JP2000106192A - Substrate tube for fuel cell and its material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate tube for improving a power generating characteristic, avoiding damages, even in the time of high temperature rise rate, and providing a high utilization ratio of fuel, by adding and mixing coarse grains into a substrate tube material of the fuel cell, realizing uneven contraction at sintering, and by heightening porosity of the substrate tube. SOLUTION: A mixture, obtained by adding coarse grains into the substrate tube material, is used as a composite material for a substrate tube, and the porosity can be heightened through uneven contraction at sintering, to enlarge the average pore diameter, thus gas permeability can be improved. Here, the size of the coarse grains added is set at more than 5 μm without the particular upper limit, also it is also effective at about 500 μm. Although the compounding ratio of the coarse grains is not particularly limited, porosity is improved in the case of the compounding ratio of 10-40 wt.%. However it will not improve further, even if the coarse grains are added beyond 40 wt.%. The sintering temperature at production of the substrate tube is preferably about 1,300-1,500 deg.C. At a temperature below 1,300 deg.C, an electrolyte and an inter connector are densified inadequately. While the densification of the fuel electrode is advanced in the sintering at a temperature exceeding 1,500 deg.C, the preferable sintering temperature is set at 1,300-1,500 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base tube for a fuel cell, which has improved porosity and pore diameter of the base tube to improve power generation characteristics of the fuel cell, and a material thereof.

[0002]

2. Description of the Related Art FIG. 1 schematically shows a base tube of a thermal spray type solid oxide fuel cell. As shown in FIG. 1, a thermal spray type solid oxide fuel cell (SOFC) is composed of a porous cylindrical tube of calcia-stabilized zirconia (CSZ) and a base tube 1 of Ni and yttria-stabilized zirconia (fuel electrode side electrode 2). YS
C) is formed by plasma spraying. Next, YSZ having oxygen ion conductivity is formed thereon as the electrolyte 3 by plasma spraying. Then, the air side electrode 4
The fuel cell is formed by depositing LaCoO ₃ by acetylene flame spraying. Finally, a conductive connecting material (interconnector) formed with a cermet of NiAl and alumina
5, the fuel electrode 2 and the air electrode 4 are connected in series.

[0003]

However, the production of a fuel cell by the conventional thermal spraying method is troublesome and requires a high production cost, and it is desired to reduce the cost.

For this reason, a co-sintering type fuel cell has been developed in which the number of times of sintering is small, and the base tube, the fuel electrode and the electrolyte are integrally sintered. There is a problem that the sex is not enough.

Another problem with the prior art base tube is that it deteriorates significantly at a high temperature rise / fall rate during a thermal cycle.

That is, when the temperature rises and falls at a rate of 50 ° C./hour or less, no change in performance is observed before and after the heat cycle.
At a heating / cooling rate of 50 ° C./hour or more, the output may decrease by about 10% per heat cycle.

[0007] This is because, when the fuel cells are assembled and used, if the temperature rise / fall rate is not made very slow, a part of the fuel cell assembly will have a temperature rise / fall rate of 50 ° C / hour or more, The cell may be damaged.

Therefore, a cell which is not damaged even at a high temperature rising / falling rate of about 200 ° C./hour is desired.

Another problem of the base tube is to improve the fuel utilization. The fuel utilization of the conventional base tube is about 70% of the injected fuel, but if the fuel utilization is improved, the efficiency of the fuel cell can be improved.

In view of the above problems, the present invention improves the porosity and pore diameter of a base tube when manufacturing a fuel cell of a base integrated sintering type, thereby improving the power generation characteristics of the fuel cell and increasing the temperature. An object of the present invention is to provide a fuel cell base tube which is not damaged even at a high speed and has a high fuel utilization rate, and a material therefor.

[0011]

According to the first aspect of the present invention, which solves the above-mentioned problems, coarse particles are added and mixed to a raw material for a base tube of a fuel cell to make shrinkage nonuniform during sintering. The porosity of the base tube is increased.

The invention according to claim 2 is the invention according to claim 1, wherein the base tube raw material has an average particle size of 0.5 to 2 μm,
The coarse particles have a particle diameter of 5 μm or more.

[0013] The invention of claim 3 is characterized in that, in claim 1 or 2, the added coarse particles are blended in an amount of 10 to 40% by weight.

According to a fourth aspect of the present invention, in the first to third aspects, the base tube material is calcia stabilized zirconia (CSZ).

The invention according to claim 5 is that the raw material for the base tube of the fuel cell is fine calcia-stabilized zirconia (CSZ), and NiO, CoO, Fe having the same particle size as the raw material for the base tube.
O, Fe ₂ O ₃ , CaTiO ₂ , SrTiO ₂ , Ba ₂
It is characterized in that added fine particles selected from one or two or more of TiO ₃ are mixed to make the shrinkage non-uniform during sintering and to increase the porosity.

A sixth aspect of the present invention is characterized in that, in the fifth aspect, the base tube material has an average particle size of 0.5 to 2 μm.

[0017] The invention of claim 7 is characterized in that, in claim 5 or 6, the added fine particles are blended in an amount of 10 to 40% by weight.

[0018] The invention of claim 8 is that the raw material for the base tube of the fuel cell is calcia-stabilized zirconia (CSZ) having an average particle size of 0.5 to 2 µm, and NiO, CoO, FeO, Fe ₂
5 μm selected from one or more of O ₃ , CaTiO ₂ , SrTiO ₂ , and Ba ₂ TiO ₃
The above additive coarse particles are added and mixed to make the shrinkage non-uniform during sintering and increase the porosity.

[0019] The invention of claim 9 is characterized in that, in claim 8, the coarse particles are blended in an amount of 10 to 40% by weight.

[0020] The invention of claim 10 is a fuel cell substrate.
Tube material is calcia-stabilized zircon having an average particle size of 0.5 to 2 μm
Near (CSZ), NiO, CoO, FeO, Fe
_TwoO _Three, CaTiO_Two, SrTiO_Two, Ba_TwoTiO_Three
0.5 selected from any one or more of
μm to 3 μm added fine particles, NiO, CoO, FeO,
Fe_TwoO_Three, CaTiO_Two, SrTiO_Two, Ba_TwoTi
O_ThreeSelected from one or more of the following
Add and mix with coarse particles of 5μm or more and shrink during sintering
Are characterized by making the porosity non-uniform and increasing the porosity.

The invention according to claim 11 is characterized in that, in claim 10, the added fine particles are blended in an amount of 5 to 30% by weight, and the added coarse particles are incorporated in an amount of 5 to 30% by weight.

The invention according to claim 12 is a material for a base tube for a solid electrolyte fuel cell having a fuel electrode side electrode, an electrolyte membrane, and an oxidant side electrode sequentially laminated on the surface, wherein the base tube material is an average. Calcia-stabilized zirconia having a particle size of 0.5 to 2 μm (C
SZ), NiO, CoO, FeO, Fe ₂ O ₃ ,
It is characterized in that coarse particles of 5 μm or more selected from one or two or more of CaTiO ₂ , SrTiO ₂ and Ba ₂ TiO ₃ are added and mixed.

A thirteenth aspect of the present invention is characterized in that, in the twelfth aspect, the coarse particles are blended in an amount of 10 to 40% by weight.

The invention according to claim 14 is a material for a base tube for a solid electrolyte fuel cell, which is formed by sequentially laminating a fuel electrode side electrode, an electrolyte membrane, and an oxidant side electrode on the surface, and has an average particle diameter of 0.1. 5
Calcium-stabilized zirconia (CSZ) having a mean particle size of 0.5 to 3 μm,
One or more of CoO and Fe ₂ O ₃ is 5 to 30% by weight, and the added coarse particles have an average particle size of 5 μm.
NiO, CoO, Fe ₂ O ₃ , CaO stabilized Zr
Any one or more of O ₂ from 5% by weight to 3%
0% by weight is added and mixed to make the shrinkage non-uniform during sintering and to increase the porosity of the base tube.

The invention according to claim 15 is a material for a base tube for a solid electrolyte fuel cell, in which a fuel electrode side electrode, an electrolyte membrane, and an oxidant side electrode are sequentially laminated on the surface, and has an average particle diameter of 0.1. 5
For calcia-stabilized zirconia (CSZ) of ~ 2 μm, CaTiO ₃ , SrTiO ₃ ,
One or more of BaTiO ₃ and CaO-stabilized ZrO _{2, in} an amount of 5 to 30% by weight, and one or more of NiO, CoO, and Fe ₂ O ₃ having an average particle size of 5 μm or more From 5% to 30% by weight
It is characterized by mixing, making shrinkage non-uniform during sintering, and increasing the porosity of the base tube.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

(1) The composite material for a base tube of the present invention is obtained by adding and mixing coarse particles to a base tube material, and has a non-uniform shrinkage during sintering and a high porosity. As a result, according to the present invention, shrinkage is made uniform during sintering, the porosity is increased, and the gas permeability is improved. I do. According to the present invention, the porosity of the base tube can be increased, and the average pore diameter of the base tube can be increased. As a result, the gas permeability can be improved.

The base tube material of the present invention is a fine calcia-stabilized zirconia (CSZ) having an average particle size of about 0.5 to 2 μm, and a coarse particle of 5 μm or more, particularly preferably about 10 μm. Of calcia-stabilized zirconia (CSZ).

The raw material for the base tube of the present invention is not particularly limited.
However, the above-mentioned calcia-stabilized zirconia (CS
Instead of Z), for example, MgO—MgAl_TwoO_Four, Ca
TiO _Three-MgAl_TwoO_Four, MgTiO_Three-MgAl_Two
O_Four, BaTiO_Three-MgAl _TwoO_FourEtc.
it can.

The upper limit of the particle size is not particularly limited as long as the coarse particles to be added have a particle size of 5 μm or more, but the effect can be exhibited even when the particle size is approximately 500 μm.

The composition of the coarse particles is not particularly limited, but is preferably 10 to 40% by weight.
This is because if the content is less than 10% by weight, the porosity is little improved, and if it exceeds 40% by weight, no further improvement can be achieved.

The sintering temperature at the time of manufacturing the base tube of the present invention is preferably about 1300 ° C. to 1500 ° C. If the sintering temperature is lower than 1300 ° C., the densification of the electrolyte and the interconnector becomes inadequate. On the other hand, if the sintering temperature exceeds 1500 ° C., the densification of the fuel electrode proceeds. Because there is no.

(2) The base material of the present invention is obtained by adding a metal oxide to the calcia-stabilized zirconia (CSZ), which is a raw material of the base tube, to reduce and shrink the metal oxide during power generation, In this case, pores are generated, the pore diameter is increased, and gas permeability is improved. As a result, according to the present invention, the porosity can be increased, the average pore diameter can be increased, and the gas permeability can be improved.

Here, the metal oxide to be added is NiO,
Any one of CoO, FeO, Fe ₂ O ₃ or 2
These are added fine particles selected from at least one kind, and the addition of the metal oxide makes the shrinkage non-uniform at the time of sintering, thereby increasing the porosity.

If the metal oxide is not mixed with the raw material having the same particle diameter as that of the raw material, but has a particle diameter of 5 μm or more, particularly preferably about 20 μm, the shrinkage effect reduced at the time of power generation with the addition of the metal oxide is obtained. By increasing the particle size of the added metal oxide and synergistic effect with the shrinkage action at the time of sintering, the porosity and the pore diameter can be improved.

The mixing ratio of the metal oxide is not particularly limited, but may be 5 to 40% by weight, preferably 10 to 30% by weight. This is because if it is less than 5% by weight, the porosity is little improved, while if it exceeds 40% by weight, no further improvement can be achieved.

The metal oxide to be added may be finely divided,
By adding a predetermined amount of coarse particles, it is possible to improve the porosity, improve the power generation efficiency of the cell, suppress the rate of increase in leak during thermal cycling, and improve the fuel utilization rate.

That is, the base tube material of the present invention is obtained by adding NiO, CoO, Fe ₂ O ₃ having an average particle size of 0.5 to 3 μm to CaO-stabilized ZrO _{2 as} a base tube raw material.
5% to 30% by weight of one or more types
And NiO, Co having an average particle size of 5 μm or more as added coarse particles
One or more of O, Fe ₂ O ₃ and CaO-stabilized ZrO ₂ are added in an amount of 5 to 30% by weight.

Further, the base tube material of the present invention comprises a titania-based composite oxide such as CaTiO ₃ , SrTiO ₃ , and BaTiO ₃ having an average particle size of 0.5 μm or more with respect to CaO-stabilized ZrO _{2 as} a base tube material. 5% to 30% by weight of one or more of CaO-stabilized ZrO ₂ and 5% by weight of one or more of NiO, CoO, and Fe ₂ O ₃ having an average particle size of 5 μm or more % To 30% by weight.

Here, in the case of NiO, CoO, FeO, Fe ₂ O _{3 and the} like, the upper limit of the particle diameter of the added metal oxide is about 200 μm. In addition, CaTi
In the case of O ₂ , SrTiO ₂ and Ba ₂ TiO ₃ , 50
The upper limit is about 0 to 700 μm. This is because NiO, CoO, FeO, Fe ₂ O _3, etc.
In the case of a particle size of 200 μm or more, heat shrinkage occurs even in a reducing atmosphere during power generation and the strength becomes weak.
In the case of a titania-based composite oxide such as iO ₂ , heat shrinkage does not occur even in a reducing atmosphere during power generation.
This is because the thermal expansion matches with the electrolyte membrane and the strength does not become weak. As a result, it is possible to suppress an increase in the leak rate during a thermal cycle. In the present invention, instead of the titania-based composite oxide, for example, Cr ₂ O ₃
Etc., chromium-based composite oxides, chromium-based LaCrO
Lanthanum-based composite compounds such as ₃ can be exemplified.

[0041]

EXAMPLES Test examples and examples showing the effects of the present invention will be described below, but the present invention is not limited to these examples.

Test Example 1 80% by weight of a CSZ raw material having an average particle size of 1 μm and 20% by weight of a coarse particle of CSZ having a particle size of 10 μm were mixed and sintered at 1350 ° C.

Test Example 2 80% by weight of a CSZ raw material having an average particle size of 1 μm and 20% by weight of a 1 μm NiO raw material were mixed and sintered at 1350 ° C.

Test Example 3 80% by weight of a CSZ raw material having an average particle diameter of 1 μm and 20% by weight of a NiO raw material having an average particle diameter of 20 μm were mixed and sintered at 1350 ° C.

Reference Example 1 As a reference example, the average particle size was 1 μm.
Similarly, sintering was performed using only the m CSZ raw material.

The results of porosity, pore diameter and cell power generation efficiency of these sintered products are shown in Table 1 below.

[0047]

[Table 1]

As shown in Table 1, it was found that the porosity of each of the base tubes according to this test example was improved and the cell power generation efficiency was improved as compared with the reference example. Further, as shown in Test Example 3, it was found that when a metal material was added and the particle size was further increased, the synergistic effect of these effects further improved the cell power generation efficiency.

<Examples 1 to 19, Comparative Examples 1 to 7, Examples 20 to 27 and Comparative Examples 8 to 11> The base tube (base portion) 1 made of the porous tube according to the present invention shown in FIG. The composition of the composite material is shown in "Table 2" and "Table 3".

The surface of the base tube 1 is coated with 100 μm Ni-
Fuel electrode side electrode 2, 100 made of zirconia cermet
3 μm of YSZ electrolyte, 1000 μm of Sr
An air-side electrode made of 0.1-doped LaMnO ₃ was stacked, and a conductive connecting material LaCrO ₃ for connecting the fuel electrode-side electrode and the air-side electrode was further stacked to obtain a battery.

After the battery was repeatedly heated and cooled rapidly, the change in the leak rate was compared. The porosity and cell power generation efficiency were also measured. As a result, the increase rate of leak was able to be suppressed by blending the examples shown in “Table 2” and “Table 3”. Also, the fuel utilization was improved.

In this example, the materials shown in Table 2 and Table 3 were prepared as the ceramic raw material for the base tube 1.

The base tube 1 is made by an extrusion molding method.
Methyl cellulose, glycerin,
Water and a stearic acid emulsion were used as a lubricant. The respective auxiliaries were 4 parts by weight, 5 parts by weight, 10 parts by weight, and 0.1 part by weight with respect to 100 parts by weight of the ceramic raw material.
2 parts by weight. Also, stearic acid emulsion is
The solid content concentration was 15% by weight, and the dispersion medium was water.

The manufacture of the base tube according to the present embodiment will be described below. First, a ceramic raw material and methylcellulose are weighed in an arbitrary ratio, put into a high-speed mixer, and mixed for 3 minutes. Next, water, glycerin and stearic acid emulsion are measured and mixed for 1 minute after the addition. Next, main kneading is performed using a biaxial kneader, and the mixture is formed into a cylindrical shape using an extruder. After molding, the fuel cell was dried at 60 ° C. for 24 hours, coated with an electrode material, and then heat-treated at 1400 ° C. for 2 hours to form a fuel cell.

With respect to these cells obtained, the power generation temperature and the temperature were raised and lowered at room temperature five times at a rate of 200 ° C./hour, and the change in cell performance was determined.

The results of the examples of the present invention are shown in Table 2 and Table 3. In order to clarify the effects of the present invention, comparative examples that are out of the scope of the present invention are also shown.

[0057]

[Table 2]

[0058]

[Table 3]

According to Table 2, in Examples 1 to 19 within the range of the components of the present invention, no increase in the leak rate was observed even when the temperature was repeatedly increased and decreased. In addition, the fuel utilization is 80% or more, which can be said to be good. Further, the cell strength was 3 kg / mm ² or more, which was good.

Here, NiO having an average particle size of 0.5 to 3 μm is used.
Is considered to contribute to suppressing the rise in the leak rate during the thermal cycle. In Comparative Example 7, when the amount of NiO having an average particle size of 0.5 to 3 μm was small, an increase in the leak rate during the thermal cycle was shown. This is considered to mean that the coefficient of thermal expansion of the base tube is increased, and the same effect can be expected for CoO, Fe ₂ O _{3 and the} like.

Further, NiO having an average particle size of 0.5 to 3 μm also has an effect of densifying the base tube, and in the case of the comparative example out of the component range of the present invention, it led to a decrease in fuel utilization. This is demonstrated by the results of Comparative Examples 1 and 6.

NiO having an average particle size of 5 μm to 200 μm
Is considered to contribute to the improvement of fuel utilization. This is evident from the fact that, as shown in Comparative Example 5, when the amount of NiO 2 having an average particle size of 5 μm to 200 μm is small, the fuel utilization is reduced.

Further, N having an average particle size of 5 μm to 200 μm
iO has an effect of improving the strength of the cell, and if it is out of the component range of the invention, the strength will be reduced. Comparative Example 2
３3 demonstrate this.

From Table 3, it can be seen that in Examples 20 to 27, NiO, CoO, F having an average particle size of 0.5 to 3 μm was used.
One or more of e ₂ O ₃ is NiO having a weight percentage of 5 to 30% by weight and an average particle size of 5 to 200 μm.
The same effect was confirmed when using a base tube to which 5 wt% to 30 wt% of one or more of CoO and Fe ₂ O ₃ was added. Comparative Example 8 outside the scope of the present invention
In Comparative Example 9, a decrease in cell strength was observed outside the range of the average particle size of the coarse particles added, and in Comparative Example 9, a decrease in the fuel utilization was observed outside the range of the amount of the coarse particles added.

Further, in Comparative Example 10 out of the scope of the present invention, when the added amount of the fine particles added was large, the fuel utilization decreased, and when the added amount of the fine particles added in Comparative Example 11 was small, the heat cycle was reduced. An increase in the leak rate was observed.

<Examples 28 to 48, Comparative Examples 12 to 18,
Examples 49 to 56 and Comparative Examples 19 to 22> [Table 4] and [Table 5] show the composition of the composite material of the base tube (base portion) 1 made of the porous tube according to the present invention shown in FIG. .

A 100 μm Ni—
Fuel electrode side electrode 2, 100 made of zirconia cermet
electrolyte 3, made of YSZ of μm, Sr of 1000 μm
An air side electrode made of LaMnO ₃ doped with 0.1 was laminated, and a conductive connecting material LaCrO ₃ for connecting the fuel electrode side electrode and the air side electrode was further laminated to obtain a battery. After the battery was repeatedly heated and cooled rapidly, the change in the leak rate was compared. The porosity and cell power generation efficiency were also measured.

As a result, it was possible to suppress the increase rate of the leak by blending the examples shown in Table 4 and Table 5. Also, the fuel utilization was improved.

In this example, the materials shown in Table 4 and Table 5 were prepared as the ceramic raw material for the base tube 1.

The base tube 1 is made by an extrusion method.
Methylcellulose, glycerin,
Water and a stearic acid emulsion were used as a lubricant. The respective auxiliaries were 4 parts by weight, 5 parts by weight, 10 parts by weight, and 0.1 part by weight with respect to 100 parts by weight of the ceramic raw material.
2 parts by weight.

The stearic acid emulsion has a solid content of 15% by weight and the dispersion medium is water.

The manufacture of the base tube according to the present embodiment will be described below. First, a ceramic raw material and methylcellulose are weighed in an arbitrary ratio, put in a high-speed mixer, and mixed for 3 minutes.
Next, water, glycerin and stearic acid emulsion are weighed and mixed for 1 minute after the addition. Next, main kneading is performed using a biaxial kneader, and the mixture is formed into a cylindrical shape using an extruder. After molding, the fuel cell was dried at 60 ° C. for 24 hours, coated with an electrode material, and then heat-treated at 1400 ° C. for 2 hours to form a fuel cell.

With respect to these cells, the power generation temperature and the room temperature were raised and lowered five times at a rate of 200 ° C./hour, and changes in cell performance were examined. Examples of the present invention are shown in "Table 4" and "Table 5". In order to clarify the effects of the present invention, comparative examples other than the present invention are also shown.

[0074]

[Table 4]

[0075]

[Table 5]

According to Table 4, in Examples 28 to 48 within the component range of the present invention, no increase in the leak rate was observed even when the temperature was repeatedly increased and decreased. In addition, the fuel utilization is 80% or more, which is good. Further, the cell strength is 3 kg / mm ² or more, which is considered to be good.

Here, C having an average particle size of 0.5 to 200 μm is used.
It is considered that the role of aTiO ₃ is to contribute to suppressing an increase in the leak rate during a thermal cycle. In Comparative Example 18, CaTiO having an average particle size of 0.5 to 200 μm was used.
It is also evident from the fact that when the amount of O ₃ is small, an increase in the leak rate during the thermal cycle is observed. This is considered to mean that the coefficient of thermal expansion of the base tube is increased, and the same effect is obtained by SrTiO ₃ , BaTiO ₃ , CaO, M
gO can be predicted.

Further, Ca having an average particle size of 0.5 to 200 μm
TiO ₃ also has the effect of densifying the base tube, and if it is out of the component range of the invention, it will lead to a decrease in fuel utilization. Comparative Examples 12 and 17 demonstrate this.

Here, it is considered that the role of NiO having an average particle size of 5 μm to 200 μm contributes to improvement of the fuel utilization rate. In Comparative Example 16, when the amount of NiO having an average particle size of 5 μm to 200 μm is small, This is evident from the drop in fuel utilization.

Further, N having an average particle size of 5 μm to 200 μm
iO has an effect of improving the strength of the cell, and if it is out of the component range of the invention, the strength is reduced. Comparative Examples 13 to 15 demonstrate this. A similar effect can be expected for CoO, Fe ₂ O _{3 and the} like.

Further, as shown in Examples 44 and 45, even in the case of CaTiO ₃ having an average particle size of 300 μm and 500 μm, both the improvement of the porosity and the cell strength were favorable.

Further, according to Table 5, Examples 49 to 56 were obtained.
CaTiO _{3 having} an average particle size of 0.5 to 200 μm,
5 wt% to 30 wt% of one or more of SrTiO ₃ and BaTiO ₃ , and 5 wt% to 30 wt of one or more of NiO, CoO, Fe ₂ O _{3 having} an average particle size of 5 μm to 200 μm. The same effect was confirmed when using the base tube added with%.

In Comparative Example 19 outside the range of the present invention, a decrease in cell strength was observed outside the range of the average particle diameter of the coarse particles added, and in Comparative Example 20, outside the range of the added amount of the coarse particles added. A decrease in fuel utilization was observed. further,
In Comparative Example 21 outside the scope of the present invention, when the added amount of the fine particles added was large, the fuel utilization decreased, and when the added amount of the fine particles added in Comparative Example 22 was small, the leakage rate during the thermal cycle increased. Was observed.

<Examples 57 to 59> Table 6 shows the composition of the composite material of the base tube (base portion) 1 composed of the porous tube according to the present invention shown in FIG. In this embodiment, NiO is used as added fine particles, and calcia-stabilized zirconia (CSZ) is used as added coarse particles.

A 100 μm Ni—
Fuel electrode side electrode 2, 100 made of zirconia cermet
electrolyte 3, made of YSZ of μm, Sr of 1000 μm
An air side electrode made of LaMnO ₃ doped with 0.1 was laminated, and a conductive connecting material LaCrO ₃ for connecting the fuel electrode side electrode and the air side electrode was further laminated to obtain a battery. After the battery was repeatedly heated and cooled rapidly, the change in the leak rate was compared. The porosity and cell power generation efficiency were also measured.

[0086]

[Table 6]

Further, according to Table 6, Examples 57 to 59 were obtained.
No increase in the leak rate was observed even when the temperature of the substrate tube was repeatedly increased and decreased. In addition, the fuel utilization is 80% or more, which is good. Further, the cell strength is 3 kg / mm ² or more, which is considered to be good.

[0088]

As described above, according to the first aspect of the present invention, coarse particles are added to and mixed with the raw material of the base tube of the fuel cell to make the shrinkage non-uniform during sintering. Since the porosity is increased, gas permeation performance is improved and cell power generation efficiency can be improved.

According to the second aspect of the present invention, in the first aspect, the average particle diameter of the base tube raw material is 0.5 to 2 μm, and the coarse particle diameter is 5 μm or more. The rate can be improved.

According to the third aspect of the present invention, in the first or second aspect, the porosity can be improved because the added coarse particles are blended in an amount of 10 to 40% by weight.

According to the fourth aspect of the present invention, in the first to third aspects, the base tube material is calcia-stabilized zirconia (CSZ), so that the porosity is particularly 20%, which is higher than that of the conventional 15%. And the cell power generation efficiency can be improved.

According to the invention of claim 5, the raw material for the base tube of the fuel cell is fine calcia stabilized zirconia (CS).
Z), and NiO, Co having the same particle size as the base tube raw material.
O, FeO, Fe ₂ O ₃ , CaTiO ₂ , SrTi
Addition of fine particles selected from one or two or more of O ₂ and Ba ₂ TiO ₃ to make the shrinkage non-uniform and increase the porosity during sintering, thereby improving the power generation efficiency of the cell Can be.

According to the sixth aspect of the present invention, since the average particle size of the base tube material is 0.5 to 2 μm in the fifth aspect, it is possible to improve the cell power generation efficiency.

According to the invention of [Claim 7], since the added fine particles are blended in 10 to 40% by weight according to Claim 5 or 6, the power generation efficiency of the cell can be improved.

According to the invention of claim 8, the fuel cell
The base tube material is a calcia-stabilized die having an average particle size of 0.5 to 2 μm.
Luconia (CSZ), NiO, CoO, FeO,
Fe _TwoO_Three, CaTiO_Two, SrTiO_Two, Ba_TwoTi
O_ThreeSelected from one or more of the following
Add and mix coarse particles of 5μm or more to reduce shrinkage during sintering.
Improves cell power generation efficiency because of non-uniformity and high porosity
You can aim up.

According to the ninth aspect of the present invention, in the eighth aspect, since the coarse particles are blended in an amount of 10 to 40% by weight, the power generation efficiency of the cell can be improved.

According to the invention of claim 10, the base tube material of the fuel cell is calcia-stabilized zirconia (CSZ) having an average particle size of 0.5 to 2 μm, and NiO, CoO, Fe
O, Fe ₂ O ₃ , CaTiO ₂ , SrTiO ₂ , Ba ₂
0.5 μm to 3 μm of added fine particles selected from one kind or two or more kinds of TiO ₃ , NiO, CoO,
FeO, Fe ₂ O ₃ , CaTiO ₂ , SrTiO ₂ , B
a ₂ TiO ₃ is added and mixed with coarse particles of 5 μm or more selected from one or two or more of them to make the shrinkage non-uniform during sintering and increase the porosity. Improvement can be achieved.

According to the invention of claim 11, claim 1 is
At 0, the added fine particles are blended in an amount of 5 to 30% by weight and the added coarse particles are blended in an amount of 5 to 30% by weight, so that the power generation efficiency of the cell can be improved.

According to the twelfth aspect of the present invention, there is provided a material for a solid electrolyte fuel cell base tube having a fuel electrode side electrode, an electrolyte membrane, and an oxidant side electrode sequentially laminated on the surface, wherein the base tube raw material is provided. Is calcia-stabilized zirconia (CSZ) having an average particle size of 0.5 to 2 μm, and NiO, CoO, FeO, Fe ₂
5 μm selected from one or more of O ₃ , CaTiO ₂ , SrTiO ₂ , and Ba ₂ TiO ₃
Since the above-mentioned added coarse particles are added and mixed, the cell power generation efficiency can be improved.

According to the invention of claim 13, claim 1 is provided.
In 2, since the coarse particles are blended in an amount of 10 to 40% by weight, the power generation efficiency of the cell can be improved.

According to the fourteenth aspect of the present invention, there is provided a solid electrolyte fuel cell base tube material having a fuel electrode side electrode, an electrolyte membrane, and an oxidizing agent side electrode sequentially laminated on a surface thereof, and having an average particle diameter. 0.5 to 2 μm calcia stabilized zirconia (CSZ)
On the other hand, N having an average particle size of 0.5 to 3 μm
One or more of iO, CoO, and Fe ₂ O ₃ is 5 wt% to 30 wt%, and NiO, CoO, Fe ₂ O ₃ , and CaO stabilized ZrO _{2 having} an average particle size of 5 μm or more are added as coarse particles. One or two or more of them are added and mixed in an amount of 5% by weight to 30% by weight to make the shrinkage non-uniform during sintering and increase the porosity of the base tube, thereby improving the cell power generation efficiency. Can be.

According to the invention of claim 15, there is provided a solid electrolyte fuel cell base tube material having a fuel electrode side electrode, an electrolyte membrane, and an oxidant side electrode sequentially laminated on a surface thereof, and having an average particle diameter. 0.5 to 2 μm calcia stabilized zirconia (CSZ)
In contrast, CaTiO ₃ , SrT having an average particle size of 0.5 μm or more
one or more of iO ₃ , BaTiO ₃ , and CaO-stabilized ZrO _{2, in} an amount of 5% by weight to 30% by weight, and any one of NiO, CoO, and Fe ₂ O ₃ having an average particle size of 5 μm or more; Addition and mixing of 5% by weight to 30% by weight of two or more types makes uneven shrinkage during sintering and increases the porosity of the base tube, so that the cell power generation efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a base tube of a thermal spray type solid oxide fuel cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base tube 2 Fuel electrode side electrode 3 Electrolyte 4 Air side electrode 5 Conductive connecting material (interconnector)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichiro Kosaka 5-717-1, Fukahori-cho, Nagasaki-shi, Nagasaki Prefecture Inside the Nagasaki Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Nagao Kurume 1-1-1, Akunoura-cho, Nagasaki-city, Nagasaki Prefecture No. Mitsubishi Heavy Industries, Ltd.Nagasaki Shipyard (72) Inventor Yoshiharu Watanabe 1-1, Akunoura-cho, Nagasaki, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd.Nagasaki Shipyard (72) Inventor Toru Hojo 5-717 Fukahoricho, Nagasaki, Nagasaki No. 1 Nagaishi Engineering Co., Ltd.

Claims (15)

[Claims] 1. A base tube for a fuel cell, wherein coarse particles are added and mixed to a base tube material of a fuel cell to make shrinkage nonuniform during sintering and to increase the porosity of the base tube. 2. The fuel cell base tube according to claim 1, wherein the base tube raw material has an average particle size of 0.5 to 2 μm, and the coarse particles have a particle size of 5 μm or more. 3. The fuel cell base tube according to claim 1, wherein the added coarse particles are blended in an amount of 10 to 40% by weight. 4. The method according to claim 1, wherein the base tube material is calcia-stabilized zirconia (CSZ).
A base tube for a fuel cell, characterized in that: 5. A material for a base material of a fuel cell, wherein the raw material of the base tube is calcia.
Stabilized zirconia (CSZ), the same as the base tube material
NiO, CoO, FeO, Fe of one particle size_TwoO _Three, CaT
iO_Two, SrTiO_Two, Ba_TwoTiO_ThreeAny kind of
Or, mixing the added fine particles selected from two or more,
It specializes in making the shrinkage uneven during sintering and increasing the porosity.
Substrates for fuel cells. 6. The base tube for a fuel cell according to claim 5, wherein the base tube raw material has an average particle size of 0.5 to 2 μm. 7. The fuel cell base tube according to claim 5, wherein the added fine particles are blended in an amount of 10 to 40% by weight. 8. The raw material for a base tube of a fuel cell has an average particle size of 0.5 to 0.5.
2 μm calcia stabilized zirconia (CSZ),
_{NiO, CoO, FeO, Fe 2} O 3, CaTiO 2,
Addition and mixing of coarse particles of 5 μm or more selected from one or two or more of SrTiO ₂ and Ba ₂ TiO ₃ to make shrinkage non-uniform and increase porosity during sintering. Substrate tube for a fuel cell. 9. The base tube for a fuel cell according to claim 8, wherein the coarse particles are blended in an amount of 10 to 40% by weight. 10. The raw material for a base tube of a fuel cell has an average particle size of 0.5.
~ 2 μm calcia stabilized zirconia (CSZ)
NiO, CoO, FeO, Fe_TwoO_Three, CaTiO
_Two, SrTiO_Two, Ba_TwoTiO_ThreeAny kind of
Or 0.5 μm to 3 μm selected from two or more types
Fine particles, NiO, CoO, FeO, Fe _TwoO_Three, CaT
iO_Two, SrTiO_Two, Ba_TwoTiO_ThreeAny kind of
Or a coarse additive of 5 μm or more selected from two or more
Add and mix with the particles to make the shrinkage uneven during sintering,
A base tube for a fuel cell, wherein the base ratio is increased. 11. The method according to claim 10, wherein the added fine particles are 5 to 30% by weight, and the added coarse particles are 5 to 3% by weight.
A base tube for a fuel cell, characterized by containing 0% by weight. 12. A material for a base tube for a solid electrolyte fuel cell comprising a fuel electrode side electrode, an electrolyte membrane, and an oxidant side electrode sequentially laminated on the surface, wherein the base tube raw material has an average particle size of 0.5 to 2 μm. Calcia-stabilized zirconia (CSZ), NiO, CoO, FeO,
Fe ₂ O ₃ , CaTiO ₂ , SrTiO ₂ , Ba ₂ Ti
A base tube material for a fuel cell, characterized by adding and mixing an additive coarse particle of 5 μm or more selected from one or more of O ₃ . 13. The base tube material for a fuel cell according to claim 12, wherein the coarse particles are blended in an amount of 10 to 40% by weight. 14. A calcia stabilized material having a mean particle size of 0.5 to 2 μm, which is a material for a base tube for a solid electrolyte fuel cell in which a fuel electrode side electrode, an electrolyte membrane and an oxidant side electrode are sequentially laminated on the surface. Zirconia (C
SZ), NiO, Co with an average particle size of 0.5 to 3 μm as added fine particles
5% by weight of one or more of O and Fe ₂ O ₃
To 30% by weight of NiO, CoO,
One or more of Fe ₂ O ₃ and CaO-stabilized ZrO ₂ are added and mixed with 5% by weight to 30% by weight to make the shrinkage non-uniform during sintering and increase the porosity of the base tube. A base tube material characterized by the following. 15. A calcia-stabilized material having a mean particle size of 0.5 to 2 μm, which is a material for a solid electrolyte fuel cell base tube having a surface on which a fuel electrode side electrode, an electrolyte membrane, and an oxidant side electrode are sequentially laminated. Zirconia (C
SZ), CaTiO ₃ , SrTiO ₃ , Ba having an average particle size of 0.5 μm or more
One or more of TiO ₃ and CaO-stabilized ZrO _{2, in} an amount of 5 to 30% by weight, and one or more of NiO, CoO, and Fe ₂ O ₃ having an average particle size of 5 μm or more From 5% to 30% by weight
Characterized by adding and mixing the following to make uneven shrinkage during sintering and increasing the porosity of the base tube.