WO2014122807A1 - Solid oxide fuel cell and method for producing same - Google Patents

Abstract

[Problem] To provide a SOFC containing a porous section and a non-porous section within a single layer, and equipped with a structure capable of obtaining favorable uniformity and strength, and preventing cracks, deformities and the like in the cells and stacks thereof. [Solution] A solid oxide fuel cell provided with one or more cells equipped with a fuel electrode to which a fuel gas is supplied, an air electrode to which an oxidizing gas is supplied, and an electrolyte, wherein: one or more of the electrode layers equipped with the fuel electrode or the air electrode as the electrode part thereof is further equipped with a sealing part positioned on at least one section of a first surface facing the channel of gas not intended for the electrode part, in order to shield the electrode part from unintended gas; and the sealing part is equipped with one or more compact sections having gas-sealing properties, and one or more thermal behavior adjustment sections which are adjacent to the one or more compact sections.

Description

Solid oxide fuel cell and method for producing the same

This application claims priority based on Japanese Patent Application No. 2013-022716 filed on Feb. 7, 2013, the entire contents of which are incorporated herein by reference. The present specification relates to a solid oxide fuel cell and a manufacturing method thereof.

The solid oxide fuel cell (SOFC) has a cell structure in which a fuel electrode having a porous structure and an air electrode are opposed to each other with an electrolyte interposed therebetween. For example, a flat-plate SOFC can secure a desired power by constructing a stack structure in which such cells are stacked via separators.

A fuel gas such as hydrogen is supplied to the fuel electrode, and an oxidant gas such as air containing oxygen is supplied to the air electrode. In general, SOFC is a non-porous sealing material for shutting off these gases at the boundary between these electrodes and the gas flow region in order to avoid mixing of oxidant gas into the fuel electrode and fuel gas into the air electrode. (Patent Document 1). For example, in the flat plate type SOFC, the sealing material is provided in contact with a part of the outer edge portion of the electrode layer.

Japanese Patent Application No. 2010-505799

The elements constituting SOFC are often ceramic materials fired at high temperatures. For this reason, at the time of manufacturing the SOFC, in order to suppress warpage, cracking, and deformation in the cell or the stack, it is necessary to make the thermal expansion and the thermal contraction equal in the intended directions among a plurality of integrated elements.

As a manufacturing method of SOFC, there is a case where one layer of a fuel electrode, an air electrode, and an electrolyte is used as a support layer and the other layer is integrally fired. However, in the case where the electrode layer having a porous structure has a sealing material having a non-porous structure, integral firing becomes difficult. In addition to the specific support layer, the separator may be integrated by firing in addition to the fuel electrode, the air electrode, and the electrolyte. However, in the case of firing including the sealing material, similarly to the above, a porous portion (electrode layer) and a non-porous portion (sealing material) are present in one layer. Since these cells are also integrated, it becomes more difficult to control thermal expansion and contraction.

As described above, in order to integrate the dense and non-porous sealing material and the porous electrode layer in the same layer, it is important to make the thermal expansion and thermal shrinkage characteristics uniform. Such firing control has not been easy.

The present specification has a structure capable of obtaining preferable integrity and strength by suppressing cracking, cracking, deformation, etc. of a cell or stack in an SOFC including a porous part and a non-porous part in the same layer. SOFC and its manufacturing method are provided.

The inventors of the present invention have studied a structure advantageous for monolithic firing of SOFC cells or stacks. As a result, a porous electrode portion and a non-porous structure are sealed to seal the surface of the electrode portion facing the gas flow path. A quality seal part, and a thermal behavior adjustment part for adjusting the thermal behavior on the surface opposite to the electrode part of the seal part, the electrode part and the seal part As a result, it was found that unintentional deformation including warping and cracking of the laminate can be reduced or avoided by integrally firing the electrode layer containing the electrode, the cell containing the electrode layer, and the stack. According to the present specification, the following means are taught based on such knowledge.

(1) A solid oxide fuel cell,
Comprising one or more cells comprising a fuel electrode supplied with fuel gas, an air electrode supplied with oxidant gas, and an electrolyte;
At least one electrode layer including either the fuel electrode or the air electrode as an electrode portion faces the unintended gas flow path of the electrode portion in order to shield the electrode portion from unintended gas. A seal portion disposed on at least a part of the surface of
The battery includes one or more dense parts having gas sealing properties, and one or more thermal behavior adjusting parts adjacent to the one or more dense parts.
(2) The battery according to (1), wherein the one or two or more thermal behavior adjusting units are porous.
(3) The one or two or more dense parts are provided adjacent to the first surface, and the one or two or more thermal behavior adjusting parts are the first or two or more dense parts. The battery according to (1) or (2), which is provided adjacent to a second surface which is a surface opposite to a surface adjacent to the surface.
(4) The battery according to any one of (1) to (3), wherein the one or more dense portions and the one or more thermal behavior adjusting portions are alternately arranged.
(5) The battery according to any one of (1) to (4), wherein the one or more thermal behavior adjusting units are provided adjacent to the first surface.
(6) The battery according to any one of (1) to (5), wherein the electrode portion has an inclined structure with a lower porosity on the first surface side in the vicinity of the first surface. .
(7) The battery according to any one of (1) to (6), wherein the seal portion is disposed adjacent to a first surface including two opposing side surfaces of the electrode portion in the electrode layer.
(8) One of the seal portions is disposed adjacent to the first surface, and the width defined by the two opposing side surfaces of the seal portion is defined as Wa.
The width of the dense part in the direction along Wa is Wb,
When the width in the direction along the Wa of the thermal behavior adjusting unit is Wc, 0 <Wb <0.25Wa, 0.15Wc <Wb <3Wc, and 0 <Wc <0.25 (Wa + Wb The battery according to (7), wherein
(9) The battery according to any one of (1) to (8), which is a flat plate solid oxide fuel cell.
(10) The battery according to any one of (1) to (9), wherein the electrode layer and the electrolyte are integrally fired.
(11) The battery according to any one of (1) to (10), comprising a plurality of the cells stacked via a separator.
(12) The battery according to any one of (1) to (11), wherein the electrode layer including the fuel electrode and the air electrode of the cell, the electrolyte, and the separator are collectively fired. .
(13) The battery according to any one of (1) to (12), wherein the fuel electrode includes nickel and yttria stabilized zirconia or scandium stabilized zirconia.
(14) The battery according to any one of (1) to (13), wherein the air electrode includes one or more selected from the group consisting of lanthanum strontium, lanthanum strontium ferrite, and lanthanum strontium cobalt ferrite.
(15) The battery according to any one of (1) to (14), wherein the dense part includes ceramics containing lanthanum, yttria stabilized zirconia, or scandium stabilized zirconia.
(16) A method for producing a solid oxide fuel cell,
The solid oxide fuel cell includes one or more cells including a fuel electrode supplied with a fuel gas, an air electrode supplied with an oxidant gas, and an electrolyte.
The electrode material band for forming either the fuel electrode or the air electrode, and the unintentional at least part of the first surface of the electrode material band facing the unintended gas flow path side of the electrode. An electrode material layer comprising at least a dense material band for blocking gas and a sealing material band including one or more thermal behavior adjusting material bands adjacent to the dense material band; A step of forming a laminate comprising the solid electrolyte material layer and / or the separator material layer adjacent to the material layer, and a method of firing the laminate in a lump.

It is a figure which shows the outline | summary of an example of SOFC, (a) is a figure which shows an example of the relationship between a cell and a stack, (b) is a figure which shows an example of the relationship between a cell and a gas supply path. (C) is a figure which shows an example of the seal | sticker part in a fuel electrode layer and an air electrode layer. It is a figure which shows another example of the seal part in a fuel electrode layer. It is a figure which shows another example of the seal part in a fuel electrode layer. It is a figure which shows another example of the seal part in a fuel electrode layer. It is a figure which shows another example of the seal part in a fuel electrode layer. It is a figure which shows an example of the relationship of the width | variety of each part of the seal part in a fuel electrode layer and an air electrode layer. It is a figure which shows another example of the relationship of the width | variety of each part of the seal part in a fuel electrode layer and an air electrode layer. It is a figure which shows an example of the seal part in a fuel electrode layer and an air electrode layer in an Example.

The disclosure of this specification relates to an SOFC and a manufacturing method thereof. According to the SOFC disclosed in this specification, a seal portion is provided on at least a part of the first surface of the electrode portion of the electrode layer facing the unintended gas flow path, and the seal portion includes a gas A dense portion having sealing properties and a thermal behavior adjusting portion adjacent to the dense portion are provided. Since such a seal portion is provided, in the electrode layer including the porous electrode portion, it is possible to suppress or avoid the occurrence of cracks, warpage, deformation and the like while ensuring the seal performance with respect to the electrode portion. Conventionally, it has been difficult to sinter the electrode layer while suppressing or avoiding deformation and the like while providing sealing properties to the electrode portion. However, according to the present disclosure, by controlling the thermal behavior such as thermal expansion and thermal shrinkage during firing of the electrode layer including the electrode portion provided with sealing properties, it is possible to suppress or avoid the occurrence of cracks, warpage, and deformation. Can do. For this reason, it is possible to obtain an SOFC having excellent integrity and strength while maintaining the intended form.

In addition, according to the indication of this specification, the structure for SOFC cells and the structure for stacks as a precursor of SOFC are also provided.

Hereinafter, representative and non-limiting specific examples of the disclosure of the present specification will be described in detail with reference to the drawings as appropriate. This detailed description is intended merely to provide those skilled in the art with details for practicing the preferred embodiments of the present disclosure and is not intended to limit the scope of the present disclosure. Absent. Further, the additional features and disclosure disclosed below can be used separately from or together with other features and inventions to provide improved methods for detecting target nucleic acids and the like.

In addition, the combination of features and steps disclosed in the following detailed description are not essential in carrying out the disclosure of the present specification in the broadest sense, and are particularly representative specific examples of the disclosure of the present specification. It is described only for the purpose of explaining. Furthermore, the various features of the exemplary embodiments described above and below, as well as those described in the independent and dependent claims, provide additional and useful embodiments of the disclosure herein. They do not have to be combined according to the specific examples described herein or in the order listed.

Hereinafter, the disclosure of this specification will be described in detail with reference to the drawings as appropriate.

(SOFC)
In this specification, the SOFC includes a cell 2 including a fuel electrode, an air electrode, and an electrolyte, or a stacked body (stack) 100 in which two or more layers of these cells 2 are stacked via a separator 60. The SOFC includes the cell 2 or the stack 100 shown below, and also includes necessary members, that is, a gas supply system from a supply source of fuel gas and air gas to the stack structure, a current collecting member, a casing, and the like. Can function as SOFC. Hereinafter, the cell 2 will be described first, and then the stack 100 will be described.

(cell)
FIG. 1 schematically shows the cell 2 and the stack 100. As shown in FIG. 1, the cell 2 includes a solid electrolyte 4, a fuel electrode layer 6 including a fuel electrode 8, and an air electrode layer 12 including an air electrode 14.

The cell 2 may be a so-called electrolyte support type or an electrode support type, but is preferably a laminate support type that ensures strength by stacking two or more cells 2. It is preferable. In such a laminate support type, it is preferable that the thickness of the fuel electrode layer 6 and the air electrode layer 14 is 30% or more and 300% or less, respectively, with respect to the thickness of the solid electrolyte 4. This is because warpage and peeling are less likely to occur during firing.

The thicknesses of the solid electrolyte 4, the air electrode layer 14, and the fuel electrode layer 6 are all preferably 1 μm or more and 150 μm or less. If these elements have a thickness in this range, there is no great limitation on adjusting the difference in thermal expansion and contraction characteristics during firing and use. For this reason, at least two elements adjacent to the cell 2, for example, in a state where the cell 2 is laminated through integral firing of the solid electrolyte 4 and the air electrode layer 14, or the cell 2 is further laminated via a separator. In this state, the stack 100 is easily formed by firing integrally. Since the cells 2 and the stack 100 having such unity can be formed, the strength can be easily secured in the cells 2 and the stack 100 as a result. More preferably, the thickness of the element of any cell 2 is 1 μm or more and 100 μm or less.

(Solid electrolyte)
As the solid electrolyte 4, a known one usually used for SOFC can be used. Examples thereof include oxide ion conductive ceramic materials such as ceria-based oxides doped with samarium, gadolinium, etc., lanthanum galide-based oxides doped with strontium or magnesium, and zirconia-based oxides containing scandium or yttrium.

The form of the solid electrolyte 4 is determined depending on the form of the cell 2 or the stack 100 and is not particularly limited. For example, when the cell 2 is a flat plate type SOFC, it has a flat plate-like three-dimensional form that approximates the flat form of the cell 2. The planar shape of the solid electrolyte 4 can take various shapes such as a square shape, a rectangular shape, and a circular shape depending on the planar shape of the cell 2.

The thermal expansion coefficient (20 ° C. to 1000 ° C.) of the solid electrolyte 4 is preferably 10 × 10 ⁻⁶ K ⁻¹ or more and 12 × 10 ⁻⁶ K ⁻¹ or less. This is because if it is within this range, peeling and cracking are unlikely to occur during firing. Considering the residual stress of the stack 100, it is more preferably 10.5 × 10 ⁻⁶ K ⁻¹ or more and 11.5 × 10 ⁻⁶ K ⁻¹ or less.

The thickness of the solid electrolyte 4 is not particularly limited, but can be 1 μm or more and 150 μm or less. Within this range, when the single electrode 2 is configured with both the fuel electrode layer 6 and the air electrode layer 8 described later, and the stack 100 is configured with the separator 60, appropriate mechanical strength and power generation characteristics can be obtained. More preferably, they are 1 micrometer or more and 100 micrometers or less, More preferably, they are 1 micrometer or more and 40 micrometers or less, More preferably, they are 1 micrometer or more and 20 micrometers or less.

(Fuel electrode layer)
The fuel electrode layer 6 has a fuel electrode 8. The fuel electrode layer 6 is an example of an electrode layer in the disclosure of the present specification, and the fuel electrode 8 is an example of an electrode portion. The fuel electrode layer 6 includes a seal portion 10 in addition to the fuel electrode 8, and the seal portion 10 will be described later.

The fuel electrode material constituting the fuel electrode 8 is not particularly limited, and a material used as a fuel electrode material in a known SOFC can be used. Examples thereof include a mixture of a metal catalyst and a ceramic powder material made of an oxide ion conductor or a composite powder thereof. As the metal catalyst used at this time, a material that is stable in a reducing atmosphere such as nickel, iron, cobalt, noble metals (platinum, ruthenium, palladium, etc.) and has hydrogen oxidation activity can be used. Further, as the oxide ion conductor, those having a fluorite structure or a perovskite structure can be preferably used. Examples of those having a fluorite structure include ceria-based oxides doped with samarium, gadolinium, and the like, and zirconia-based oxides containing scandium and yttrium. In addition, examples of those having a perovskite structure include lanthanum galide oxides doped with strontium and magnesium. Among the above materials, the fuel electrode 8 is preferably formed of a mixture of an oxide ion conductor and nickel. Typically, nickel and scandium stabilized zirconia or yttria stabilized zirconia. Moreover, the ceramic material mentioned above can be used individually by 1 type or in mixture of 2 or more types. Moreover, the fuel electrode 8 can also be comprised using a metal catalyst alone.

The average particle size of the fuel electrode material powder is preferably 10 nm or more and 100 μm or less, more preferably 50 nm or more and 50 μm or less, and further preferably 100 nm or more and 10 μm or less. In addition, in this specification, an average particle diameter can be measured according to JISR1619, for example. The fuel electrode layer 6 is also formed in a layered body depending on the planar form of the cell 2, similarly to the solid electrolyte 4.

The thermal expansion coefficient (20 ° C. to 1000 ° C.) of the fuel electrode 8 is preferably 10 × 10 ⁻⁶ K ⁻¹ or more and 12.5 × 10 ⁻⁶ K ⁻¹ or less. This is because peeling is less likely to occur at the interface with the solid electrolyte 4 within this range. Considering the residual stress of the stack 100, it is more preferably 10 × 10 ⁻⁶ K ⁻¹ or more and 12 × 10 ⁻⁶ K ⁻¹ or less.

The thickness of the fuel electrode layer 6 is not particularly limited, but can be 1 μm or more and 150 μm or less. Within this range, when configuring the cell 2 and further configuring the stack 100 together with the separator 60, appropriate mechanical strength and power generation characteristics can be obtained. More preferably, they are 1 micrometer or more and 100 micrometers or less, More preferably, they are 5 micrometers or more and 40 micrometers or less, More preferably, they are 5 micrometers or more and 20 micrometers or less.

(Fuel gas flow path)
The fuel electrode 8 can include one or more fuel gas passages (not shown). The fuel gas flow path may be provided on the adjacent separator 60 side, but is preferably formed within the thickness range (inside the layer) of the fuel electrode 8. That is, it is preferable that the fuel gas flow path is contained in the fuel electrode 8 in a state surrounded by the material constituting the fuel electrode 8. By doing so, the fuel gas can be efficiently supplied to the entire fuel electrode 8. Preferably, the fuel gas flow paths are evenly arranged in the thickness direction of the fuel electrode 8. For example, at least one fuel gas flow path center portion may be disposed at substantially the center in the thickness direction of the fuel electrode 8, or two or more fuel gas flows may be evenly distributed along the thickness direction. The form by which the path is arrange | positioned may be sufficient.

The size of the opening of the fuel gas channel to the fuel gas supply channel is not particularly limited. The opening shape of the fuel gas channel is not particularly limited. Examples include a substantially circular shape, an elliptical shape, a rectangular shape, and an indefinite shape, and a substantially circular shape is preferable. This is because the gas diffusion direction from the fuel gas flow path to the fuel electrode 7 is isotropic and uniform diffusion is possible when it is substantially circular.

The fuel gas flow path is formed so that the fuel gas can flow in the intended direction in the fuel electrode 8. Moreover, the fuel electrode 8 can be provided with 1 type or 2 or more types of patterns combining about 1 or 2 or more fuel gas flow paths. The pattern may be a two-dimensional arrangement form along the surface direction of the fuel electrode 8 of the one or two or more fuel gas passages 16, or a three-dimensional arrangement form across the surface direction and the thickness direction. .

It is preferable that the pattern of the fuel gas flow path has at least one bent portion. According to such a pattern, supply of fuel gas can be realized with a higher degree of design freedom. The degree of bending or bending of the bent portion is not particularly limited. It may be rounded from an obtuse angle to an acute angle. Furthermore, the pattern may have at least two bent portions.

Examples of patterns include, for example, a straight shape, a U-shape, a zigzag shape, a radial shape, a spiral shape, and a network (lattice) shape.

A fuel gas supply path 70 for supplying fuel gas to the fuel gas flow path of the fuel electrode 8 is provided. The fuel gas supply path 70 may be provided so as to be supplied from, for example, one side surface of the cell 2 or two opposite side surfaces. Further, the fuel gas supply path 70 may be provided so as to penetrate the fuel electrode 8 along the stacking direction of the elements in the cell 2.

(Air electrode layer)
The air electrode layer 12 includes an air electrode 14. The air electrode layer 12 is an example of an electrode layer in the disclosure of the present specification, and the air electrode 14 is an example of an electrode part. The air electrode layer 12 includes a seal portion 16 in addition to the air electrode 14, and the seal portion 16 will be described later.

As an air electrode material which comprises the air electrode 14, what is used as an air electrode material in a well-known solid oxide fuel cell can be used without specifically limiting. For example, a metal oxide made of La, Sr, Co, Fe, Ni, Cr, Mn, or the like having a perovskite structure or the like can be used. Specifically, (Sm, Sr) CoO ₃ , (La, Sr) MnO ₃ , (La, Sr) FeO ₃ , (La, Sr) CoO ₃ , (La, Sr) (Fe, Co) O ₃ , ( An oxide such as La, Sr) (Fe, Co, Ni) O ₃ may be mentioned, and (La, Sr) MnO ₃ is preferable. The ceramic material mentioned above can be used individually by 1 type or in mixture of 2 or more types.

The average particle diameter of the air electrode material powder is preferably 10 nm or more and 100 μm or less, more preferably 50 nm or more and 50 μm or less, and further preferably 100 nm or more and 10 μm or less.

The thermal expansion coefficient (20 ° C. to 1000 ° C.) of the air electrode 14 is preferably 10 × 10 ⁻⁶ K ⁻¹ or more and 15 × 10 ⁻⁶ K ⁻¹ or less. This is because peeling is less likely to occur at the interface with the solid electrolyte 4 within this range. Considering the residual stress of the stack 100, it is more preferably 10 × 10 ⁻⁶ K ⁻¹ or more and 12 × 10 ⁻⁶ K ⁻¹ or less.

The thickness of the air electrode layer 12 is not particularly limited, but may be 1 μm or more and 150 μm or less. Within this range, when configuring the single cell 2 and further configuring the stack 100 together with the separator 60, appropriate mechanical strength and power generation characteristics can be obtained. More preferably, they are 1 micrometer or more and 100 micrometers or less, More preferably, they are 5 micrometers or more and 40 micrometers or less, More preferably, they are 5 micrometers or more and 20 micrometers or less.

(Oxidant gas flow path)
The air electrode 14 can include one or more oxidant gas flow paths (not shown). With respect to the oxidant gas flow path 00, the same embodiment as the fuel gas flow path in the fuel electrode 8 can be applied except that the oxidant gas flows in the air electrode 14. Note that the oxidant gas flow channel 00 may not have the same pattern as the fuel gas flow channel, or may have a different pattern. Moreover, it is preferable that the oxidant gas channel does not have an opening on the side surface side of the cell 2 where the fuel gas channel opens.

An oxidant gas supply path 80 for supplying oxidant gas to the oxidant gas flow path of the air electrode 14 is provided. The oxidant gas supply path 80 varies depending on the pattern of the oxidant gas flow path. For example, the cell 2 is configured to be supplied from one side where the fuel gas supply path 70 is not provided or from two opposite sides. Has been. Further, the oxidant gas supply path 80 may be provided so as to penetrate the air electrode 14 along the stacking direction of the elements in the cell 2.

(Fuel electrode layer seal)
The fuel electrode layer 6 has a seal portion 10 on at least part of the first surface 20 facing the oxidant gas supply path 00 of the fuel electrode 8 in order to shield the fuel electrode 8 from unintended gas, that is, oxidant gas. It has. The seal portion 10 can be integrated with at least a part of the first surface 20 of the fuel electrode 8 to form the fuel electrode layer 6 together with the fuel electrode 8.

The seal portion 10 disclosed in the present specification is intended to adjust the thermal behavior of the cell 2 and the stack 100 during the firing and sintering of the fuel electrode layer 6 in addition to the gas sealability in the cell 2 or the stack 100. ing. The first surface 20 only needs to be provided in a region where the thermal behavior is sufficiently adjusted under the planned firing conditions. In other regions of the first surface 20, only a mere seal portion intended only for gas sealing properties may be formed. The fuel electrode layer 6 has a seal portion 10 within the range of the thickness of the fuel electrode layer 6. Preferably, the seal portion 10 has a degree corresponding to the thickness of the fuel electrode layer 6. The seal portion 10 is preferably provided on the entire first surface 20.

The seal portion 10 can include a dense portion 10a having gas sealing properties and a thermal behavior adjusting portion 10b adjacent to the dense portion 10a. The dense portion 10a is for shielding the fuel electrode 8 from the oxidant gas. The dense portion 10a is formed to be nonporous so as to exhibit the airtightness required in SOFC. Porosity p _b of the dense portion 10a is not particularly limited, preferably 10% or less. This is because if it exceeds 10%, it becomes difficult to obtain gas sealing properties. More preferably, it is 5% or less. In this specification, the porosity can be measured by a known method, but is preferably measured by a specific surface area measurement method.

The dense part 10a may be dense enough to have gas sealing properties, and the degree of non-porosity is not particularly limited. The dense portion 10a is preferably formed so as to be included in a range of preferable thermal expansion / contraction characteristics in the separator 60 or the solid electrolyte 4. In this way, when separating the cells 2 with the separator 60, or when configuring the solid electrolyte 4 and the cell 2, it is possible to avoid the difference in thermal expansion and contraction characteristics between these materials laminated, and to integrate In addition, the cell 2 and the stack 100 having excellent thermal shock resistance can be obtained. The thermal expansion / contraction characteristic includes at least a thermal expansion coefficient. Further, “equal in terms of thermal expansion and contraction characteristics” means a range that is the same as that of the separator 60 or the solid electrolyte 4 or that does not significantly impair the integrity of the stack 100 in the temperature range given to the SOFC in the production and operation of the SOFC. According to the experiments by the present inventors, the range that does not significantly hinder the integrity of the stack 100 is 0.85 times or more to 1.18 times the thermal expansion coefficient of the separator 60 or the solid electrolyte 4. It is known that it is about the following.

Depending on the thermal expansion coefficients of the separator 60 and the solid electrolyte 4, the thermal expansion / shrinkage characteristics of the dense portion 10 a can be equal to the thermal expansion / shrinkage characteristics of both the solid electrolyte 4 and the separator 60. Such an aspect is most preferable from the viewpoint of improving the mechanical strength and thermal shock resistance of the stack 100.

The dense portion 10 a may have a material common to the separator 60 or the solid electrolyte 4. If the dense part has a common material for the separator 60 or the solid electrolyte 4, the thermal expansion / shrinkage characteristics as a whole are homogenized and integrated well by firing when integrated with either of them. In addition to improving the thermal shock resistance of the cell 2 and the stack 100, the mechanical strength can be improved.

The dense portion 10a may include one or more materials constituting the separator 60, may include one or more materials constituting the solid electrolyte 4, and may be a material derived from the separator and Both materials derived from the solid electrolyte 4 may be included. The dense portion 10a may have the same composition as either the separator 60 or the solid electrolyte 4.

The dense part 10 a may have a material common to the material of the fuel electrode 8 or the air electrode 14. Since the dense portion 10a has the same material as that of the fuel electrode 8 or the air electrode 14, the overall thermal expansion / contraction characteristics can be homogenized, and the integrity during firing can be improved. Thereby, the thermal shock resistance of the cell 2 and the stack 100 can be improved, and the mechanical strength can be improved.

The dense portion 10 a may contain one or more materials that constitute the fuel electrode 8, may contain one or more materials that constitute the air electrode 14, and is derived from the fuel electrode 8. Both the material and the material derived from the air electrode 14 may be included. The dense portion 10 a may have the same composition as either the fuel electrode 8 or the air electrode 14.

The dense portion 10a is, for example, (Sm, Sr) CoO ₃ , (La, Sr) MnO ₃ , (La, Sr) FeO ₃ , (La, Sr) CoO ₃ , (La, Sr) (Fe, Co). Fuel electrode such as air electrode material such as O ₃ , (La, Sr) (Fe, Co, Ni) O ₃ and / or ceria oxide doped with samarium or gadolinium, zirconia oxide containing scandium or yttrium Materials can be used. The air electrode material and the fuel electrode material may be mixed and used in an arbitrary range, or only one of them may be used.

The thermal behavior adjusting unit 10 b is intended to suppress or avoid deformation of the fuel electrode layer 6 including the fuel electrode 8, and consequently the cell 2 and the stack 100, by providing the dense part 10 a in the fuel electrode layer 6. The thermal expansion / contraction characteristics, arrangement, form, and size of the thermal behavior adjusting unit 10b are determined in consideration of the thermal expansion / contraction characteristics, arrangement, form, size, and the like of the fuel electrode 8 and the dense part 10a.

The thermal behavior adjusting unit 10b is set in a range where the above intention can be realized. For this reason, the dense part 10b may be porous or non-porous. The thermal behavior adjusting portion 10b is preferably porous from the viewpoint of suppressing or avoiding the influence of the thermal expansion / contraction characteristics of the dense portion 10a. Porosity p _c of thermal behavior adjustment unit 10b is not particularly limited, (porosity dense portion 10a) p _b from the relationship between the dense areas 10a <it is preferable that p _c ≦ 50%. If the porosity of the thermal behavior adjusting portion 10b is the same as the porosity of the dense portion 10a, the thermal behavior adjusting ability is difficult to exert, and if it is larger than 50%, the difference in thermal behavior becomes too large. Because. Preferably, 20% < _pc ≦ 35%. The thermal behavior adjusting unit 10b preferably has the same material as the fuel electrode 8, more preferably has the same material as the fuel electrode 8, and more preferably has the same composition as the fuel electrode 8. . The porosity may be substantially the same as that of the fuel electrode 8, but is not necessarily the same, may be adjusted as appropriate, may be higher than the fuel electrode 8, or may be higher than that of the fuel electrode 8. It may be low.

The dense portion 10a and the thermal behavior adjusting portion 10b are provided with respect to the first surface 00 so as to provide gas sealing properties to the fuel electrode 8 and to suppress or avoid deformation of the fuel electrode layer 6 and the like. It only has to be.

For example, as shown in FIG. 1, when the oxidant gas supply path 80 is on the side surface side of the cell 2, the dense portion 10 a has an oxidant gas supply path with respect to the first surface 20 on the supply path 80 side. It may be provided adjacent to the first surface 20 facing 80, that is, in direct contact with the first surface 20. In this case, the thermal behavior adjusting portion 10b is provided adjacent to the surface on the opposite side of the dense portion 10b facing the first surface 20.

Further, as shown in FIG. 2, a dense portion 10a may be provided adjacent to the thermal behavior adjusting portion 10b provided adjacent to the first surface 20.

Further, for example, as shown in FIG. 3, one or more dense portions 10a and one or more thermal behavior adjusting portions 10b may be provided. The dense portions 10a and the thermal behavior adjusting portions 10b may be alternately provided.

For example, as shown in FIG. 4, when the oxidant gas supply path 80 passes through the cell, the seal portion 10 is provided for the first surface 20 on the supply path 80 side. . The dense portion 10a and the thermal behavior adjusting portion 10b in the seal portion 10 can take various arrangement patterns similar to those in FIGS.

In the case where the dense portion 10a is provided adjacent to the first surface 20 of the fuel electrode 8 that is porous, the closer the fuel electrode 8 is to the first surface 20 in the vicinity of the first surface 20, It may have an inclined structure having a lower porosity. Further, when the porous thermal behavior adjusting portion 10b is adjacent to the dense portion 10a, the closer to the surface adjacent to the dense portion 10a of the thermal behavior portion 10b, the inclined structure having a lower porosity. You may do it. Such an inclined structure is easily obtained as a result of firing the fuel electrode layer 6 including the dense portion 10a, the thermal behavior adjusting portion 10b, and the fuel electrode 8 together. Such an inclined structure is effective for homogenizing the thermal expansion and contraction characteristics.

The arrangement pattern of the seal portion 10 can be set for the fuel electrode 8 according to the fuel gas flow path pattern in the fuel electrode 8, the arrangement form of the oxidant gas supply path 80 to the cell 2 or the stack 100, and the like. More specifically, the seal portion 10 is formed on the side surface of the fuel electrode 8 that is the first surface 20 on the side of the supply path 80 of the oxidant gas so that the exposure of the fuel electrode 8 to the oxidant gas is avoided. Yes. For example, as shown in FIG. 5, when the oxidant gas supply path 80 is one side surface of the rectangular cell 2, the first surface 20 is a surface on the one side surface side of the fuel electrode 8. In this case, a seal portion 10 is provided on the one side surface. In addition, as shown in FIGS. 1 to 3, when the oxidant gas supply path 24 is two opposite side surfaces of the cell 2, the first surface 20 is formed on the two side surfaces of the fuel electrode 8. Surface. In this case, the seal portion 10 is provided on the two side surfaces of the fuel electrode 8.

(Air electrode layer seal)
Similarly to the fuel electrode layer 6, the air electrode layer 12 includes a seal portion 16 for blocking the air electrode 14 from an unintended gas, that is, a fuel gas. As shown in FIG. 1, the seal portion 16 is provided on at least a part of the first surface 30 facing the fuel gas supply path 00 of the air electrode 14. The seal portion 16 of the air electrode layer 12 can be integrated with at least a part of the first surface 30 of the air electrode 14 to form the air electrode layer 12 together with the air electrode 14. The seal portion 16 can have the same configuration as the seal portion 10 except that the exposure of the air electrode 14 to the fuel gas is prevented. That is, various aspects such as the dense portion 10a, the thermal behavior adjusting portion 10b, the material and the arrangement pattern of the seal portion 10 described above are changed to the dense portion 16a, the thermal behavior adjusting portion 16b, the material and the arrangement pattern of the seal portion 16. Applicable.

For example, it is preferable to adopt the pattern shown in FIG. 6 of the seal portion 10 or the seal portion 16 in the fuel electrode layer 6 or the air electrode layer 12. That is, in the example shown in FIG. 6, the seal portion 10 or the seal portion 16 is provided on the first surface 20 or the second surface 30 of the fuel electrode layer 6 or the air electrode layer 12 facing each other. The seal portion 10 or the seal portion 16 includes the dense portions 10a and 16a in the shape of a belt adjacent to the first surfaces 20 and 30, respectively, and the dense portions 10a and 16a. The thermal behavior adjusting units 10b and 16b are provided adjacent to the entire second surface 00. According to this pattern, the dense portions 10a and 16a are provided symmetrically with the fuel electrode 8 or the air electrode 14 in between, and the thermal behavior adjusting portions 10b and 10b are respectively provided on the second surfaces of the dense portions 10a and 16a. Since 16b is provided, the thermal behavior along the y direction acting by the dense portions 10a and 16a is adjusted by the thermal behavior adjusting portion 10b or 16b.

In the embodiment illustrated in FIG. 6, the width defined by the first surface 00 of the fuel electrode 8 or the air electrode 14 is Wa, and the width of the dense portion 10a or 16a in the direction along Wa is Wb. When the width in the direction along Wa of the portion 10b or 16b is Wc, 0 <Wb <0.25Wa is preferable. Within this range, the thermal behavior in the direction parallel to the interface between the dense portion 10a and the fuel electrode 8 or in the direction parallel to the interface between the dense portion 16a and the air electrode 14 is likely to match. It is also preferable that 0.15Wc <Wb <3Wc. This is because if the width of the thermal behavior adjusting portion is within this range, the thermal behavior in the direction parallel to the interface between the dense portion 10a or 16a and the thermal behavior adjusting portion is easily matched. More preferably, 0 <Wb <0.15Wa and Wc <Wb <2Wc.

Also preferably, 0 <Wc <0.25 (Wa + Wb). If the width of the thermal behavior adjusting portion is too wide, the difference in thermal shrinkage / thermal expansion from the seal portion becomes significant, and cracks may occur. Moreover, if the width is wide, the layer that does not contribute to power generation becomes bulky. More preferably, 0 <Wc <0.15 (Wa + Wb).

Furthermore, when 20 mm <Wa <300 mm, 0.1 mm <Wb <75 mm and 0.5 mm <Wc <94 mm are preferable. More preferably, when 30 mm <Wa <100 mm, 1 mm <Wb <15 mm and 1 mm <Wc <17 mm.

Further, it is preferable that the seal portion 10 or the seal portion 16 adopts the pattern shown in FIG. That is, in the example shown in FIG. 7, each gas supply path is provided so as to penetrate the fuel electrode 8 or the air electrode 14, and the seal portion 10 or the seal portion 16 is provided on the first surface 00 facing the gas supply passage side. It has. At this time, the width defined by the longer first surface of the fuel electrode 8 or the air electrode 14 is Wa, the width of the dense portion 10a or 16a in the direction along Wa is Wb, and the thermal behavior adjusting portion 10b or 16b. When the width in the direction along Wa is Wc, the embodiment of the gas flow path configuration shown in FIG. 6 can be applied as it is.

In the cell 2 including either or both of the fuel electrode layer 6 including the seal portion 10 and the air electrode layer 12 including the seal portion 16, such a layer, the solid electrolyte 4 and / or the separator 60 are collectively fired and sintered. It is preferable that they are integrated. Since the thermal expansion and contraction characteristics of the fuel electrode layer 6 and / or the air electrode layer 12 are adjusted to suppress deformation and the like, batch firing of these layers, the solid electrolyte 4 and the separator 60 is facilitated. As a result, the cell 2 itself has sufficient integrity and strength by suppressing deformation and the like. More preferably, the solid electrolyte 4, the fuel electrode layer 6 and the air electrode layer 12, which are constituent elements of the cell 2, are sintered together and sintered and integrated. Furthermore, in addition to each component of the cell 2, it is preferable that the separator 60 is fired at once and these are sintered and integrated.

In the cell 2 or the stack 100, the fuel gas supply path 70 and the oxidant gas supply path 80 are separated, and the seal portion 10 and the seal portion 16 in the fuel electrode layer 6 and the air electrode layer 12 Are separated from each other along the stacking direction of the elements or the stacking direction of the cells 2 in the stack 100. Accordingly, these supply paths exist at different positions in the plane of the cell 2 or the stack 100, and as a result, the pattern of the first surface in the fuel electrode layer 6 and the air electrode layer 12 and the seal portion 10 and the seal portion 16. The pattern is different. For this reason, the thermal behavior of the cell 2 and the stack 100 as a whole is more easily adjusted, and deformation and the like are more effectively suppressed.

(stack)
The SOFC disclosed in this specification preferably takes the form of a stack 100 in which two or more cells 2 are stacked via a separator 60. Since the cells 2 constituting the stack 100 are each provided with the seal portion 10 and / or the seal portion 16, the thermal behavior of the cell 2 and the stack 100 can be easily adjusted by the thermal behavior adjusting portions 10b and / or 16b, so Is suppressed, and the stack 100 is excellent in unity and strength.

Preferably, the stack 100 includes 5 or more cells 2 stacked, more preferably 6 or more cells 2 stacked, and even more preferably 7 or more cells 2 stacked, and more preferably. Eight or more cells 2 are stacked. More preferably, 10 cells are laminated, and even more preferably 12 cells or more are laminated.

(Separator)
The separator 60 preferably has a form that can be stacked in the same manner as the solid electrolyte 4, the fuel electrode layer 6, and the air electrode layer 12. Typically, a flat plate shape is preferable. As the material of the separator 60, various conductive materials known as SOFC separators can be used. For example, in addition to a stainless steel metal material, a lanthanum chromite metal ceramic material can be used.

As will be described later, in order to obtain the stack structure 20 of the present invention, it is preferable to fire each component of the single cell and the separator 60 together and co-sinter them. In such an embodiment, the separator 60 is preferably a ceramic material that is sintered at a relatively low temperature. As such a ceramic material, in order to improve the sinterability, for example, lanthanum chromium-based oxide (LaCrO ₃ ), lanthanum strontium chromium-based oxide (La _(1-x) Sr _x CrO ₃ , 0 <x ≦ 0.5 It is preferable to use a ceramic containing a lanthanum-chromium perovskite oxide such as), or a zirconia in which such a lanthanum-chromium perovskite oxide and a rare earth element are dissolved. By firing containing a rare earth solid solution zirconia (general formula (1-x) ZrO ₂ .xY ₂ O ₃ , where Y represents a rare earth element and 0.02 ≦ x ≦ 0.20), Lanthanum-chromium-based perovskite oxide can be densely sintered at a lower temperature than before. As a result, the separator can be densified at a temperature of about 1400 ° C. or less at which the cell components can be co-sintered. Such lanthanum-chromium-based perovskite oxide may be dissolved in other metal elements such as calcium.

Examples of the rare earth in the rare earth solid solution zirconia include yttrium (Y), scandium (Sc), ytterbium (Yb), cerium (Ce), neodymium (Nd), samarium (Sm), and preferably yttrium (Y ), Scandium (Sc), and ytterbium (Yb), and more preferably yttrium (Y). X in the rare earth solid solution zirconia (general formula (1-x) ZrO ₂ .xY ₂ O ₃ , where Y represents a rare earth element) is preferably 0.02 or more and 0.20 or less, more preferably It is 0.02 or more and 0.1 or less.

The thermal expansion coefficient (20 ° C. to 1000 ° C.) of the separator 60 is preferably 8 × 10 ⁻⁶ K ⁻¹ or more and 12 × 10 ⁻⁶ K ⁻¹ or less. This is because peeling within the air electrode layer or the fuel electrode layer can be suppressed within this range. When the residual stress of the stack 100 is taken into consideration, it is more preferably 9.5 × 10 ⁻⁶ K ⁻¹ or more and 11.5 × 10 ⁻⁶ K ⁻¹ or less. The thickness of the separator 60 is not particularly limited, but can be 1 μm or more and 200 μm or less. Within this range, when the stack 100 is formed by stacking so as to separate the single cells 2, appropriate mechanical strength and power generation characteristics can be obtained. Preferably they are 10 micrometers or more and 50 micrometers or less, More preferably, they are 10 micrometers or more and 40 micrometers or less.

In the stack 100, each component of the cell 2 and the separator 60 preferably have a thickness of 150 μm or less.

(SOFC system)
The SOFC system disclosed in this specification can include a SOFC type SOFC that is the cell 2 or the stack 100. The SOFC system may be a single SOFC system, but usually includes one or a plurality of modules in which a plurality of SOFCs are combined so as to output intended power. The SOFC system can further include elements of a known SOFC system, such as a fuel gas reformer, a heat exchanger, and a turbine.

(SOFC manufacturing method)
The SOFC manufacturing method disclosed in this specification includes one or more cells including a fuel electrode to which a fuel gas is supplied, an air electrode to which an oxidant gas is supplied, and a solid electrolyte. It is a manufacturing method of SOFC. This manufacturing method is not intended for at least a part of the electrode material band for forming either the fuel electrode or the air electrode and the first surface of the electrode material band facing the unintended gas flow path side of the electrode. An electrode material layer comprising at least a dense material band for blocking gas and a sealing material band including one or more thermal behavior adjusting material bands adjacent to the dense material band, A step of forming a laminate including the solid electrolyte material layer and / or the separator material layer adjacent to an electrode material layer, and the laminate are collectively fired.

According to this manufacturing method, since the electrode material layer includes the sealing material band including the thermal behavior adjusting material band, the thermal behavior of the electrode material layer and the laminated body during the firing of the laminated body is adjusted. The deformation of the cell 2 and the stack 100 that are formed is suppressed. Thereby, the deformation | transformation etc. are suppressed and the cell 2 and the stack 100 with improved integrity and strength can be obtained.

(Laminate formation process)
The laminate forming step is a step of forming a laminate including at least an electrode material layer and further including a separator material layer and / or a solid electrolyte material layer. The electrode material layer includes an electrode material band, a dense material band for blocking unintended gas on at least a part of the first surface of the electrode material band facing the unintended gas flow path of the electrode, And a sealing material band including one or more thermal behavior adjusting material bands adjacent to the dense material band. The electrode material strip can be prepared with the intention of either a fuel electrode or an air electrode. About each material, the already demonstrated material can be selected suitably and can be used. In addition, the seal material band can be appropriately selected and used from the material of the dense part and the material of the thermal behavior adjusting part already described. The pattern of the sealing material band, and the dense material band and the thermal behavior adjusting material band constituting the sealing material band can be determined based on the design concept of the seal portion and the like already described.

In forming a solid electrolyte material layer made of a solid electrolyte material or a separator material layer made of a separator material, the materials described above can be used as appropriate for each material of the solid electrolyte and the separator. As the separator material, it is preferable to use a ceramic powder containing a lanthanum-chromium perovskite oxide and a rare earth element solid solution zirconia. By including the rare earth element-stabilized zirconia, the lanthanum-chromium perovskite oxide can be densely sintered even at a firing temperature of about 1400 ° C. or less, and co-sintering with the cell constituent elements becomes possible. Also, high conductivity can be maintained. In this material, the rare earth solid solution zirconia is preferably 0.05% by mass or more and 10% by mass or less based on the mass of the lanthanum-chromium perovskite oxide ceramics. This is because if it is less than 0.05% by mass, the effect of lowering the sintering temperature is not sufficiently obtained, and even if it exceeds 10% by mass, the conductivity may decrease.

In addition, you may provide suitably the loss | disappearance material for a fuel gas flow path or an oxidizing gas flow path with respect to a separator material layer or an electrode material belt | band | zone suitably.

The electrode material layer, the separator material layer, and the solid electrolyte material layer can be formed according to a conventional method. For example, a slurry containing a layer material as a main component and further added with an appropriate amount of a binder resin, an organic solvent, or the like is obtained using a sheet forming method by casting such as a tape casting method using a coating apparatus such as a knife coat or a doctor blade. be able to. The obtained sheet can be dried according to a conventional method. Moreover, you may heat-process as needed (sintering is not intended).

An electrode material layer having different bands can be obtained by a sheet forming method by casting such as a tape casting method using a coating device such as a doctor blade. The casting method is determined as appropriate. The electrode material strip and the seal material strip may be cast at that time. That is, the slurry having different compositions along the casting direction is discharged at the same time, and the different slurry zones are integrated without being mixed after casting. At this time, such different composition band can be integrally applied by adjusting the fluidity of the slurry for forming different bands. The electrode material layer can be formed by drying the coated material thus obtained in accordance with a conventional method and subjecting it to heat treatment as necessary.

In addition, the porosity of the electrode material band, the dense material band, and the thermal behavior adjusting material band in the electrode material layer can be adjusted by a known method such as adding a foaming material or the like as appropriate.

A laminate can be formed by laminating other layers on one layer. The stacking order and stacking method are appropriately determined. That is, each layer may be formed as an independent sheet body, and the sheet body may be laminated, or may be sequentially integrated with other layers by coating so as to be laminated on other layers. The laminate may be a precursor before firing intended for only a part of the cell 2 or may be intended for the cell 2. Furthermore, what added the separator 60 to the cell 2 may be intended, and the stack 100 may be intended. In the present manufacturing method, preferably, a stack 100 in which a plurality of cells 2 are stacked via a separator 60 is intended.

(Baking process)
Next, this laminate is fired. That is, the material layers in the laminate are fired and sintered together. The firing step is performed so that the firing conditions are a desired dense or porous for each material layer. Preferably, all of the cell components and separator are co-sintered. For example, the heat treatment can be performed at a temperature of 1250 ° C. to 1550 ° C., and preferably 1300 ° C. to 1500 ° C. More preferably, it is 1300 degreeC or more and 1400 degrees C or less. It can be fired in air.

By the firing step, the layers constituting the laminate can be integrated to obtain the cell 2 or the stack 100 that is the SOFC disclosed in this specification or a part thereof. In this manufacturing method, as already described, it is preferable to prepare a laminate intended for the stack 100 in which a plurality of cells 2 are laminated and to fire the laminate. According to this method, since the electrode material layer includes the sealing material band including the thermal behavior adjusting material band, even in the stack 100 in which a plurality of the cells 2 are stacked, the deformation and the like are suppressed, and the integrity and strength are improved. An excellent stack 100 can be obtained. For the preferred number of layers, the aspect already described for the stack 100 can be applied.

As described above, according to the present method, the SOFC cell 2 or the stack 100 or a part of the SOFC cell 2 having good integrity and strength is formed by forming a laminate including at least an electrode material layer and firing the laminate. Can be obtained. In addition, another material layer can also be laminated | stacked and baked with respect to such obtained cell 2 or stack 100, or its part. In addition, a current collecting element or the like necessary for SOFC can be appropriately provided.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, A various change is possible unless it deviates from the meaning of this invention.

(Electrode sheet for SOFC)
The SOFC electrode sheet of the present invention can include an electrode material band containing a fuel electrode material or an air electrode material, and a seal material band. According to this sheet, a seal portion having a thermal behavior adjusting portion and a dense portion can be formed in the fuel electrode layer or the air electrode layer. For this reason, while being able to provide a reliable and simple seal structure, the thermal behavior in the cell 2 or the stack 100 can be adjusted well, the deformation or the like is suppressed, and the cell 2 or the stack 100 having excellent integrity and strength can be obtained.

For the electrode sheet of the present invention, various aspects can be applied to the fuel electrode, the air electrode, the separator, the solid electrolyte, and the seal portion already described for the stack 100. Moreover, the manufacturing method of SOFC already demonstrated can be referred for manufacture of the sheet | seat for electrodes of this invention.

As mentioned above, although several embodiment of this invention was described, this invention is not limited to this, A various change is possible unless it deviates from the meaning of this invention.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the following examples.

In this example, as shown in FIG. 8, a stack was manufactured in which cells each provided with a fuel electrode layer 6 and air electrode layers 12 provided with seal portions 10 and 16 on both sides were laminated. Each of the sealing portions 10 and 16 includes dense portions 10a and 16a adjacent to the fuel electrode 8 or the air electrode 14, and further includes thermal behavior adjusting portions 10b and 16b on the outside thereof. As shown in FIG. 8, the cell has a square plate shape of 35 mm × 35 mm, and the width Wb of the dense portions 10 a and 16 a of the seal portion in each electrode layer is about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, and The width Wc of the thermal behavior adjusting units 10b and 16b was about 2 mm. Moreover, what made only the dense parts 10a and 16a2mm without providing the thermal behavior adjustment parts 10b and 16b was also produced. The cell stacks were 5 to 12 cells, and stacks having various types of seal portions were formed.

Ni / 8YSZ cermet as the fuel electrode material (Ni: 8YSZ = 50: 50 (molar ratio)), La _1-x Sr _x MnO ₃ (x = 0.2-0.3) (LSM) as the air electrode material, 8YSZ was used as the electrolyte material, and La _0.79 Ca _0.06 Sr _0.15 CrO _x (LaCaSCr) was used as the separator. As the dense material, a dense LSM that can ensure the gas sealing property, which is an air electrode material, is made dense enough to ensure the gas sealing property. Dense areas 10a, porosity p _b of 16a were prepared dense material to be 2% in the present embodiment. As the thermal behavior adjusting material, porous LSM was used for both the air electrode and the fuel electrode layer. Porosity p _c of thermal behavior adjuster to prepare a thermal behavior modifying material such that 25% in this embodiment. In addition, the thickness of these material layers after firing was set to be about 100 μm for the electrode layer, about 20 μm for the separator layer and the electrolyte layer. Further, the electrode layer was prepared by arranging a polymer material that disappears at a firing temperature in a linear channel structure.

In preparing the slurry for the fuel electrode, ethanol, allyl ether copolymer, and polyvinyl butyral were used in addition to the pore-forming material of methyl methacrylate polymer. In preparing the slurry for the air electrode, ethanol, allyl ether copolymer and polyvinyl butyral were used in addition to the pore-forming material of methyl methacrylate polymer. In preparing the slurry for the solid electrolyte, ethanol, allyl ether copolymer, and polyvinyl butyral were used. In preparing the slurry for the separator, ethanol, allyl ether copolymer and polyvinyl butyral were used.

A ceramic green sheet was prepared using each slurry. In preparing the fuel electrode sheet and the air electrode sheet, the slurry was cast while a plurality of vanishing filaments were embedded in the casting direction in a straight line at regular intervals in the approximate center of the sheet thickness. Moreover, in producing the separator sheet and the solid electrolyte sheet, the sheet was produced without embedding the filament.

Each electrode sheet, solid electrolyte sheet and separator sheet thus obtained were laminated, and finally 5 to 12 cells were laminated and fired at 1300 ° C. for 5 hours. The thicknesses of the fuel electrode, air electrode, solid electrolyte, and separator in the fired body were about 100 μm, 100 μm, 20 μm, and 20 μm, respectively.

The observation results of these fired bodies revealed the following. In the case of a stack having an electrode layer without a thermal behavior adjusting portion, integration by firing was possible only up to 5 cells, and cracks occurred when attempting to integrate more cells. Further, in the case of a stack having an electrode layer provided with a thermal behavior adjusting portion of Wc of 2 mm or more, even a 12 cell could be integrated by batch firing. On the other hand, when Wc was 2 mm, when the width Wb of the dense part was 6 mm or more, cracks occurred regardless of the presence or absence of the thermal behavior adjusting part. Further, when Wb was 5 mm or less, preferably 4 mm or less, there was no crack, and a fired body having good integrity and shape could be obtained.

From the above, it has been found that the thermal behavior adjusting unit can effectively suppress deformation such as generation of cracks in the cell and the stack. Further, it has been found that if the width Wc of the thermal behavior adjusting portion is too narrow relative to Wb or Wa, the function of controlling thermal contraction and thermal expansion becomes weak. For example, it was found that 3Wc> Wb was preferable, and 2Wc> Wb was more preferable. It was also found that 0 <Wb <0.25Wa, 0.15Wc <Wb <3Wc, and 0 <Wc <0.25 (Wa + Wb).

All features described in this specification and / or claims, apart from the configuration of the features described in the examples and / or claims, are individually disclosed as limitations on the original disclosure and claimed specific matters. And are intended to be disclosed independently of each other. Further, all numerical ranges and group or group descriptions are intended to disclose intermediate configurations thereof as a limitation to the original disclosure and claimed subject matter.

Claims (16)

1. A solid oxide fuel cell,
   Comprising one or more cells comprising a fuel electrode supplied with fuel gas, an air electrode supplied with oxidant gas, and an electrolyte;
   At least one electrode layer including either the fuel electrode or the air electrode as an electrode portion faces the unintended gas flow path of the electrode portion in order to shield the electrode portion from unintended gas. A seal portion disposed on at least a part of the surface of
   The battery includes one or more dense parts having gas sealing properties, and one or more thermal behavior adjusting parts adjacent to the one or more dense parts.
2. The battery according to claim 1, wherein the one or more thermal behavior adjusting portions are porous.
3. The one or more dense portions are provided adjacent to the first surface, and the one or more thermal behavior adjusting portions are adjacent to the first surface of the one or more dense portions. The battery according to claim 1, wherein the battery is provided adjacent to a second surface which is a surface opposite to a surface to be operated.
4. 4. The battery according to claim 1, wherein the one or more dense portions and the one or more thermal behavior adjusting portions are alternately arranged.
5. The battery according to any one of claims 1 to 4, wherein the one or more thermal behavior adjusting units are provided adjacent to the first surface.
6. The battery according to any one of claims 1 to 5, wherein the electrode portion has an inclined structure with a lower porosity on the first surface side in the vicinity of the first surface.
7. The battery according to any one of claims 1 to 6, wherein the seal portion is disposed adjacent to a first surface including two opposite side surfaces of the electrode portion in the electrode layer.
8. One of the seal portions is disposed adjacent to the first surface, and the width defined by the two opposing side surfaces of the seal portion is defined as Wa.
   The width of the dense part in the direction along Wa is Wb,
   When the width in the direction along the Wa of the thermal behavior adjusting unit is Wc,
   The battery according to claim 7, wherein 0 <Wb <0.25Wa, 0.15Wc <Wb <3Wc, and 0 <Wc <0.25 (Wa + Wb).
9. The battery according to any one of claims 1 to 8, which is a flat plate solid oxide fuel cell.
10. The battery according to any one of claims 1 to 9, wherein the electrode layer and the electrolyte are integrally fired.
11. The battery according to any one of claims 1 to 10, comprising a plurality of the cells stacked via separators.
12. The battery according to any one of claims 1 to 11, wherein the electrode layer including the fuel electrode and the air electrode of the cell, the electrolyte, and the separator are calcined together.
13. The battery according to any one of claims 1 to 12, wherein the fuel electrode contains nickel and yttria stabilized zirconia or scandium stabilized zirconia.
14. The battery according to any one of claims 1 to 13, wherein the air electrode includes one or more selected from the group consisting of lanthanum strontium, lanthanum strontium ferrite, and lanthanum strontium cobalt ferrite.
15. The battery according to any one of claims 1 to 14, wherein the dense portion includes ceramics containing lanthanum, yttria stabilized zirconia or scandium stabilized zirconia.
16. A method for producing a solid oxide fuel cell, comprising:
    The solid oxide fuel cell includes one or more cells including a fuel electrode supplied with a fuel gas, an air electrode supplied with an oxidant gas, and an electrolyte.
    The electrode material band for forming either the fuel electrode or the air electrode, and the unintentional at least part of the first surface of the electrode material band facing the unintended gas flow path side of the electrode. An electrode material layer comprising at least a dense material band for blocking gas and a sealing material band including one or more thermal behavior adjusting material bands adjacent to the dense material band; A step of forming a laminate comprising the solid electrolyte material layer and / or the separator material layer adjacent to the material layer, and a method of firing the laminate in a lump.
    

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