JPH05299104A - Manufacture of thin film for solid electrolyte fuel battery - Google Patents

Abstract

PURPOSE:To facilitate the manufacture of a thin film for a solid electrolyte fuel battery by using a CVD method and an EVD method capable of realizing the masking adhered closely to a substrate and facilitating the process of masking and demasking. CONSTITUTION:When a thin film for a solid electrolyte fuel battery, such as an interconnector thin film 12, an electrolyte thin film 14 and the like is manufactured by using a CVD method and an EVD method, a lanthanum maganate powder slurry is coated in advance on a substrate (For example, base tube 10 or interconnector thin film 12) and sintered at the temperature of 900 to 1050 deg.C to form a masking film 16 and then to made a thin films with the EVD method and the like. Thereby, since the masking material is chemically stable, the masking material does not react to a substrate, any adverse effect is not given to the substrate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a thin film for a solid oxide fuel cell.

[0002]

2. Description of the Related Art Conventionally, an electrolyte thin film or interconnector thin film for a solid electrolyte fuel cell has been prepared by using a CVD method (chemical vapor deposition method) or an EVD method (electrochemical vapor deposition method). It is known how to make such. Especially, much research has been conducted on the EVD method,
In the production of solid oxide fuel cells, which is said to be the most advanced at present, EV is the main production method for thin films.
D method is adopted.

By the way, when a thin film is formed by such a method, it is necessary to carry out masking in order to prevent the film from being formed on an unnecessary portion on the substrate. However, at a film forming temperature of about 1,000 ° C., it is not easy to carry out masking so that the film is in close contact with the substrate, is stable, and does not adversely affect the substrate. Heretofore, there has been no prior art disclosed as an excellent masking method.

An object of the present invention is to provide a method for producing a thin film capable of performing masking having the following characteristics at a film forming temperature near 1,000 ° C. 1. Masking that adheres to the substrate is possible. 2. Masking and demasking can be done easily. 3. The masking material itself is chemically stable under the film forming conditions. 4. Under the film forming conditions, the masking material does not react with the substrate and does not adversely affect the substrate.

[0005]

The method of the present invention is a CVD method.
The method is characterized in that the lanthanum manganate powder slurry is used as a masking material when a thin film for a solid oxide fuel cell is manufactured by using the PVD method or the EVD method.

That is, when a thin film for a solid electrolyte fuel cell such as an interconnector thin film and an electrolyte thin film is manufactured by using the CVD method or the EVD method, a substrate [for example, lanthanum manganate as a cathode (LaMn) is prepared in advance.
Lanthanum manganate powder slurry was applied on a lanthanum chromium oxide (LaCrO _x ) thin film which is an O _x ) substrate tube or an interconnector, and 900 to 1.0
After sintering at 50 ° C. and masking, a thin film is formed by the EVD method or the like.

The lanthanum manganate powder slurry used here is obtained by suspending the lanthanum manganate powder in water, which is a solvent containing polyvinyl alcohol as a binder and a surfactant. However, the binder and the solvent are not limited to polyvinyl alcohol and water.

[0008]

[Operation] After applying the lanthanum manganate powder slurry on the substrate, the temperature is raised to 900 to 1,050 ° C.
Extremely weak sintering occurs between the powder particles, and a lanthanum manganate porous film is formed on the substrate to complete masking. Since this film is weakly sintered and weakly sintered with the substrate,
After the film formation by the CVD method or the EVD method is completed, it is easy to remove (demasking) from the substrate.

The material of the substrate is usually a lanthanum manganate sintered body, lanthanum chromium oxide, yttria-stabilized zirconia or the like. It is used as a cathode material of (1), does not react with the substrate under the conditions of thin film production and does not adversely affect the surface of the substrate, and has sufficient heat resistance.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.

Example 1 On a cylindrical substrate tube 10 formed by sintering lanthanum manganate, La _{0. An} interconnector thin film 12 made of ₉₆ Sr _0.03 CrO _{3 ± δ} thin film is formed in a vertical stripe pattern (a), and this is used as a substrate by the EVD method.
Yttria-stabilized zirconia (YS
Z) An electrolyte thin film 14 composed of a thin film was formed (c). Before this film formation, La _0.81 Sr _0.09 MnO
_Since an aqueous slurry consisting of 100 parts by weight of _{3 ± δ} powder, 1 part by weight of polyvinyl alcohol and 70 parts by weight of water was previously applied on the interconnector thin film 12, E
The slurry is dried by the temperature rise during film formation by the VD method.
The porous masking film 16 was formed by sintering (b).

After the electrolyte thin film 14 was formed by the EVD method, the masking film 16 could be easily peeled off together with the electrolyte thin film 14 formed thereon (d). That is, the electrolyte thin film 14 formed on the portion to which the slurry had been applied could be easily peeled off, and the purpose of masking could be fulfilled.

After the masking film 16 was peeled off, the surface of the interconnector thin film 12 was analyzed by an X-ray microanalyzer, and the masking material remained that could impair the function of the interconnector and the reaction between the masking material and the interconnector. No peeling of the interconnector was found.

In this embodiment, the lanthanum manganate powder slurry was used for masking when forming the electrolyte thin film, but this can be applied when forming the interconnector thin film. is there. In that case, after forming a masking film on the substrate tube 10, an interconnector thin film may be formed.

Further, as a film forming method, a CVD method can also be carried out.

[0016]

According to the manufacturing method of the present invention, not only the masking which is in close contact with the substrate but also the masking and the demasking can be easily carried out. Therefore, the thin film for a solid electrolyte fuel cell using the CVD method or the EVD method. Makes it easier to manufacture. Further, since the masking material itself used in the present invention is chemically stable under the film forming conditions, the masking material does not react with the substrate and does not adversely affect the substrate.

[Brief description of drawings]

FIG. 1 is a process diagram schematically showing an embodiment of the present invention.

[Explanation of symbols]

 10 Base tube 12 Interconnector thin film 14 Electrolyte thin film 16 Masking film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masamichi Ichimatsu Matsumoto, 4-1-2, Hirano-cho, Chuo-ku, Osaka City, Osaka Gas Co., Ltd. (72) Inventor, Atsuko Kajimura 22-10-202, Kotsuen

Claims (2)

[Claims] 1. A method for producing a thin film for a solid electrolyte fuel cell by using a CVD method or an EVD method, wherein a lanthanum manganate powder slurry is used as a masking material. 2. A method for producing a thin film for a solid oxide fuel cell using a CVD method or an EVD method, which comprises coating a lanthanum manganate powder slurry on a substrate in advance at 900 to 1,050 ° C. A method of forming the thin film after sintering and masking.