JP2004303712A - Solid oxide fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolyte film of a solid oxide fuel cell having high output performance. <P>SOLUTION: The solid oxide fuel cell is equipped with a unit cell having an air electrode on one side of an electrolyte film and a fuel electrode on the other side, and an interconnector for electrical connection, and the electrolyte film has a first layer comprising a material having oxygen ion conductivity S1 on the air electrode side; a third layer comprising a material having oxygen ion conductivity S3 on the fuel electrode side; a second layer comprising a material having oxygen ion conductivity S2 between the first layer and the third layer and containing at least zirconia, and the relation of the oxygen ion conductivity S1 and the oxygen ion conductivity S2 is S1>S2, and the relation of the oxygen ion conductivity S3 and the oxygen ion conductivity S2 is S3>S2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a solid oxide fuel cell having excellent output performance. In particular, the present invention relates to a solid oxide fuel cell having an electrolyte membrane having excellent oxygen ion conductivity and having no gas permeability and having high output performance even at a power generation temperature of 900 ° C. or lower.

A layer made of zirconia in which yttria is dissolved (hereinafter, referred to as YSZ) has been proposed as an electrolyte membrane of a conventional solid oxide fuel cell. (For example, see Patent Document 1). Since YSZ has excellent sinterability, it is possible to easily produce an electrolyte membrane without gas permeability.However, the output performance of a solid oxide fuel cell using this material for the electrolyte membrane is 900 ° C or less. At low temperatures, the oxygen ion conductivity of the electrolyte membrane is reduced, and the reaction of the formula (1) between the air electrode and the electrolyte membrane does not proceed efficiently, so that there is a problem that the output performance is reduced.
^{_{1 / 2O 2 + 2e - →}} O 2- ... (1)

In addition, the electrolyte membrane having no gas permeability shown here is evaluated by a gas permeation amount passing therethrough when a pressure difference is provided between one side and the opposite side of the electrolyte membrane, and a gas permeation amount Q ≦ 2.8 × 10 ⁻⁹ ms ⁻¹ Pa ⁻¹ (more preferably, Q ≦ 2.8 × 10 ⁻¹⁰ ms ⁻¹ Pa ⁻¹ ).

  As an electrolyte membrane of a solid oxide fuel cell, a layer made of zirconia in which scandia is dissolved (hereinafter, referred to as SSZ) has been proposed. (For example, see Patent Document 2). SSZ has higher oxygen ion conductivity than YSZ, and it is expected that the use of this material for the electrolyte membrane will increase the output performance of the solid oxide fuel cell. However, although an electrolyte membrane was manufactured using the material disclosed in Patent Document 2, it was difficult to manufacture an electrolyte membrane having no gas permeability according to the results of tests performed by us.

As an electrolyte membrane for a solid oxide fuel cell, a layer made of a cerium-containing oxide in which ceria is dissolved in samarium, gadria, or the like has been proposed (for example, see Patent Documents 3 and 4). The materials proposed in Patent Literature 3 and Patent Literature 4 have electronic conductivity under a fuel gas atmosphere of a solid oxide fuel cell, so that when an electrolyte membrane is formed using only the proposed materials, output performance is reduced. There was a problem.

As an electrolyte membrane of a solid oxide fuel cell, a layer made of lanthanum gallate has been proposed (for example, see Patent Documents 5 and 6). The materials proposed in Patent Documents 5 and 6 use an oxide containing manganese, such as lanthanum manganite, as the air electrode of a solid oxide fuel cell. Therefore, there is a problem that when the electrolyte membrane is composed of only the proposed materials, the output performance is reduced.
JP-A-10-158894 (pages 1-6, FIGS. 1-12) JP-A-7-6774 (pages 1-5, FIGS. 1-5) JP-A-11-273451 (pages 1-8, FIGS. 1-5) Patent Publication No. 2813355 (Pages 1-5, FIGS. 1-5) JP-A-2002-15756 (pages 1-9, FIGS. 1-9) JP-A-11-335164 (pages 1-12, FIGS. 1-12)

  The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a solid oxide fuel cell having excellent output performance by optimizing constituent materials of an electrolyte membrane.

  In order to achieve the above object, the present invention provides a solid oxide type comprising: a cell having an air electrode on one side of an electrolyte membrane and a fuel electrode on the other side; and an interconnector having a role of electrical connection. In a fuel cell, the electrolyte membrane includes a first layer made of a material having an oxygen ion conductivity S1 on the air electrode side, and a third layer made of a material having an oxygen ion conductivity S3 on the fuel electrode side. A second layer made of a material containing at least zirconia and having an oxygen ion conductivity S2 between the first layer and the third layer, wherein the oxygen ion conductivity S1 and the oxygen ion conductivity S2 are provided. Has a relationship of S1> S2, and the oxygen ion conductivity S3 and the oxygen ion conductivity S2 have a relationship of S3> S2.

  According to the present invention, the electrolyte membrane has a structure in which a layer made of a material having high oxygen ion conductivity is provided on the surface in contact with the air electrode and the fuel electrode, and a layer made of a material containing at least zirconia is sandwiched between those layers. A solid oxide fuel cell having excellent performance can be provided.

The reason for this is that oxygen ions generated by the reaction of the formula (1) occurring between the air electrode and the electrolyte membrane can be efficiently supplied to the electrolyte membrane, and that the electrolyte membrane having the second layer has gas permeability. This is because oxygen ions can be efficiently supplied to the fuel electrode side, and the reactions of the equations (2) and (3) occurring between the electrolyte membrane and the fuel electrode can be efficiently advanced.
^{_{1 / 2O 2 + 2e - →}} O 2- ... (1)
_{^{H 2 + O 2- → H 2}} O + 2e - ... (2)
_{^{CO + O 2- → CO 2 +}} 2e - ... (3)

Strictly speaking, the reaction of the formula (2) has been reported to be a two-step reaction of the formulas (4) and (5). Here, Ni will be described as an example.
^{O 2- + Ni → NiO + 2e} - ... (4)
NiO + H ₂ → Ni + H ₂ O… (5)
However, since it is difficult to strictly separate the above reactions, the electrode reaction is described here by (4) + (5), that is, equation (2).

In a preferred embodiment of the present invention, the first layer made of the material having the oxygen ion conductivity S1 and the third layer made of the material having the oxygen ion conductivity S3 have the same composition.

According to the present invention, the same material having high oxygen ion conductivity is provided on the air electrode side and the fuel electrode side, and at least a material made of zirconia is provided in the middle, so that a solid oxide fuel cell having excellent output performance is provided. Can be provided.

  The reason for this is that oxygen ions generated by the reaction of the formula (1) occurring between the air electrode and the electrolyte membrane can be efficiently supplied to the electrolyte membrane, and that the electrolyte membrane having the second layer has gas permeability. This is because oxygen ions can be efficiently supplied to the fuel electrode side, and the reactions of the equations (2) and (3) occurring between the electrolyte membrane and the fuel electrode can be efficiently advanced.

In a preferred embodiment of the present invention, the thickness of the second layer in the electrolyte membrane is from 10 to 90% of the total thickness of the electrolyte membrane.

  According to the present invention, it is possible to provide a solid oxide fuel cell that is inexpensive and has excellent output performance by setting the thickness of the second layer in the electrolyte membrane to the above range.

  The reason for this is that if it is less than 10%, the cost of the electrolyte membrane material is high and impractical, or there is a problem that the electrolyte membrane without gas permeability cannot be easily produced. If it is too large, the oxygen ion conductivity of the total electrolyte membrane decreases, and it becomes impossible to efficiently supply the oxygen ions generated by the formula (1) to the fuel electrode side, and output performance is reduced.

  In a preferred embodiment of the present invention, the thickness of the second layer is 20 to 70% of the total thickness of the electrolyte membrane.

  According to the present invention, by setting the thickness of the second layer to the above-mentioned range that is further limited, oxygen ion conductivity is high, and the production of an electrolyte membrane without gas permeability can be facilitated, and the output performance is excellent. A solid oxide fuel cell can be provided.

  The reason for this is that if the content is less than 20%, there is a possibility that the cost of the electrolyte membrane material is somewhat high or that it is difficult to produce an electrolyte membrane having no gas permeability at a low temperature. %, The oxygen ion conductivity of the electrolyte membrane as a whole is slightly lower, and the output performance may be reduced in power generation at 900 ° C. or lower.

  In a preferred embodiment of the present invention, the second layer in the electrolyte membrane is a YSZ material.

By including the YSZ material in the electrolyte membrane, an electrolyte membrane having no gas permeability can be easily produced, and a solid oxide fuel cell having excellent output performance can be provided.

The reason is that the YSZ material has a high sinterability and can form an electrolyte membrane having no gas permeability at a low temperature, so that a reduction in output performance due to a reaction between electrodes, diffusion of a Mn component, and the like can be suppressed. This is because we can do it.

In a preferred embodiment of the present invention, the second layer in the electrolyte membrane is a zirconia (ScYSZ) material in which at least scandia and yttria are dissolved.

By including the ScYSZ material in the electrolyte membrane, an electrolyte membrane having no gas permeability can be easily produced, and a solid oxide fuel cell having excellent output performance can be provided.

The reason is that ScYSZ has a high sinterability and can form an electrolyte membrane without gas permeability at low temperatures, so that it is possible to suppress a decrease in output performance due to a reaction between electrodes or diffusion of a Mn component. That's why.

In a preferred embodiment of the present invention, the first and third layers are SSZ materials.

By providing an SSZ material on the air electrode side and the fuel electrode side of the electrolyte membrane, it is possible to produce an electrolyte membrane having excellent oxygen ion conductivity and no gas permeability, thereby providing a solid oxide fuel cell having excellent output performance. Can be.

The reason is that the reaction of formula (1) that occurs between the air electrode and the electrolyte membrane, and the reaction that occurs between the electrolyte membrane and the fuel electrode, because the SSZ material with high oxygen ion conductivity is provided on the air electrode side and the fuel electrode side Since the reaction of the formulas (2) and (3) can be performed efficiently, and since the second layer is provided between the SSZ layers, an electrolyte membrane having no gas permeability can be produced at a low temperature. It is.

In a preferred embodiment of the present invention, the first layer in the electrolyte membrane is a general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd, Y, 0.05 ≦ X ≦ 0.15), and the third layer is a zirconia material in which scandia is dissolved.

Cerium-containing represented by the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15) on the air electrode side of the electrolyte membrane By providing the oxide and the SSZ material on the fuel electrode side, a solid oxide fuel cell having excellent output performance can be provided.

The reason for this is that the cerium-containing oxide layer having the above composition is provided on the air electrode side, so that the reaction of the formula (1) occurring between the air electrode and the electrolyte membrane can be efficiently advanced, and the oxygen Since the SSZ material layer having high ionic conductivity is provided, the reaction of the formulas (2) and (3) that occur between the electrolyte membrane and the fuel electrode can be efficiently performed, and the second one made of a material containing at least zirconia This is because an electrolyte membrane having no gas permeability can be formed because of having the layer.

In a preferred embodiment of the present invention, the first layer in the electrolyte membrane general formula _{La 1-a A a Ga 1} -b B b O 3 or _{La 1-a A a Ga 1} -bc B b C c O 3 ( However, A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, and C is one or more of Co, Fe, Ni, Cr) The lanthanum gallate represented and the third layer is an SSZ material.

By providing a lanthanum gallate layer composed of the above composition on the air electrode side of the electrolyte membrane and providing an SSZ material layer on the fuel electrode side, an electrolyte membrane with excellent oxygen ion conductivity and no gas permeability can be manufactured, so output performance is improved. An excellent solid oxide fuel cell can be provided.

  The reason for this is that the lanthanum gallate material has high oxygen ion conductivity, can efficiently promote the reaction of the formula (1) that occurs between the air electrode and the electrolyte membrane, and has a high oxygen conductivity on the fuel electrode side in SSZ. Since the material layer is provided, the reaction of the formulas (2) and (3) occurring between the electrolyte membrane and the fuel electrode can be efficiently performed, and the gas permeation can be achieved by having the second layer made of a material containing at least zirconia. This is because an electrolyte membrane having no property can be manufactured at a low temperature.

In a preferred embodiment of the present invention, the first layer in the electrolyte membrane is a ScYSZ material, and the third layer is an SSZ material.

A solid oxide fuel cell with excellent oxygen ion conductivity and excellent gas-permeability by providing a ScYSZ material on the air electrode side of the electrolyte membrane and an SSZ material on the fuel electrode side. Can be provided.

The reason is that the ScYSZ material with excellent sinterability and relatively high oxygen ion conductivity is provided on the air electrode side, so that the reaction of equation (1) that occurs between the air electrode and the electrolyte membrane can be efficiently advanced. In addition, since a layer made of an SSZ material having high oxygen ion conductivity is provided on the fuel electrode side, it is possible to efficiently perform the reactions of Formulas (2) and (3) occurring between the electrolyte membrane and the fuel electrode, and that the ScYSZ This is because an electrolyte membrane having no gas permeability can be manufactured at a low temperature because it has the first layer made of a material and the second layer made of a material containing at least zirconia.

In a preferred embodiment of the present invention, the first layer in the electrolyte membrane is an SSZ material, and the third layer is a general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is Sm , Gd, and Y are cerium-containing oxides represented by 0.05 ≦ X ≦ 0.15).

The SSZ material is provided on the air electrode side of the electrolyte membrane, and the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is one of Sm, Gd, Y, 0.05 ≦ X By providing the cerium-containing oxide represented by ≦ 0.15), a solid oxide fuel cell having excellent output performance can be provided.

The reason is that the layer made of SSZ material having high oxygen ion conductivity is provided on the air electrode side, so that the reaction of the formula (1) that occurs between the air electrode and the electrolyte membrane can be efficiently promoted, and that the fuel electrode side Since a layer made of the cerium-containing oxide having the above composition having high oxygen ion conductivity is provided, the reaction of the formulas (2) and (3) occurring between the electrolyte membrane and the fuel electrode can be efficiently performed, and at least This is because an electrolyte membrane having no gas permeability can be formed because of having the second layer made of a material containing zirconia.

In a preferred embodiment of the present invention, the first layer and the third layer in the electrolyte membrane are represented by the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd and Y One type is a cerium-containing oxide represented by 0.05 ≦ X ≦ 0.15).

The general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is one of Sm, Gd and Y, 0.05 ≦ X ≦ 0.15) is provided on the air electrode side and fuel electrode side of the electrolyte membrane. By providing the cerium-containing oxide to be provided, a solid oxide fuel cell having excellent oxygen ion conductivity and excellent output performance can be provided.

The reason for this is that a layer made of the cerium-containing oxide having the above composition having high oxygen ion conductivity is provided on the air electrode side and the fuel electrode side, so that the reaction of the formula (1) that takes place between the air electrode and the electrolyte membrane and the electrolyte The reaction of formulas (2) and (3) occurring between the membrane and the fuel electrode can be performed efficiently, and an electrolyte membrane with no gas permeability is formed because it has a second layer made of a material containing at least zirconia. This is because you can do it.

In a preferred embodiment of the present invention, the first layer has the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (provided that A is represented by one or more of Sr, Ca, Ba, B is represented by one or more of Mg, Al, In, and C is represented by one or more of Co, Fe, Ni, Cr) The third layer is represented by the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15) It is a cerium-containing oxide represented.

The general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (where A is Sr, Ca, Ba One or more, B is one or more of Mg, Al, In, C is one or more of Co, Fe, Ni, Cr) _Provide a cerium-containing oxide represented by the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15) on the pole side Therefore, a solid oxide fuel cell having high oxygen ion conductivity and excellent output performance can be provided.

The reason for this is that the layer of lanthanum gallate having the above composition is provided on the air electrode side, so that the reaction of the formula (1) occurring between the air electrode and the electrolyte membrane can be efficiently promoted, and the oxygen ion conductivity Since a layer made of a cerium-containing oxide having a high composition is provided, it is possible to efficiently perform the reaction of the formulas (2) and (3) occurring between the electrolyte membrane and the fuel electrode, and a material containing at least zirconia. This is because an electrolyte membrane having no gas permeability can be produced at a low temperature since the second layer made of

In a preferred embodiment of the present invention, the first layer is a ScYSZ material, the third layer is a general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is Sm, Gd, A cerium-containing oxide represented by any one of Y, 0.05 ≦ X ≦ 0.15).

Since a layer made of a ScYSZ material is provided on the air electrode side of the electrolyte membrane and a layer made of the cerium-containing oxide having the above composition is provided on the fuel electrode side, a solid oxide fuel cell having excellent output performance can be provided.

The reason is that a layer made of ScYSZ material with excellent sinterability and relatively high oxygen ion conductivity is provided on the air electrode side, so that the reaction of the formula (1) that occurs between the air electrode and the electrolyte membrane can be efficiently promoted And a layer made of the cerium-containing oxide having the above composition having high oxygen ion conductivity is provided on the fuel electrode side, so that the reaction of the formulas (2) and (3) occurring between the electrolyte membrane and the fuel electrode can be efficiently performed. This is because it can be performed well, and the electrolyte layer having no gas permeability can be formed at a low temperature because it has the first layer made of the ScYSZ material and the second layer made of at least the material containing zirconia.

In a preferred embodiment of the present invention, the first layer is an SSZ material and the third layer is of the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _{1 -bc} B _b C _c O ₃ (where A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is Co, Fe, Ni, Cr Lanthanum gallate represented by one or two or more).

Since a layer made of SSZ material is provided on the air electrode side of the electrolyte membrane and a layer made of lanthanum gallate having the above composition is provided on the fuel electrode side, a solid oxide fuel cell having excellent output performance can be provided.

The reason is that the layer made of SSZ material having high oxygen ion conductivity is provided on the air electrode side, so that the reaction of the formula (1) that occurs between the air electrode and the electrolyte membrane can be efficiently promoted, and that the fuel electrode side Since the lanthanum gallate having the above composition having high oxygen ion conductivity is provided, the reaction of the formulas (2) and (3) occurring between the electrolyte membrane and the fuel electrode can be efficiently performed, and the material containing at least zirconia is used. This is because an electrolyte membrane having no gas permeability can be formed at a low temperature because of having the second layer. In addition, since it can be formed at a low temperature, even if an oxide containing manganese is used for the air electrode, a decrease in output performance due to manganese diffusion can be suppressed.

In a preferred embodiment of the present invention, the first layer has a general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd, Y, 0.05 ≦ X ≦ 0.15 ) Is a cerium-containing oxide represented by the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (However, A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is one or more of Co, Fe, Ni, Cr ).

A layer made of the cerium-containing oxide having the above composition is provided on the air electrode side of the electrolyte membrane, and the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _{1- bc} B _b C _c O ₃ (However, A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is Co, Fe, Ni, Cr Since one or more layers of lanthanum gallate are provided, a solid oxide fuel cell having excellent output performance can be provided.

The reason for this is that since the layer made of the cerium-containing oxide having the above composition having high oxygen ion conductivity is provided on the air electrode side, the reaction of the formula (1) occurring between the air electrode and the electrolyte membrane can be efficiently promoted. In addition, since a layer made of lanthanum gallate having the above composition having high oxygen ion conductivity is provided on the fuel electrode side, the reaction of Formulas (2) and (3) occurring between the electrolyte membrane and the fuel electrode can be efficiently performed. This is because the electrolyte membrane having at least a second layer made of a material containing at least zirconia can be manufactured at a low temperature without gas permeability.

In a preferred embodiment of the present invention, the first layer and the third layer have the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (where A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is one or two of Co, Fe, Ni, Cr Above).

Since a layer made of lanthanum gallate having the above composition is provided on the air electrode side and the fuel electrode side of the electrolyte membrane, a solid oxide fuel cell having excellent output performance can be provided.

The reason is that the lanthanum gallate having the above composition having high oxygen ion conductivity is provided on the air electrode side and the fuel electrode side, so that the reaction of the formula (1) occurring between the air electrode and the electrolyte membrane can be efficiently advanced. An electrolyte membrane having no gas permeability because it can efficiently perform the reaction of the formulas (2) and (3) occurring between the electrolyte membrane and the fuel electrode and has a second layer made of a material containing at least zirconia. Can be produced at a low temperature.

In a preferred embodiment of the invention, the first layer is a ScYSZ material and the third layer is of the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _{1 -bc} B _b C _c O ₃ (where A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is Co, Fe, Ni, Cr Lanthanum gallate represented by one or two or more).

A layer made of ScYSZ material is provided on the air electrode side of the electrolyte membrane, and the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c is provided on the fuel electrode side. O ₃ (where A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is one or two of Co, Fe, Ni, Cr By providing the lanthanum gallate represented by the above), a solid oxide fuel cell having excellent output performance can be provided.

The reason for this is that a layer made of ScYSZ material with excellent sinterability and relatively high oxygen ion conductivity is provided on the air electrode side, so that the reaction of equation (1) that occurs between the air electrode and the electrolyte membrane can be efficiently promoted. And the layer of lanthanum gallate having the above composition having high oxygen ion conductivity is provided on the fuel electrode side, so that the reaction of the formulas (2) and (3) occurring between the electrolyte membrane and the fuel electrode can be efficiently performed. This is because it has a first layer made of a ScYSZ material and a second layer made of a material containing at least zirconia, so that an electrolyte membrane having no gas permeability can be manufactured at a low temperature.

In a preferred embodiment of the present invention, the first layer is an SSZ material and the third layer is a ScYSZ material.

By providing a layer made of the SSZ material on the air electrode side of the electrolyte membrane and providing a layer made of the ScYSZ material on the fuel electrode side, a solid oxide fuel cell having excellent output performance can be provided.

The reason is that the SSZ material with high oxygen ion conductivity is provided on the air electrode side, so that the reaction of the formula (1) that occurs between the air electrode and the electrolyte membrane can be efficiently advanced, and the ScYSZ material is provided on the fuel electrode side. This is because an electrolyte membrane having no gas permeability can be formed at a low temperature.

In a preferred embodiment of the present invention, the first layer has a general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd, Y, 0.05 ≦ X ≦ 0.15 ), And the third layer is a ScYSZ material.

Since a layer made of the cerium-containing oxide having the above composition is provided on the air electrode side of the electrolyte membrane and a layer made of the ScYSZ material is provided on the fuel electrode side, a solid oxide fuel cell having excellent output performance can be provided.

The reason for this is that the cerium-containing oxide having the above composition is provided on the air electrode side, so that the reaction of the formula (1) that occurs between the air electrode and the electrolyte membrane can be efficiently advanced, and the layer made of ScYSZ on the fuel electrode side. This is because an electrolyte membrane having no gas permeability can be formed at a low temperature.

In a preferred embodiment of the present invention, the first layer has the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (provided that A is represented by one or more of Sr, Ca, Ba, B is represented by one or more of Mg, Al, In, and C is represented by one or more of Co, Fe, Ni, Cr) Lanthanum gallate, and the third layer is a ScYSZ material.

By providing a layer made of the lanthanum gallate having the above composition on the air electrode side of the electrolyte membrane and providing a layer made of the ScYSZ material on the fuel electrode side, a solid oxide fuel cell having excellent output performance can be provided.

The reason for this is that, since a layer made of lanthanum gallate having the above composition having high oxygen ion conductivity is provided on the air electrode side, the reaction of the formula (1) occurring between the air electrode and the electrolyte membrane can be efficiently advanced, and This is because the layer made of ScYSZ having excellent sinterability is provided on the fuel electrode side, so that an electrolyte membrane having no gas permeability can be formed at a low temperature.

In a preferred embodiment of the present invention, the first layer and the third layer are ScYSZ materials.

By providing the ScYSZ material on the air electrode side and the fuel electrode side of the electrolyte membrane, a solid oxide fuel cell having excellent output performance can be provided.

The reason is that the ScYSZ material is excellent in sinterability, so that an electrolyte membrane having no gas permeability can be formed at a low temperature. Since the conductivity is relatively high, the reaction of equation (1) that occurs between the air electrode and the electrolyte membrane and the reactions of equations (2) and (3) that occur between the electrolyte membrane and the fuel electrode can proceed efficiently. That's why.

In a preferred embodiment of the present invention, the amount of scandia in the SSZ is 3 to 12 mol%.

By setting the solid solution amount of scandia to 3 to 12 mol%, the reaction of formulas (1) and / or (2) and (3) can proceed more efficiently, and solid oxide fuel with excellent output performance A battery can be provided.

The reason for this is that if the solid solution amount is less than 3 mol%, the oxygen ion conductivity of the material is lowered, and the output performance is lowered. On the other hand, if it exceeds 12 mol%, the crystal phase is cubic and rhombohedral. This is because crystals are formed and oxygen ion conductivity is reduced.

In a preferred embodiment of the present invention, the SSZ material, further _{CeO 2, Sm 2 O 3,} Gd 2 O 3, Yb 2 O 3, at least one oxide of selected from Er ₂ O ₃ and Bi ₂ O ₃ 5 mol% or less is dissolved.

According to the present invention, at least one oxide selected from CeO ₂ , Sm ₂ O ₃ , Gd ₂ O _3, Yb ₂ O _3, Er ₂ O ₃ and Bi ₂ O ₃ forms a solid solution of 5 mol% or less. A solid oxide fuel cell having excellent output performance can be provided.

  The content of 5 mol% or less is preferable because the oxygen ion conductivity increases, the sinterability of the material improves, and at least one of the effects is produced. That is, if the oxygen ion conductivity is improved, the output performance is improved, and if the sinterability is improved, it is possible to form an electrolyte membrane having no gas permeability at low temperatures. It is preferable to use two or more kinds of solid solutions since both effects of oxygen ion conductivity and sinterability may be obtained. On the other hand, if the content is more than 5 mol%, a rhombohedral crystal phase other than a cubic crystal is precipitated as a crystal phase, and oxygen ion conductivity may decrease.

In a preferred embodiment of the present invention, in a zirconia material in which at least scandia and yttria are dissolved, a total solid solution amount of scandia and yttria in the zirconia material in which scandia and yttria are dissolved is 3 to 12 mol%.

According to the present invention, by setting the total solid solution amount of scandia and yttria to 3 to 12 mol%, a solid oxide fuel cell excellent in output performance can be provided.

The reason for this is that if the total solid solution content of scandia and yttria is less than 3 mol%, the oxygen ion conductivity will be low and the output performance will be reduced. However, in addition to cubic crystals, rhombohedral crystals may be generated and oxygen ion conductivity may decrease.

The zirconia material in which at least scandia and yttria are solid-dissolved as shown here may be zirconia in which at least two types of scandia and yttria are solid-dissolved, and other compositions may be solid-dissolved. For example, a zirconia material in which scandia, yttria, and ceria are dissolved is also applicable.

In a preferred embodiment of the present invention, the ScYSZ material, further _{CeO 2, Sm 2 O 3,} Gd 2 O 3, Yb 2 O 3 of at least one oxide of selected from, Er ₂ O ₃ and Bi ₂ O ₃ 5 mol% or less is dissolved.

According to the present invention, the ScYSZ material further contains 5 mol% of at least one oxide selected from CeO ₂ , Sm ₂ O ₃ , Gd ₂ O ₃ , Yb ₂ O ₃ , Er ₂ O ₃ and Bi ₂ O _3. A solid oxide fuel cell having excellent output performance can be provided by being solid-dissolved below.

  The content of 5 mol% or less is preferable because the oxygen ion conductivity increases, the sinterability of the material improves, and at least one of the effects is produced. That is, if the oxygen ion conductivity is improved, the output performance is improved, and if the sinterability is improved, it is possible to form an electrolyte membrane having no gas permeability at low temperatures. It is preferable to use two or more kinds of solid solutions since both effects of oxygen ion conductivity and sinterability may be obtained. On the other hand, if the content is more than 5 mol%, a rhombohedral crystal phase other than a cubic crystal is precipitated as a crystal phase, and oxygen ion conductivity may decrease.

In a preferred embodiment of the present invention, the amount of yttria in the YSZ material is 3 to 12 mol%.

When the solid solution amount of yttria is in the above range, an electrolyte membrane having no gas permeability can be easily produced, and a solid oxide fuel cell having excellent output performance can be provided.

The reason for limiting the solid solution range of yttria to 3 to 12 mol% is that if it is less than 3 mol%, the oxygen ion conductivity is low and the stability of the crystal phase is reduced. This is because, in addition to the cubic crystal, a rhombohedral crystal phase is precipitated and oxygen ion conductivity is reduced.

In a preferred embodiment of the present invention, between the electrolyte membrane and the air electrode, an oxygen gas and an electron are used to promote a reaction for generating oxygen ions, and an air-side electrode reaction layer having open pores connected to each other is interposed. I have.

By promoting the reaction of generating oxygen ions between the electrolyte membrane and the air electrode and providing a layer having open pores connected to each other, a solid oxide fuel cell having excellent output performance can be provided.

The reason for this is that the microstructure into which oxygen gas can easily enter has a function of generating oxygen ions, so that the reaction of formula (1) is promoted and oxygen ions can be efficiently supplied to the electrolyte membrane.

In a preferred embodiment of the present invention, the air-side electrode reaction layer forms a solid solution of lanthanum manganite and scandia represented by (La _1-x A _x ) _y MnO ₃ (where A is either Ca or Sr). Is a layer (hereinafter, referred to as LaAMnO ₃ / SSZ) in which zirconia is uniformly mixed.

According to the present invention, a solid oxide fuel cell having excellent output performance even at a power generation temperature of about 700 ° C. is provided by providing an air-side electrode reaction layer made of LaAMnO ₃ / SSZ between an air electrode and an electrolyte membrane. can do.

The reason is that LaAMnO ₃ / SSZ has high electron conductivity and oxygen ion conductivity even at a low temperature of about 700 ° C., so that the reaction of equation (1) that occurs between the air electrode and the electrolyte membrane can be efficiently advanced. Since the oxygen ion conductivity of the electrolyte membrane material on the air electrode side of the electrolyte membrane of the present invention is high, oxygen ions can be efficiently sent to the fuel electrode side, and high output performance can be obtained even at a low temperature of about 700 ° C. This is because we can do it.

The layer in which lanthanum manganite and SSZ represented by (La _1-x A _x ) _y MnO ₃ (where A is either Ca or Sr) is homogeneously mixed here is a solution prepared by a coprecipitation method or the like. It can be obtained by using a raw material produced by a phase method. That is, the uniformity shown here means that the raw material obtained by the coprecipitation method is sufficiently uniform if there is uniformity.

In a preferred embodiment of the present invention, the air electrode is represented by (La _1-x A _x ) _y MnO ₃ (where A is either Ca or Sr) (hereinafter referred to as LaAMnO ₃ ). ).

According to the present invention, a solid oxide fuel cell having excellent output performance can be provided by employing the above-described materials for the air electrode.

The reason for this is that the solid oxide fuel cell has high electron conductivity under an air atmosphere and is stable as a material.

In a preferred embodiment of the present invention, at least hydrogen gas (H ₂ ) and / or carbon monoxide gas (CO) contained in the fuel gas between the electrolyte membrane and the fuel electrode, and oxygen ions (O ²⁻ ), A fuel-side electrode reaction layer having open pores which promotes a reaction for generating electrons with H ₂ O and / or CO _{2 from the} fuel cell is interposed.

A microstructure that allows hydrogen gas (H ₂ ) and / or carbon monoxide gas (CO) to easily enter between the electrolyte membrane and the fuel electrode, and by providing a layer that promotes the reactions of equations (2) and (3) A solid oxide fuel cell having excellent output performance can be provided.

The reason for this is that oxygen ions that have moved through the electrolyte membrane can be efficiently converted into H ₂ O and / or CO ₂ and electrons.

In a preferred embodiment of the present invention, the fuel-side electrode reaction layer is a layer in which zirconia in which NiO and scandia are solid-dissolved is uniformly mixed (hereinafter, referred to as NiO / SSZ) or zirconia in which Ni and scandia are solid-dissolved. Are uniformly mixed layers (hereinafter, referred to as Ni / SSZ).

According to the present invention, by providing a fuel-side electrode reaction layer made of NiO / SSZ or Ni / SSZ between the fuel electrode and the electrolyte membrane, a solid oxide fuel excellent in output performance even at a power generation temperature of about 700 ° C. A battery can be provided.

The reason for this is that NiO / SSZ or Ni / SSZ has high electron conductivity and oxygen ion conductivity even at a low temperature of about 700 ° C, so that the reactions of Eqs. (2) and (3) that occur between the electrolyte membrane and the fuel electrode can be efficiently performed. The oxygen ion conductivity of the electrolyte membrane material on the fuel electrode side of the electrolyte membrane of the present invention is high and oxygen ions can be efficiently sent to the fuel electrode, and high output even at a low temperature of about 700 ° C. This is because performance can be obtained.

  NiO shown here is reduced to Ni in a fuel gas atmosphere, and the layer becomes Ni / SSZ.

Note that the layer in which Ni and zirconia in which scandia are dissolved as a solid solution shown here is uniformly mixed can be obtained by using a raw material produced by a liquid phase method such as a coprecipitation method. That is, the uniformity shown here means that the raw material obtained by the coprecipitation method is sufficiently uniform if there is uniformity.

In a preferred embodiment of the present invention, the fuel electrode is a layer in which zirconia in which NiO and yttria are solid-dissolved (hereinafter, referred to as NiO / YSZ) or a layer in which zirconia in which Ni and yttria are dissolved are uniformly formed. It is a mixed layer (hereinafter referred to as Ni / YSZ).

According to the present invention, it is possible to provide a solid oxide fuel cell having excellent output performance by forming the fuel electrode in the above layer.

This is because the solid oxide fuel cell has high electron conductivity, excellent durability, and is stable under a fuel gas atmosphere.

NiO shown here is reduced to Ni in a fuel gas atmosphere, and the layer becomes Ni / YSZ.

In a preferred embodiment of the present invention, the interconnector is lanthanum chromite in which Ca is dissolved.

  By employing lanthanum chromite in which Ca is dissolved, a film having no gas permeability can be easily produced and an interconnector having high electronic conductivity can be produced.

  The reason is that lanthanum chromite in which a solid solution other than Ca is dissolved requires firing at a temperature higher than 1500 ° C to produce a membrane with no gas permeability, and firing a solid oxide fuel cell at this temperature Then, a reaction occurs between the other constituent materials to lower the output performance.

The membrane having no gas permeability shown here is evaluated by a gas permeation amount passing therethrough when a pressure difference is provided between one side and the opposite side of the interconnector, and a gas permeation amount Q ≦ 2.8 × 10 ^{− 9} ms ^-1 Pa ^-1 (more preferably, Q ≦ 2.8 × 10 ^-10 ms ^-1 Pa ^-1 ).

  In a preferred embodiment of the present invention, the electrolyte membrane is formed on the surface of the air-side electrode reaction layer and then sintered at 1350 to 1500 ° C.

  After forming the electrolyte membrane on the surface of the air-side electrode reaction layer, sintering at 1350-1500 ° C efficiently promotes the reaction of equation (1) that occurs between the air electrode and the electrolyte membrane, and has no gas permeability An electrolyte membrane can be formed.

  The reason for this is that sintering at a temperature lower than 1350 ° C has a low sintering temperature, making it difficult to produce an electrolyte membrane without gas permeability. This is because the reactivity of the liquid crystal is increased and the output performance is reduced.

  In a preferred embodiment of the present invention, after being formed on the surface of the fuel-side electrode reaction layer, it is sintered at 1350 to 1500 ° C.

  After forming an electrolyte membrane on the surface of the fuel-side electrode reaction layer, by sintering at 1350 to 1500 ° C, the reaction of equations (2) and (3) occurring between the electrolyte membrane and the fuel electrode proceeds efficiently, and gas An electrolyte membrane having no permeability can be formed.

  The reason for this is that the sintering temperature is lower at 1350 ° C, and it is difficult to produce an electrolyte membrane without gas permeability. This is because the reactivity with the reaction layer increases and the output performance decreases.

An air electrode on one side of the electrolyte membrane, a unit cell having a fuel electrode disposed on the opposite side thereof, and an interconnector having a role of electrical connection, a solid oxide fuel cell comprising: A first layer made of a material having an oxygen ion conductivity S1 on the air electrode side, a third layer made of a material having an oxygen ion conductivity S3 on the fuel electrode side, the first layer and the third layer; A second layer made of a material containing at least zirconia with an oxygen ion conductivity S2 is provided between the layers, and the oxygen ion conductivity S1 and the oxygen ion conductivity S2 have a relationship of S1> S2, Since the oxygen ion conductivity S3 and the oxygen ion conductivity S2 provide the relationship of S3> S2, a solid oxide fuel cell having excellent output performance can be provided.

The solid oxide fuel cell according to the present invention will be described with reference to FIG.
FIG. 1 is a diagram showing a cross section of a cylindrical solid oxide fuel cell. A strip-shaped interconnector 2 and an electrolyte membrane 3 are formed on a cylindrical air electrode support 1, and a fuel electrode 4 is formed on the electrolyte membrane 3 so as not to contact the interconnector 2. When air is flowed inside the air electrode support and fuel gas is flown outside, oxygen in the air is changed into oxygen ions at the interface between the air electrode and the electrolyte membrane, and the oxygen ions reach the fuel electrode through the electrolyte membrane. Then, the fuel gas and oxygen ions react to form water and carbon dioxide. These reactions are represented by equations (2) and (3). By connecting the fuel electrode 4 and the interconnector 2, electricity can be taken out.
^{_{H 2 + O 2- → H 2}} O + 2e - ... (2)
_{^{CO + O 2- → CO 2 +}} 2e - ... (3)

    FIG. 2 shows that an electrode reaction layer 1a is provided between the air electrode 1 and the electrolyte membrane 3, and a fuel-side electrode reaction layer 4a is provided between the electrolyte membrane 3 and the fuel electrode 4. FIG. 4 is a cross-sectional view showing a type having three layers of a first layer 3a, a second layer 3b, and a first layer 3c toward the side.

  Further, FIG. 3 shows a first layer and a third layer in which the electrolyte membrane has three layers including a first layer 3a, a second layer 3b, and a third layer 3a from the air electrode side toward the fuel electrode side. It is sectional drawing shown about the type which made the layer the same composition.

Details of the power generation will be described with reference to FIG. The air-side electrode reaction layer 1a is a layer provided to promote the reaction of formula (1) in which oxygen gas is generated from oxygen gas and electrons from the air electrode, and oxygen ions generated in the electrode reaction layer 1a are It moves to the fuel electrode side through the electrolyte membranes 3a, 3b and 3c. Then, the reactions shown in the equations (2) and (3) are performed in the fuel-side electrode reaction layer 4a, and electricity can be extracted to the outside by connecting the fuel electrode 4 and the interconnector 2. Therefore, by optimizing the air-side electrode reaction layer, the electrolyte membrane, and the fuel-side electrode reaction layer, it is possible to provide a solid oxide fuel cell having excellent output performance up to a low temperature of about 700 ° C.
^{_{1 / 2O 2 + 2e - →}} O 2- ... (1)

  The electrolyte membrane in the present invention is a membrane that has high oxygen ion conductivity, is a gas-impermeable membrane, and has no electronic conductivity at the power generation temperature of a solid oxide fuel cell in an air atmosphere and a fuel gas atmosphere. Preferably, there is. In particular, from the viewpoint of efficiently proceeding the reaction of Equation (1) and efficiently proceeding the reactions of Equations (2) and (3), providing a material having high oxygen ion conductivity on the air electrode side and the fuel electrode side Is preferred.

  Materials with high oxygen ion conductivity, such as SSZ and lanthanum gallate, which have been developed to date, have problems such as high material cost and low sinterability. Considering this, it is preferable to stack materials having a low material cost, high sinterability, and a certain degree of oxygen ion conductivity. From this viewpoint, as the electrolyte membrane, a first layer made of a material having high oxygen ion conductivity on the air electrode side, a third layer made of a material having high oxygen ion conductivity on the fuel electrode side, and a first layer In the present invention, an electrolyte membrane having a structure in which a second layer made of a material having excellent sinterability and containing at least zirconia is laminated between the third layers is used in the present invention.

As the first layer and the third layer in the electrolyte membrane of the present invention, a material having high oxygen ion conductivity is preferable. From this viewpoint, as the first layer and the third layer, SSZ, a cerium-containing oxide, a mixed layer of SSZ and a cerium-containing oxide, a general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (However, A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is Lanthanum gallate represented by one or more of Co, Fe, Ni, and Cr). In addition, ScYSZ and SSZ in which CeO ₂ , Bi ₂ O _{3, and the} like are dissolved in solid form also correspond to these.

The cerium-containing oxide shown here is not particularly limited as long as it is an oxide containing cerium, but from the viewpoint of high oxygen ion conductivity, the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15) is preferable.

The material having high oxygen ion conductivity shown here is preferably 0.1 Scm ^-1 or more at 1000 ° C., more preferably 0.02 Scm ^-1 or more at 700 ° C. The reason is that if a material having an oxygen ion conductivity of 0.1 Scm ^-1 or more at 1000 ° C. is used for the electrolyte membrane, a solid oxide fuel cell having high output performance at 900 to 1000 ° C. can be provided. This is because if it is 0.02 Scm ⁻¹ or more at 700 ° C., it is possible to provide a solid oxide fuel cell having high output performance even at a low temperature of about 700 ° C.

  Here, a method for measuring the oxygen ion conductivity will be described. A binder such as PVA was mixed with the electrolyte membrane material, press-formed with a disk-shaped mold, and sintered to prepare a sample having no gas permeability. After mounting a platinum electrode on the sample, the temperature was raised to 1000 ° C., and the oxygen ion conductivity was measured by an AC impedance measurement method. Further, the oxygen ion conductivity was measured at 700 ° C. in the same manner.

Here, the data at 1000 ° C. and 700 ° C. are described. However, the oxygen ion conductivities S1, S2, and S3 in the present invention are S1> S2, S2 < Refers to S3. Table 1 shows an example of the result of the oxygen ion conductivity obtained by the above method.

The second layer in the electrolyte membrane of the present invention is preferably a material having a sintering property for easily producing an electrolyte membrane having no gas permeability and a certain degree of oxygen ion conductivity. From this viewpoint, a material in which Bi ₂ O ₃ and rare earth oxide are further dissolved in YSZ and SSZ is preferable. Further, ScYSZ may be used.

The second layer in the electrolyte membrane of the present invention is not particularly limited as long as it has a certain degree of oxygen ion conductivity (for example, 0.01 Scm ^-1 or more at 1000 ° C.) and contains at least zirconia. Zirconia in which a rare earth oxide other than yttria and scandia is dissolved may be used. However, in order to obtain better performance than an electrolyte membrane formed only of a material having high oxygen ion conductivity, a material having excellent sinterability is more preferable. The reason for this is that if the material has excellent sinterability, the electrolyte membrane without gas permeability can be sintered at a low temperature.For example, when LaAMnO ₃ is used as the air electrode material, the manganese to the electrolyte membrane can be reduced. This is because it is possible to suppress the diffusion of, and to suppress a decrease in output performance.

  For the combination of the first layer, the second layer, and the third layer in the electrolyte membrane according to the present invention, the oxygen ion conductivity may be a material in which the first layer and the third layer are higher than the second layer. There is no particular limitation. Referring to the data in Table 1, Table 2 shows examples of combinations of the first layer, the second layer, and the third layer.

The first layer and the third layer in the electrolyte membrane of the present invention may be materials having higher oxygen ion conductivity than the second layer, and may have the same composition. For example, the pattern shown in the twelfth or seventeenth in Table 2 may be used.

As the raw material powder for the electrolyte membrane in the present invention, it is preferable that a membrane having no gas permeability can be produced. When the BET value is 0.5 to ²⁰ m ² g ⁻¹ , the particle size distribution is more than 0.1% for 3% diameter, 2% or less for 97% diameter, and the average particle diameter is controlled to be about 0.3 to 1 μm. preferable. By using a raw material powder controlled in this range, it is possible to produce an electrolyte membrane having no gas permeability even with a combination of electrolyte materials having low sinterability.

  The BET value shown here is a value obtained by measurement using a flow type specific surface area measuring apparatus Flowsorb II2300 manufactured by Shimadzu Corporation. The particle size distribution is a value obtained by measurement using a laser diffraction type particle size distribution analyzer SALD-2000 manufactured by Shimadzu Corporation. Further, the average particle diameter is a value of a median diameter (50% diameter) obtained by using a laser diffraction type particle size distribution analyzer SALD-2000 manufactured by Shimadzu Corporation.

  The method for producing the electrolyte membrane in the present invention is not particularly limited, but a slurry coating method, a screen printing method, and a sheet bonding method are preferable from the viewpoint of excellent mass productivity and low cost.

  The method for producing the electrolyte membrane raw material in the present invention is not particularly limited. The coprecipitation method is common.

The air electrode in the present invention preferably has high electron conductivity and high oxygen gas permeability in an air atmosphere of a solid oxide fuel cell, and can efficiently perform the reaction of the formula (1). From this viewpoint, a preferable material is LaAMnO ₃ .

  From the viewpoint that the reaction of the formula (1) can be carried out efficiently and the output performance is improved, it is preferable that an air-side electrode reaction layer is interposed between the air electrode and the electrolyte membrane.

Since the air-side electrode reaction layer is a layer provided for efficiently performing the reaction of the formula (1) and improving the output performance, it is preferable that the oxygen-ion conductivity is high. Further, it is more preferable that the air-side electrode reaction layer further has electron conductivity because the reaction of the formula (1) can be further promoted. Further, it is preferable that the material has a coefficient of thermal expansion close to that of the electrolyte membrane material, low reactivity with the electrolyte membrane and the air electrode, and good adhesion. If the material is good for all these characteristics, high output characteristics can be obtained even at a low temperature of about 700 ° C. From the above viewpoint, a preferable material is LaAMnO ₃ / SSZ.

In the present invention, the composition of the lanthanum manganite represented by LaAMnO ₃ in LaAMnO ₃ / SSZ air-side electrode reaction layer (either A = Ca or Sr), the electron conductivity in 700 ° C. or higher, stable materials In terms of properties and the like, when expressed as (La _1-x A _x ) _y MnO ₃ , the values of x and y are more preferably in the range of 0.15 ≦ x ≦ 0.3 and 0.97 ≦ y ≦ 1.

The reason is that the electron conductivity decreases in the range of x <0.15 and x> 0.3, and the reactivity increases and the activity of the electrode reaction layer decreases in the case of y <0.97. This is to lower the output performance of the battery in order to generate an insulating layer represented by La ₂ Zr ₂ O ₇ .

In the SSZ of the air-side electrode reaction layer in the present invention, any one or more oxides of CeO ₂ , Sm ₂ O ₃ , Gd ₂ O ₃ , Bi ₂ O ₃ , and Y ₂ O ₃ are further dissolved in 5 mol% or less. It may be. When these materials are dissolved, it is preferable to include them because an improvement in oxygen ion conductivity and / or an improvement in sinterability can be expected.

In order to increase the electrode activity of the air-side electrode reaction layer made of LaAMnO ₃ / SSZ in the present invention, a structure in which the average particle diameter and BET value of the raw material powder used are inclined may be used. For example, the average particle diameter may be 5 μm, 3 μm, 1 μm from the air electrode side toward the electrolyte membrane, or the BET value may be 1 m ² g ⁻¹ , 3 m ² g ⁻¹ , 5 m ² g ⁻¹ . From the viewpoint of efficiently performing the reaction of the formula (1), those composed of those having inclined average particle diameters or BET values are more preferable.

A structure in which the composition is inclined to enhance the electrode activity of the air-side electrode reaction layer made of LaAMnO ₃ / SSZ in the present invention may be used. For example, LaAMnO ₃ / SSZ may be set to 80/20, 50/50, or 20/80 from the air electrode side toward the electrolyte membrane. From the viewpoint that the difference in thermal expansion between the air electrode and the electrolyte membrane can be reduced and the reaction of the formula (1) can be performed efficiently, it is preferable to make the composition gradient.

LaAMnO ₃ air-side electrode reaction layer made of LaAMnO ₃ / SSZ in the present invention, Ce from the viewpoint of suppression of diffusion of the Mn component into the electron conductivity enhancing or electrolyte membrane, Sm, Pr, Nd, Co , Al, It may be a solid solution of Fe, Ni, Cr and the like. In particular, it is preferable to make Ni a solid solution.

The solid solution amount of scandia in the SSZ of the air-side electrode reaction layer composed of LaAMnO ₃ / SSZ in the present invention is preferably ₃ to 12 mol%. The reason for this is that the composition in this range has high oxygen ion conductivity. From the viewpoint of high oxygen ion conductivity, 8 to 12 mol% is more preferable.

LaAMnO ₃ / SSZ in the present invention may be a solid solution or mixed cerium-containing oxide. The reason is that the use of a solid solution or a mixture of cerium-containing oxides can suppress the diffusion of the Mn component into the electrolyte membrane, and is a solid oxide fuel excellent in output performance and durability performance. This is because a battery can be provided.

From the viewpoint of suppressing the diffusion of the Mn component into the electrolyte membrane, a layer in which LaAMnO ₃ and the cerium-containing oxide are uniformly mixed (hereinafter, LaAMnO ₃ / cerium-containing oxide) is preferable.

As the first layer in the electrolyte membrane, the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (where A is Sr, Ca, When using lanthanum gallate represented by one or more of Ba, B is one or more of Mg, Al, In, and C is one or more of Co, Fe, Ni, Cr) In particular, since the diffusion of the Mn component is particularly large, the diffusion of the Mn component such as a solid solution or a mixture of the cerium-containing oxide in the LaAMnO ₃ / SSZ or the LaAMnO ₃ / cerium-containing oxide is preferable. It is preferable to use an air-side electrode reaction layer capable of suppressing the occurrence of an air-fuel ratio.

The cerium-containing oxide shown here is not particularly limited as long as it is an oxide containing cerium. _{Those represented by the} general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15) have high oxygen ion conductivity, preferable.

The method for producing the raw material of LaAMnO ₃ / SSZ in the present invention is not particularly limited as long as it can satisfy the preferable characteristics as the air-side electrode reaction layer. Co-precipitation method, powder mixing method, spray pyrolysis method, sol-gel method and the like.

In the present invention, the composition of lanthanum manganite represented by LaAMnO ₃ (A = Ca or Sr) of the air electrode may be (La _{1− When} expressed as _x Ax) _y MnO ₃ , the values of x and y are preferably in the range of 0.15 ≦ x ≦ 0.3 and 0.97 ≦ y ≦ 1.

The reason is that the electron conductivity decreases in the range of x <0.15 and x> 0.3, and the reactivity increases and the activity of the electrode reaction layer decreases in the case of y <0.97. This is to lower the output performance of the cell in order to generate an insulating layer represented by La ₂ Zr ₂ O ₇ .

  Lanthanum manganite at the air electrode may be a solid solution of Ce, Sm, Gd, Pr, Nd, Co, Al, Fe, Cr, Ni, etc. in addition to Sr or Ca.

  The method for producing the cathode material in the present invention is not particularly limited. Examples of the method include a method using a powder mixing method, a coprecipitation method, a spray pyrolysis method, and a sol-gel method.

  It is preferable that the fuel electrode in the present invention has high electron conductivity in a fuel gas atmosphere of a solid oxide fuel cell, high fuel gas permeability, and can efficiently perform the reaction of formulas (2) and (3). . From this viewpoint, a preferable material is a layer in which NiO and zirconia in which yttria is dissolved are uniformly mixed (hereinafter, referred to as NiO / YSZ) or a layer in which NiO and cerium-containing oxide are uniformly mixed. (Hereinafter, referred to as NiO / cerium-containing oxide). NiO is reduced to Ni in the fuel gas atmosphere of the solid oxide fuel cell, and the layer becomes Ni / YSZ or Ni / cerium-containing oxide.

The cerium-containing oxide shown here is not particularly limited as long as it is an oxide containing cerium. _{Those represented by the} general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15) have high oxygen ion conductivity, preferable.

  From the viewpoint that the reactions of the formulas (2) and (3) can be performed efficiently and the output performance is improved, it is preferable to provide a fuel-side electrode reaction layer between the electrolyte membrane and the fuel electrode.

  In the present invention, when using a zirconia-based material such as a zirconia material in which scandia is dissolved as a third layer of the electrolyte membrane, the fuel-side electrode reaction layer is excellent in both electronic conductivity and oxygen ion conductivity. A layer in which NiO and zirconia in which scandia is dissolved as a solid solution is uniformly mixed (hereinafter, referred to as NiO / SSZ) is preferable. NiO is reduced to Ni under the fuel atmosphere of the solid oxide fuel cell, and the layer becomes Ni / SSZ. Further, the ratio of NiO / SSZ is preferably 10/90 to 50/50 by weight. The reason is that if it is less than 10/90, the electronic conductivity is too low, while if it is more than 50/50, the oxygen ion conductivity is too low.

  The scandia solid solution amount of SSZ in the NiO / SSZ of the present invention is preferably 3 to 12 mol%. The reason for this is that within this range, the oxygen ion conductivity is high and the reactions of formulas (2) and (3) can be promoted. Further, since the oxygen ion conductivity is high even at a low temperature of about 700 ° C., a solid oxide fuel cell having high output performance up to a low temperature of about 700 ° C. can be provided.

In the SSZ in the NiO / SSZ of the present invention, at least one selected from CeO ₂ , Sm ₂ O ₃ , Gd ₂ O ₃ , Er ₂ O ₃ , Y ₂ O ₃ , and Bi ₂ O ₃ is further dissolved in 5 mol% or less. May be. Also, two or more solid solutions may be used. When these materials are dissolved, not only oxygen ion conductivity but also electron conductivity can be expected to be improved in a fuel gas atmosphere.

In the present invention, the cerium-containing oxide or the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O _{3 is} used as the third layer of the electrolyte membrane. (However, A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is one or more of Co, Fe, Ni, Cr) When a lanthanum gallate represented by the following formula is used, a NiO / cerium-containing oxide excellent in both electronic conductivity and oxygen ion conductivity is preferable as the fuel-side electrode reaction layer. NiO is reduced to Ni under the fuel atmosphere of the solid oxide fuel cell, and the layer becomes Ni / cerium-containing oxide. Further, the ratio of NiO / cerium-containing oxide is preferably 10/90 to 50/50 by weight. The reason is that if it is less than 10/90, the electronic conductivity is too low, while if it is more than 50/50, the oxygen ion conductivity is too low.

The cerium-containing oxide shown here is not particularly limited as long as it is an oxide containing cerium. A compound represented by the general formula (CeO ₂ ) _1-2X (C ₂ O ₃ ) _X (however, C = Sm, Gd, Y, or La, one of 0.05 ≦ X ≦ 0.15) is preferable.

  It is preferable that the fuel electrode in the present invention has high electron conductivity in order to reduce IR loss. From this viewpoint, the ratio of NiO / YSZ and NiO / cerium-containing oxide is preferably 50/50 to 90/10 by weight. The reason is that if it is less than 50/50, the electronic conductivity is low, while if it is more than 90/10, the output performance is reduced due to aggregation of Ni particles.

  Regarding the composition of the fuel electrode in the present invention, NiO / YSZ, NiO / SSZ as a composition other than the cerium-containing oxide, a layer in which zirconia in which NiO and calcium are dissolved in a solid solution are uniformly mixed (hereinafter, NiO / CSZ Shown). YSZ is preferred because YSZ is cheaper than SSZ, but NiO / CSZ is most preferred from the viewpoint of cost because CSZ is cheaper than YSZ. Note that NiO / CSZ also becomes Ni / CSZ under the fuel gas atmosphere of the fuel cell.

  The method of synthesizing the fuel electrode raw material in the present invention is not particularly limited as long as the fuel electrode materials such as NiO / SSZ and NiO / YSZ are uniformly mixed. Examples include a coprecipitation method and a spray drying method.

  The interconnector in the present invention is preferably one having high electron conductivity, no gas permeability, and stable in an oxidation-reduction atmosphere in an air atmosphere and a fuel gas atmosphere at the power generation temperature of the solid oxide fuel cell. From this viewpoint, lanthanum chromite is most preferred.

  Since lanthanum chromite is difficult to sinter, it is difficult to manufacture an interconnector having no gas permeability at the firing temperature (1500 ° C. or lower) of a solid oxide fuel cell. In order to improve sinterability, Ca, Sr, and Mg are preferably used as a solid solution. A solid solution of Ca is most preferable because it has the highest sinterability and can produce a membrane having no gas permeability at the same temperature as other materials of the solid oxide fuel cell.

  There is no particular limitation on the solid solution amount of lanthanum chromite in which Ca is used as the solid solution for the interconnector. Although the electronic conductivity increases as the amount of Ca solid solution increases, the stability of the material decreases, so the amount of Ca solid solution is preferably about 10 to 40 mol%.

  The shape of the solid oxide fuel cell in the present invention is not particularly limited, and may be a flat plate type or a cylindrical type. In the flat type, the interconnector is called a separator, and the role is the same as that of the interconnector. In the case of a separator, a heat-resistant metal such as ferritic stainless steel may be used.

The solid oxide fuel cell according to the present invention is applicable to a microtube type (outer diameter of 10 mm or less, more preferably 5 mm or less).

(Example 1)
The cylindrical solid oxide fuel cell shown in FIG. 1 was used for the basic configuration. In other words, a strip-shaped interconnector 2 and an electrolyte membrane 3 are formed on a cylindrical air electrode support 1, and a fuel electrode 4 is formed on the electrolyte membrane so as not to contact the interconnector. In the present embodiment, as shown in FIG. 2, an electrode reaction layer is provided between the air electrode and the electrolyte membrane, and a fuel-side electrode reaction layer is provided between the electrolyte membrane and the fuel electrode. The used type was used.

(1) Preparation of air electrode support The air electrode is a lanthanum manganite with a solid solution of Sr represented by La _0.75 Sr _0.25 MnO ₃ composition, prepared by coprecipitation method and heat treated to obtain air electrode raw material powder. Was. The average particle size was 30 μm. A cylindrical molded body was produced by an extrusion molding method. Further, sintering was performed at 1500 ° C. to obtain an air electrode support.

(2) As a manufacturing air-side electrode reaction layer on the air side electrode reaction layer, LaAMnO ₃ / SSZ and then, examples of the composition and the weight _{ratio, La 0.75 Sr 0.25 MnO 3/} 90 mol% ZrO 2 -10mol% Sc 2 O ₃ = 50/50 was used. The aqueous solution of La, Sr, Mn, Zr and Sc was mixed to have the above-mentioned composition using the respective nitrate aqueous solutions, and then oxalic acid was added to precipitate. The precipitate and the supernatant were dried and further heat-treated to obtain a raw material powder after controlling the particle size. The average particle size was 2 μm. 40 parts by weight of the electrode reaction layer powder, 100 parts by weight of solvent (ethanol), 2 parts by weight of binder (ethyl cellulose), 1 part by weight of dispersant (polyoxyethylene alkyl phosphate), 1 part by weight of defoamer (sorbitan sesquiolate) After mixing, the slurry was sufficiently stirred to prepare a slurry. The slurry viscosity was 100 mPas. The slurry was formed on an air electrode support (outside diameter: 15 mm, wall thickness: 1.5 mm, effective length: 400 mm) by a slurry coating method, and then sintered at 1400 ° C. The thickness was 20 μm.

(3) Preparation of slurry for electrolyte membrane (first layer):
The material of the first layer was SSZ, and the composition was 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ . ZrO ₂ was dissolved in concentrated nitric acid of 3N or more heated at 100 ° C. and diluted with distilled water to obtain a nitrate aqueous solution. For Sc ₂ O ₃ , a nitrate aqueous solution was obtained in the same manner. Each nitrate aqueous solution was prepared so as to have the above-mentioned composition, and an oxalic acid aqueous solution was added thereto for coprecipitation. The precipitate and the supernatant obtained by co-precipitation were dried at about 200 ° C., thermally decomposed at 500 ° C., and further heat-treated at 800 ° C. for 10 hours to obtain a raw material powder. The average particle size was 0.5 μm. 40 parts by weight of the powder were mixed with 100 parts by weight of a solvent (ethanol), 2 parts by weight of a binder (ethyl cellulose), 1 part by weight of a dispersant (polyoxyethylene alkyl phosphate), and 1 part by weight of an antifoaming agent (sorbitan sesquiolate). After mixing, the slurry was sufficiently stirred to prepare a slurry. The slurry viscosity was 140 mPas.

(4) Preparation of slurry for electrolyte membrane (second layer):
The material of the second layer was YSZ, and the composition was 90 mol% ZrO ₂ -10 mol% Y ₂ O ₃ . ZrO ₂ was dissolved in concentrated nitric acid of 3N or more heated at 100 ° C. and diluted with distilled water to obtain a nitrate aqueous solution. A nitrate aqueous solution was obtained from Y ₂ O _{3 by} the same method. Each nitrate aqueous solution was prepared so as to have the above-mentioned composition, and an oxalic acid aqueous solution was added thereto for coprecipitation. The precipitate and the supernatant obtained by co-precipitation were dried at about 200 ° C., thermally decomposed at 500 ° C., and further heat-treated at 800 ° C. for 10 hours to obtain a raw material powder. The average particle size was 0.5 μm. 40 parts by weight of the powder, 100 parts by weight of a solvent (ethanol), 2 parts by weight of a binder (ethyl cellulose), 1 part by weight of a dispersant (polyoxyethylene alkyl phosphate), and 1 part by weight of an antifoaming agent (sorbitan sesquiolate) After mixing, the slurry was sufficiently stirred to prepare a slurry. The slurry viscosity was 140 mPas.

(5) Slurry preparation of electrolyte membrane (third layer):
The material of the third layer was SSZ, and the composition was 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ . ZrO ₂ was dissolved in concentrated nitric acid of 3N or more heated at 100 ° C. and diluted with distilled water to obtain a nitrate aqueous solution. For Sc ₂ O ₃ , a nitrate aqueous solution was obtained in the same manner. Each nitrate aqueous solution was prepared so as to have the above-mentioned composition, and an oxalic acid aqueous solution was added thereto for coprecipitation. The precipitate and the supernatant obtained by co-precipitation were dried at about 200 ° C., thermally decomposed at 500 ° C., and further heat-treated at 800 ° C. for 10 hours to obtain a raw material powder. The average particle size was 0.5 μm. 40 parts by weight of the powder, 100 parts by weight of a solvent (ethanol), 2 parts by weight of a binder (ethyl cellulose), 1 part by weight of a dispersant (polyoxyethylene alkyl phosphate), and 1 part by weight of an antifoaming agent (sorbitan sesquiolate) After mixing, the slurry was sufficiently stirred to prepare a slurry. The slurry viscosity was 140 mPas.

(6) Preparation of electrolyte membrane First, a first layer was formed on the air-side electrode reaction layer by a slurry coating method. Subsequently, a second layer was formed by a slurry coating method, and a third layer was formed by a slurry coating method. Thereafter, sintering was performed at 1400 ° C. The thickness of the obtained electrolyte membrane was 30 μm (the first layer on the air electrode side: 10 μm, the second layer: 10 μm, and the third layer: 10 μm). The portion where the interconnector is to be formed in a later step was masked so that the film was not applied.

(7) Preparation of slurry for fuel-side electrode reaction layer The material for the fuel-side electrode reaction layer was NiO / SSZ, the composition was NiO / 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ , Ni, Zr and Sc Each of the aqueous solutions of nitrate was mixed so as to have the above-mentioned composition, and then oxalic acid was added for precipitation. After drying the precipitate and the supernatant, it was further subjected to a heat treatment to control the particle size to obtain a raw material. The weight ratio of the fuel-side electrode reaction layer was Ni / 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ = 20/80 and 50/50, and the average particle diameter was 0.5 μm. Was. 100 parts by weight of the powder, 500 parts by weight of an organic solvent (ethanol), 10 parts by weight of a binder (ethyl cellulose), 5 parts by weight of a dispersant (polyoxyethylene alkyl phosphate), 1 part by weight of an antifoaming agent (sorbitanses oxolate) After mixing 5 parts by weight of a plasticizer (DBP), the mixture was sufficiently stirred to prepare a slurry. The viscosity of this slurry was 70 mPas.

(8) Preparation of fuel-side electrode reaction layer Mask the battery so that the area of the fuel-side electrode reaction layer becomes 150 cm ² , and place NiO / 90 mol% ZrO ₂ -10 mol% Sc ₂ on the electrolyte membrane by the slurry coating method. O ₃ (average particle diameter) = 20/80 (0.5 μm) and 50/50 (0.5 μm) in this order. The film thickness (after sintering) was 10 μm.

(9) Slurry preparation of fuel electrode:
The material of the fuel electrode was NiO / YSZ, and the composition was NiO / 90 mol% ZrO ₂ -10 mol% Y ₂ O ₃ . After using the aqueous nitrate solutions of Ni, Zr and Y to prepare the above composition, oxalic acid was added for precipitation. After drying the precipitate and the supernatant, the mixture was further subjected to a heat treatment to control the particle size, thereby obtaining a raw material. The composition and the weight ratio were NiO / 90 mol% ZrO ₂ -10 mol% Y ₂ O ₃ = 70/30, and the average particle size was 2 μm. 100 parts by weight of the powder, 500 parts by weight of an organic solvent (ethanol), 20 parts by weight of a binder (ethyl cellulose), 5 parts by weight of a dispersant (polyoxyethylene alkyl phosphate), 1 part by weight of an antifoaming agent (sorbitanses oxolate) After mixing 5 parts by weight of a plasticizer (DBP), the mixture was sufficiently stirred to prepare a slurry. The viscosity of this slurry was 250 mPas.

(10) Preparation of fuel electrode A fuel electrode was formed on the fuel-side electrode reaction layer by a slurry coating method. The thickness (after sintering) was 90 μm. Further, the fuel-side electrode reaction layer and the fuel electrode were co-sintered at 1400 ° C.

(11) Fabrication of interconnectors:
The interconnector was lanthanum chromite in which Ca represented by La _0.80 Ca _0.20 CrO ₃ was dissolved. After production by the spray pyrolysis method, heat treatment was performed to obtain a raw material powder. The average particle diameter of the obtained powder was 1 μm. 40 parts by weight of the powder, 100 parts by weight of a solvent (ethanol), 2 parts by weight of a binder (ethyl cellulose), 1 part by weight of a dispersant (polyoxyethylene alkyl phosphate), and 1 part by weight of an antifoaming agent (sorbitan sesquiolate) After mixing, the slurry was sufficiently stirred to prepare a slurry. The slurry viscosity was 100 mPas. An interconnector was formed by a slurry coating method and sintered at 1400 ° C. The thickness after sintering was 40 μm.

(Example 2)
In the electrolyte membrane, the material of the first layer was ScYSZ, and the composition was the same as that of Example 1 except that the composition was 90 mol% ZrO ₂ -5 mol% Sc ₂ O ₃ -5 mol% Y ₂ O ₃ .

(Example 3)
In the electrolyte membrane, the material of the first layer and SSZ / YSZ, the composition was _{90mol% ZrO 2 -10mol% Sc 2} O 3 / 90mol% ZrO 2 -10mol% Y 2 O 3 = 50/50. 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ powder having an average particle diameter of 0.5 μm produced by the coprecipitation method, and 90 mol% ZrO ₂ -10 mol% Y having an average particle diameter of 0.5 μm produced by the coprecipitation method Example 2 was repeated except that 20 parts by weight of ₂ O ₃ powder was added to prepare a slurry.

(Example 4)
Example 1 was repeated except that the material of the first layer was SSZ and the composition was 89 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ -1 mol% CeO ₂ .

(Example 5)
The same as Example 1 except that the material of the first layer was SSZ and the composition was 89 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ -0.5 mol% Bi ₂ O ₃ -0.5 mol% CeO ₂ did.

(Example 6)
Except that the material of the first layer was (CeO ₂ ) _0.8 (Gd ₂ O ₃ ) _0.1 , CeO ₂ and Gd ₂ O ₃ were produced by the above-mentioned coprecipitation method, and the average particle diameter was 0.5 μm, As in Example 1.

(Example 7)
The material of the first layer is (CeO ₂ ) _0.8 (Gd ₂ O ₃ ) _0.1 , the material of the second layer is ScYSZ, and the composition is 90 mol% ZrO ₂ -5 mol% Sc ₂ O ₃ -5 mol% Y ₂ except that the O ₃ were the same as in example 1.

(Example 8)
Example 3 was the same as Example 1 except that the material of the third layer was ScYSZ, and the composition was 90 mol% ZrO ₂ -5 mol% Sc ₂ O ₃ -5 mol% Y ₂ O ₃ .

(Example 9)
Example 1 was repeated except that the material of the first and third layers was ScYSZ and the composition was 90 mol% ZrO ₂ -5 mol% Sc ₂ O ₃ -5 mol% Y ₂ O ₃ .

(Example 10)
The material of the first layer is (CeO ₂ ) _0.8 (Gd ₂ O ₃ ) _0.1 , the material of the third layer is ScYSZ, and the composition is 90 mol% ZrO ₂ -5 mol% Sc ₂ O ₃ -5 mol% Y ₂ except that the O ₃ were the same as in example 1.

(Example 11)
The material of the first layer and the third layer is ScYSZ, the composition is 90 mol% ZrO ₂ -8 mol% Sc ₂ O ₃ -2 mol% Y ₂ O _3, and the material of the second layer is ScYSZ. Was changed to 90 mol% ZrO ₂ -5 mol% Sc ₂ O ₃ -5 mol% Y ₂ O ₃ in the same manner as in Example 1.

(Comparative Example 1)
The electrolyte membrane was the same as in Example 1 except that the electrolyte membrane was composed of only 90 mol% ZrO ₂ -10 mol% Y ₂ O ₃ and the film thickness was 30 μm.

(Power generation test)
A power generation test was performed using the cells (effective area of fuel electrode: 150 cm ² ) obtained in Examples 1 to 11 and Comparative Example 1. The operating conditions at this time were as follows.
Fuel: (H ₂ + 11% H ₂ O): N ₂ = 1: 2
Oxidizing agent: Air
Power generation temperature: 800 ° C
Current density: 0.3Acm ^-2

(Gas leak test)
For the batteries obtained in Examples 1 to 11 and Comparative Example 1, nitrogen gas was flown into the inside of the air electrode support, a pressure of 0.1 MPa was applied from the inside of the air electrode, and the amount of gas permeated through the electrolyte membrane was measured. Thereby, it was evaluated whether the electrolyte membrane was a membrane having no gas permeability.

Table 3 shows the results of the potential and the gas permeation amount of the electrolyte membrane in the power generation test. In Examples 1 to 11 and Comparative Example 1, the gas permeation amount Q ≦ 2.8 × 10 ⁻¹⁰ ms ⁻¹ Pa ⁻¹ , which is more preferable as the electrolyte membrane, is in the range, and it is confirmed that there is no problem in gas permeability of the electrolyte membrane. Was done. In addition, the generated potential was 0.6 V or more in Examples 1 to 11, but in Comparative Example 1, the result was clearly low at 0.57 V. From the above results, the first layer, the second layer and the third layer in the electrolyte membrane, SSZ and YSZ and SSZ, SSZ / YSZ and YSZ and SSZ, (CeO ₂ ) _0.8 (Gd ₂ O ₃ ) _0.1 It was confirmed that a solid oxide fuel cell having excellent output performance could be provided by using a configuration such as ScYSZ and SSZ, and ScYSZ and YSZ and ScYSZ.

Example 4, of at least one selected from Examples 5 and further CeO ₂ to the SSZ as shown in Table _{1, Sm 2 O 3, Gd} 2 O 3, Yb 2 O 3, Er 2 O 3 and Bi ₂ O ₃ It was confirmed that the use of an oxide in which the oxide was dissolved in an amount of 5 mol% or less improved the power generation performance or reduced the gas permeation amount of the electrolyte membrane, and was more preferable.

(Example 12)
The material of the third layer in the electrolyte membrane was a cerium-containing oxide, and the composition was (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 . (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 was prepared by the above-mentioned coprecipitation method and the average particle diameter was 0.5 μm. After forming a film on the first layer and the second layer as in Example 1, sintering was performed at 1420 ° C. Subsequently, the material of the fuel-side electrode reaction layer and the fuel electrode was NiO / cerium-containing oxide, and the composition was NiO / (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 . Ni, Ce and Sm were each prepared using the respective nitrate aqueous solutions so as to have the above-mentioned composition, and then oxalic acid was added for precipitation. After drying the precipitate and the supernatant, it was further subjected to a heat treatment to control the particle size to obtain a raw material. The composition of the fuel-side electrode reaction layer and its weight ratio were NiO / (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 = 20/80 and 50/50, and the average particle diameter was 0.5 μm for both. did. The composition of the fuel electrode and its weight ratio were NiO / (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 = 70/30. Except for these, the procedure was the same as in Example 1.

(Example 13)
Example 12 was the same as Example 12 except that the first layer in the electrolyte membrane was a cerium-containing oxide and the composition was (CeO ₂ ) _0.8 (Gd ₂ O ₃ ) _0.1 .

(Example 14)
The first layer in the electrolyte membrane is a cerium-containing oxide, the composition is (CeO ₂ ) _0.8 (Gd ₂ O ₃ ) _0.1 , the second layer is ScYSZ, and the composition is 90 mol% ZrO ₂ -5 mol% Sc Same as Example 12 except that ₂ O ₃ -5 mol% Y ₂ O ₃ was used.

(Example 15)
Example 12 was repeated except that the first layer in the electrolyte membrane was ScYSZ and the composition was 90 mol% ZrO ₂ -5 mol% Sc ₂ O ₃ -5 mol% Y ₂ O ₃ .

(Comparative Example 2)
Example 12 was the same as Example 12 except that the electrolyte membrane was composed only of (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 , the film thickness was 30 μm, and the sintering temperature was 1430 ° C.

(Power generation test)
A power generation test was performed using the batteries (effective fuel electrode area: 150 cm ² ) obtained in Examples 12 to 15 and Comparative Examples 1 and ² . The operating conditions at this time were as follows.
Fuel: (H ₂ + 11% H ₂ O): N ₂ = 1: 2
Oxidizing agent: Air
Power generation temperature: 800 ° C
Current density: 0.3Acm ^-2

(Gas leak test)
For the batteries obtained in Examples 12 to 15 and Comparative Examples 1 and 2, nitrogen gas was allowed to flow inside the air electrode support, a pressure of 0.1 MPa was applied from the inside of the air electrode, and the amount of gas permeated through the electrolyte membrane was measured. did. Thereby, it was evaluated whether the electrolyte membrane was a membrane having no gas permeability.

Table 4 shows the results of the potential and the gas permeation amount of the electrolyte membrane in the power generation test. In Examples 12, 15 and Comparative Example 1, the more preferable gas permeation amount as an electrolyte membrane was within the range of Q ≦ 2.8 × 10 ⁻¹⁰ ms ⁻¹ Pa ⁻¹ , and in Examples 13 and 14, and The preferable gas permeation amount Q as a membrane was within the range of Q ≦ 2.8 × 10 ⁻⁹ ms ⁻¹ Pa ⁻¹ , and it was confirmed that there was no problem in gas permeability as an electrolyte membrane in any case. On the other hand, the generated electric potential was extremely low at 0.57 V in Comparative Example 1 and 0.1 V in Comparative Example 2, while the electric potential was 0.6 V or more in Examples 12 to 15. The potential of Comparative Example 2 is extremely low when only (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 has the cerium-containing oxide exposed to the oxidation-reduction atmosphere and has electronic conductivity, and the electromotive force is greatly reduced. That's because As shown in Examples 12 to 15, the first layer, the second layer, and the third layer of the electrolyte membrane were formed of SSZ, YSZ, (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 , (CeO ₂ ) _0.8 (Gd ₂ O ₃ ) _0.1 and YSZ and (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 , ScYSZ and YSZ and (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 It has been confirmed that a solid oxide fuel cell having excellent performance can be provided.

(Example 16)
The material of the first layer was lanthanum gallated, and the composition was La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ . La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ is a mixture of La ₂ O ₃ , SrCO ₃ , Ga ₂ O ₃ , MgO so as to have the above composition, mixed in a ball mill, heat treated at 1200 ° C., and pulverized. The average particle size was 0.5 μm. For the air-side electrode reaction layer, La _0.75 Sr _0.25 MnO ₃ , 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ and (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 Then, after pulverizing and controlling the particle size, a raw material powder was obtained. The average particle size was 2 μm. Mixing composition of the raw material was _{La 0.75 Sr 0.25 MnO 3/90} mol% ZrO 2 -10mol% Sc 2 O 3 / (CeO 2) 0.8 (Sm 2 O 3) 0.1 = 40/40/20 in weight ratio Except for this, the procedure was the same as in Example 1.

(Example 17)
The material of the first layer was lanthanum gallated, and the composition was La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ . Example 16 was repeated except that the third composition was ScYSZ and the composition was 90 mol% ZrO ₂ -5 mol% Sc ₂ O ₃ -5 mol% Y ₂ O ₃ .

(Example 18)
The material of the first layer was lanthanum gallated, and the composition was La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ . For the air-side electrode reaction layer, La _0.75 Sr _0.25 MnO ₃ , 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ and (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 Then, after pulverizing and controlling the particle size, a raw material powder was obtained. The average particle size was 2 μm. Mixing composition of the raw material was _{La 0.75 Sr 0.25 MnO 3/90} mol% ZrO 2 -10mol% Sc 2 O 3 / (CeO 2) 0.8 (Sm 2 O 3) 0.1 = 40/40/20 in weight ratio . The material of the third layer was a cerium-containing oxide, and the composition was (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 . A raw material of (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 was prepared by the above-mentioned coprecipitation method and the average particle diameter was 0.5 μm. The material of the fuel-side electrode reaction layer and the fuel electrode was NiO / cerium-containing oxide, and the composition was NiO / (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 . Ni, Ce and Sm were each prepared using the respective nitrate aqueous solutions so as to have the above-mentioned composition, and then oxalic acid was added for precipitation. After drying the precipitate and the supernatant, it was further subjected to a heat treatment to control the particle size to obtain a raw material. The composition of the fuel-side electrode reaction layer and its weight ratio are NiO / (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 = 20/80 and 50/50, and the average particle size of the raw material powder is 0.5 μm And The composition of the fuel electrode and its weight ratio were NiO / (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 = 70/30. Except for these, the procedure was the same as in Example 1.

(Example 19)
Example 18 was the same as Example 18 except that the material of the third layer was lanthanum gallate and the composition was La _0.8 Sr _0.2 Ga _0.8 Mg _0.115 Co _0.085 O ₃ .

(Example 20)
The material of the first layer was a cerium-containing oxide, and the composition was (CeO ₂ ) _0.8 (Gd ₂ O ₃ ) _0.1 . Further, the same procedure as in Example 18 was performed, except that the material of the third layer was lanthanum gallate, and the composition was La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ .

(Example 21)
Example 18 was the same as Example 18 except that the material of the first layer and the third layer was lanthanum gallate, and the composition was La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ .

(Example 22)
The material of the first layer was ScYSZ, and the composition was 90 mol% ZrO ₂ -5 mol% Sc ₂ O ₃ -5 mol% Y ₂ O ₃ . Further, the same procedure as in Example 18 was performed, except that the material of the third layer was lanthanum gallate, and the composition was La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ .

(Example 23)
The material of the first layer and the third layer was lanthanum gallate, and the composition was La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ . The material of the second layer was SSZ, and the composition was the same as that of Example 18 except that the composition was 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ .

(Example 24)
The material of the first layer was a cerium-containing oxide, and the composition was (CeO ₂ ) _0.8 (Gd ₂ O ₃ ) _0.1 . The material of the third layer was lanthanum gallate, and the composition was La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ . Example 18 was the same as Example 18 except that the material of the second layer was SSZ and the composition was 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ .

(Comparative Example 3)
Example 18 was the same as Example 18 except that the electrolyte membrane was composed of only La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ and the film thickness was 30 μm.

(Power generation test)
A power generation test was performed using the batteries (effective fuel electrode area: 150 cm ² ) obtained in Examples 16 to 24 and Comparative Examples 1 to 3. The operating conditions at this time were as follows.
Fuel: (H ₂ + 11% H ₂ O): N ₂ = 1: 2
Oxidizing agent: Air
Power generation temperature: 800 ° C
Current density: 0.3Acm ^-2

(Gas leak test)
Nitrogen gas was flown inside the air electrode support for the batteries obtained in Examples 16 to 24 and Comparative Examples 1 to 3, a pressure of 0.1 MPa was applied from the inside of the air electrode, and the amount of gas permeating the electrolyte membrane was measured. did. Thereby, it was evaluated whether the electrolyte membrane was a membrane having no gas permeability.

Table 5 shows the results of the potential and the gas permeation amount of the electrolyte membrane in the power generation test. In Examples 16 to 24 and Comparative Examples 1 and 3, the more preferable gas permeation amount for the electrolyte membrane was Q ≦ 2.8 × 10 ⁻¹⁰ ms ⁻¹ Pa ⁻¹ , and in Comparative Example 2, a gas preferable as the electrolyte membrane was used. The permeation amount Q was within a range of 2.8 × 10 ⁻⁹ ms ⁻¹ Pa ⁻¹ , and it was confirmed that there was no problem in gas permeability as an electrolyte membrane in any case. On the other hand, regarding the generated potential, the potential exceeds 0.6 V in Examples 16 to 24, whereas the comparative example 1 has an extremely low value of 0.57 V, the comparative example 2 has 0.1 V, and the comparative example 3 has 0.3 V. became. This is because, only (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 , the cerium-containing oxide has electronic conductivity due to exposure to an oxidation-reduction atmosphere, and the electromotive force is greatly reduced. _This is because, when only _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ is used, Mn from the air-side electrode reaction layer and the air electrode enters La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O ₃ and has electron conductivity, and the electromotive force is reduced. In contrast, as shown in Examples 16 to 24, a second electrolyte layer containing at least zirconia was provided in the middle, and (CeO ₂ ) _0.8 (Sm ₂ O ₃ ) _0.1 or La _0.8 Sr _0.2 Ga _0.8 Mg _0.2 O It was confirmed that by providing ₃ on the air electrode side and / or the fuel electrode side, it was possible to provide a solid oxide fuel cell having excellent output performance.

From the results of Examples 1 to 24 and Comparative Examples 1 to 3, the second layer in which the electrolyte membrane is made of a material containing at least zirconia, and the first layer made of a material having higher oxygen ion conductivity than the second layer Is provided on the air electrode side, and a third layer made of a material having higher oxygen ion conductivity than the second layer is provided on the fuel electrode side, thereby providing a solid oxide fuel cell having excellent output performance. I was able to confirm that I could do it.

(About the ratio of the thickness in the electrolyte membrane of the second layer)
(Example 25)
Example 1 was repeated except that the thickness of the first layer was 1 μm, the thickness of the second layer was 28 μm, and the thickness of the third layer was 1 μm.

(Example 26)
Example 1 was repeated except that the thickness of the first layer was 1.5 μm, the thickness of the second layer was 27 μm, and the thickness of the third layer was 1.5 μm.

(Example 27)
Example 1 was repeated except that the thickness of the first layer was 3 μm, the thickness of the second layer was 24 μm, and the thickness of the third layer was 3 μm.

(Example 28)
Example 1 was repeated except that the thickness of the first layer was 4.5 μm, the thickness of the second layer was 21 μm, and the thickness of the third layer was 4.5 μm.

(Example 29)
Example 1 was repeated except that the thickness of the first layer was 7.5 μm, the thickness of the second layer was 15 μm, and the thickness of the third layer was 7.5 μm.

(Example 30)
Example 1 was repeated except that the thickness of the first layer was 10.5 μm, the thickness of the second layer was 9 μm, and the thickness of the third layer was 10.5 μm.

(Example 31)
Example 1 was repeated except that the thickness of the first layer was 12 μm, the thickness of the second layer was 6 μm, and the thickness of the third layer was 12 μm.

(Example 32)
Example 1 was repeated except that the thickness of the first layer was 13.5 μm, the thickness of the second layer was 3 μm, and the thickness of the third layer was 13.5 μm.

(Example 33)
Example 1 was repeated except that the thickness of the first layer was 14 μm, the thickness of the second layer was 2 μm, and the thickness of the third layer was 14 μm.

(Comparative Example 4)
The procedure was the same as that of Example 1 except that the electrolyte membrane was composed only of 90 mol% ZrO ₂ -10 mol% Sc ₂ O ₃ , the film thickness was 30 μm, and sintering was performed at 1420 ° C.

(Power generation test)
A power generation test was performed using the cells (effective fuel electrode area: 150 cm ² ) obtained in Examples 1, 25 to 33 and Comparative Examples 1 and 4. The operating conditions at this time were as follows.
Fuel: (H ₂ + 11% H ₂ O): N ₂ = 1: 2
Oxidizing agent: Air
Power generation temperature: 800 ° C
Current density: 0.3Acm ^-2

(Gas leak test)
Nitrogen gas was flown into the air electrode support for the batteries obtained in Examples 1 and 25 to 33 and Comparative Examples 1 and 4, and a pressure of 0.1 MPa was applied from the inside of the air electrode to allow gas permeation through the electrolyte membrane. Was measured. Thereby, it was evaluated whether the electrolyte membrane was a membrane having no gas permeability.

Table 6 shows the results of the power generation potential and the gas permeation amount of the electrolyte membrane of the battery in which the thickness of the second layer was changed. The generated potential was higher than that of Comparative Example 1, and it was confirmed that the output performance was improved by providing the first layer on the air electrode side and the third layer on the fuel electrode side. Looking at the generated potential, Example 25 is almost the same as Comparative Example 1, but when the thickness of the second layer in Example 26 is reduced to 90% or less, the potential rapidly increases, and the ratio of the thickness is reduced to 30%. Up to this point, the potential tended to increase. Further, when the thickness ratio was set to 30% or less, the electric potential tended to decrease. On the other hand, when looking at the gas permeation amount, the gas permeation amount becomes larger as the thickness of the second layer becomes thinner, although the gas permeation amount is preferably within the range of Q ≦ 2.8 × 10 ⁻⁹ ms ⁻¹ Pa ⁻¹ as an electrolyte membrane. When the thickness of the second layer was smaller than 10%, the gas permeation amount tended to increase sharply. From the above results, when the second layer is thicker than 90%, the effect of improving the potential is small. When the thickness is smaller than 10%, the gas permeation amount is large and the potential is reduced. It has been confirmed that a range of 90% is preferable. Furthermore, it was confirmed from the results of the electric power generation potential and the result of the gas permeation amount that 20 to 70% was more preferable.

(Effect of sintering temperature)
(Example 34)
It was the same as Example 1 except that the sintering temperature of the electrolyte membrane was 1340 ° C.

(Example 35)
It was the same as Example 1 except that the sintering temperature of the electrolyte membrane was 1350 ° C.

(Example 36)
It was the same as Example 1 except that the sintering temperature of the electrolyte membrane was 1450 ° C.

(Example 37)
Example 1 was the same as Example 1 except that the sintering temperature of the electrolyte membrane was 1500 ° C.

(Example 38)
Example 1 was repeated except that the sintering temperature of the electrolyte membrane was changed to 1510 ° C.

(Power generation test)
A power generation test was performed using the batteries (effective area of fuel electrode: 150 cm ² ) obtained in Examples 1, 34 to 38 and Comparative Example 1. The operating conditions at this time were as follows.
Fuel: (H ₂ + 11% H ₂ O): N ₂ = 1: 2
Oxidizing agent: Air
Power generation temperature: 800 ° C
Current density: 0.3Acm ^-2

(Gas leak test)
Nitrogen gas was flown inside the air electrode support for the batteries obtained in Examples 1, 34 to 38 and Comparative Example 1, a pressure of 0.1 MPa was applied from the inside of the air electrode, and the amount of gas permeated through the electrolyte membrane was measured. did. Thereby, it was evaluated whether the electrolyte membrane was a membrane having no gas permeability.

Table 7 shows the results of the power generation potential and the gas permeation amount with respect to the sintering temperature of the electrolyte membrane. It can be seen that the generated potentials at 1340 ° C. and 1510 ° C. are higher than those in Comparative Example 1, but there is almost no difference. In addition, the gas permeation amount is in the range of gas permeation amount Q ≦ 2.8 × 10 ⁻⁹ ms ⁻¹ Pa ⁻¹ which is preferable as an electrolyte membrane. From the above results, it was confirmed that the sintering temperature of the electrolyte membrane was preferably in the range of 1350 to 1500 ° C.

  In the present embodiment, an example in which the film is formed on the air electrode support is shown. However, even when the film is formed on the fuel electrode support, the electrolyte film having the above-described configuration can be used between the electrolyte film and the fuel electrode. When the same power generation performance is obtained, it is possible to efficiently advance the reactions of equations (2) and (3) that occur and efficiently advance the reaction of equation (1) that occurs between the air electrode and the electrolyte membrane. Conceivable.

(Power generation test)
A power generation test was performed using the cells (effective fuel electrode area: 150 cm ² ) obtained in Examples 12, 4, 7 to 9, 11 and Comparative Example 1. The operating conditions at this time were as follows.
Fuel: (H ₂ + 11% H ₂ O): N ₂ = 1: 2
Oxidizing agent: Air
Power generation temperature: 700-1000 ℃
Current density: 0.3Acm ^-2

FIG. 4 shows the generated potential at 700 to 1000 ° C. At 900 to 1000 ° C., almost no difference is observed as compared with Comparative Example 1.However, when the temperature is 900 ° C. or less, the potential difference with the comparative example increases, and at 700 ° C., a difference of about 0.2 V is confirmed. Was. From the above results, it is possible to provide a solid oxide fuel cell having excellent output performance in the range of 700 ° C. to 1000 ° C. by using the electrolyte membrane configuration represented by Examples 1, 2, 4, 7 to 9, 11. Could be confirmed.

It is a figure which shows the cross section of a cylindrical type solid oxide fuel cell. FIG. 2 is a cross-sectional view showing in detail an air electrode, an electrolyte membrane, and a fuel electrode configuration of the solid oxide fuel cell shown in FIG. 1. FIG. 2 is a cross-sectional view showing in detail an air electrode, an electrolyte membrane, and a fuel electrode configuration of the solid oxide fuel cell shown in FIG. 1. 4 is a graph showing a relationship between a power generation temperature (horizontal axis) and a power generation potential (vertical axis) of a test battery.

Explanation of reference numerals

1: Air electrode support
2: Interconnector
3: Electrolyte membrane
4: Fuel electrode
1a: Electrode reaction layer
3a: First layer
3a ': Third layer (same material as first layer)
3b: Second layer
3c: Third layer
4a: Fuel electrode side electrode reaction layer

Claims (36)

An air electrode on one side of the electrolyte membrane, a unit cell having a fuel electrode disposed on the opposite side thereof, and an interconnector having a role of electrical connection, a solid oxide fuel cell comprising: A first layer made of a material having an oxygen ion conductivity S1 on the air electrode side, a third layer made of a material having an oxygen ion conductivity S3 on the fuel electrode side, the first layer and the third layer; A second layer made of a material containing at least zirconia with an oxygen ion conductivity S2 is provided between the layers, and the oxygen ion conductivity S1 and the oxygen ion conductivity S2 have a relationship of S1> S2, A solid oxide fuel cell, wherein the oxygen ion conductivity S3 and the oxygen ion conductivity S2 have a relationship of S3> S2. The solid oxide according to claim 1, wherein a first layer made of a material having an oxygen ion conductivity S1 and a third layer made of a material having an oxygen ion conductivity S3 in the electrolyte membrane have the same composition. Physical fuel cell. 3. The solid oxide fuel cell according to claim 1, wherein the thickness of the second layer is 10 to 90% of the total thickness of the electrolyte membrane. 4. 4. The solid oxide fuel cell according to claim 1, wherein a thickness of the second layer is 20% to 70% of a total thickness of the electrolyte membrane. 5. The solid oxide fuel cell according to any one of claims 1 to 4, wherein the second layer is a zirconia material in which yttria is dissolved. The solid oxide fuel cell according to any one of claims 1 to 4, wherein the second layer is a zirconia material in which at least scandia and yttria are dissolved. The solid oxide fuel cell according to any one of claims 1 to 6, wherein the first layer and the third layer are a zirconia material in which scandia is dissolved. The first layer is a cerium-containing oxide represented by a general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15). The solid oxide fuel cell according to any one of claims 1 to 6, wherein the third layer is a zirconia material in which scandia is dissolved. The first layer has the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (where A is Sr, Ca, Ba One or more, B is one or more of Mg, Al, In, C is one or more of Co, Fe, Ni, Cr) lanthanum gallate represented by The solid oxide fuel cell according to any one of claims 1 to 6, wherein the third layer is a zirconia material in which scandia is dissolved. The method according to claim 1, wherein the first layer is a zirconia material in which at least scandia and yttria are dissolved, and the third layer is a zirconia material in which scandia is dissolved. The solid oxide fuel cell according to claim 1. The first layer is a zirconia material in which scandia is dissolved, and the third layer is a general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is Sm, Gd, The solid oxide fuel cell according to claim 1, wherein the cerium-containing oxide is any one of Y and 0.05 ≦ X ≦ 0.15). The first layer and the third layer are represented by the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd and Y, 0.05 ≦ X ≦ 0.15) The solid oxide fuel cell according to any one of claims 1 to 6, which is a cerium-containing oxide represented. The first layer has a general formula of La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (where A is Sr, Ca, Ba One or more, B is Mg, Al, one or more of In, C is Co, Fe, Ni, one or more of Cr) is a lanthanum gallate represented by The third layer is a cerium-containing oxide represented by the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15) The solid oxide fuel cell according to any one of claims 1 to 6, which is a product. The first layer is a zirconia material in which at least scandia and yttria are dissolved, and the third layer has a general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is Sm , Gd, Y, a cerium-containing oxide represented by the formula: 0.05 ≦ X ≦ 0.15), the solid oxide fuel cell according to any one of claims 1 to 6, wherein The first layer is a zirconia material in which scandia is dissolved, and the third layer has a general formula of La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _{1 -bc} B _b C _c O ₃ (where A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is Co, Fe, Ni, Cr The solid oxide fuel cell according to any one of claims 1 to 6, which is a lanthanum gallate represented by one or more of the following: The first layer has a cerium content represented by the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15). An oxide, and the third layer has a general formula of La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (where A is Lanthanum represented by one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, and C is one or more of Co, Fe, Ni, Cr) The solid oxide fuel cell according to any one of claims 1 to 6, wherein the fuel cell is gallate. The first layer and the third layer are represented by the general formula La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (where A is Lanthanum represented by one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, and C is one or more of Co, Fe, Ni, Cr) The solid oxide fuel cell according to any one of claims 1 to 6, wherein the fuel cell is gallate. The first layer is a zirconia material in which at least scandia and yttria are dissolved, and the third layer has a general formula of La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (however, A is one or more of Sr, Ca, Ba, B is one or more of Mg, Al, In, C is Co, Fe, The solid oxide fuel cell according to any one of claims 1 to 6, wherein the fuel cell is lanthanum gallate represented by one or more of Ni and Cr). The method according to claim 1, wherein the first layer is a zirconia material in which scandia is dissolved, and the third layer is a zirconia material in which at least scandia and yttria are dissolved. The solid oxide fuel cell according to claim 1. The first layer has a cerium content represented by the general formula (CeO ₂ ) _1-2X (B ₂ O ₃ ) _X (where B is any one of Sm, Gd, and Y, 0.05 ≦ X ≦ 0.15). The solid oxide fuel cell according to any one of claims 1 to 6, wherein the third layer is an oxide, and the third layer is a zirconia material in which at least scandia and yttria are dissolved. The first layer has a general formula of La _1-a A _a Ga _1-b B _b O ₃ or La _1-a A _a Ga _1-bc B _b C _c O ₃ (where A is Sr, Ca, Ba One or more, B is Mg, Al, one or more of In, C is Co, Fe, Ni, one or more of Cr) is a lanthanum gallate represented by The solid oxide fuel cell according to any one of claims 1 to 6, wherein the third layer is a zirconia material in which at least scandia and yttria are dissolved. The solid oxide fuel cell according to any one of claims 1 to 6, wherein the first layer and the third layer are a zirconia material in which at least scandia and yttria are dissolved. The solid oxide fuel according to any one of claims 7 to 11, 15, and 19, wherein the amount of scandia dissolved in the scandia zirconia material is 3 to 12 mol%. battery. 5 mol of at least one oxide selected from CeO ₂ , Sm ₂ O ₃ , Gd ₂ O ₃ , Yb ₂ O _3, Er ₂ O ₃ and Bi ₂ O ₃ is further contained in the zirconia material in which the scandia is dissolved. The solid oxide fuel cell according to any one of claims 7 to 11, 15, 19, and 23, wherein the solid oxide is a solid solution of not more than 25%. The total amount of scandia and yttria in the zirconia material obtained by dissolving scandia and yttria is 3 to 12 mol%, according to any one of claims 6, 10, 14, 18 to 22. The solid oxide fuel cell as described in the above. The zirconia material in which the scandia and yttria are dissolved as a solid solution further includes CeO ₂ , Sm ₂ O ₃ , Gd ₂ O ₃ , Yb ₂ O _3, Er ₂ O ₃ and at least one oxide selected from Bi ₂ O ₃ The solid oxide fuel cell according to any one of claims 6, 10, 14, 18 to 22, and 25, wherein is a solid solution of 5 mol% or less. The solid oxide fuel cell according to claim 5, wherein the amount of yttria in the zirconia material in which yttria is dissolved is 3 to 12 mol%. Between the electrolyte membrane and the air electrode, an air-side electrode reaction layer having an open pore that promotes a reaction of generating oxygen ions from oxygen gas and electrons is interposed. A solid oxide fuel cell according to any one of claims 1 to 27. In the air-side electrode reaction layer, lanthanum manganite represented by (La _1-x A _x ) _y MnO ₃ (where A is either Ca or Sr) is uniformly mixed with zirconia in which scandia is dissolved. 29. The solid oxide fuel cell according to claim 28, wherein the layer is a coated layer. The air _{electrode, (La 1-x A x} ) y MnO 3 ( where, A is either Ca or Sr) claim 1 to 29, characterized in that it consists of lanthanum manganite represented by A solid oxide fuel cell according to claim 1. Between the electrolyte membrane and the fuel electrode, at least hydrogen gas (H ₂ ) and / or carbon monoxide gas (CO) contained in the fuel gas, oxygen ions (O ²⁻ ), and H ₂ O and / or or a CO _2, to promote the reaction to form the electron, solid oxide according to any one of claims 1 to 30 for fuel-side electrode reaction layer having communicating open pores is characterized in that it is interposed Physical fuel cell. The fuel-side electrode reaction layer comprises a layer in which zirconia in which NiO and scandia are dissolved in a solid solution is uniformly mixed, or a layer in which Ni and zirconia in which scandia is dissolved in a solid solution is uniformly mixed. Item 32. The solid oxide fuel cell according to Item 31, The fuel electrode comprises a layer in which zirconia in which NiO and yttria are dissolved in a solid solution is uniformly mixed, or a layer in which zirconia in which Ni and yttria are dissolved in a solid solution is uniformly mixed. 33. The solid oxide fuel cell according to any one of 32. The solid oxide fuel cell according to any one of claims 1 to 33, wherein the interconnector is lanthanum chromite in which Ca is dissolved. The solid oxide fuel cell according to any one of claims 1 to 34, wherein the electrolyte membrane is formed on the surface of the air-side electrode reaction layer and then sintered at 1350 to 1500 ° C. . The solid oxide fuel cell according to any one of claims 1 to 34, wherein the electrolyte membrane is formed on the surface of the fuel-side electrode reaction layer and then sintered at 1350 to 1500 ° C. .

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