JPH0850899A - Cell for solid electrolyte fuel cell - Google Patents

Abstract

PURPOSE:To provide a cell for a solid electrolyte fuel cell in which the performance of a fuel electrode does not decrease for a long time by using a brazing filler material which increases wettability of metal and ceramic as the main material of the fuel electrode. CONSTITUTION:A fuel electrode is constituted by using metal, ceramic, and a brazing filler material which increases wettability of the metal and the ceramic as the main material. Since the fuel electrode made of this main material highly maintains the affinity between the metal and the ceramic, drop in performance of the fuel electrode is suppressed and the cell life is lengthened. The brazing filler material is a metal material having an expansion coefficient of 4-14X10<-6>.K<-1>, and at lest one element selected from the group comprising Ti, Nb, Ta, Zr, Mo, and W is preferably used as the main component. An alloy having a thermal expansion coefficient of 10.3-13.3X10<-6>.K<-1> is preferable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high temperature solid electrolyte fuel cell, and more particularly to improvement of a fuel electrode of a cell for a solid electrolyte fuel cell.

[0002]

2. Description of the Related Art A fuel cell is a cell of a type that directly converts chemical energy of a supplied gas into electric energy, so that high power generation efficiency can be expected. Since the battery is operated, higher power generation efficiency can be expected by effectively utilizing the high temperature waste heat. Therefore, it is drawing attention as a third-generation fuel cell that replaces the phosphoric acid fuel cell and the molten carbonate fuel cell.

By the way, the basic structure of a solid electrolyte fuel cell is a solid electrolyte having oxygen ion conductivity at high temperature,
A fuel electrode and an oxidant electrode are arranged on both sides of the electrolyte, and the fuel gas and the oxidant gas can be continuously supplied to the electrode from the outside. The power generation principle of this battery is that oxygen ions pass from the oxidant electrode side through the electrolyte to the fuel electrode side and react with the fuel gas at the fuel electrode to generate H ₂ O and electrons (e ⁻ ). Because
This electron (e ⁻ ) is caused to flow from the external circuit to the oxidant electrode to convert oxygen into oxygen ions (O ²⁻ ) and to take out an electric current from the external circuit. From this power generation principle,
The material of the fuel electrode constituting this type of fuel cell must be a material having excellent heat resistance because it is electronically conductive and has a high cell operating temperature of about 1000 ° C. Further, a porous material having good gas permeability is desirable in order to reduce the effect of concentration polarization and increase the electrode reaction area.

Therefore, conventionally, as an electrode material satisfying such properties, a mixture of metal and ceramics such as nickel-stabilized zirconia cermet or nickel-ceria oxide cermet has been used. FIG. 5 shows an enlarged schematic view of a cross section in a plane direction of a fuel electrode using nickel / stabilized zirconia cermet as an electrode material. As shown in FIG. 5, this fuel electrode has a fine structure suitable for an electrode in which nickel 12 is overlapped to form a so-called conductive path, and ceramics 13 have large and small pores 14 and 15. Therefore, high power generation capacity can be exhibited.

[0005]

However, in the conventional fuel electrode using the cermet as the electrode material as described above, the structure suitable for the electrode is maintained at the beginning of the cell operation. Since the wettability between nickel and ceramics is poor, when the operating time is long, it is affected by high heat around 1000 ° C, and nickel particles aggregate and sinter into coarse particles as shown in Fig. 6. As a result, the preferred microstructure gradually collapses. Then, since the conductive path that was initially formed by connecting the nickel particles to each other is cut by the agglomeration of the nickel particles, the conductivity of the electrode decreases. Further, coarsening of nickel reduces the total surface area of nickel in the electrode,
As a result, the so-called three-phase interface (Ni, gas, solid electrolyte) formed near the boundary surface between the fuel electrode and the electrolyte is reduced.
For this reason, there is a problem that when the battery is operated for a long period of time, the electrode performance gradually deteriorates.

An object of the present invention is to solve the above problems and provide a cell for a solid electrolyte fuel cell in which the performance of the fuel electrode does not deteriorate for a long period of time.

[0007]

In order to achieve the above object, the invention of claim 1 provides a cell for a solid electrolyte fuel cell in which a fuel electrode and an oxidant electrode face each other through a solid electrolyte. It is characterized in that the pole is mainly composed of a metal and a ceramic and a brazing material that enhances the wettability of the metal and the ceramic in a battery operating temperature range.

According to a second aspect of the present invention, in the solid electrolyte fuel cell according to the first aspect, the metal is nickel and the ceramic is stabilized zirconia [provided that
CaO, MgO, Y ₂ O ₃ , Sc ₂ O as dopants
_{3], (CeO 2) 0.8 X 0.} 2 [where, X is Sm
₂ O ₃ , Y ₂ O ₃ , La ₂ O ₃ ], PrOx [however, 0
<X ≦ 3], BaCe _1-x M _x O _3-x [where 0 < _x
≦ 0.3, M is any one of Dy, Gd, Y, Sn, Yb, and Nd].

According to a third aspect of the present invention, in the cell for a solid electrolyte fuel cell according to the first aspect, the brazing material is 4 to
It is characterized by being a metal material having an expansion coefficient in the range of 14 × 10 ⁻⁶ · K ⁻¹ . A fourth aspect of the present invention is the solid electrolyte fuel cell according to the third aspect, wherein the brazing material is one or more metal elements selected from the group consisting of Ti, Nb, Ta, Zr, Mo and W. It is characterized by being a metal material containing as a main component.

According to a fifth aspect of the present invention, in the solid electrolyte fuel cell of the first aspect, the brazing material is 10.3.
It is characterized by being an alloy having a coefficient of thermal expansion in the range of ˜13.3 × 10 ⁻⁶ · K ⁻¹ . According to a sixth aspect of the present invention, in the cell for a solid electrolyte fuel cell according to the fifth aspect, the brazing material is a Ti-Ni alloy, a Ti-Mo alloy, or a Ti-Ni alloy.
A binary alloy selected from the group consisting of Ni alloys, or a ternary alloy selected from the group consisting of Ti-Ni-Mo alloys, Ti-Mo-Nb alloys and Ni-Mo-Nb alloys. Alloy, 10.3-13.3 × 10 ^-6
-It is characterized by having an expansion coefficient in the range of K- ¹ .

[0011]

In the invention of claim 1, the fuel electrode is mainly composed of metal and ceramics (hereinafter referred to as cermet), and a brazing material which enhances the wettability of the metal and the ceramics at a cell operating temperature. ing. In the case of the fuel electrode made of such an electrode material, the brazing material improves the wettability between the metal and the ceramics and maintains the good affinity between the metal and the ceramics. The deterioration of the fuel electrode performance due to
Therefore, the cell life is significantly improved.

This will be described further. When a battery having a high operating temperature of about 1000 ° C. is operated for a long time, the metal in the cermet becomes semi-molten due to the high temperature. put it here,
In the conventional fuel electrode, since the metal and the ceramic have poor wettability, the metal in a semi-molten state has a higher surface tension than the affinity for the ceramic, so that the surface area is reduced by aggregation. Therefore, in the solid state, the metal that is uniformly dispersed in the ceramic aggregates with neighboring metal particles to become coarse particles. It is considered that the coarsening of the metal particles leads to cutting of the conductive path (reduction of conductivity) and reduction of the three-phase interface, so that the electrode performance is deteriorated.

However, when the brazing material is blended in the cermet, the brazing material enhances the affinity between the semi-molten metal and the ceramics. Therefore, even when the metal is in the semi-molten state, the metal particles are not separated from each other. Does not aggregate. Therefore,
It is unlikely that the conductive paths are cut or the three-phase interface is reduced due to the aggregation and coarsening of metal particles. In addition, since the brazing filler metal improves the wettability between the fuel electrode and the solid and the fuel electrode and the current collector, the adhesiveness with these cell constituent members is increased, and the contact resistance between the fuel electrode and each member is reduced. It Therefore, also from this aspect, the cell performance can be improved.

As described above, according to the first aspect of the present invention, since the deterioration of the fuel electrode due to the operation of the cell can be suppressed, high cell performance can be maintained for a long period of time. According to the invention of claim 2,
The cell for a solid oxide fuel cell according to claim 1, wherein the metal in the cermet is nickel, and the ceramic is stabilized zirconia (provided that CaO, M as a dopant is used).
_{gO, Y 2 O 3, Sc} 2 O 3 ], (CeO _{2) 0. 8} X
_0.2 [however, X is Sm ₂ O ₃ , Y ₂ O ₃ , La
₂ O ₃ ], PrOx [where 0 <x ≦ 3], BaCe
_1-x M _x O _3-x [where 0 < _x ≤0.3, M is Dy,
Any one of Gd, Y, Sn, Yb, and Nd]. A fuel electrode composed of an electrode material in which a brazing material is mixed with the cermet, the cermet preferably holds the gas permeability of the electrode, ionic conductivity, and electronic conductivity, and the brazing material is composed of ceramics and nickel. Since it acts to improve the wettability, a fuel electrode with high performance and little deterioration can be obtained, and thereby a cell having high power generation efficiency can be obtained.

According to a third aspect of the present invention, in the cell for a solid electrolyte fuel cell according to the first aspect, the brazing material is 4 to 4 to
It had a coefficient of expansion of 14 × 10 ⁻⁶ · K ⁻¹ . With a brazing filler metal having an expansion coefficient within this range, there is no extreme difference in the expansion coefficient between nickel and ceramics, so the thermal stress between the brazing filler metal and nickel or ceramics due to temperature changes in the cell is relaxed. Therefore, cracks and the like due to thermal stress are less likely to occur, and the brazing filler metal can suitably act in a wider temperature range. Therefore, the deterioration of the fuel electrode due to the temperature change can be effectively prevented.

According to a fourth aspect of the invention, in the solid electrolyte fuel cell of the third aspect, the brazing material is Ti,
A metal element selected from one or more selected from the group consisting of Nb, Ta, Zr, Mo, and W was the main component. Such a metal has a high effect as a brazing filler metal, and has a coefficient of thermal expansion in the range of about 7 to 14 × 10 ⁻⁶ · K ⁻¹ and a small difference in expansion coefficient from the cermet constituent material.
The function as a brazing material can be suitably exhibited at the battery operating temperature. That is, the cell life can be further extended.

According to the invention of claim 5, 10.3 to 13.3
A brazing material having an expansion coefficient in the range of × 10 ^-6 · K ^-1 was used. With such a brazing filler metal, the expansion coefficient is almost the same as that of the cermet, so that cracks and the like due to the thermal stress generated between the brazing filler metal and the cermet due to the thermal change of the fuel electrode do not occur. Further, the effect of improving the wettability with the cermet is high at the battery operating temperature.

According to a sixth aspect of the invention, in the cell for a solid electrolyte fuel cell according to the fifth aspect, the brazing material is T
Binary alloy selected from the group consisting of i-Ni alloy, Ti-Mo alloy, and Ti-Ni alloy, or Ti-N
i-Mo alloy, Ti-Mo-Nb alloy, Ni-Mo-N
A ternary alloy selected from the group consisting of alloy b and having a coefficient of expansion in the range of 10.3 to 13.3 × 10 ⁻⁶ · K ⁻¹ . When a plurality of metals are alloyed, the melting point and the coefficient of thermal expansion can be adjusted appropriately. Therefore, the brazing material can function more favorably as compared with the case where a single metal is used as the brazing material. That is, in the fuel electrode in which the cermet containing the brazing material is used as the electrode material, the brazing material acts more effectively, and therefore the electrode performance is less deteriorated over a long period of time.

[0019]

EXAMPLES The present invention will be specifically described based on examples. Further, the contents of the present invention will be clarified by comparing the performances of the battery of this example and the conventional battery (comparative example). [Example] An outline of a solid oxide fuel cell according to an example of the present invention will be described with reference to FIG. 4 which is a schematic sectional view thereof. First, the cell 4 is a solid electrolyte 1 made of a dense sintered body of zirconia (YSZ) stabilized with 8% yttria.
A fuel electrode 2 made of Ni-YSZ cermet mixed with a brazing material on both sides of the outer dimensions (150 mm x 150 mm, thickness 0.2 mm) and an oxidation formed by mixing YSZ with perovskite type oxide such as LaSrMnO _3. It has a structure in which the agent electrode 3 is arranged. In the battery, the cell 4 is sandwiched between a pair of separators 5 and 6, and the fuel electrode 2 and the separator 5 are arranged.
Between the fuel electrode side current collector 7, the oxidizer electrode 3 and the separator 6
An oxidant electrode side current collector 8 is interposed between
In addition, a sealing material 9 is interposed between the non-electrode coated surface of the solid electrolyte 1 and the separators 5 and 6. The fuel electrode side current collector 7 is made of Ni felt, and the oxidant electrode side current collector 8 is made of fibrous Inconel alloy.

The method for producing the fuel electrode and the oxidant electrode, which are the main constituent members of the cell, will be described below. (Preparation of fuel electrode) 200 parts by weight of NiO powder and TiNi
20 parts by weight of alloy powder and Y ₂ O ₃ -stabilized ZrO ₂ powder 1
50 parts by weight and binder (polyvinyl butyral resin)
5 parts by weight and 100 parts by weight of the solvent (terpineol) were sufficiently mixed in a ball mill, and fine bubbles contained in the slurry were stirred and removed under reduced pressure to prepare a fuel electrode slurry. This fuel electrode slurry was applied to one surface of the solid electrolyte 1 so as to have a thickness of 50 μm, dried and then calcined in air at 1250 ° C. for 2 hours to form a fuel electrode on the solid electrolyte surface. did.

(Preparation of oxidizer electrode) La _0.9 Sr _0.1 Mn
400 parts by weight of O ₃ powder and Y ₂ O ₃ stabilized ZrO ₂ 10
0 parts by weight and binder (polyvinyl butyral resin) 5
By weight, 70 parts by weight of the solvent and 70 parts by weight of the solvent (terpineol) were sufficiently mixed in a ball mill, and fine bubbles contained in the slurry were removed by stirring under reduced pressure to prepare an oxidizer electrode slurry. This oxidizer electrode slurry was applied to the other surface of the above-mentioned solid electrolyte having a fuel electrode formed on one surface so as to have a thickness of 50 μm, dried, and then dried in air 1100.
It was fired at 4 ° C. for 4 hours to form an oxidant electrode 3 on the other surface of the electrolyte. In this way, the cell 4 having the structure in which the fuel electrode and the oxidant electrode were formed with the solid electrolyte sandwiched could be manufactured.

(Assembly of Fuel Cell) A current collector 8 made of Inconel alloy felt is arranged on the side of the oxidizer electrode 3 of the cell, and a separator 6 is further arranged thereon. On the other hand, fuel electrode 2
A current collector 7 made of Ni felt 7 was placed on the side, and a separator 5 was placed on the current collector 7 to assemble the inventive battery.

The fuel electrode incorporated in the battery of the present invention is hereinafter referred to as electrode A. Comparative Example A comparative battery was prepared in the same manner as the inventive battery except that no TiNi powder was added to the fuel electrode. The fuel electrode incorporated in this comparative cell is hereinafter referred to as electrode X.

[Experiment 1] With respect to the above-mentioned inventive battery and comparative battery (both of which are external cells of 150 mm × 150 mm in size), the temperature was raised to 1000 ° C., and then humidified hydrogen gas was used as fuel and air was used as oxidant. , Current density 300mA / c
A continuous discharge was performed at m ^{2 for} 400 hours, and the relationship between the battery operation time and the battery voltage was investigated. Further, the electrical conductivity of the fuel electrodes (A and X) of each cell was measured over time by the DC four-terminal method, and the relationship between the cell operating time and the fuel electrode electrical conductivity was investigated.

The experimental results are shown in FIGS. 1 and 2, respectively. As is apparent from FIG. 1, the battery of the present invention (solid line)
Indicates that the battery voltage at the beginning of operation of the battery was higher than that of the comparative battery (broken line), and no decrease in battery voltage was observed thereafter. On the other hand, in the comparative battery, the battery voltage decreased as the battery operating time passed.

Further, from FIG. 2, the fuel electrode A of the battery of the present invention is shown.
Had almost no difference in the electric conductivity between the beginning of battery operation and that after 400 hours had elapsed. On the other hand, the fuel electrode X of the comparative cell
The electrical conductivity decreased sharply at the beginning of operation, and the decreasing tendency was recognized thereafter. It is considered that these experimental results are due to the following reasons. First, in the electrode X of the comparative battery, as shown in FIG. 5, at the beginning of the battery operation, a conductive path was formed by nickel (12) and good gas permeability was ensured by the relatively large pores 15. It is considered that the one having a suitable electrode structure changed its fine structure as shown in FIG. 6 with the elapse of the operating time. That is, the nickel in the cermet gradually becomes a semi-molten state at a battery operating temperature as high as about 1000 ° C., but since the electrode X has poor wettability between nickel and Y ₂ O ₃ -stabilized ZrO ₂ , it becomes a semi-molten state. The resulting nickel particles have a higher surface tension than their affinity with the Y ₂ O ₃ -stabilized ZrO _2, and therefore a force acts to agglomerate to reduce the surface area. For this reason, the nickel particles were initially appropriately dispersed in the cermet and were in contact with each other to form a so-called conductive path, but with the passage of the battery operating time, the nickel particles gradually become closer to each other as shown in FIG. Coagulates with particles to form coarse particles. Therefore, the conductive path is cut,
The conductivity of the electrodes is reduced. Further, the coarsening of nickel causes a decrease in the nickel surface area, resulting in a decrease in the three-phase interface (Ni / gas / electrolyte) formed in the vicinity of the boundary between the fuel electrode and the solid electrolyte. Therefore, it is considered that the electrode performance was lowered and the cell voltage was lowered with the passage of the battery operation time.

On the other hand, the electrode A of the battery of the present invention has the electrode structure as shown in FIG. 3 in which TiNi alloy powder as the brazing material is mixed. In FIG. 3, 11 is TiNi, 12
Indicates nickel, 13 indicates Y ₂ O ₃ -stabilized ZrO ₂ , 14 indicates micropores, and 15 indicates pores. As shown in FIG. 3, TiNi (11) is composed of nickel and Y ₂ O ₃ stabilized Zr.
It is interposed between O ₂ and nickel and Y ₂ O ₃ stabilizing Z
It acts to improve the wettability with rO ₂ . Therefore, even when nickel is in a semi-molten state during battery operation, the affinity between nickel and Y ₂ O ₃ -stabilized ZrO ₂ is retained, and nickel is prevented from agglomerating and becoming coarse particles. Therefore, it is considered that cutting of the conductive path and reduction of the three-phase interface can be prevented. The effect of improving the wettability of the brazing filler metal also contributes to the improvement of the adhesion between the fuel electrode and the solid electrolyte and between the fuel electrode and the current collector.

That is, by the above-described action of the brazing material,
Since the fine structure of the fuel electrode is maintained in a suitable state even when the battery is in operation for a long period of time, deterioration of cell performance is suppressed,
Therefore, it is considered that the battery A did not show a decrease in cell voltage. (Other Matters) It goes without saying that the present invention is not limited to the scope specifically described in the above embodiments.

That is, in the above embodiment, the main constituent material of the fuel electrode
As Ni-Y₂O₃Stabilized ZrO₂Use cermet
Although it was used, a known cermet that can be used as an electrode material
And the wettability between metal and ceramics is poor
All electrode materials are targeted. Because the present invention is a brazing material
By blending, the wettability between metal and ceramics
This is because there is a gist in the point of improving. Other services
As the metal of the met, for example, Ru or the like can be used.
As a ceramic material, CaO, MgO, Y₂O
₃, Sc₂O₃Stabilized zirco with other dopants
Near, (CeO ₂)_0.8X_0.2[However, X is Sm
₂O₃, Y₂O₃, La₂O₃], PrOx [however, 0
<X ≦ 3], BaCe_1-xM_xO_3-x[However, 0 <_x 
≦ 0.3, M is Dy, Gd, Y, Sn, Yb, Nd
One or the like] can be used. However,
Nickel is used as the metal of the alloy because of its melting point and cost.
It is preferable that the
And Y₂O₃Stabilized ZrO₂Is particularly preferable.

In the above embodiment, TiN is used as the brazing material.
Although the i alloy is used, the present invention is not limited to this, and various brazing materials that are physically and chemically stable at the battery operating temperature and can enhance the wettability between nickel and ceramics can be used in the present invention. However, if the difference in the coefficient of thermal expansion between the brazing material and the cermet is large, when a temperature change occurs, thermal stress is generated at the joint surface between the materials, and cracks or the like occur. Therefore, it is desirable that the thermal expansion coefficient of the cermet and the thermal expansion coefficient of the brazing material are close to each other. The coefficient of thermal expansion of a metal such as nickel is approximately 13 to 14 × 10 ^-6 · K ^-1 ,
The coefficient of thermal expansion of ceramics such as zirconia is about 10
Since at ~11 × 10 ^-6 · K ^-1, when considering the experience of the present inventors on these values, about 4~14 × 10 ^-6 · K
Metallic materials having a coefficient of thermal expansion in the range of ⁻¹ can be used, and examples of such metallic materials include Ti, Nb, Ta,
Examples include Zr, Mo and W.

However, from the viewpoint of relaxation of thermal stress, it is more preferable that the thermal expansion coefficient of the brazing filler metal lies between the thermal expansion coefficient of the metal such as nickel and the thermal expansion coefficient of the ceramic such as zirconia. Then, the Ti, Nb, Ta,
When two or more metals such as Zr, Mo and W are combined to form an alloy, an alloy having a coefficient of thermal expansion of 10 to 14 × 10 ^-6 · K ^-1 can be obtained. The melting point is lowered, and the effect of improving the wettability between nickel and zirconia is enhanced. Therefore, the above Ti, Nb, Ta, Zr, M
It is preferable to alloy and use metals such as o and W. Examples of such alloys include Ti-Ni alloys and Ti-Mo.
Alloys, binary alloys selected from the group consisting of Ti-Ni alloys, Ti-Ni-Mo alloys, Ti-Mo
A ternary alloy selected from the group consisting of —Nb alloy and Ni—Mo—Nb alloy can be given.

[0032]

According to the present invention, in a solid electrolyte fuel cell having an electrolyte and a pair of electrodes, a cermet whose fuel electrode is made of metal / ceramic and a brazing material for improving the wettability between the metal and ceramic are added. It is composed of the following materials. Therefore, according to the present invention, a phenomenon caused by poor wettability between metal and ceramics, that is, cutting of a conductive path due to aggregation of nickel particles (decrease in electrode conductivity), decrease in three-phase interface, electrode-electrolyte. Since it is possible to prevent a decrease in adhesion between the electrode and the current collector, the life of the cell is significantly improved. Therefore, when the cell according to the present invention is used, it is possible to provide a solid electrolyte battery that can exhibit high power generation capacity for a long period of time.

[Brief description of drawings]

FIG. 1 shows a solid electrolyte battery using the cell of the present invention,
It is a graph which shows the relationship between a battery voltage and operation continuation time.

FIG. 2 is a graph showing the relationship between the electrical conductivity of the fuel electrode and the operation duration time according to the present invention.

FIG. 3 is an enlarged schematic sectional view showing a fine structure of a fuel electrode according to the present invention.

FIG. 4 is an explanatory view showing the structure of the cell of the present invention.

FIG. 5 is an enlarged schematic cross-sectional view showing a fine structure of a fuel electrode according to a comparative example.

FIG. 6 is an enlarged schematic sectional view showing how the fine structure of the fuel electrode according to the comparative example is changed.

Front page continued (72) Inventor Shunsuke Taniguchi 2-5-5 Keihan Hondori, Moriguchi Sanyo Electric Co., Ltd. (72) Inventor Kouji Yaseo 2-5-5 Keihan Hondori, Moriguchi Sanyo Electric Co., Ltd. (72) Inventor Yukinori Akiyama 2-5-5 Keihan Hondori, Moriguchi Sanyo Electric Co., Ltd. (72) Inventor Toshihiko Saito 2-5-5 Keihan Hondori, Moriguchi Sanyo Denki Co., Ltd.

Claims (6)

[Claims] 1. A cell for a solid electrolyte fuel cell in which a fuel electrode and an oxidant electrode face each other via a solid electrolyte, wherein the fuel electrode comprises a metal and a ceramic, and the metal and the ceramic in a battery operating temperature range. And a brazing filler metal for increasing the wettability of the solid electrolyte fuel cell. 2. The metal is nickel and the ceramic is stabilized zirconia (provided that C is used as a dopant).
aO, MgO, Y ₂ O ₃ , Sc ₂ O ₃ ], (CeO ₂ )
_0.8 X _0.2 [However, X is Sm ₂ O ₃ , Y ₂ O ₃ , La ₂
O ₃ ], PrOx [where 0 <x ≦ 3], BaCe _1-x
M _x O _3-x [where 0 < _x ≤ 0.3, M is Dy, G
Any one of d, Y, Sn, Yb, and Nd] is used for the solid electrolyte fuel cell according to claim 1. 3. The brazing material is 4 to 14 × 10 ⁻⁶ · K ^−1.
The cell for a solid electrolyte fuel cell according to claim 1, wherein the cell is a metal material having an expansion coefficient in the range. 4. The brazing material is Ti, Nb, Ta, Z.
The cell for a solid electrolyte fuel cell according to claim 3, which is a metal material containing as a main component one or more metal elements selected from the group consisting of r, Mo, and W. 5. The brazing material is 10.3 to 13.3 × 1.
The cell for a solid electrolyte fuel cell according to claim 1, which is an alloy having a coefficient of thermal expansion in the range of 0 ^-6 · K ^-1 . 6. The brazing material is a Ti—Ni alloy, Ti—
Binary alloy selected from the group consisting of Mo alloys and Ti-Ni alloys, or Ti-Ni-Mo alloys and Ti-
A ternary alloy selected from the group consisting of Mo-Nb alloys and Ni-Mo-Nb alloys, 10.3-1.
The cell for a solid electrolyte fuel cell according to claim 5, which has a coefficient of expansion in the range of 3.3 × 10 ^-6 · K ^-1 .