JP2957822B2 - Method for producing anode container in sodium-sulfur battery - Google Patents

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 an anode container in a sodium-sulfur battery.

[0002]

2. Description of the Related Art In general, in a sodium-sulfur battery, an anode container is formed of a metal material such as aluminum or an aluminum alloy, and a solid electrolyte tube made of ceramic such as beta alumina is suspended in the anode container. Is being worn. Then, sodium is contained in the cathode chamber inside the solid electrolyte tube, and sulfur is contained in the outside anode chamber.

In this type of sodium-sulfur battery, it is heated to 300 to 350 ° C. during operation, and
When stopped, heat is dissipated and cooled. At this time, since the metal anode container has a larger coefficient of thermal expansion than the ceramic solid electrolyte tube, the gap between the anode container and the lower end portion of the solid electrolyte tube increases during operation, and this gap decreases when stopped. Become.

However, when the sodium polysulfide in the molten state during operation is cooled to around 240 ° C., it solidifies and forms a solid phase in the gap between the anode container and the lower end of the solid electrolyte tube. Cannot be shrunk to the original size when cooled. For this reason, when the operation-stop of the battery is repeatedly performed, the anode container may gradually elongate in the axial direction and damage the solid electrolyte tube.

In order to solve such a problem, a sodium-sulfur battery has been proposed in which a constricted portion is provided in the vicinity of the upper end of the outer periphery of the anode container so that expansion and contraction caused by heat change of the anode container can be absorbed and reduced. Has been proposed.

Further, in order to prevent the anode container from being corroded by contact with sodium or sulfur, a sodium-sulfur battery formed by spraying a corrosion-resistant coating on the inner peripheral surface of the anode container has been proposed.

[0007]

However, in a conventional sodium-sulfur battery, when an anode container is manufactured, a corrosion-resistant film is spray-formed on the inner surface of a straight tubular metal pipe, and then the metal pipe is formed by bead processing or the like. A constriction was formed on the outer periphery. Therefore, when a corrosion-resistant film is formed by thermal spraying on the inner surface of a straight tubular metal pipe, the metal pipe expands and contracts in the longitudinal direction due to the spraying heat, and peeling and cracks are formed in the corrosion-resistant film near both ends of the metal pipe. There was a problem that it easily occurred.

Further, since the constricted portion is processed after the formation of the corrosion-resistant film, an impact or the like is applied to the corrosion-resistant film at the time of processing the constricted portion, so that the corrosion-resistant film near the constricted portion is liable to peel or crack. Was.

The present invention has been made in view of the problems existing in such prior art, and has as its object to have a constricted portion on the outer periphery and a corrosion-resistant coating on the inner surface. An object of the present invention is to provide a method for manufacturing an anode container in a sodium-sulfur battery, which can easily manufacture an anode container without causing peeling or cracking of a corrosion-resistant film.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, a solid electrolyte tube is attached in a suspended state in a metal anode container, and the solid electrolyte tube is attached. While containing sodium in the cathode chamber inside the
In a method for manufacturing an anode container in a sodium-sulfur battery in which sulfur is stored in an outer anode chamber, a constriction is formed on the outer periphery of a straight tubular metal pipe, and then a corrosion-resistant coating is spray-formed on the inner surface of the metal pipe. When paired with the neck
It is characterized in that thermal spraying is performed so that the corresponding portion is the last .

[0011]

[0012]

According to the method for manufacturing an anode container in a sodium-sulfur battery according to the first aspect, after forming a constricted portion on the outer periphery of a straight tubular metal pipe, a corrosion-resistant coating is formed on the inner surface of the metal pipe by thermal spraying. Even if the metal pipe expands and contracts in the longitudinal direction due to thermal spraying during the thermal spraying of the corrosion resistant film, the expansion and contraction of the metal pipe is absorbed and reduced in the constricted portion.
Therefore, at the time of thermal spray formation of the corrosion resistant film, it is possible to prevent the corrosion resistant film from being peeled or cracked in the vicinity of the opening at both ends of the metal pipe.

Further, since the constricted portion is processed before the thermal spraying of the corrosion resistant film, no impact or the like is applied to the corrosion resistant film when the constricted portion is processed. Therefore, at the time of processing the constricted portion, it is also possible to prevent the corrosion-resistant coating near the constricted portion from being peeled or cracked.

Furthermore, when the spraying form a corrosion resistant coating on the inner surface of the metallic pipe, for spraying as portions corresponding to the constricted portion is the last, the spraying of the flat portion occupying most of the inner surface of the metal pipe Until the end, the expansion and contraction of the metal pipe due to the thermal spraying heat can be absorbed and reduced in the constricted portion where the corrosion resistant film is not formed. Therefore, at the time of thermal spray formation of the corrosion resistant film, the possibility of peeling or cracking of the corrosion resistant film can be more effectively prevented.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. First, the configuration of the sodium-sulfur battery will be described. As shown in FIG. 2, the anode container 1 is formed in a cylindrical shape from a metal material such as aluminum or an aluminum alloy, and a bottom plate 2 is fitted and fixed to the lower end opening. Have been. The constricted portion 3 is formed on the outer periphery of the anode container 1 at a predetermined interval in the longitudinal direction, and the constricted portion 3 absorbs and reduces expansion and contraction of the anode container 1 due to a thermal change. The corrosion-resistant coating 4 is formed by thermal spraying on the inner peripheral surface of the anode container 1, and the corrosion-resistant coating 4 prevents corrosion of the anode container 1.

The support fitting 5 is fitted and fixed to the upper end opening of the anode container 1, and an insulating ring 6 made of alpha alumina is fixedly joined to the upper surface thereof. A bottomed cylindrical solid electrolyte tube 7 made of a ceramic material such as beta-alumina is joined and fixed to the inner periphery of the lower end of the insulating ring 6 in a suspended state, and a cathode chamber R1 is defined inside the solid electrolyte tube 7. At the same time, an anode chamber R2 is defined on the outside.

The cartridge 8 is provided in the cathode chamber R1, and contains sodium Na as a cathode active material. The small hole 9 is provided at the bottom of the cartridge 8, and sodium Na in the cartridge 8 is supplied to the gap between the cartridge 8 and the solid electrolyte tube 7 through the small hole 9.

Inert gas G such as nitrogen gas or argon gas
Is sealed at a predetermined pressure in the upper space of the cartridge 8, and the inert gas G pressurizes sodium Na in the cartridge 8 in a direction of flowing out from the small holes 9.
The anode conductive material 10 such as a carbon mat is used for the anode chamber R.
The anode conductive material 10 is impregnated with sulfur S as an anode active material.

The cathode lid 11 is fixedly joined to the insulating ring 6 and has a central disk portion 12 and a cylindrical portion 13 provided on the outer periphery of the disk portion 12. The lower end of the cylindrical portion 13 of the cathode lid 11 is connected to the sodium Na supplied to the gap between the cartridge 8 and the solid electrolyte tube 7.
, And current collection on the cathode side is performed.

The bottomed cylindrical safety tube 14 is disposed in the gap between the cartridge 8 and the solid electrolyte tube 7 at predetermined intervals from the cartridge 8 and the solid electrolyte tube 7, respectively, and has corrosion resistance. It is formed from a metal material such as aluminum or stainless steel. The sodium N supplied from the small hole 9 of the cartridge 8 at the time of discharge
a is moved upward in the gap between the safety pipe 14 and the cartridge 8, and then moves over the upper end of the safety pipe 14 and downwards in the gap between the safety pipe 14 and the solid electrolyte pipe 7. Be moved. Further, sodium Na permeates the solid electrolyte tube 7 as sodium ions and moves to the anode chamber R2 side.

Next, a method of manufacturing the anode container 1 will be described. In this embodiment, as shown in FIG. 1, first, the outer periphery of a straight tubular metal pipe 15 made of a metal material such as aluminum or an aluminum alloy. Then, a constricted portion 3 is formed by beading or the like. Then, spray gun 1
By using 6 or the like, a corrosion-resistant metal material such as a stellite alloy is sprayed on the inner surface of the metal pipe 15 to form the corrosion-resistant coating 4 having a predetermined thickness. The thickness of the corrosion resistant film 4 is 50
It may be set arbitrarily in the range of ~ 300 μm,
It is desirable to set it to μm or less.

As described above, if the corrosion resistant film 4 is formed by thermal spraying after the formation of the constricted portion 3, even if the metal pipe 15 expands and contracts in the longitudinal direction due to the thermal spraying during the thermal spraying of the corrosion resistant film 4, the expansion and contraction of the metal pipe 15 does not occur. Is absorbed and relaxed in the constricted portion 3. Therefore, at the time of thermal spray formation of the corrosion resistant film 4, it is possible to prevent the possibility that the corrosion resistant film 4 is peeled or cracked in the vicinity of the opening at both ends of the metal pipe 15.

According to this manufacturing method, the constricted portion 3
Is performed before the thermal spraying of the corrosion-resistant coating 4 is performed, so that no impact or the like is applied to the corrosion-resistant coating 4 when the constricted portion 3 is processed. Therefore, at the time of processing the constricted portion 3, it is possible to prevent the possibility that the corrosion-resistant coating 4 near the constricted portion 3 is peeled or cracked.

Further, in the above-described method for manufacturing the anode container 1, when the corrosion-resistant coating 4 is formed by thermal spraying on the inner surface of the metal pipe 15, the flat portion 15a on the inner surface of the metal pipe 15 is formed.
Spraying is started from the portion 15b corresponding to the constricted portion 3
It is preferable to perform the thermal spraying operation so that the thermal spraying is last.

In this manner, the expansion and contraction of the metal pipe 15 by the thermal spraying heat is performed in the constricted portion 3 where the corrosion-resistant coating 4 is not formed until the spraying of the flat portion 15a occupying most of the inner surface of the metal pipe 15 is completed. Can be absorbed and alleviated. Therefore, at the time of thermal spray formation of the corrosion resistant film 4, the possibility that the corrosion resistant film 4 is peeled or cracked can be more effectively prevented.

By the way, the outer diameter is 60 mm and the length is 360
mm, a metal pipe 15 having a thickness of 2.2 mm,
When the corrosion-resistant film 4 is formed in the range of 00 μm,
The case where the constriction 3 of 7 mm is formed in advance and the case where the constriction 3
When the defect inspection of the corrosion-resistant coating 4 was performed by X-ray observation with and without the case where was formed in advance, the results shown in Table 1 were obtained.

[0027]

[Table 1]

(However, ○: no defect, Δ: crack generation, ×: peeling and crack generation) As is apparent from the inspection results, when the corrosion-resistant coating 4 was formed by thermal spraying without forming the constricted portion 3. Only when the coating thickness was 50 μm, no peeling or cracking occurred, but when the corrosion resistant coating 4 was formed by thermal spraying after forming the constricted portion 3, the coating thickness was 50 to 250 μm in a wide range. No peeling or cracking was observed.

The present invention is not limited to the configuration of the above-described embodiment. For example, as shown in FIG. 3, the present invention is applied to a method of manufacturing an anode container 1 having a pair of constrictions 3 above and below the outer periphery. For example, the depth of the concave portion of the constricted portion 3 may be increased to such an extent that a defect does not occur due to bead processing, and may be arbitrarily changed and embodied without departing from the spirit of the present invention.

[0030]

Since the present invention is constructed as described above, peeling and cracking occur in the corrosion-resistant coating when manufacturing an anode container having a constriction on the outer periphery and a corrosion-resistant coating on the inner surface. This has an excellent effect that the fear can be effectively prevented .

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a method for manufacturing an anode container in a sodium-sulfur battery embodying the present invention.

FIG. 2 is a longitudinal sectional view of the sodium-sulfur battery showing a state where the anode container is assembled.

FIG. 3 is a cross-sectional view showing another embodiment of the anode container.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Anode container, 3 ... Constriction part, 4 ... Corrosion-resistant coating, 7 ... Solid electrolyte tube, 15 ... Metal pipe, R1 ... Cathode compartment, R2 ... Anode compartment, Na ... Sodium, S ... Sulfur.

Claims (1)

(57) [Claims] A solid electrolyte tube is suspended in a metal anode container, and sodium is accommodated in a cathode chamber inside the solid electrolyte tube, and sulfur is accommodated in an outer anode chamber. Volume in sodium-sulfur battery
In the manufacturing method of the vessel, forming a constricted portion on the outer periphery of a straight tubular metal pipe, and then, when spraying a corrosion-resistant coating on the inner surface of the metal pipe ,
Sodium portions corresponding to the constricted portion and wherein the this <br/> for spraying so that the end - producing how the anode container in sulfur battery.