JP2001185159A - Solid electrolyte fuel cell and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid electrolyte fuel cell for obtaining initial high output density and maintaining high output density for a long period, and its manufacturing method. SOLUTION: The solid electrolyte fuel cell comprises a solid electrolyte 31 and a fuel pole 33 laminated in sequence on the surface of an air pole 32 formed of perovskite composite oxide containing at least La and Mn, wherein the amount of Mn in the fuel pole 33 is 0.35% by weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to
The present invention relates to a solid electrolyte type fuel cell in which a solid electrolyte and a fuel electrode containing metal particles are sequentially laminated, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, since a solid oxide fuel cell has a high operating temperature of 900 to 1050 ° C., it has a high power generation efficiency and is expected as a third generation power generation system.

[0003] In general, a cylindrical type and a flat type are known as solid oxide fuel cells. Flat fuel cells are
Although it has the feature that the power density per unit volume of power generation is high, there are problems such as incomplete gas sealing and non-uniformity of temperature distribution in the cell in practical use. On the other hand,
Cylindrical fuel cells are characterized by low mechanical strength of the cells, while maintaining a uniform temperature within the cells, although the output density is low. Both types of solid oxide fuel cells are being actively researched and developed utilizing their respective characteristics.

As shown in FIG. 3, a single cell of a cylindrical fuel cell has a porous air electrode support tube 2 made of a LaMnO ₃ -based material having an open porosity of about 30 to 40%, and Y is formed on the surface thereof. _A solid electrolyte 3 composed of ₂ O ₃ stabilized ZrO ₂ is coated, and a porous Ni-zirconia fuel electrode 4 is provided on the surface thereof.

In the fuel cell module, each single cell is connected via a LaCrO ₃ -based current collector (interconnector) 5. For power generation, air (oxygen) 6 flows inside the cathode support tube 2 and fuel (hydrogen) 7 flows outside, and 1000
It is performed at a temperature of 1050 ° C. In addition, as a support tube material having the function of an air electrode, La is made of Ca by 20%.
A solid solution material substituted by 10% to 15% by atom or Sr is used.

As a method of manufacturing the above-described fuel cell, for example, an insulating powder made of CaO-stabilized ZrO ₂ is formed into a cylindrical shape by an extrusion method or the like, and then fired to form a cylindrical support. Then, a slurry of an air electrode, a solid electrolyte, a fuel electrode, and a current collector is applied to the outer peripheral surface of the support, and the slurry is sequentially fired and laminated, or an electrochemical vapor deposition method is applied to the surface of the cylindrical support. An air electrode, a solid electrolyte, a fuel electrode, and a current collector are sequentially formed by (EVD method), a plasma spraying method, or the like.

In recent years, a so-called co-sintering method has been proposed in which at least two of the constituent materials are simultaneously fired in order to simplify the manufacturing process of the cell and reduce the manufacturing cost. In this co-sintering method, for example, a solid electrolyte molded body and a current collector molded body are wound in a roll shape around a cylindrical air electrode molded body, and simultaneously fired, and then a fuel electrode layer is formed on the surface of the solid electrolyte layer. Is the way. Further, for simplification of the process, a co-sintering method has been proposed in which a fuel electrode compact is further laminated on the surface of the solid electrolyte compact and fired simultaneously.

[0008] This co-sintering method is a very simple process with a small number of manufacturing steps, and is advantageous in improving the yield and cost reduction in manufacturing cells. In such a fuel cell by the co-sintering method, Y ₂ O ₃ stabilized or partially stabilized ZrO _{2 is used.}
LaMn is used as an air electrode material in order to match the coefficient of thermal expansion with the solid electrolyte.
A perovskite-type composite oxide composed of O _{3 in} which a part of La is substituted with Y and Ca is used (see Japanese Patent Application Laid-Open No. 10-162847).

[0009]

When a cylindrical fuel cell is manufactured by using the co-sintering method described above,
The Mn element, which is a component of the air electrode, evaporates into the atmosphere around the solid oxide fuel cell, and the evaporated Mn
Diffuses into the anode, as a result, the amount of Mn in the anode increases, the polarization value of the anode site and the actual resistance of the cell components are high, and as a result, the initial power density is low. there were.

An object of the present invention is to provide a solid oxide fuel cell capable of obtaining a high output density at an initial stage and maintaining a high output density for a long period of time, and a method for producing the same.

[0011]

The present inventors have found that there is a strong correlation between the Mn content inside the fuel electrode caused by diffusion and the power generation performance. As the Mn content inside the fuel electrode decreases, the polarization value of the fuel electrode site and the power generation performance decrease. The present inventors have found that the actual resistance value of the cell components can be reduced, and thereby the output density can be increased, leading to the present invention.

Further, the present inventors have found that the amount of Mn diffused into the fuel electrode depends on the La / Mn ratio of the LaMnO ₃ -based perovskite-type composite oxide (ABO ₃ ) constituting the air electrode, that is, the A site and the B site. (A / B ratio), and it was found that controlling the A / B ratio could reduce the amount of Mn diffused into the fuel electrode, leading to the present invention.

That is, the solid oxide fuel cell of the present invention has a solid electrolyte, a solid electrolyte, on the surface of an air electrode made of a perovskite-type composite oxide containing at least La and Mn.
In a solid oxide fuel cell unit in which fuel electrodes are sequentially stacked, the amount of Mn in the fuel electrode is 0.35% by weight or less.

By controlling the amount of Mn in the fuel electrode to 0.35% by weight or less in this manner, the polarization value of the fuel electrode site and the actual resistance value of the cell components can be reduced, thereby increasing the power density. And high power density can be maintained over a long period of time.

This is because, when the amount of Mn present in the fuel electrode is large, the sinterability of the fuel electrode is excessively promoted, the grain growth of the metal particles in the fuel electrode becomes excessive, and the metal particles and the solid electrolyte This is because the contact area with the anode decreases, and the polarization value of the fuel electrode site increases. Further, since Mn is precipitated between the metal particles, the conductivity decreases, and the actual resistance value of the cell component increases. .

The thickness of the fuel electrode is preferably 5 to 20 μm. With this, even if the air electrode molded body, the solid electrolyte molded body, and the fuel electrode molded body are sequentially laminated and fired at the same time, the stress caused by the difference in firing shrinkage generated in each molded body can be relaxed. The separation of the electrodes can be prevented, and the difference in firing shrinkage between the fuel electrode and the solid electrolyte can be reduced.

As described above, since the difference in firing shrinkage between the fuel electrode and the solid electrolyte can be reduced, it is possible to prevent cracks generated in the solid electrolyte from the interface between the solid electrolyte and the fuel electrode. As a result, an increase in the polarization value between the fuel electrode and the solid electrolyte and an increase in the actual resistance value of the solid electrolyte component can be prevented, and accordingly, an initial high power density can be maintained for a long period of time.

The method for producing a solid oxide fuel cell according to the present invention is characterized in that the surface of an air electrode molded body (which includes an air electrode calcined body) comprising a perovskite-type composite oxide containing at least La and Mn. A method for producing a solid electrolyte fuel cell, which comprises firing a laminated molded body formed by sequentially laminating a solid electrolyte molded body (including a calcined solid electrolyte body) and a fuel electrode molded body, The perovskite-type composite oxide constituting the compact is represented by an A site containing at least La and a B site containing at least Mn, and the ratio of the A site to the B site (A / B ratio) is 0. .95 to 0.99.

For example, when a cell is co-sintered using a cylindrical air electrode material made of a perovskite-type composite oxide containing La, Ca, Y and Mn, each component constituting the air electrode during co-sintering is obtained. Among the elements, the diffusion (evaporation and diffusion in the solid phase) of the Mn element is particularly fast. Therefore, in order to reduce the diffusion of the Mn element, free Mn
It is preferable to use a material in a composition region where an O-based oxide (second phase) does not exist, that is, a material having a stable stoichiometric composition (A / B ratio is 1) in which a perovskite (LaMnO ₃ ) phase is a single phase. When a material having a Mn-rich nonstoichiometric composition, that is, a material having a small A / B site ratio, is used, a MnO-based oxide is generated as a second phase in addition to a perovskite phase. Abnormally higher than.

On the other hand, when an air electrode material having a stoichiometric composition (A / B ratio is 1) is used, a reaction product of CaZrO ₃ and Y ₂ O ₃ is formed between the air electrode and the solid electrolyte during co-sintering. As a result, delamination of the interface progresses with time, resulting in a sharp output deterioration in performance.
Based on these facts, it is necessary to carefully control the ratio between the A site and the B site.

In the solid oxide fuel cell according to the present invention,
As the air electrode material, a perovskite-type composite oxide slightly free of Mn richer than the stoichiometric composition side without the above-mentioned reaction products and decomposition products is used. That is, L constituting the air electrode
The A / B site ratio of the aMnO ₃ -based composite oxide is slightly smaller than 1, and the A / B ratio of the air electrode compact is 0.95 to 0.95.
By setting it to 0.99 and approaching the stoichiometric composition side, the content of free MnO-based oxide (second phase) decreases,
The diffusion of Mn can be reduced, and a reaction or a decomposition product that increases polarization resistance at the interface between the air electrode and the solid electrolyte is not generated. On the other hand, since the diffusion of Mn occurs relatively remarkably in a high-temperature region of 1400 ° C. or higher, the temperature during co-sintering is lowered, and the holding time during firing is reduced as much as possible, so that Mn in the fuel electrode is further reduced. The amount can be reduced. Further, it is also an effective means to keep the gas generated from the air electrode during firing from approaching the fuel electrode side.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A solid oxide fuel cell according to the present invention has a cylindrical solid electrolyte 31 as shown in FIG.
An air electrode 32 is formed on the inner surface and a fuel electrode 33 is formed on the outer surface to form a cell body 34. A current collector 35 (interconnector) is electrically connected to the air electrode 32.

That is, the notch 36 is formed in a part of the solid electrolyte 31.
Is formed, a part of the air electrode 32 formed on the inner surface of the solid electrolyte 31 is exposed, and the surface of the solid electrolyte 31 near the exposed surface 37 and the notch 36 is covered with the current collector 35, Current collectors 35 are joined to the surfaces of both ends of the solid electrolyte 31 and the surface of the air electrode 32 exposed from the notch 36 of the solid electrolyte 31. A current collector 35 electrically connected to the air electrode 32 is formed on an outer surface of the cell body 34,
It is formed so as to cover the continuous same surface 39 having almost no level difference, and is not electrically connected to the fuel electrode 33. This current collector 35 is electrically connected to the fuel electrode of another cell via Ni felt when connecting the cells, thereby forming a fuel cell module. Continuous same surface 39
Is formed by polishing between both ends of the solid electrolyte until both ends of the solid electrolyte and a part of the air electrode are continuous and substantially flush with each other. The solid electrolyte 31 is, for example, 3 to
Partially stabilized or stabilized ZrO ₂ containing 15 mol% of Y ₂ O ₃ is used. In addition, as the air electrode 32,
For example, LaMnO _{3 in} which La or Ca is replaced with Ca or Sr by 10 to 30 at% and Y by 5 to 20 at% is used. As the current collector 35, for example, Cr is mainly made of Mg.
Used is LaCrO ₃ substituted by 10 to 30 atomic%. The fuel electrode 33, is used ZrO ₂ (Y ₂ O ₃ content) cermet containing 50-80 wt% Ni. The solid electrolyte 31, the current collector 35, and the fuel electrode 33 are not limited to the above examples, and may be made of known materials. In addition, at least La and M
What is necessary is just to consist of a perovskite type complex oxide containing n.

In the solid oxide fuel cell of the present invention, the Mn content in the fuel electrode 33 is 0.35% by weight.
It is characterized by the following. Here, the reason why the amount of Mn diffusion is set in the above range is that when the amount of Mn in the fuel electrode 33 exceeds 0.35% by weight, the output density is low from the initial stage, and the output density decreases with time. Because. The amount of Mn in the fuel electrode 33 can be set as long as the air electrode 32 containing at least La and Mn, the solid electrolyte 31, and the fuel electrode 33 are simultaneously fired (co-sintered).
Although n is inevitably diffused into the fuel electrode 33, 0.25% by weight or less is desirable for the above reason.

The thickness of the fuel electrode 33 is 5 to 5.
It is desirable to control to a range of 20 μm. This is because, within this range, the stress caused by the difference in firing shrinkage generated in each compact can be alleviated, so that separation of the fuel electrode from the solid electrolyte can be prevented and the difference in firing shrinkage between the fuel electrode and the solid electrolyte can be reduced. It is possible to reduce the size and to prevent cracks (cracks) generated inside the solid electrolyte from the interface between the solid electrolyte and the fuel electrode, thereby increasing the polarization value between the fuel electrode and the solid electrolyte and real resistance of the solid electrolyte component. This is because the value can be prevented from increasing and the initial high power density can be maintained for a long period of time.

On the other hand, when the film thickness is larger than 20 μm, the fuel electrode film itself tends to peel off from the interface with the solid electrolyte with a difference in thermal expansion after co-sintering. Grain growth occurs remarkably between Ni particles in the parallel direction, the difference in firing shrinkage at the interface with the solid electrolyte increases at the co-sintering stage, cracks easily propagate from the interface to the inside of the solid electrolyte, and the actual resistance increases. This causes the value to increase and the power density decreases with time. For the above reason, the thickness of the fuel electrode 33 is preferably in the range of 10 to 15 μm.

In the method for producing the solid oxide fuel cell constructed as described above, first, a cylindrical air electrode molded body is formed. The cylindrical air electrode molded body is made of, for example, La ₂ O ₃ , Y ₂ O ₃ , CaCO ₃ , MnO according to a predetermined composition.
Weigh and mix the _two raw materials. At this time, it is necessary to weigh the perovskite-type composite oxide constituting the air electrode molded body so that the A / B ratio satisfies 0.95 to 0.99.

When the A / B ratio is smaller than 0.95, M
There is no n-diffusion suppression effect, and 0.35
% Or more, and if it is more than 0.99, CaZrO ₃ , Y is placed between the air electrode and the solid electrolyte.
_This is because a reaction product of ₂ O ₃ is generated and the output density is reduced.

Thereafter, for example, the mixture is calcined at a temperature of about 1500 ° C. for 2 to 10 hours, and then pulverized to a particle size of 4 to 8 μm. A binder is mixed and kneaded with the prepared powder to produce a cylindrical air electrode molded body by an extrusion molding method, further debindered, and calcined at 1200 to 1250 ° C. to form a cylindrical air electrode temporary body. Prepare a fired body. Since the diffusion of Mn is remarkable at 1400 ° C. or higher, Mn hardly diffuses at the calcining temperature of the air electrode compact.

As a sheet-like first solid electrolyte molded body,
Toluene, a binder, a slurry obtained by adding a commercially available dispersant to a predetermined powder, by a method such as a doctor blade, for example, using a molded thing to a thickness of 100 ~ 120μm, the cylindrical air electrode calcined body The first solid electrolyte molded body is adhered to the surface and calcined, and the first electrode is calcined on the surface of the air electrode calcined body.
A solid electrolyte calcined body is formed.

Next, a sheet-shaped fuel electrode molded body is manufactured. First, for example, a slurry prepared by adding toluene and a binder to a Ni / YSZ mixed powder prepared at a predetermined ratio is prepared. Similarly to the production of the first solid electrolyte molded body, the molded body is dried and formed into a sheet-shaped second solid electrolyte molded body having a thickness of, for example, 15 μm.

After printing and drying the fuel electrode layer molded body on the second solid electrolyte molded body, the first solid electrolyte calcined body is
The second solid electrolyte molded body on which the fuel electrode layer molded body is formed,
The first solid electrolyte calcined body is wound and laminated so that the second solid electrolyte molded body is in contact with the first solid electrolyte calcined body.

The Ni / YSZ mixed powder constituting the fuel electrode layer compact has an average particle diameter of the Ni powder of 0.2 to 0.4 μm,
The raw material powder having an average particle size of YSZ powder of 0.4 to 0.8 μm is used.
Wet pulverization and mixing are performed using rO ₂ balls. If the particle diameter of the YSZ powder constituting the fuel electrode is larger than 0.8 μm, there is no problem in terms of the difference in firing shrinkage, but Ni particles are locally supported because Ni particles are not sufficiently supported on a micro level.

If the YSZ powder has a particle size of 0.8 μm or more, there is no problem in terms of the difference in shrinkage during firing, but the growth of Ni particles cannot be suppressed, and as a result, the fuel electrode The output performance decreases as the polarization of the site increases.

As a result, the number of contacts between Ni and YSZ is reduced in terms of the number of reaction sites, and as a result, the polarization value of the fuel electrode site is extremely increased, and the output performance is reduced. On the other hand, if the Ni content ratio is higher than 80%, the thermal expansion coefficient of the solid electrolyte membrane tends to be inconsistent, and the separation tends to occur.

Next, as in the preparation of the solid electrolyte compact, 10
A current collector molded body having a thickness of 0 to 120 μm is attached to a predetermined location.

Thereafter, the laminated body of the cylindrical air electrode calcined body, the first solid electrolyte calcined body, the second solid electrolyte molded body, the fuel electrode molded body, and the current collector molded body is, for example, 1400-1000 in the atmosphere.
At a temperature of 1550 ° C., four layers are co-fired simultaneously.

Since the diffusion of Mn also affects the firing temperature and the holding time, the Mn content can be further reduced by lowering the firing temperature as much as possible and shortening the firing time as much as possible.

The thickness of the fuel electrode layer molded body is 9 to 60 μm.
And the thickness. When the thickness of the fuel electrode layer molded body is thinner than 9 μm, the difference in firing shrinkage is promoted with the growth of Ni grains, while when the thickness is larger than 60 μm, the fuel electrode is inconsistent with the coefficient of thermal expansion between the solid electrolytes. It is easy to peel off. From such a point, the thickness of the fuel electrode compact is particularly preferably 25 to 40.
μm is desirable.

In such a production method, the A / A
By setting the B ratio to 0.95 to 0.99 and approaching the stoichiometric composition side, the content of free MnO-based oxide (second phase) is reduced, and the diffusion of Mn to the fuel electrode by evaporation is reduced. Thus, the amount of Mn in the fuel electrode can be controlled to 0.35% by weight or less, whereby the power density can be increased and the high power density can be maintained for a long time.

Further, since the A / B ratio of the air electrode molded body is smaller than 1, no reaction or decomposition product is generated at the interface between the air electrode and the solid electrolyte, which increases polarization resistance. Does not occur, and high power density can be maintained for a long period of time.

In the above example, a cylindrical solid electrolyte fuel cell is described. However, the present invention is not limited to the above example, and may be applied to a flat fuel cell.

Also, in a cylindrical solid electrolyte fuel cell, it is sufficient that the solid electrolyte has an air electrode formed on one surface and a fuel electrode formed on the other surface, and the structure is not limited to FIG. .

Further, in the above example, the air electrode calcined body, the first
Although the example in which the solid electrolyte calcined body is formed has been described, these may be an air electrode molded body or a first solid electrolyte molded body.

[0045]

EXAMPLE In order to produce a cylindrical solid oxide fuel cell by the co-sintering method, first, a cylindrical air electrode calcined body was produced by the following procedure. La _{2 with} a purity of 99.9% or more commercially available
_{O 3, Y 2 O 3,} CaCO 3, the Mn ₂ O ₃ as starting _{material, (La 0.56 Y 0.14 Ca 0.3} ) xMnO 3 of x,
That is, after weighing so that the A / B ratio becomes the value shown in Table 1, using this, after extrusion molding, de-bubbling was performed at 1250 ° C.
Calcination was performed to prepare an air electrode calcined body.

Next, a slurry was prepared using ZrO ₂ powder containing Y ₂ O ₃ at a ratio of 8 mol% and having an average particle size of 1 to ₂ μm, and the thickness was 100 μm by a doctor blade method.
Then, sheets as first and second solid electrolyte molded bodies having a thickness of 15 μm were prepared.

Next, the fabrication of the fuel electrode compact will be described. Z containing 8 mol% of Y ₂ O ₃ having an average particle diameter of 0.6 μm with respect to Ni powder having an average particle diameter of 0.4 μm.
An rO ₂ powder is prepared, mixed so that the Ni / YSZ ratio (weight fraction) is 65/35, and pulverized and mixed.
A slurry was formed.

Thereafter, the prepared slurry was printed on the entire surface of the second solid electrolyte molded body at the thickness shown in Table 1. Table 1 shows the sheet thickness and the fired film thickness of the fuel electrode compact.

Next, commercially available La _{2 having} a purity of 99.9% or more was used.
Starting from O ₃ , Cr ₂ O ₃ and MgO, this is
a (Mg _0.3 Cr _0.7 ) _0.97 O ₃ After weighing and mixing to obtain a composition of 0.73, the mixture was calcined and pulverized at 1500 ° C. for 3 hours to prepare a slurry using the solid solution powder. An electric molded body was produced.

First, the first solid electrolyte molded body was wound around the air electrode calcined body in a roll shape so that both ends thereof were opened, and calcined at 1150 ° C. for 5 hours. After calcining, the first solid electrolyte calcined body was polished flat so as to expose the air electrode calcined body, and worked so as to form the same continuous surface.

Next, the second solid electrolyte molded body having the fuel electrode molded body formed thereon is placed on the surface of the first solid electrolyte calcined body so that the first solid electrolyte calcined body and the second solid electrolyte molded body come into contact with each other. After drying, a current collector molded body was adhered to the same continuous surface, and then co-sintered at 1500 ° C. for 6 hours in the atmosphere to produce a co-sintered body.

Next, using the co-sintered body, a sample for evaluating the amount of Mn diffusion inside the fuel electrode was prepared. First, length 1
Inside the fuel electrode of the cross section of the sample cut out to about 0 mm, all the constituent components were quantified using an X-ray microanalyzer (EPMA). Then, the concentration of the Mn component with respect to all components of the fuel electrode was calculated. Table 1 shows the results.

Next, in order to produce a cylindrical cell for power generation, a sealing member was joined to one end of the co-sintered body. The joining of the sealing member was performed in the following procedure. Y ₂ O ₃
Having an average particle size of 1 μm containing 8 mol% of
A slurry is prepared by adding water as a solvent to the O ₂ powder, and one end of the co-sintered body is immersed in the slurry to a thickness of 10%.
It was applied to one end of the outer peripheral surface so as to have a thickness of 0 μm and dried. A molded body having a cap shape as a sealing member was subjected to isostatic pressing (rubber pressing) using a powder having the same composition as the slurry composition, and was cut. Thereafter, one end of the co-sintered body coated with the slurry was inserted into a molding for a sealing member, and baked at a temperature of 1300 ° C. for 1 hour in the atmosphere.

For power generation, air was flowed inside the cell and hydrogen was flown outside at 1000 ° C., and the performance was measured and evaluated based on the initial value when the output value was stabilized and the value after holding for 1000 hours. These measurement results are shown in Table 1 together with the results of the Mn amount.

[0055]

[Table 1]

From Table 1, it can be seen that Sample No. which has an extremely large Mn content and is out of the range of the present invention. In each of Examples 1 and 2, the output density was low from the initial stage, and it was confirmed that the output density was deteriorated after 1000 hours. Observation of the sample after power generation suggested that the adhesion between the fuel electrode and the solid electrolyte interface was weak, and that the polarization and the actual resistance component on the fuel electrode side in power generation performance were high. On the other hand, the sample No. 3-11 is 0.33 from the beginning
The output density was more than W / cm ² , and the output density tended to be almost stable or increased after 1000 hours. FIG. 2 is a graph showing the relationship between the Mn content and the output density of each sample.

[0057]

As described above in detail, in the cylindrical fuel cell of the present invention, the amount of Mn diffused from the air electrode side toward the inside of the fuel electrode during co-sintering is reduced to 0.35% by weight or less. By performing the reduction control, the output density can be improved and the change over time can be reduced, so that the initial high output density can be maintained for a long time.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a cylindrical solid oxide fuel cell according to the present invention.

FIG. 2 is a graph showing the relationship between the amount of Mn and the output density.

FIG. 3 is a perspective view showing a conventional cylindrical solid oxide fuel cell.

[Explanation of symbols]

 31 ... solid electrolyte 32 ... air electrode 33 ... fuel electrode 35 ... current collector 36 ... notch

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G031 AA03 AA04 AA08 AA09 AA19 AA39 BA03 CA01 CA08 5H018 AA06 AS02 AS03 EE02 EE13 HH03 HH05 5H026 AA06 BB00 CV02 EE13 HH03 HH05

Claims (3)

[Claims] A solid electrolyte fuel cell in which a solid electrolyte and a fuel electrode are sequentially laminated on the surface of an air electrode made of a perovskite-type composite oxide containing at least La and Mn. A solid oxide fuel cell having an amount of 0.35% by weight or less. 2. The solid oxide fuel cell according to claim 1, wherein the thickness of the fuel electrode is 5 to 20 μm. 3. A solid electrolyte obtained by firing a laminate formed by sequentially laminating a solid electrolyte molded body and a fuel electrode molded body on the surface of an air electrode molded body composed of a perovskite-type composite oxide containing at least La and Mn. A method for producing a fuel cell, wherein the perovskite-type composite oxide constituting the air electrode molded body is represented by an A site containing at least La, a B site containing at least Mn, and the A site A method for producing a solid oxide fuel cell, wherein the ratio of the B site (A / B ratio) is 0.95 to 0.99.