JP3340367B2 - Fuel cell material coating apparatus, fuel cell material coating method, and fuel cell material film forming method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell material coating apparatus, a fuel cell material coating method, and a fuel cell material film forming method using the same.

[0002]

2. Description of the Related Art Conventionally, as a solid electrolyte fuel cell of the cylindrical vertical stripe type, for example, Japanese Patent Application Laid-Open No. Hei 7-263001 has been proposed, and a solid electrolyte fuel cell 110 having a structure shown in FIG. 7 has been proposed. This conventional solid oxide fuel cell 110 has a fuel supply conductive tube 1 at the center.
A fuel electrode 112, a solid electrolyte 113, and an air electrode 114 are sequentially formed from the inside, and a porous fuel supply conductive tube 111 for fuel ejection is inserted into the center. , This conductive tube 1
11 is filled with a conductive felt 115 having a fuel reforming function, and a conductive tube 111
The fuel gas 116 is supplied to the fuel cell and air 117 flows around the outer periphery.

The power generation operation of the solid oxide fuel cell 110 will be described.
A fuel gas 116 such as natural gas, methane, or coal gasification gas is supplied into the inside 11, and the fuel gas 116 is ejected to a portion of the conductive felt 115 through a porous tube wall of the conductive tube 111.
The conductive felt 115, the fuel electrode 112, and the solid electrolyte 113 generally have a temperature of 650 ° C to 105 ° C under a high temperature condition.
Under the condition of 0 ° C., a reforming reaction of the following chemical formula 1 is caused.

[0004]

Embedded image The solid electrolyte 11 reacts with hydrogen generated by this reforming reaction.
A power generation reaction of the following formula (2) occurs in a portion between the fuel electrode 112 and the air electrode 114 opposite to each other through 3, and the generated electrons are collected to generate power.

[0005]

Embedded image That is, in the fuel electrode 112, as shown in Formula 2 (a), the hydrogen generated by the reforming reaction is converted into the solid electrolyte 113.
Reacts with the oxide ions supplied from the gas to generate water vapor and electrons. Then, the electrons generated at the fuel electrode 112 pass through the conductive felt 115 and the conductive tube 111 and the cathode 1
18 to an external circuit, and through the anode 119, the air electrode 11
4, at the cathode 114,
As shown in the formula (b), it reacts with oxygen in the air 117 to generate oxide ions, which are released to the solid electrolyte 113 and reach the fuel electrode 112 to be subjected to the reaction of the formula (a). It is done.

In the cylindrical solid electrolyte fuel cell 110 having such a power generation mechanism, the air electrode 114 and the solid electrolyte 11
The portion 3 and the fuel electrode 112 are conventionally formed as follows. First, a lanthanum manganate-based porous base tube serving as the air electrode 114 is subjected to electrochemical vapor deposition, that is, CVD (Chemical Vapor Deposition) -EVD.
A thin and dense YSZ film is formed as the solid electrolyte 113 using an (Electrocheical Vapor Deposition) method. The slurry is coated, dried and fired to form a porous fuel electrode 112.

[0007]

However, in such a conventional method for forming a fuel cell material, since a method for forming a solid electrolyte uses an electrochemical deposition method, it takes a long time to form a film. In addition, there is a problem that equipment and production costs such as equipment and raw materials are increased.

Conventionally, as a method of forming a fuel electrode, a method has been used in which a fuel electrode material slurry is applied to the inner peripheral surface of a base tube by slurry coating, dried, and then fired under a predetermined high temperature environment. However, in the case of slurry coating, a relatively low-viscosity slurry is sprayed onto the inner periphery of the base tube and applied, or a relatively high-viscosity slurry is applied to the inner periphery of the base tube by a sludge casting method. However, with the method of spraying the fuel cell material slurry onto the inner peripheral surface of the base tube, it is difficult to insert the spray tube inside the base tube when the base tube is long or thin. In addition, when the slurry for the fuel electrode material is applied to the inner peripheral surface of the base tube by the sludge casting method, there is a problem that it is difficult to apply the slurry only to a necessary place.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and can reduce the equipment cost, and even when the inner diameter of the tube is small, the solid electrolyte material slurry or the like can be placed at a desired position on the inner peripheral surface of the base tube. Fuel cell material coating apparatus and fuel cell material coating method capable of applying a fuel electrode material slurry reliably and in a predetermined film thickness, and thus forming a solid electrolyte or a fuel electrode having a uniform film thickness And a method for forming a film of a fuel cell material using the same.

[0010] The present invention also provides a fuel cell material coating apparatus and a fuel cell material coating method capable of uniformly coating a fuel cell material on the inner peripheral surface of the base tube even if the base tube has an elliptical shape and forming a film. And a method for forming a film of a fuel cell material using the same.

[0011]

According to a first aspect of the present invention, there is provided a fuel cell material coating apparatus, wherein a base tube holding means for holding a base tube, and a base tube held by the base tube holding means are axially movable. And a slurry supply pipe for supplying the fuel cell material slurry into the base pipe from the slurry discharge port at the tip thereof, and an air supply pipe inserted into the slurry supply pipe and having a rubber elastic balloon attached to the tip. And forming a fuel cell material coating film by slid the fuel cell material slurry discharged from the slurry discharge port to a predetermined thickness on the inner wall of the base tube by the balloon by moving the slurry in the axial direction. It is like that.

In the fuel cell material applying apparatus according to the first aspect of the present invention, the base tube is held by the base tube holding means, and while the fuel cell material slurry is supplied into the base tube through a slurry supply pipe inserted into the base tube, the slurry is supplied. The supply pipe is moved in the longitudinal direction of the base pipe, and the fuel cell material slurry discharged from the slurry discharge port is discharged from the inner wall of the base pipe by a rubber-elastic balloon attached to the tip of the air supply pipe inserted into the slurry supply pipe. To form a coating film of a fuel cell material.

According to a second aspect of the present invention, there is provided a fuel cell material coating method, wherein a slurry is supplied to a solid electrolyte material slurry through a slurry supply tube inserted into the substrate tube while holding the substrate tube. Is moved in the longitudinal direction of the substrate pipe, and the solid electrolyte material slurry discharged from the slurry discharge port is applied to the inner wall of the substrate pipe by a balloon having rubber elasticity attached to the outside of the slurry discharge port of the slurry supply pipe. It is characterized in that it is rubbed to a predetermined film thickness.

In the method for applying a fuel cell material according to a second aspect of the present invention, the solid electrolyte material slurry supplied through the slurry supply pipe into the base tube is rubbed on the inner wall of the base tube with a rubber-elastic balloon. By moving the slurry supply tube, even if the shape of the base tube is not a perfect cylinder but a cylindrical shape, the flexibility of the balloon allows the material slurry to be rubbed with uniform pressure on each part of the inner peripheral surface. While moving, a coating film of the solid electrolyte material slurry is formed with a uniform film thickness. Further, the coating thickness of the material slurry is appropriately controlled by adjusting the air pressure in the balloon. Further, when the material coating is formed only at a desired position in the longitudinal direction of the base tube, the position at which the material slurry is discharged from the slurry supply tube is adjusted.

According to a third aspect of the invention, there is provided a method of forming a fuel cell material, comprising drying the solid electrolyte material slurry applied to the inside of the base tube by the fuel cell material application method according to the second aspect, and drying the slurry at a predetermined firing temperature. The method is characterized in that a solid electrolyte material film is fired to form a solid electrolyte film.

According to a fourth aspect of the present invention, there is provided a fuel cell material coating method, wherein a fuel electrode material slurry is supplied into the substrate tube through a slurry supply tube inserted into the substrate tube while holding the substrate tube. Is moved in the longitudinal direction of the base pipe, and the fuel electrode material slurry discharged from the slurry discharge port is applied to the inner wall of the base pipe by a balloon having rubber elasticity attached to the outside of the slurry discharge port of the slurry supply pipe. It is characterized in that it is rubbed to a predetermined film thickness.

According to a fourth aspect of the present invention, the fuel electrode material slurry supplied through the slurry supply pipe into the base tube is rubbed on the inner wall of the base tube by a rubber-elastic balloon. By moving together with the slurry supply tube, even if the shape of the base tube is not a perfect cylinder but an ellipse, the flexibility of the balloon allows the material slurry to be rubbed with uniform pressure on each part of the inner peripheral surface thereof. It moves to form a coating film of the anode material slurry with a uniform film thickness. Further, the coating thickness of the material slurry is appropriately controlled by adjusting the air pressure in the balloon. Further, when the material coating is formed only at a desired position in the longitudinal direction of the base tube, the position at which the material slurry is discharged from the slurry supply tube is adjusted.

According to a fifth aspect of the present invention, there is provided a method of forming a fuel cell material, wherein the fuel electrode material slurry applied in the base tube by the fuel cell material applying method of the fourth aspect is dried, and the fuel electrode material slurry is heated at a predetermined firing temperature. The fuel electrode material film is fired to form a fuel electrode.

According to a sixth aspect of the present invention, there is provided a method for forming a film of a fuel cell material, comprising preparing a plurality of types of material slurries which gradually change from a solid electrolyte composition to a fuel electrode composition; Are selected one by one in the order from the solid electrolyte composition to the fuel electrode composition, holding the base tube, and supplying the selected material slurry into the base tube through a slurry supply tube inserted into the base tube, The slurry supply pipe is moved in the longitudinal direction of the base pipe, and the selected material slurry discharged from the slurry discharge port is discharged from the slurry discharge port by a rubber elastic balloon attached to the outside of the slurry discharge port of the slurry supply pipe. The inner wall of the pipe is rubbed and applied to a predetermined thickness to form a coating film of the material slurry having the plural kinds of compositions in order, and forming a plurality of layers of the plural kinds of compositions. It is characterized in that the deposition of the graded material layer of composition throughout the membrane simultaneously firing the solid electrolyte composition an inner peripheral surface of the substrate tube to the anode composition.

In the method for forming a fuel cell material according to the invention of claim 6, a slurry supply pipe prepared by preparing a plurality of types of material slurries which gradually change from a solid electrolyte composition to a fuel electrode composition, and inserted into the base tube. The step of applying the selected material slurry discharged from the slurry discharge port by a balloon having rubber elasticity to a predetermined thickness on the inner wall of the base tube while supplying the material slurry into the base tube through By repeating the process for each of the material slurries having a plurality of types of compositions, a coating film having a graded composition ranging from the solid electrolyte composition to the fuel electrode composition can be uniformly formed on the inner peripheral surface of the base tube. For this reason, a material film having a gradient composition from the solid electrolyte composition to the fuel electrode composition can be formed in a uniform thickness by the subsequent firing step.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

<Embodiment of Method for Applying Solid Electrolyte Material and Method for Forming Solid Electrolyte> In the first embodiment, a solid electrolyte material is applied to an inner peripheral surface of a base tube to a predetermined thickness, and then fired. This is a method of forming a solid electrolyte film by performing the above steps.

The base tube 10 is a cylindrical porous air electrode made of strontium-added lanthanum manganate (LSM). Although the dimensions of the base tube 10 are not particularly limited, the base tube 10 is used for a solid oxide fuel cell. In the following, a case will be described in which an outer diameter of 21 mmφ, an inner diameter of 17 mmφ, and a length of 0.5 to 1 m is used.

The solid electrolyte material slurry has a particle size of 0.1 μm.
A mixture of YSZ powder of m to 1.0 μm and a diluent such as ethanol. The mixing ratio is 10-4
About 0 wt%, 1,000-200,000 mPaS
Is preferred.

As shown in FIG. 1, a base tube 10 is held horizontally or vertically, and a double tube of an internal slurry supply tube 11 and a balloon air supply tube 13 having a rubber balloon 12 attached to the tip is provided. The base tube 10 is inserted to a predetermined depth at the back. Then, air of a predetermined pressure is supplied to the balloon air supply pipe 1.
3, the balloon 12 at the tip is inflated and brought into pressure contact with the inner peripheral surface of the base tube 10. In this state, the above-mentioned solid electrolyte material slurry 14 is supplied into the slurry supply pipe 11 by a pump (not shown), and is discharged into the base pipe 10 from the tip discharge port of the slurry supply pipe 11. 11 and the balloon air supply tube 13 are both moved in the axial direction in a slowly withdrawing direction. As a result, the balloon 12 moves while rubbing the solid electrolyte material slurry 14 discharged into the base tube 10 onto the inner peripheral surface of the base tube 10, and the coating film 1 having a uniform thickness of the solid electrolyte material slurry 14.
Move while forming 5. This solid electrolyte material slurry 14 is applied on the inner peripheral surface of the base tube 10 by 50 to 150 μm.
m.

The internal pressure of the balloon 12 and the moving speed of the balloon 12 (therefore, the moving speed of the slurry supply pipe 11 and the balloon air supply pipe 13) are experimentally determined by the concentration, supply flow rate, and temperature of the solid electrolyte slurry. For example, when the balloon 12 has a thickness of 0.15 mm, the slurry concentration is 30 wt% and the supply flow rate is 10 cubic cm /
Min, balloon internal pressure 0.7kg / square cm, moving speed 5c
By setting m / sec, the coating film 15 having a thickness of about 100 μm can be formed.

The solid electrolyte material coating 15 applied to the inner peripheral surface of the base tube 10 in this manner is applied to the solid electrolyte material while the balloon 12 having rubber elasticity contacts the entire inner peripheral surface of the base tube 10 at a uniform pressure. Since the electrolyte material slurry 14 was applied by rubbing the inner peripheral surface of the base tube 10,
The coating film has a uniform thickness.

After the solid electrolyte material slurry 14 is applied to a predetermined film thickness, the coating film 15 is dried and further baked in a conventional manner, as shown in FIG. 15 is a dense solid electrolyte membrane 16
Is formed. The sintering conditions are not particularly limited.
000-1600 ° C. for about 1-20 hours.

The solid electrolyte membrane 16 thus formed on the inner peripheral surface of the base tube 10 is attached to the balloon 1 on the inner peripheral surface of the base tube 10.
The material film 15 is applied to the inner peripheral surface of the base tube 10 in a uniform thickness by applying the solid electrolyte material slurry 14 so as to be rubbed by the movement of 2, and then dried and fired. Since it is a film, the film has a uniform thickness and good adhesion to the base tube 10.

<Embodiment of Method for Applying Fuel Electrode Material and Method for Forming Fuel Electrode> The second embodiment is directed to a base tube 10 in which a solid electrolyte is already formed on the air electrode and its inner peripheral surface.
On the other hand, a method of applying a fuel electrode material slurry to the inner peripheral surface to a predetermined thickness, further drying and firing, to form a fuel electrode.

The base tube 10 is made of strontium-added lanthanum manganate (LS) in the same manner as described in the conventional example.
M), a dense solid electrolyte 2 made of yttria-stabilized zirconia (YSZ) is provided on the inner peripheral surface of a cylindrical porous air electrode 1.
Formed by a slurry coating method, a CVD-EVD method, or the above-described film forming method (as shown in FIG. 3, a base tube 1 is formed by an air electrode 1 and a solid electrolyte 2).
0). The dimensions of the base tube 10 are not particularly limited, but for a solid oxide fuel cell, the outer diameter is 21 mmφ, the inner diameter is 17 mmφ, and the length is 0.5 to 1 m.
The case where the above is used will be described.

The fuel electrode material slurry is nickel (Ni).
Powder, cobalt (Co) powder, nickel oxide (NiO)
Powder, cobalt oxide (CoO) powder, or nickel zirconia cermet powder and YSZ powder at 60 wt.
%: A mixture of a mixed powder mixed at a ratio of 40 wt% and a diluent such as a cellulose-based binder.
The mixing ratio is preferably 5% by weight.

The coating apparatus used is the same as that of the first embodiment shown in FIG. However, in the case of the second embodiment, as the base tube 10, the one in which a solid electrolyte is formed on the inner periphery thereof together with the air electrode is used. Is different. In the step of applying the fuel electrode material slurry 14, a coating film 15 having a thickness of 50 to 250 μm is formed on the inner peripheral surface of the base tube 10.

The internal pressure of the balloon 12 and the moving speed of the balloon 12 are experimentally determined depending on the concentration of the anode material slurry, the supply flow rate, and the temperature. For example, the balloon 12 has a wall thickness of 0.15 mm. In this case, by setting the slurry concentration at 50 wt%, the supply flow rate at 20 cubic cm / min, the balloon inner pressure at 1.2 kg / square cm, and the moving speed at 3 cm / sec, the coating film 15 having a thickness of about 200 μm is formed. Can be.

After the anode material slurry 14 is applied to a predetermined thickness to form an anode material coating film 15, the coating film 15 is dried and baked in the same manner as in the first embodiment. As shown in FIG.
A cermet-formed porous fuel electrode 17 is formed on the inner peripheral surface of the substrate. The sintering conditions are not particularly limited.
１1400 ° C. for about 1 to 20 hours.

The fuel electrode 17 thus formed on the inner peripheral surface of the base tube 10 is applied to the inner peripheral surface of the base tube 10 by applying the fuel electrode material slurry 14 by moving the balloon 12 so as to rub it. The material coating 15 is adhered to the inner peripheral surface of the tube 10 to a uniform thickness, and then dried and fired, so that the film is uniform, and the adhesion to the substrate tube 10 is uniform. It will be good.

<Method of Applying Solid Electrolyte Material and Fuel Electrode Material and Method of Forming Solid Electrolyte and Fuel Electrode> The third embodiment is directed to the method of applying a solid electrolyte material described in the first embodiment. The solid electrolyte material is applied to the inner peripheral surface of the air electrode forming the base tube by using the method described above, and the inner electrode surface of the solid electrolyte coating is further applied by using the method for applying the fuel electrode material described in the second embodiment. It is characterized in that a fuel electrode material is applied and baked simultaneously to form a film. That is, as shown in FIG. 4A, a solid electrolyte coating 15a is first applied to the inner peripheral surface of the air electrode serving as the base tube 10 by using the solid electrolyte material application method of the first embodiment. Then, as shown in FIG. 2B, the anode electrode coating 15b is applied to the inner peripheral surface of the solid electrolyte coating 15a by using the anode electrode application method of the second embodiment. I do. The dimensions, material composition, film forming conditions, and the like of the base tube 10 are all the same as in the first embodiment,
This is common to the second embodiment.

After the coating films 15a and 15b of these two materials are applied and formed, they are fired under the same firing conditions as in the first embodiment, so that the solid electrolyte and the fuel electrode are provided inside the air electrode of the base tube 10. A cylindrical solid oxide fuel cell on which a film is formed is obtained.

According to the solid electrolyte material and fuel electrode material applying method and the solid electrolyte and fuel electrode film forming method of the third embodiment, both the solid electrolyte and the fuel electrode are formed by a slurry coating method. Therefore, the manufacturing time can be shortened as compared with the conventional film forming method using the electrochemical deposition method, and the same effect as in the first and second embodiments can be expected.

In the case of the third embodiment, a coating 15a of a solid electrolyte material is applied to the inner peripheral surface of the base tube 10, dried, and fired to form a solid electrolyte film first. Thereafter, a coating 1 of the fuel electrode material is formed on the solid electrolyte membrane.
5b may be applied, dried and fired to form a fuel electrode.

Next, a method of applying a fuel cell material and a method of forming a fuel cell material according to the fourth embodiment will be described. The feature of the fourth embodiment is that a plurality of material slurry layers having a composition gradient from the solid electrolyte composition to the fuel electrode composition are applied to the inner peripheral surface of the base tube 10 composed of the air electrode,
The point is that, by further firing, a gradient composition film 18 having a gradient from the solid electrolyte composition to the fuel electrode composition is simultaneously formed. Hereinafter, regarding the coating method and the film forming method,
A description will be given based on FIG.

As the base tube 10, a base tube forming the same air electrode as that of the first embodiment is used. The solid electrolyte material slurry prepared to have the same solid electrolyte composition as that of the first embodiment is applied to the inner peripheral surface of the base tube 10 by the apparatus shown in FIG. 1 to form a coating film 21a of the solid electrolyte material composition. And
Dry (see FIG. 5A).

Subsequently, nickel (Ni) powder and cobalt (Co) were used in an intermediate composition between the solid electrolyte composition and the fuel electrode composition.
Powder, nickel oxide (NiO) powder, cobalt oxide (C
oO) A slurry obtained by mixing powder or a mixed powder obtained by mixing nickel zirconia cermet powder and YSZ powder at a ratio of 60 wt%: 40 wt% and a diluent such as a cellulose-based binder, and a mixing ratio of about 50 wt% Use The material slurry having the intermediate composition is applied to the solid electrolyte material coating film 21 by the apparatus shown in FIG.
The intermediate composition material coating film 21b is formed by coating on the inner peripheral surface of a, and dried (see FIG. 5B).

Next, the slurry of the fuel electrode composition used in the second embodiment is applied to the inner peripheral surface of the intermediate composition material coating film 21b by the apparatus shown in FIG. 21c is formed and dried (see FIG. 5C).

Thereafter, the material coatings 21a to 21c having a gradient composition between the solid electrolyte material composition and the fuel electrode material are prepared.
By firing the substrate tube 10 on which is formed the same conditions as in the first embodiment, the inner peripheral surface of the substrate tube 10 is changed from a solid electrolyte composition to a fuel electrode composition as shown in FIG. The graded composition film 22 having a graded composition can be formed.

The gradient composition film 22 from the solid electrolyte composition to the fuel electrode composition thus formed on the inner peripheral surface of the base tube 10 is
Since material slurries of a plurality of compositions are sequentially applied to the inner peripheral surface of the base tube 10 by the balloon 12 to form the coating films 21a to 21c, the same effects as in the first to third embodiments may be expected. As a result, the gradient composition film 22 also has a uniform thickness and good adhesion to the base tube 10. Also, since the solid electrolyte and the fuel electrode are formed in the same film forming process,
The manufacturing process can be simplified and the film formation time can be shortened.

[0047]

(Example 1) An outer diameter of 21 mmφ serving as an air electrode,
A LSM base tube having an inner diameter of 17 mm and a length of 50 cm is held vertically, and a slurry balloon of 12 mm inside and a rubber balloon with a thickness of 0.15 mm attached to the tip with a 6 mm diameter balloon air supply tube. What was inserted. And the balloon is 0.7kg / square cm
The YSZ powder is slowly expanded at a rate of 5 cm / sec while a solid electrolyte material slurry obtained by mixing 10 wt% of YSZ powder with an ethanol diluent is supplied into the base tube at a rate of 10 cubic cm / minute by a slurry supply tube. I went.

When the coating film of the solid electrolyte material formed inside was observed, it was found to have a thickness of about 100 μm and to be uniformly applied to the inner peripheral surface of the base tube.

Subsequently, the substrate tube was placed in a firing furnace and fired. The firing conditions were 1400 ° C. for 10 hours. As a result, the solid electrolyte film formed on the inner peripheral
The thickness was uniform at 0 μm.

(Example 2) Outer diameter 21 mmφ serving as air electrode
A YSZ film serving as a solid electrolyte is formed on the inner peripheral surface of the LSM tube having an outer diameter of 21 mmφ, an inner diameter of 17 mmφ, and a length of 5 mm.
The substrate tube of 0 cm was held vertically, and the same slurry supply tube and balloon air supply tube as in Example 1 were inserted therein. Then, the balloon is inflated at a pressure of 1.2 kg / square cm, and a fuel electrode material slurry obtained by mixing a mixed powder of Ni powder 50 wt%: YSZ powder 50 wt% with an ethanol diluent in a ratio of 50 wt%: 50 wt% is supplied. While feeding into the base tube at a rate of 20 cubic cm / min by the tube,
It was slowly pulled out at a speed of 3 cm / sec.

When the fuel electrode material layer coating film formed inside was observed, it was found to have a uniform thickness of 150 μm.

Subsequently, the substrate tube was placed in a firing furnace and fired. The firing conditions were the same as in Example 1. As a result,
The fuel electrode film formed on the inner peripheral surface of the base tube had a uniform thickness of 60 μm.

Example 3 A solid electrolyte material slurry in which 20 wt% of YSZ powder was mixed with an ethanol diluent was applied to the inner peripheral surface of a base tube having the same specifications as in Example 1 under the same conditions as in Example 1. , 50 μm solid electrolyte material coating 21
a was formed and dried.

Subsequently, the inner surface of the solid electrolyte material coating film 21a is coated with nickel powder and YSZ powder for 50 watts.
A solid electrolyte material slurry using a slurry having an intermediate composition between the solid electrolyte composition and the fuel electrode composition in which a mixed powder mixed at a ratio of t%: 50 wt% and a diluent of a cellulosic binder mixed at a ratio of 5: 5. Was applied under the same conditions as in Example 1 to form a material coating 21b having a composition of 50 μm between the solid electrolyte and the fuel electrode, and dried.

Further, a fuel electrode material slurry having the same composition as in Example 2 was applied to the inner peripheral surface of the material coating film 21b having this intermediate composition under the same conditions as in Example 2 to obtain a 50 μm fuel electrode material coating film. 21c was formed and dried.

Thereafter, the base tube 10 on which the three material coatings 21a to 21c were formed was fired in a firing furnace. The firing conditions were 1200 ° C. for 10 hours. As a result, a gradient composition film 22 having a composition gradient from the solid electrolyte composition to the fuel electrode composition can be formed on the inner peripheral surface of the base tube,
The film thickness was uniform at 60 μm as a whole.

[0057]

As described above, according to the fuel cell material applying apparatus of the first aspect of the present invention, the fuel cell material slurry supplied through the slurry supply pipe into the base pipe is applied to the inner wall of the base pipe by the balloon having rubber elasticity. Because it moves while rubbing, even if the shape of the base tube is not a perfect cylinder but an ellipse, it moves while rubbing the material slurry with uniform pressure on each inner peripheral surface due to the flexibility of the balloon. In addition, a uniform thickness of the fuel cell material coating film can be formed, and the thickness of the material slurry coating film can be appropriately controlled by adjusting the air pressure in the balloon. The material coating can be formed only at a desired position in the direction.

According to the fuel cell material coating method of the second aspect of the present invention, the solid electrolyte material slurry supplied through the slurry supply tube into the substrate tube is moved while being rubbed on the inner wall of the substrate tube by a balloon having rubber elasticity. Therefore, even if the shape of the base tube is not a perfect cylinder but an ellipse, it moves while rubbing the material slurry with uniform pressure to each part of the inner peripheral surface due to the flexibility of the balloon, resulting in a uniform film. A thick solid electrolyte material coating film can be formed, the coating pressure of the material slurry can be appropriately controlled by adjusting the air pressure in the balloon, and furthermore, a desired position in the longitudinal direction of the base tube can be obtained. It is also possible to form a material coating by limiting only to the above.

According to the third aspect of the present invention, the solid electrolyte material slurry applied to the inside of the base tube by the method of applying the fuel cell material according to the second aspect is dried, and the slurry is heated at a predetermined firing temperature. Since the solid electrolyte film is formed by firing the solid electrolyte material film, a solid electrolyte having a uniform film thickness can be easily formed.

According to the fuel cell material coating method of the invention, the fuel electrode material slurry supplied through the slurry supply pipe into the base pipe is moved while being rubbed on the inner wall of the base pipe by the balloon having rubber elasticity. Therefore, even if the shape of the base tube is not a perfect cylinder but an ellipse,
Due to the flexibility of the balloon, it moves while rubbing the material slurry with uniform pressure on each part of the inner peripheral surface, and can form a coating film of the fuel electrode material slurry with a uniform film thickness. By adjusting the thickness, the coating thickness of the material slurry can be appropriately controlled, and the material coating can be formed only at a desired position in the longitudinal direction of the base tube.

According to the method for forming a fuel cell material according to the fifth aspect of the present invention, the fuel electrode material slurry applied to the inside of the base tube by the method for applying the fuel cell material according to the fourth aspect is dried.
Since the fuel electrode material film is fired at a predetermined firing temperature to form a fuel electrode, a fuel electrode having a uniform thickness can be easily formed.

According to the method for forming a fuel cell material according to the sixth aspect of the invention, a plurality of types of material slurries which change stepwise from a solid electrolyte composition to a fuel electrode composition are prepared, and the slurry inserted into the base tube is prepared. A step of applying the selected material slurry discharged from the slurry discharge port with a balloon having rubber elasticity to a predetermined thickness on the inner wall of the base tube while supplying the material slurry into the base tube through a supply pipe; Is repeated for each of the material slurries of the plurality of layers, whereby a coating film having a graded composition from the solid electrolyte composition to the fuel electrode composition can be formed on the inner peripheral surface of the base tube to have a uniform thickness. By the subsequent firing step, a material film having a gradient composition from the solid electrolyte composition to the fuel electrode composition can be formed to a uniform thickness.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a coating apparatus used for a method for coating a fuel cell material according to the present invention.

FIG. 2 is a cross-sectional view showing a state in which a solid electrolyte material is applied to the inner peripheral surface of the base tube by the method for applying a fuel cell material according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state in which a fuel electrode material is applied to an inner peripheral surface of a base tube by a method for applying a fuel cell material according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a state in which a solid electrolyte material and a fuel electrode material are applied to an inner peripheral surface of a base tube by a method for applying a fuel cell material according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a state in which three types of gradient composition material coatings are applied in a method for forming a fuel cell material according to a fourth embodiment of the present invention.

FIG. 6 is a cross-sectional view of a fuel cell formed by the method for forming a fuel cell material according to the fourth embodiment.

FIG. 7 is a sectional view showing the structure of a general cylindrical solid oxide fuel cell.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 air electrode 2 solid electrolyte 10 base tube 11 slurry supply tube 12 balloon 13 balloon air supply tube 14 fuel cell material slurry 15, 15a, 15b coating film 16 solid electrolyte 17 fuel electrode 21a, 21b, 21c coating film 22 inclined composition film

Continued on the front page (72) Inventor Riki Iwasawa 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Corporation (72) Inventor Masataka Mochizuki 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Corporation (72) Invention Person Masakatsu Nagata 1-5-1 Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Namiko Kanda 1-5-1, Kiba Koto-ku, Tokyo Inside Fujikura Co., Ltd. (56) References JP-A-4-315769 ( JP, A) JP-A-5-36433 (JP, A) JP-A-6-72787 (JP, A) JP-A 8-273676 (JP, A) JP-A-56-1112067 (JP, A) 63-39469 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 8/02 B05C 7/08 B05D 7/22 H01M 8/12

Claims (6)

(57) [Claims] 1. A base tube holding means for holding a base tube, wherein the fuel cell material slurry is axially movably inserted into a base tube held by the base tube holding means, and the fuel cell material slurry is discharged from a slurry discharge port at the tip thereof. A slurry supply pipe to be supplied into the base pipe; and an air supply pipe inserted into the slurry supply pipe and having a rubber-elastic balloon attached to a tip thereof, wherein the fuel cell material slurry discharged from the slurry discharge port is provided. A fuel cell material coating device, wherein the coating is formed by rubbing the inner wall of the base tube to a predetermined thickness by the balloon by the axial movement. 2. While holding the substrate tube, supplying the solid electrolyte material slurry into the substrate tube through a slurry supply tube inserted into the substrate tube, moving the slurry supply tube in the longitudinal direction of the substrate tube, The solid electrolyte material slurry discharged from the slurry discharge port is rubbed to a predetermined thickness on the inner wall of the base pipe by a balloon having rubber elasticity attached to the outside of the slurry discharge port of the slurry supply pipe. How to apply fuel cell material. 3. The solid electrolyte material slurry applied to the base tube by the fuel cell material application method according to claim 2 is dried, and the solid electrolyte material film is fired at a predetermined firing temperature to form a solid electrolyte film. A method for forming a film of a fuel cell material. 4. While holding the substrate tube, supplying the anode material slurry into the substrate tube through a slurry supply tube inserted into the substrate tube, moving the slurry supply tube in the longitudinal direction of the substrate tube, The fuel electrode material slurry discharged from the slurry discharge port is rubbed with a predetermined thickness on the inner wall of the base pipe by a balloon having rubber elasticity attached to the outside of the slurry discharge port of the slurry supply pipe. How to apply fuel cell material. 5. The fuel electrode material slurry applied to the base tube by the fuel cell material application method according to claim 4, and the fuel electrode material film is fired at a predetermined firing temperature to form a fuel electrode. A method for forming a film of a fuel cell material. 6. A material slurry having a plurality of kinds of compositions that changes stepwise from a solid electrolyte composition to a fuel electrode composition is prepared, and the material slurries of the plurality of kinds of compositions are added in order from the solid electrolyte composition to the fuel electrode composition. By selecting each type, holding the substrate tube, moving the slurry supply tube in the longitudinal direction of the substrate tube while supplying the selected material slurry into the substrate tube through a slurry supply tube inserted into the substrate tube. The selected material slurry discharged from the slurry discharge port is rubbed to a predetermined thickness on the inner wall of the base pipe by a rubber-elastic balloon attached to the outside of the slurry discharge port of the slurry supply pipe. And sequentially forming a coating film of the material slurry having the plurality of compositions, and simultaneously firing a plurality of coating films having the plurality of compositions on the inner peripheral surface of the base tube. Method of forming a fuel cell material, characterized by the deposition of the graded material film compositions ranging from the body electrolyte composition to the fuel electrode composition.