JP2002141108A - Manufacturing method of cathode container for sodium- sulfur battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a cathode container for a sodium-sulfur battery having high reliability and high safety as the cathode container for the sodium-sulfur battery, capable of shortening and simplifying a manufacturing process, and reducing a manufacturing cost. SOLUTION: This manufacturing method of the cathode container for the sodium-sulfur battery has a first process for forming a corrosion resistant film 23 by flame spraying on the inner surface of a cylindrical metal container 30 with bottom, a second process for inserting a cylindrical mold 26 impregnated with sulfur into the cylindrical metal container 30 with bottom, and a third process for forming a constricted part 21 in the vicinity of an opening end of the cylindrical metal container 30 with bottom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a sodium-sulfur battery anode container used for storing sulfur in a sodium-sulfur battery.

[0002]

2. Description of the Related Art A sodium-sulfur battery has molten metal sodium as a cathode active material on one side and molten sulfur as an anode active material on the other side, and both have selective permeability to sodium ions. This is a high-temperature secondary battery operated at 300 to 350 ° C. isolated by a β-alumina solid electrolyte.

[0003] The structure of such a sodium-sulfur battery is, for example, as shown in FIG. 3, a bottomed cylindrical anode container 1 containing molten sulfur S impregnated in carbon felt or the like.
And a cartridge (sodium protective tube) 6 for storing molten metal sodium Na, a cylindrical solid electrolyte tube 5 having a bottom and having a function of storing the cartridge 6 therein and selectively transmitting sodium ions Na ^+. And a bottomed cylindrical partition tube 11 disposed at a predetermined distance from the cartridge 6 and the solid electrolyte tube 5 in a gap between the cartridge 6 and the solid electrolyte tube 5.

The solid electrolyte tube 5 is connected to the anode container 1 via an α-alumina insulating ring 4 and an anode cylindrical metal fitting 3 which are glass-joined to the open end thereof. A cathode fitting 8 is joined to the upper end surface of the insulating ring 4 by heat and pressure, and a cathode lid 9 is fixed to the cathode fitting 8 by welding. An anode terminal 2 and a cathode terminal 10 are provided on the outer peripheral upper portion of the anode container 1 and the upper surface of the cathode lid 9, respectively. An inert gas G such as nitrogen gas or argon gas is sealed at a predetermined pressure in the upper space of the cartridge 6, and sodium Na in the cartridge 6 is removed by the inert gas G.
It is pressurized in the direction flowing out of the small holes 7 provided at the bottom.

In the sodium-sulfur battery having such a structure, the sodium Na supplied from the small hole 7 of the cartridge 6 at the time of discharging moves upward in the gap between the partition tube 11 and the cartridge 6, 11, moves downward in the gap between the partition tube 11 and the solid electrolyte tube 5, and further passes through the solid electrolyte tube 5 as sodium ions Na ^+, and the sulfur S in the anode container 1 is removed.
And reacts with electrons that have passed through the external circuit to produce sodium polysulfide. During charging, contrary to discharging, sodium Na
And the reaction of producing sulfur S occurs.

Here, a conventional anode container for a sodium-sulfur battery is manufactured by a process shown in FIG. That is, a constriction 2 is formed at one end of a metal pipe 20 (a) made of aluminum or an aluminum alloy or the like.
1 (b), and a corrosion-resistant coating 23 is formed on the inner surface 22 of the metal pipe.
(C), the other end of the metal pipe 20 is cut to provide a fitting portion 25 for fitting to the bottom cover 24 (d), and a cylindrical mold made of graphite or carbon felt impregnated with sulfur S is formed. 26 is inserted (e), the fitting portion 25 of the metal pipe 20 is fitted to the bottom cover 24, and then welded (f) to manufacture. The bottom cover 24 is made of a metal pipe 2.
As in the case of No. 0, it is made of aluminum or an aluminum alloy (g), and a corrosion resistant film 23 is formed on the bottom inner surface (R surface) 27 by thermal spraying (h).

[0007]

SUMMARY OF THE INVENTION In the conventional method for manufacturing an anode container for a sodium-sulfur battery as described above, the number of manufacturing steps is large, the manufacturing cost is high, and it is important to reduce the number of manufacturing steps. It is an issue.
In addition, a large number of manufacturing steps means that a series of inspection steps such as a quality inspection performed simultaneously for each step are also included in a large number. Therefore, it takes time and effort for that, and reduction of the number of steps is desired. I was

Further, since the anode container is composed of two types of members, a metal pipe and a bottom lid, it requires a separate step of forming a corrosion-resistant coating by thermal spraying, which takes time and labor, and reduces the time and effort. Was desired. Further, after forming a corrosion-resistant film on the inner surface of the metal pipe, a cutting process is required to provide a fitting portion with the bottom lid, which increases the number of processes and increases the corrosion resistance in the processed portion as shown in FIG. Problems such as peeling of the film 23 may occur. Therefore, during long-term use, internal corrosion or the like may progress in the fitting portion 25 (near the joining portion),
Avoiding this is also one of the important technical issues. Further, when the mold is inserted into the metal pipe 20 after the cutting process, there is a possibility that sulfur or the like adheres to the vicinity of the fitting portion 25 of the metal pipe 20. It can also cause defects. That is, since there is a possibility that a problem such as leakage may occur very rarely at the welded portion, reliability is impaired even in securing stable quality and safety as an anode container for a sodium-sulfur battery particularly used under high temperature conditions. May be lost.

The present invention has been made in view of the above-mentioned problems of the related art, and has as its object to have reliability and safety as an anode container for a sodium-sulfur battery, An object of the present invention is to provide a method for manufacturing an anode container for a sodium-sulfur battery in which the steps are shortened and simplified, and the manufacturing cost is reduced.

[0010]

That is, according to the present invention, there is provided a first step of spray-forming an anticorrosion film on the inner surface of a bottomed cylindrical metal container, and sulfur is impregnated in the bottomed cylindrical metal container. An anode container for a sodium-sulfur battery, comprising: a second step of inserting the formed cylindrical mold; and a third step of forming a constricted portion near an opening end of the bottomed cylindrical metal container. Is provided.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and is within the scope of the present invention. It should be understood that design changes, improvements, etc. may be made as appropriate based on the knowledge of

The method for producing an anode container for a sodium-sulfur battery of the present invention includes a first step of spray-forming an anticorrosion film on the inner surface of a bottomed cylindrical metal container, and sulfur is contained in the bottomed cylindrical metal container. The method includes a second step of inserting the impregnated cylindrical mold, and a third step of forming a constricted portion near the open end of the bottomed cylindrical metal container. Hereinafter, the details will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing one embodiment of the present invention. In the first step of the method for manufacturing an anode container for a sodium-sulfur battery according to the present invention, a bottom inner surface (R surface) 27 and a body portion of a bottomed cylindrical metal container 30 made of a nonferrous metal material such as aluminum or an aluminum alloy. Inner surface 30
Next, a powder material made of a chromium-iron alloy or the like is plasma-sprayed in the air to form a corrosion-resistant film 23. According to the conventional manufacturing method (FIG. 2), a corrosion-resistant coating 23 is formed by spraying on the inner surface 22 of the metal pipe provided with the constricted portion 21 and the inner surface (R surface) 27 of the bottom of the bottom lid 24 forming the anode container is formed. Also, it is necessary to form the corrosion-resistant coating 23 by thermal spraying. Therefore, according to the method of the present invention, the thermal spray formation of the corrosion resistant film may be performed only once for one member, and the number of steps is reduced as compared with the conventional method.

The method of spraying the inner surface of the bottomed cylindrical metal container and the conditions thereof may be in accordance with the description in the specification of Japanese Patent Application No. 2000-336438 filed on the same day by the present applicant. . That is, it is possible to preferably employ a method in which the bottom of the cylindrical metal container having a bottom is set up on the upper side, and the thermal spraying is performed using the air ejection / suction nozzle.

Further, the bottomed cylindrical metal container 30 used in the present invention has an advantage that the number of parts is reduced since it has a structure in which the conventional metal pipe and the bottom lid are integrated. Besides, there is an advantage that a cutting process for providing the fitting portion is not required. others,
Since the bottomed cylindrical metal container used in the present invention does not have a fitting portion, problems such as peeling of the corrosion resistant film 23 as shown in FIG. 4 can be solved.

In the second step of the method for manufacturing an anode container for a sodium-sulfur battery according to the present invention, sulfur is impregnated in a bottomed cylindrical metal container in which a corrosion-resistant coating 23 is spray-formed on the inner surface in the first step. A cylindrical mold 26 made of graphite or carbon felt is inserted. Therefore, since the conventional problem that sulfur adheres to the fitting portion 25 shown in FIG. 4 can be solved, a problem such as leakage of contents at the bottom of the anode container is extremely unlikely to occur. It is also possible to manufacture a positively charged anode container.

Further, in the third step of the method for manufacturing the anode container for a sodium-sulfur battery according to the present invention, the vicinity of the open end of the bottomed cylindrical metal container 30 after the mold 26 manufactured in the second step is inserted. A constriction 21 is formed. Therefore, the number of steps, the number of parts, the inspection after each step, and the like are greatly reduced as compared with the conventional manufacturing steps shown in FIG. 2, so that it is easy to automate the manufacturing steps. That is, the number of personnel involved in the production can be reduced, and the production cost of the anode container can be significantly reduced in terms of labor costs.

[0018]

As described above, according to the method for manufacturing an anode container for a sodium-sulfur battery of the present invention, a bottomed cylindrical metal container is used as a material, and after forming a corrosion-resistant coating on its inner surface by thermal spraying, Next, a cylindrical mold impregnated with sulfur was inserted, and a constriction was formed at the end, so that the number of steps, the number of parts, and the number of parts after each step were smaller than those of a conventional sodium-sulfur battery anode container manufacturing process. Inspections have been greatly reduced. Therefore, a significant reduction in manufacturing cost has been achieved, and it is possible to manufacture an anode container having long-term reliability as a member for a sodium-sulfur battery.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of the present invention.

FIG. 2 is a schematic view showing a manufacturing process of a conventional anode container.

FIG. 3 is a sectional view showing a structure of a sodium-sulfur battery.

FIG. 4 is a schematic view showing a peeled state of a corrosion-resistant film at a fitting portion of a metal pipe.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Anode container, 2 ... Anode side terminal, 3 ... Anode cylindrical fitting, 4
... insulating ring, 5 ... solid electrolyte tube, 6 ... cartridge,
7 ... Small hole, 8 ... Cathode fitting, 9 ... Cathode lid, 10 ... Cathode side terminal, 11 ... Partition tube, 20 ... Metal pipe, 21 ... Constriction part, 22 ... Metal pipe inner surface, 23 ... Corrosion resistant coating, 24 …
Bottom cover, 25: fitting part, 26: mold, 27: bottom inner surface (R surface), 30: bottomed cylindrical metal container, 31: trunk inner surface, 32: bottom.

Claims (1)

[Claims] 1. A first step of spray-forming a corrosion-resistant coating on an inner surface of a bottomed cylindrical metal container, and a second step of inserting a sulfur-impregnated cylindrical mold into the bottomed cylindrical metal container. A method for producing an anode container for a sodium-sulfur battery, comprising a third step of forming a constricted portion near an open end of the bottomed cylindrical metal container.