JP5805232B2 - Solid oxide fuel cell - Google Patents

Description

  The present invention relates to a solid oxide fuel cell including an air electrode.

  A solid oxide fuel cell generally includes a fuel electrode, an air electrode, and a solid electrolyte layer disposed between the fuel electrode and the air electrode.

Here, in Patent Document 1, an air electrode current collector composed of La (Ni, Cu, Fe) O ₃ on an air electrode active layer composed of a perovskite complex oxide represented by the general formula ABO _3. Techniques for forming layers have been proposed.

JP2012-49115A

  However, in the solid oxide fuel cell described in Patent Document 1, the air electrode active layer and the air electrode current collector are sintered during sintering of the air electrode active layer and the air electrode current collector layer or during power generation of the solid oxide fuel cell. Peeling may occur at the interface of the layers.

  The present invention has been made in view of the above-described situation, and an object of the present invention is to provide a solid oxide fuel cell capable of suppressing the occurrence of peeling at the interface between the air electrode active layer and the air electrode current collecting layer. To do.

The solid oxide fuel cell according to the present invention includes a fuel electrode, an air electrode, and a solid electrolyte layer disposed between the fuel electrode and the air electrode. The air electrode has an air electrode current collecting layer and an air electrode active layer disposed on the solid electrolyte layer side of the air electrode current collecting layer. The air electrode current collecting layer is represented by the general formula ABO ₃ and contains, as a main component, a perovskite complex oxide containing at least La at the A site and at least Ni, Fe, and Cu at the B site. The air electrode active layer is represented by the general formula ABO ₃ and contains a perovskite complex oxide containing at least one of La and Sr at the A site as a main component. The air electrode current collecting layer is represented by the general formula ABO ₃ in an interface region within a predetermined distance from the interface between the air electrode current collecting layer and the air electrode active layer, and includes at least La and Sr at the A site, and at the B site. It contains a perovskite complex oxide containing at least Ni, Fe and Cu.

  ADVANTAGE OF THE INVENTION According to this invention, the solid oxide fuel cell which can suppress that peeling arises in the interface of an air electrode active layer and an air electrode current collection layer can be provided.

Enlarged sectional view showing the structure of a solid oxide fuel cell SEM image showing cross section of air electrode

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the ratio of each dimension may be different from the actual one. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Configuration of Solid Oxide Fuel Cell 10)
A configuration of a solid oxide fuel cell (SOFC) 10 will be described with reference to the drawings. FIG. 1 is an enlarged cross-sectional view showing a configuration of a solid oxide fuel cell 10.

  The solid oxide fuel cell 10 is a vertical, horizontal, fuel electrode support, electrolyte flat plate, or cylindrical fuel cell. As shown in FIG. 1, the solid oxide fuel cell 10 includes a fuel electrode 20, a solid electrolyte layer 30, a barrier layer 40, and an air electrode 50.

  The fuel electrode 20 functions as an anode of the solid oxide fuel cell 10. As illustrated in FIG. 1, the fuel electrode 20 includes a fuel electrode current collecting layer 21 and a fuel electrode active layer 22.

The anode current collecting layer 21 is a porous plate-like fired body. As a constituent material of the anode current collecting layer 21, materials conventionally used for SOFC anode current collecting layers can be used, and examples thereof include NiO / Ni—Y ₂ O ₃ . The thickness of the anode current collecting layer 21 can be set to 0.2 mm to 5.0 mm.

  The anode active layer 22 is disposed on the anode current collecting layer 21. The anode active layer 22 is a porous plate-like fired body. As a constituent material of the anode active layer 22, materials conventionally used for SOFC anode active layers can be used, and examples thereof include NiO / Ni-8YSZ. The thickness of the anode active layer 22 can be 5 μm to 30 μm.

  The solid electrolyte layer 30 is disposed between the fuel electrode 20 and the barrier layer 40. The solid electrolyte layer 30 has a function of transmitting oxygen ions generated at the air electrode 50. Examples of the material of the solid electrolyte layer 30 include yttria-stabilized zirconia such as 3YSZ, 8YSZ, and 10YSZ, and zirconia-based materials such as ScSZ. The thickness of the solid electrolyte layer 30 can be 3 μm to 30 μm.

The barrier layer 40 is disposed between the solid electrolyte layer 30 and the air electrode 50. The barrier layer 40 has a function of suppressing the formation of a high resistance layer between the solid electrolyte layer 30 and the air electrode 50. Examples of the material of the barrier layer 40 include ceria (CeO ₂ ) and a ceria-based material containing a rare earth metal oxide dissolved in CeO ₂ . Examples of such ceria-based materials include gadolinium-doped ceria (GDC) and samarium-doped ceria (SDC). The thickness of the barrier layer 40 can be 3 μm to 20 μm.

  The air electrode 50 is disposed on the barrier layer 40. The air electrode 50 functions as a cathode of the solid oxide fuel cell 10. As shown in FIG. 1, the air electrode 50 has an air electrode current collecting layer 51 and an air electrode active layer 52.

  The air electrode current collecting layer 51 is a porous plate-like fired body. The thickness of the air electrode current collecting layer 51 can be 10 μm to 500 μm.

The air electrode current collecting layer 51 is represented by the general formula ABO ₃ and contains, as a main component, a perovskite complex oxide containing at least La at the A site and containing at least Ni, Fe, and Cu at the B site. Such a perovskite complex oxide can be represented by the following formula (1). However, substances other than La may be contained in the A site of the formula (1), and substances other than Ni, Fe and Cu may be contained in the B site.

_{La m (Ni 1-x-} y Fe x Cu y) n O 3-δ ··· (1)
In the formula (1), m and n are 0.95 or more and 1.05 or less, x is 0.03 or more and 0.3 or less, y is 0.05 or more and 0.5 or less, and δ Is 0 or more and 0.8 or less. In the following description, the oxide of the formula (1) is expressed as La (Ni, Fe, Cu) O ₃ .

  In the present embodiment, the composition X “contains the substance Y as a main component” means that the substance Y preferably accounts for 60% by weight or more, more preferably 70% by weight or more in the entire composition X. Means more preferably 90% by weight or more.

  Here, FIG. 2 is a SEM (Scanning Electron Microscope) image showing a cross section of the air electrode 50. As shown in FIG. 2, the air electrode current collecting layer 51 includes a region (hereinafter referred to as “interface region”) 51 a within a predetermined distance Da from the interface P with the air electrode active layer 52. The predetermined distance Da can be 0.1 μm to 30 μm.

The air electrode current collecting layer 51 is represented by the general formula ABO ₃ in the interface region 51a, and contains a perovskite complex oxide containing at least La and Sr at the A site and at least Ni, Fe and Cu at the B site. It may be. Such a perovskite complex oxide can be represented by the following formula (2). However, substances other than La and Sr may be included in the A site of the formula (2), and substances other than Ni, Fe, and Cu may be included in the B site.

_{(La 1-a Sr a)} m (Ni 1-x-y Fe x Cu y) n O 3-δ ··· (2)
In Formula (2), a is 0.01 or more and 0.5 or less, and m and n are 0.95 or more and 1.05 or less. In the formula (2), x is 0.03 or more and 0.3 or less, y is 0.05 or more and 0.5 or less, and δ is 0 or more and 0.8 or less. In the following description, the compound of the formula (2) is expressed as (La, Sr) (Ni, Fe, Cu) O ₃ .

  In addition, the compound of Formula (2) should just be contained in one part particle | grains among all the particles which comprise the interface area | region 51a. Moreover, only one part of one particle may be comprised with the compound of Formula (2), and the whole one particle may be comprised with the compound of said Formula (2).

The area occupancy of (La, Sr) (Ni, Fe, Cu) O ₃ in an arbitrary cross section of the interface region 51a is preferably 0.1% or more. The area occupancy ratio of (La, Sr) (Ni, Fe, Cu) O _{3 in} the interface region 51a may decrease as the distance from the interface P increases, or may be uniform as a whole.

The area occupancy of (La, Sr) (Ni, Fe, Cu) O _{3 in} the interface region 51a is determined by SEM-EDS (energy dispersive X-ray analyzer: Energy Dispersion Spectroscopy) or EPMA (Electron Probe Microanalyzer: Electron Probe). It can be obtained by mapping the atomic concentration distribution of each constituent element by Micro Analyzer). That is, the area occupancy of (La, Sr) (Ni, Fe, Cu) O ₃ is detected by superimposing La, Sr, Ni, Fe, Cu, and O with respect to the entire area of the measurement area of the atomic concentration. It is the ratio of the total area of the area. The measurement target region may be, for example, the entire range measured by SEM-EDS, or may be a part of the actually measured range. The measurement target region preferably includes a plurality of regions where La, Sr, Ni, Fe, Cu, and O are detected in an overlapping manner.

When the air electrode current collecting layer 51 includes (La, Sr) (Ni, Fe, Cu) O ₃ in the interface region 51a, the predetermined distance Da indicating the thickness of the interface region 51a is the total thickness of the air electrode current collecting layer 51. It is preferable that it is 0.42% or more of Db.

The air electrode current collecting layer 51 is represented by the general formula ABO ₃ in the interface region 51a, and a perovskite type complex oxide containing at least La at the A site and at least Ni, Fe, Cu, and Co at the B site. You may contain. Such a perovskite complex oxide can be represented by the following formula (3). However, substances other than La may be included in the A site of the formula (3), and substances other than Ni, Fe, Cu, and Co may be included in the B site.

_{La m (Ni 1-x-} y-z Fe x Cu y Co z) n O 3-δ ··· (3)
In Formula (3), m and n are 0.95 or more and 1.05 or less, x is 0.02 or more and 0.2 or less, y is 0.05 or more and 0.5 or less, and z is 0. It is 0.01 or more and δ is 0 or more and 0.8 or less. In the following description, the compound of the formula (3) is expressed as La (Ni, Fe, Cu, Co) O ₃ .

  In addition, the compound of Formula (3) should just be contained in one part particle | grains among all the particles which comprise the interface area | region 51a. Moreover, only one part of one particle may be comprised with the compound of Formula (3), and one whole particle may be comprised with the compound of said Formula (3).

The area occupation ratio of La (Ni, Fe, Cu, Co) O _{3 in} the interface region 51a is preferably 0.03% or more. The area occupancy of La (Ni, Fe, Cu, Co) O _{3 in} the interface region 51a may decrease as the distance from the interface P increases, or may be uniform as a whole.

When the air electrode current collecting layer 51 includes La (Ni, Fe, Cu, Co) O ₃ in the interface region 51a, the predetermined distance Da indicating the thickness of the interface region 51a is equal to the total thickness Db of the air electrode current collecting layer 51. It is preferable that it is 0.60% or more.

  The air electrode active layer 52 is a porous plate-like fired body. The air electrode active layer 52 is disposed on the solid electrolyte layer 30 side of the air electrode current collecting layer 51. The air electrode active layer 52 forms an interface P with the air electrode current collecting layer 51. The thickness of the air electrode active layer 52 can be 10 μm to 100 μm.

The air electrode active layer 52 is represented by the general formula ABO ₃ and contains a perovskite complex oxide containing at least one of La and Sr at the A site as a main component. Such perovskite complex oxides include LSCF, that is, (La, Sr) (Co, Fe) O ₃ , LSF, that is, (La, Sr) FeO ₃ , LSC, that is, (La, Sr) CoO ₃ , LSM, that is, La , Sr) MnO _{3 and the} like.

  The air electrode active layer 52 contains a zirconia material or a ceria material including yttria stabilized zirconia such as 3YSZ, 8YSZ and 10YSZ and scandia stabilized zirconia such as ScSZ in order to improve oxygen ion conductivity. It may be.

(Method for Manufacturing Solid Oxide Fuel Cell 10)
Next, an example of a method for manufacturing the solid oxide fuel cell 10 will be described. However, various conditions such as the material, particle size, temperature, and coating method described below can be changed as appropriate.

  First, a molded body of the anode current collecting layer 21 is formed by molding an anode current collecting layer powder by a die press molding method.

  Next, a slurry is prepared by adding PVA (polyvinyl butyral) as a binder to a mixture of the fuel electrode active layer powder and a pore-forming agent (for example, PMMA (polymethyl methacrylate)). Then, the molded body of the anode active layer 22 is formed by printing the slurry on the molded body of the anode current collecting layer 21 using a printing method or the like. Thus, a molded body of the fuel electrode 20 is formed.

  Next, water and a binder are mixed with the solid electrolyte layer powder to prepare a slurry. Then, the molded body of the solid electrolyte layer 30 is formed by applying the slurry onto the molded body of the fuel electrode 20 using a coating method or the like.

  Next, water and a binder are mixed with the barrier layer powder to prepare a slurry. And the molded object of the barrier layer 40 is formed by apply | coating a slurry on the molded object of the solid electrolyte layer 30 using the apply | coating method.

  By co-sintering the laminate of each molded body produced as described above at 1300 to 1600 ° C. for 2 to 20 hours, a co-fired body of the fuel electrode 20, the dense solid electrolyte layer 30, and the dense barrier layer 40 is formed. To do.

  Next, water and a binder are mixed with air electrode active layer powder (for example, LSCF, LSF, LSC, and LSM-8YSZ) to prepare a slurry. And the molded object of the air electrode active layer 52 is formed by apply | coating a slurry on the barrier layer 40 using the apply | coating method.

Next, a slurry is prepared by mixing water and a binder with (La, Sr) (Ni, Fe, Cu) O ₃ powder. Then, by applying the slurry onto the molded body of the air electrode active layer 52 using a coating method or the like, a molded body of the interface region 51 a in the air electrode current collecting layer 51 is formed.

Next, water and a binder are mixed with La (Ni, Fe, Cu) O ₃ powder to prepare a slurry. Then, by applying the slurry onto the molded body in the interface region 51a using a coating method or the like, a molded body in a region other than the interface region 51a in the air electrode current collecting layer 51 is formed. Thus, a molded body of the air electrode 50 is formed.

  Next, the compact of the air electrode 50 formed on the co-fired body is sintered at 1000 to 1100 ° C. for 1 to 10 hours to complete a solid oxide fuel cell.

(Other embodiments)
The present invention is not limited to the embodiment described above, and various modifications or changes can be made without departing from the scope of the present invention.

  (A) Although not specifically mentioned in the above embodiment, the solid oxide fuel cell 10 includes other layers between the fuel electrode 20 and the solid electrolyte layer 30 and between the barrier layer 40 and the air electrode 50. It may be. For example, the solid oxide fuel cell 10 may include a porous barrier layer between the barrier layer 40 and the air electrode 50. Further, the solid oxide fuel cell 10 may not include the barrier layer 40.

(B) In the above embodiment, the air electrode current collecting layer 51 may include (La, Sr) (Ni, Fe, Cu) O ₃ represented by the formula (2) in the interface region 51a. However, the region other than the interface region 51a may contain (La, Sr) (Ni, Fe, Cu) O ₃ . Similarly, the air electrode current collecting layer 51 may include La (Ni, Fe, Cu, Co) O ₃ represented by the formula (3) in a region other than the interface region 51a.

  Examples of the cell according to the present invention will be described below. However, the present invention is not limited to the examples described below.

[Sample No. 1-No. Production of 38]
(Comparative example)
As a comparative example, Sample No. 1,8,13,16,19,26,31,35 were produced.

  First, a molded body of the air electrode active layer was formed from the powder for air electrode active layer described in Tables 1 and 2 using a screen printing method.

Next, water and a binder were mixed with La (Ni, Fe, Cu) O ₃ powder to prepare a slurry. And the molded object of the air electrode current collection layer was formed by apply | coating the slurry on the molded object of an interface area | region using the apply | coating method. Under the present circumstances, the thickness of the whole air cathode current collection layer was adjusted as shown in Table 1 and Table 2 by changing the application quantity of a slurry.

  Next, the air electrode which concerns on a comparative example was produced by baking the laminated body of each molded object of an air electrode active layer and an air electrode current collection layer at 1000-1100 degreeC for 1 to 5 hours.

(Example 1)
In the following manner, sample No. 2-7, 9-12, 14, 15, 17, 18, 20-25, 27-30, 32-34, 36-38 were produced.

  First, a molded body of the air electrode active layer was formed from the powder for air electrode active layer described in Tables 1 and 2 using a screen printing method.

Next, a mixed powder of La (Ni, Fe, Cu) O ₃ and (La, Sr) (Ni, Fe, Cu) O ₃ was mixed with water and a binder to prepare a slurry. And the molded object of the interface area | region was formed among the air electrode current collection layers by apply | coating a slurry on the molded object of an air electrode active layer using the apply | coating method. At this time, La (Ni, Fe, Cu ) O 3 with respect to powder (La, Sr) (Ni, Fe, Cu) O 3 by adjusting the amount of powder, in the interface region (La, Sr) (Ni, The area occupancy of Fe, Cu) O ₃ was adjusted for each sample as shown in Tables 1 and 2. Moreover, the thickness of the interface region (“predetermined distance Da” in the above embodiment) was adjusted for each sample as shown in Tables 1 and 2 by changing the amount of slurry applied.

Next, water and a binder were mixed with La (Ni, Fe, Cu) O ₃ powder to prepare a slurry. And the molded object of area | regions other than an interface area | region among air electrode current collection layers was formed by apply | coating a slurry on the molded object of an interface area | region using the apply | coating method. Under the present circumstances, the thickness of the whole air cathode current collection layer was adjusted for every sample as shown in Table 1 and Table 2 by changing the application quantity of a slurry.

  Next, an air electrode according to Example 1 was manufactured by firing a laminate of molded bodies of the air electrode active layer and the air electrode current collecting layer at 1000 to 1100 ° C. for 1 to 5 hours.

(Example 2)
In the following manner, sample No. 39-58 were produced.

  First, a molded body of an air electrode active layer was formed from the powder for air electrode active layer described in Tables 3 and 4 using a screen printing method.

Next, a mixed powder of La (Ni, Fe, Cu) O ₃ and La (Ni, Fe, Cu, Co) O ₃ was mixed with water and a binder to prepare a slurry. And the molded object of the interface area | region was formed among the air electrode current collection layers by apply | coating a slurry on the molded object of an air electrode active layer using the apply | coating method. At this time, by adjusting the amount of La (Ni, Fe, Cu, Co) O ₃ powder added to La (Ni, Fe, Cu) O ₃ powder, La (Ni, Fe, Cu, Co) in the interface region is adjusted. The area occupancy of O ₃ was adjusted for each sample as shown in Tables 3 and 4. Further, the thickness of the interface region was adjusted for each sample as shown in Tables 3 and 4 by changing the amount of slurry applied.

Next, water and a binder were mixed with La (Ni, Fe, Cu) O ₃ powder to prepare a slurry. And the molded object of area | regions other than an interface area | region among air electrode current collection layers was formed by apply | coating a slurry on the molded object of an interface area | region using the apply | coating method. Under the present circumstances, the thickness of the whole air cathode current collection layer was adjusted for every sample as shown in Table 3 and Table 4 by changing the application quantity of a slurry.

  Next, an air electrode according to Example 2 was manufactured by firing a laminate of molded bodies of the air electrode active layer and the air electrode current collecting layer at 1000 to 1100 ° C. for 1 to 5 hours.

[Area occupancy]
Sample No. 1-No. For 38, the area occupancy of (La, Sr) (Ni, Fe, Cu) O ₃ in the cross section of the interface region was calculated. Specifically, first, the concentration distribution of La, Sr, Ni, Fe, Cu, and O was mapped by SEM-EDS in the cross section of the air electrode current collecting layer. And the ratio of the total area of the area | region where La, Sr, Ni, Fe, Cu, and O were detected by overlapping was calculated with respect to the area of a measurement object area | region. The calculation results of area occupancy are summarized in Tables 1 and 2.

Sample No. 39-No. For 58, the area occupancy of La (Ni, Fe, Cu, Co) O ₃ in the cross section of the interface region was calculated. In calculating the area occupancy of La (Ni, Fe, Cu, Co) O ₃ , the concentration distribution of La, Ni, Fe, Cu, Co and O is mapped by SEM-EDS, and La, Ni, Fe, Cu are mapped. The ratio of the area where Co and O were detected in a superimposed manner was calculated. The calculation results of the area occupancy are summarized in Table 3 and Table 4.

[Presence or absence of peeling after firing]
Sample No. after firing 1-No. 18, no. 39-No. The cross section of 48 was observed with a microscope to confirm the presence or absence of peeling at the interface between the air electrode active layer and the air electrode current collecting layer. The confirmation results are summarized in Tables 1 and 3.

  In Tables 1 and 3, a sample in which peeling of 5 μm or more that could affect the air electrode characteristics was evaluated as “x”, and a sample in which peeling was not confirmed was evaluated as “◎”.

[Peeling after thermal cycle test]
Sample No. 19-No. 38, no. 49-No. With respect to 58, while maintaining the reducing atmosphere, the cycle of raising the temperature from room temperature to 800 ° C. in 2 hours and then lowering to room temperature in 4 hours was repeated 10 times.

  Thereafter, sample No. 19-No. 38, no. 49-No. The presence or absence of peeling at the interface between the air electrode active layer and the air electrode current collecting layer was confirmed by observing the 58 cross section with a microscope. The confirmation results are summarized in Table 2 and Table 4.

  In Tables 2 and 4, a sample in which peeling of 5 μm or more that could affect the air electrode characteristics was evaluated as “x”, and a sample in which only peeling of 5 μm or less was confirmed was evaluated as “◯”. Samples for which peeling was not confirmed were evaluated as “◎”.

As can be seen from Table 1, sample No. 1 containing particles of (La, Sr) (Ni, Fe, Cu) O ₃ in the interface region. In 2 to 7, 9 to 12, 14, 15, 17, and 18, it was possible to suppress the occurrence of separation that would affect the characteristics of the air electrode after firing the air electrode.

Therefore, when (La, Sr) (Ni, Fe, Cu) O ₃ is included in the interface region, the area occupation ratio of (La, Sr) (Ni, Fe, Cu) O ₃ is set to 0.1% or more. By doing this, it was confirmed that the interface peeling between the air electrode active layer and the air electrode current collecting layer can be suppressed.

  Further, as can be seen from Table 2, the thickness of the interface region (“predetermined distance Da” in the above embodiment) is 0.42% or more of the total thickness of the air electrode current collecting layer. In 21 to 25, 28 to 30, 33, 34, 37, and 38, no peeling was confirmed at the interface even after the thermal cycle test.

Therefore, when (La, Sr) (Ni, Fe, Cu) O ₃ is included in the interface region, the air electrode active layer and the air electrode are formed by setting the thickness of the interface region to 0.42% or more of the total thickness. It was confirmed that the interface peeling of the current collecting layer can be further suppressed.

As can be seen from Table 3, sample No. 1 containing La (Ni, Fe, Cu, Co) O ₃ in the interface region. In 40 to 44 and 46 to 48, it was possible to suppress the occurrence of peeling that would affect the characteristics of the air electrode after firing the air electrode.

Therefore, when La (Ni, Fe, Cu, Co) O ₃ is included in the interface region, by making the area occupancy of La (Ni, Fe, Cu, Co) O ₃ 0.03% or more, It was confirmed that interface peeling between the air electrode active layer and the air electrode current collecting layer can be suppressed.

  In addition, as can be seen from Table 4, the thickness of the interface region (“predetermined distance Da” in the above embodiment) is not less than 0.60% of the total thickness of the air electrode current collecting layer. In 50-54 and 56-5, peeling was not confirmed at the interface even after the thermal cycle test.

Accordingly, when La (Ni, Fe, Cu, Co) O ₃ is included in the interface region, the air electrode active layer and the air electrode current collector are obtained by setting the thickness of the interface region to 0.60% or more of the total thickness. It was confirmed that the interfacial peeling of the layer can be further suppressed.

DESCRIPTION OF SYMBOLS 10 Fuel cell 20 Fuel electrode 21 Fuel electrode current collection layer 22 Fuel electrode active layer 30 Solid electrolyte layer 40 Barrier layer 50 Air electrode 51 Air electrode current collection layer 52 Air electrode active layer

Claims (6)

An anode,
The air electrode,
A solid electrolyte layer disposed between the fuel electrode and the air electrode;
With
The air electrode includes an air electrode current collecting layer, and an air electrode active layer disposed on the solid electrolyte layer side of the air electrode current collecting layer,
The air electrode current collecting layer is represented by the general formula ABO ₃ and contains, as a main component, a perovskite type complex oxide containing at least La at the A site and at least Ni, Fe and Cu at the B site,
The air electrode active layer is represented by the general formula ABO ₃ and contains, as a main component, a perovskite complex oxide containing at least one of La and Sr at the A site.
The air electrode current collecting layer is a region within a predetermined distance from the interface between the air electrode current collecting layer and the air electrode active layer, and is represented by the general formula ABO ₃ and includes at least La and Sr at the A site. , Having an interface region which is a region containing a perovskite complex oxide containing at least Ni, Fe and Cu at the B site as an auxiliary component,
In the cross section of the interface region, the area occupancy of the perovskite complex oxide represented by the general formula ABO ₃ and containing at least La and Sr at the A site and at least Ni, Fe and Cu at the B site is 0.1. % Or more and 5.0% or less,
Solid oxide fuel cell. The predetermined distance is 0.42% or more of the thickness of the air electrode current collecting layer.
The solid oxide fuel cell according to claim 1. The predetermined distance is 27.3% or less of the thickness of the air electrode current collecting layer.
The solid oxide fuel cell according to claim 1 or 2. An anode,
The air electrode,
A solid electrolyte layer disposed between the fuel electrode and the air electrode;
With
The air electrode includes an air electrode current collecting layer, and an air electrode active layer disposed on the solid electrolyte layer side of the air electrode current collecting layer,
The air electrode current collecting layer is represented by the general formula ABO ₃ and contains, as a main component, a perovskite type complex oxide containing at least La at the A site and at least Ni, Fe and Cu at the B site,
The air electrode active layer is represented by the general formula ABO ₃ and contains, as a main component, a perovskite complex oxide containing at least one of La and Sr at the A site.
The air electrode current collecting layer is a region within a predetermined distance from the interface between the air electrode current collecting layer and the air electrode active layer, and is represented by the general formula ABO _{3. The} A site includes at least La, and B Having an interface region that is a region containing a perovskite complex oxide containing at least Ni, Fe, Cu, and Co as a subcomponent at the site;
In the cross section of the interface region, the area occupancy of the perovskite complex oxide represented by the general formula ABO ₃ and containing at least La at the A site and at least Ni, Fe, Cu, and Co at the B site is 0.03. % Or more and 4.5% or less,
Solid oxide fuel cell. The predetermined distance is 0.60% or more of the thickness of the air electrode current collecting layer.
The solid oxide fuel cell according to claim 4. The predetermined distance is 8.9% or less of the thickness of the air electrode current collecting layer.
The solid oxide fuel cell according to claim 4 or 5.