JPH07142072A - Formation of electrolyte film - Google Patents

Abstract

PURPOSE:To make an electrolyte film highly dense, and reduce a process by baking the electrolyte film regularly after the process that an electrode support pipe is soaked in slurry of particles larger than the pare diameter and is pulled up and is baked temporarily is repeated several times. CONSTITUTION:After masking 12 is applied to a film formation unnecessary part of an electrode support pipe (fuel electrode pipe) 11, a plug 13 is put in an opening part on one end side of the pipe 11, and a suction pump 15 is installed in an opening part on the opposite side through a suction pipe 14, and the whole is installed on a vertically moving device 16. A vessel 18 housing slurry like electrolyte slurry 17 is arranged under the pipe 11, and the particle diameter of the electrolyte is larger than the pore diameter of the pipe 11. The suction pump 15 is actuated, and the pipe 11 is soaked in the slurry 17, and after an electrolyte film 19 is formed by sucking near electrolyte particles, the pipe 11 is pulled up, and is dried. After this is repeated ten times, it is baked temporarily. After the process is repeated, it is baked regularly, and the electrolyte film 19 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an electrolyte membrane.

[0002]

2. Description of the Related Art Conventionally, a method for forming an electrolyte in a cylindrical sintered solid oxide fuel cell has been carried out as shown in FIGS. First, masking 2 is applied to a portion of the electrode support tube (fuel electrode tube) 1 where the electrolyte membrane is unnecessary,
Prepare an electrolyte slurry (slurry) 3 (Fig. 6)
(See (A)). In FIG. 6 (A), reference numeral 4 indicates a vertical movement device for moving the electrode support tube 1 up and down. next,
After immersing the electrode support tube 1 in the electrolyte slurry 3 as shown in FIG. 6 (B), the electrode support tube 1 is taken out of the electrolyte slurry 3 as shown in FIG. 6 (C) and dried at about 90 ° C. in this state. Let Here, the dipping process and the drying process are called dipping. Continue to dip 9 times (total 10
Times), and finally firing is performed to obtain a dense electrolyte membrane 5.

[0003]

By the way, as the properties required for the electrolyte of the solid oxide fuel cell, there are thinning and densification. Here, in the conventional electrolyte film forming method (the order of steps is shown in (1) to (5) below), a relatively dense and thin film is obtained, but the obtained film has variations. Therefore, there are variations in the performance of the solid oxide fuel cell, which in turn results in a decrease in performance. Further, in the conventional electrolyte film-forming method, dipping and calcination are performed 5 times, which is rate-limiting in terms of process.

(1) Mask the electrode support tube. (2) Immerse the electrode support tube in the electrolyte slurry. (3) The electrolyte particles attached to the electrode support tube are dried.

(4) After 10 times of dipping, calcination is performed. (5) When the process of one calcination is completed 5 times for every 10 dippings, the electrolyte membrane is finally calcined to obtain a membrane. The steps (2) to (3) above are collectively called dipping.

The present invention has been made in view of these circumstances, and it is an object of the present invention to provide a method of forming an electrolyte membrane which is dense and has little variation and which improves the performance of a solid electrolyte fuel cell and can reduce the number of steps. To aim.

[0007]

According to the present invention, the inside of a cylindrical electrode support tube is hermetically sealed, and air inside the electrode support tube can be sucked from one end side of the electrode support tube. The electrolyte is calcinated by immersing it in an electrolyte slurry of particles having a pore size larger than that of the electrode support tube, then pulling up the electrode support tube and repeating drying several times to calcine the electrolyte, and further repeating the dipping step and calcination step several times. The present invention relates to a method for forming an electrolyte membrane, which is characterized by performing firing after firing.

[0008]

FIG. 2 is an explanatory view showing an essential part of the method of the present invention.
FIG. 3 is an enlarged view of the main part of FIG. In the figure, reference numeral 21 in the figure is an electrolyte particle, reference numeral 22 is an electrode support tube, reference numeral 2
Reference numeral 3 represents a suction pump. When the electrolyte membrane is formed by the method of the present invention, as shown in FIGS. 2 and 3, the slurry-like electrolyte slurry of the suction pump 23 has the electrolyte particles favorably attached to the electrode support tube. After that, if calcination is performed and the same steps are repeated, even if the electrolyte is not dense in the previous calcination, it is possible to close the non-dense portion by the suction force, and a dense electrolyte membrane can be obtained. Further, it is considered that the film thickness can be adjusted if the suction force can be operated by a suction pump. On the other hand, according to the conventional method, as shown in FIG. 6, a certain amount of the electrolyte particles 21 are attached to the surface of the electrode support tube 22, but since the effect of the suction pump as in the method of the present invention is not exerted, sufficient electrolyte particles 21 are not formed. There is no sticking.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
This will be described with reference to (C). (1) First, after masking 12 on the cylindrical electrode support tube (fuel electrode tube) 11 where film formation is not required, plug 13 on the open end of the electrode support tube 11 on the opposite side. Suction tube at the open part of
The suction pump 15 is attached via 14 and the whole is attached to the vertical movement device 16. At this time, by preparing a plurality of electrode support tubes 11 at the same time and attaching them to the vertical movement device 16, productivity can be improved. Separately from this, an electrode support tube
A container 18 containing a slurry-like electrolyte slurry 17 is arranged below 11 (see FIG. 1A). Here, the particle size of the electrolyte in the electrolyte slurry 17 is larger than the pore size of the electrode support tube 11.

(2) Next, the suction pump 15 is operated,
While sucking air in the electrode tube support tube 11, the electrode support tube
11 is dipped in the electrolyte slurry 17 (see FIG. 1B), and when the electrolyte particles are absorbed on the surface and the electrolyte membrane 19 is formed, the electrode support tube 11 is pulled out from the electrolyte slurry 17.

(3) Subsequently, in this state, the electrode support tube 11 is dried at about 90 ° C. (4) Next, the steps (2) and (3) above (dipping; Dip
(Ping) is repeated 10 times, and then calcination is performed.

(5) Next, the above steps (2), (3) and (4) are repeated several times to make the electrolyte membrane 19 have a required thickness. (6) Finally, the entire electrode support tube 11 is fired to form the electrolyte membrane 19
Film formation is completed, and a solid oxide fuel cell is manufactured (Fig. 1
(See (C)).

As described above, according to the above embodiment, as shown in FIG.
As shown in FIG. 3, the slurry-like electrolyte slurry 17 of the suction pump 23 has the electrolyte particles favorably attached to the electrode support tube 11. Then, by calcination and repeating the same steps, even if the electrolyte is not dense in the previous calcination, it is possible to close the non-dense portion by the suction force, and the dense electrolyte membrane 19 can be obtained. Further, if this suction force can be operated by the suction pump 23, the film thickness can be adjusted.

FIG. 4 shows the gas permeation coefficients of the electrolyte membranes obtained by the method according to the above-described embodiment and the conventional method, by the number of times of calcination after dipping. In FIG. 4, curve (a) shows the method of the present invention, and curve (b) shows the conventional method. It can be seen from FIG. 4 that the method of the present invention has a smaller gas permeation coefficient than the conventional method and is considerably dense. In addition, the number of times of calcination after dipping was smaller than that of the conventional method, and a dense film was obtained. It was suggested that the suction force adopted this time is quite effective for increasing the density of the electrolyte and reducing the number of steps. Therefore, by forming the film of the electrolyte of the cylindrical sintered electrolyte fuel cell by the method of the present invention, it can be expected that it often exhibits higher performance (high open circuit voltage etc.) than the conventional cell.

[0015]

As described above in detail, according to the present invention,
It is possible to provide a method for forming an electrolyte membrane that is dense and has little variation and that can improve the performance of the solid electrolyte fuel cell and reduce the number of steps.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method of forming a solid electrolyte membrane of a solid electrolyte fuel cell according to an embodiment of the present invention in the order of steps.

FIG. 2 is a conceptual diagram of attachment of an electrolyte according to the method for forming an electrolyte membrane according to the present invention.

FIG. 3 is a characteristic diagram showing the relationship between the gas permeation coefficient and the number of times of calcination of the electrolyte membrane according to the present invention method and the conventional method.

FIG. 4 is a circuit configuration diagram showing details of a main part of FIG.

FIG. 5 is an explanatory view showing a method of forming a solid electrolyte membrane of a conventional solid electrolyte fuel cell in the order of steps.

FIG. 6 is a conceptual diagram of attachment of an electrolyte by a conventional method of forming an electrolyte membrane.

[Explanation of symbols]

11 ... Electrode support tube (fuel electrode tube), 12 ... Masking,
13 ... Plug, 14 ... Suction tube, 15 ... Suction pump, 16 ... Vertical movement device, 17 ... Electrolyte slurry,
18 ... Container, 19 ... Electrolyte membrane, 21 ... Electrolyte particles.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Ikeda 1-1 1-1 Atsunoura-machi, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries Ltd. Nagasaki Shipyard

Claims (1)

[Claims] 1. A cylindrical electrode support tube is hermetically sealed, and air in the electrode support tube can be sucked from one end side of the electrode support tube, and then the electrode support tube is made smaller than the pore diameter of the electrode support tube. Characterized by immersing in an electrolyte slurry of large particles, then raising the electrode support tube and repeating drying several times to calcine the electrolyte, and further repeating the dipping step and calcining step several times and then performing main firing And a method for forming an electrolyte membrane.