector 107 is disposed on the fuel electrode active part 106.

  The anode active portion 106 has a first portion 106 a arranged between the anode current collector 107 and the solid electrolyte 105, and a second portion 106 b exposed from the anode current collector 107. The average Zr concentration in the anode active portion 106 is lower than the average Zr concentration in the solid electrolyte 105 and higher than the average Zr concentration in the anode current collector 107. As described above, by providing the second portion 106b in the fuel electrode active portion 106 having a high affinity with the solid electrolyte 105, the contact area between the fuel electrode current collector 107 and the solid electrolyte 105 can be reduced, It is possible to suppress peeling from occurring in the contact region between the fuel electrode current collector 107 and the solid electrolyte 105.

41: fuel electrode current collector 42: fuel electrode active part 42a: first portion 42b: second portion 5: solid electrolyte 6: air electrode 20: support substrate 22: first main surface (an example of main surface)
23: Recess 301: Fuel cell 100: Solid electrolyte (an example of a supporting substrate)
100S: First main surface (an example of main surface)
101: fuel electrode active part 101a: first part 101b: second part 102: fuel electrode current collector part 103: air electrode 302: fuel cell 104: air electrode (an example of a support substrate)
105: Solid electrolyte (example of membrane)
106: Fuel electrode active part 106a: First part 106b: Second part 107: Fuel electrode current collector part 303: Fuel cell

Claims (3)

A fuel electrode current collector,
A fuel electrode active portion disposed on the fuel electrode current collector,
A solid electrolyte disposed on the fuel electrode active portion,
Equipped with
The average Zr concentration of the anode active portion is higher than the average Zr concentration of the anode current collector and lower than the average Zr concentration of the solid electrolyte,
The anode active portion has a first portion arranged between the anode current collector and the solid electrolyte, and a second portion exposed from the anode current collector.
Fuel cell. A support substrate having a main surface and a recess formed in the main surface;
The anode current collector is disposed in the recess,
The second portion of the anode active portion is disposed on the main surface,
The fuel cell according to claim 1. The solid electrolyte is a supporting substrate having a main surface , or is a film having a main surface formed on the supporting substrate,
The anode active portion is disposed on the main surface of the supporting substrate or the membrane ,
The fuel cell according to claim 1.

Images