JPH05266918A - Connecting structure between insulating ring and cylindrical fitting in sodium-sulfur battery - Google Patents

Abstract

PURPOSE:To provide a connection structure between an insulating ring and a cylindrical fitting in a sodium-sulfur battery, in which the life of an active material against corrosion can be exetnded, and in which a negative electrode cylindrical fitting and a positive electrode cylindrical fitting can be press- connected simultaneously to the insulating ring by increasing the connection area between the insulating ring and the cylindrical fitting without increasing the diameter of the insulating ring. CONSTITUTION:An insulating ring 4 is connected to the opening end of a solid electrolyte tube 5. A cylindrical fitting 8 having a cylindrical part 8a and a flange part 8b is thermally press-connected to the end surface of the insulating ring 4. A connection surface 12 extending in the direction crossing a surface in parallel to the radial direction perpendicular to the axis of a battery, is provided between the end surface of the insulating ring 4 and the flange part 8b of the cylindrical fitting 8. A connection surface 17 for connecting the insulating ring 4 and a positive electrode cylindrical fitting 3 together is provided. The connection surfaces 12, 17 can thus be press-connected simultaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure between an insulating ring and a tubular metal fitting in a sodium-sulfur battery.

[0002]

2. Description of the Related Art In a conventional sodium-sulfur battery, as shown in FIG. 6, an insulating ring made of α-alumina is provided at the open end of a solid electrolyte tube 21 for partitioning the inside of the battery into an anode chamber and a cathode chamber. 22 is joined and its insulating ring 22
A cathode tubular metal member 23 having a cylindrical portion 23a and a flange portion 23b is thermocompression bonded to the upper end surface of the. Then, the cathode lid is welded and fixed to the cylindrical portion 23a of the cathode tubular metal piece 23.

Further, the flange portion 25b of the anode tubular metal fitting 25 is thermocompression bonded to the lower end surface of the insulating ring 22.

[0004]

However, in this conventional structure, the flange portion 23b of the cathode tubular metal member 23 is formed to extend outward from the lower end edge of the cylindrical portion 23a at a right angle.
Since the flange portion 23b is joined to the upper end surface of the insulating ring 22 via the joint surface 24 that extends in the radial direction, the area of the joint surface 24 cannot be sufficiently secured and corrosion of the active material is prevented. There was a problem that the life was shortened.

In order to secure a large area for the joint surface 24, it is conceivable to make the insulating ring 22 large in diameter, but in the case of such a construction, a new problem arises that the entire battery becomes large. Has occurred.

Further, as shown in FIG. 7, the solid electrolyte tube 2
In order to increase the thickness of the end portion of No. 1 and to increase the strength at the open end portion of the solid electrolyte tube 21, a notch is provided in the lower end surface of the insulating ring 22, and the solid electrolyte tube 21 is joined to the insulating ring 22. In the case of the structure described above, the joint surface 26 between the flange portion 25b of the anode tubular fitting 25 and the insulating ring 22 becomes smaller, and the area of the joint surface 26 cannot be sufficiently secured, so that the life of the active material against corrosion is shortened. There was also the problem of shortening.

Furthermore, since the distance between the tip portion 25c of the flange portion 25b of the anode tubular metal fitting 25 and the solid electrolyte tube 21 is as far as possible from the point of electrical insulation, the joint surface 26 becomes smaller and smaller. There was also the problem of becoming. In addition, the cathode tubular metal fitting 23 and the anode tubular metal fitting 25
In the case of simultaneously thermocompressively bonding the insulating ring 22 to each other, the bonding surface 24 of the upper end surface and the bonding surface 26 of the lower end surface of the insulating ring 22 have different areas. Differently, since either one of the joint surfaces 24 and 26 does not have a predetermined pressing force, simultaneous pressurization cannot be performed.

The present invention has been made by paying attention to the problems existing in such a conventional technique, and its object is to make the end surface of the insulating ring without increasing the diameter of the insulating ring. It is possible to increase the area of the joint surface between the and the flange part of the tubular metal fitting, extend the service life of the active material against corrosion, and simultaneously install the cathode tubular metal fitting and the anode tubular metal fitting on the insulating ring. Sodium that can be pressure-bonded
It is to provide a joint structure between an insulating ring and a tubular metal fitting in a sulfur battery.

[0009]

In order to achieve the above object, according to the present invention, an insulating ring is joined to the open end of a solid electrolyte tube, and the end face of the insulating ring has a cylindrical portion and a flange portion. In a sodium-sulfur battery in which tubular metal fittings are bonded by heat and pressure, between the end surface of the insulating ring and the flange portion of the tubular metal fitting extends in a direction intersecting a plane parallel to a radial direction orthogonal to the axis of the battery. A joint surface is provided.

[0010]

According to the joint structure of the insulating ring and the tubular metal member in the sodium-sulfur battery configured as described above,
Between the end surface of the insulating ring and the flange of the tubular metal fitting, there is a joint surface extending in the direction intersecting the radial direction orthogonal to the axis of the battery. The surface area can be increased. Therefore,
The life of the active material against corrosion can be extended.

Further, when the cathode tubular metal member and the anode tubular metal member are simultaneously pressure-bonded to the insulating ring, the pressing force per unit area on both bonding surfaces can be made the same, so that the pressure bonding can be performed at the same time. In addition, since the joint surface can be arbitrarily selected, the degree of freedom in design is increased.

[0012]

An embodiment of a sodium-sulfur battery embodying the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, an anode container 1 is formed in a cylindrical shape with a bottom, and an anode-side terminal 2 is provided on the upper periphery of the anode container 1. Anode tubular metal fitting 3 made of aluminum, aluminum alloy, titanium or the like is welded and fixed to the inner periphery of the upper end of anode container 1 and has a cylindrical portion 3a and a flange portion 3b.

An insulating ring 4 made of α-alumina is thermocompression-bonded to the flange portion 3b of the anode tubular metal fitting 3, and a bottomed cylindrical solid electrolyte tube made of β-alumina or the like is provided on the lower inner peripheral surface thereof. 5 is bonded and fixed at the open end.
A cathode chamber R1 is defined inside the solid electrolyte tube 5, and an anode chamber R2 is defined outside.

The cartridge 6 is arranged in the cathode chamber R1, and the cartridge 6 contains sodium Na as a cathode active material. The small hole 7 is provided at the bottom of the cartridge 6, and the sodium Na in the cartridge 6 is supplied to the gap between the cartridge 6 and the solid electrolyte tube 5 through the small hole 7.

In the upper space of the cartridge 6,
An inert gas G such as nitrogen gas or argon gas is filled at a predetermined pressure, and the inert gas G pressurizes sodium Na in the cartridge 6 in a direction to flow out from the small holes 7. Further, sulfur S as an anode active material is accommodated in the anode chamber R2.

The cathode tubular metal fitting 8 made of aluminum, aluminum alloy, titanium or the like is thermocompression bonded to the upper end surface of the insulating ring 4 and has a cylindrical portion 8a and a flange portion 8b. The cathode lid 9 is a cylindrical portion 8a of the cathode tubular metal fitting 8.
Is fixed by welding, and the cathode side terminal 10 is projectingly provided on the upper surface thereof. Then, the lower end of the cylindrical portion of the cathode lid 9 comes into contact with sodium Na supplied to the gap between the cartridge 6 and the solid electrolyte tube 5, and the cathode side current is collected.

The bottomed cylindrical safety tube 11 is disposed in the gap between the cartridge 6 and the solid electrolyte tube 5 at predetermined intervals from the cartridge 6 and the solid electrolyte tube 5, and has corrosion resistance. It is made of a metal material such as aluminum or stainless steel.

The sodium Na supplied from the small holes 7 of the cartridge 6 at the time of discharge is the safety pipe 11
After being moved upward in the gap between the safety tube 11 and the cartridge 6, the safety tube 11 is moved over the upper end and moved downward in the gap between the safety tube 11 and the solid electrolyte tube 5.
Permeate solid electrolyte tube 5 as sodium ions,
This sodium Na is moved to the anode chamber R2 side.
Reacts with sulfur S in the anode chamber R2 to produce sodium polysulfide.

Next, the joining structure of the cathode tubular metal member 8 to the insulating ring 4 will be described in detail. The upper end surface of the insulating ring 4 is tapered so as to have a middle height. Further, the flange portion 8b of the cathode tubular metal fitting 8 is
It is formed in a slanted shape so as to gradually lower outward from the lower edge of a. And this flange part 8
b is joined to the upper end surface of the insulating ring 4 via an inclined joint surface 12 extending in a direction intersecting the radial direction.

Although not shown, the joining surface 12 between the upper end surface of the insulating ring 4 and the flange portion 8b of the cathode tubular metal member 8 may have a three-layer structure of aluminum, silicon and magnesium if necessary. The intermediate joining material
The joining surface 12 is thermocompression-bonded via this intermediate joining material.

Now, in this sodium-sulfur battery, as described above, the upper end surface of the insulating ring 4 and the flange portion 8b of the cathode tubular metal fitting 8 extend in a direction intersecting the radial direction with an inclined joint surface 12. Because it is joined through
The area of the joint surface 12 can be increased without increasing the diameter of the insulating ring 4. Therefore, it is possible to secure a sufficient bonding area between the insulating ring 4 and the cathode tubular metal member 8,
The life of the active material against corrosion can be extended.

[0023]

Another Embodiment Next, another embodiment of the present invention will be described with reference to FIGS. First, in the embodiment shown in FIG. 2, the flange portion 8b of the cathode tubular metal member 8 is formed to extend outward from the lower end edge of the cylindrical portion 8a at a right angle. Further, between the flange portion 8b and the upper end surface of the insulating ring 4, a joint surface 13 having a substantially square cross section is provided so as to form a joint surface extending in a direction intersecting the radial direction. The joint area between the insulating ring 4 and the cathode tubular metal member 8 is increased.

Next, in the embodiment shown in FIG.
In place of the quadrangular rugged joint surface 13 in the above embodiment, a joint surface 14 having a substantially triangular cross section is provided between the flange portion 8b of the cathode tubular metal member 8 and the upper end surface of the insulating ring 4. As a result, the joint area between the insulating ring 4 and the cathode tubular metal member 8 is increased.

Further, in the embodiment shown in FIG. 4, instead of the square concave-convex joint surface 13 in the embodiment of FIG. 2, a space between the flange portion 8b of the cathode tubular metal member 8 and the upper end surface of the insulating ring 4 is provided. Is provided with a joint surface 15 having a substantially circular cross section.
As a result, the joint area between the insulating ring 4 and the cathode tubular metal member 8 is increased.

Further, in the embodiment shown in FIG. 5, contrary to the embodiment shown in FIG. 1, the upper end surface of the insulating ring 4 is formed in a taper shape so as to have an intermediate height, and the flange of the cathode tubular metal fitting 8 is formed. The portion 8b is formed so as to extend in an inclined shape so as to gradually increase outward from the lower end edge of the cylindrical portion 8a. Then, this flange portion 8b is inclined with respect to the upper end surface of the insulating ring 4, and the inclined joint surface 1 extends in a direction intersecting the radial direction.
6 and the joint area between the insulating ring 4 and the cathode tubular metal member 8 is increased.

The joining of the insulating ring 4 and the anode tubular metal member 3 can be performed by the same method as the above-mentioned method. Further, even when the cathode tubular metal member 8 and the anode tubular metal member 3 are simultaneously joined to the insulating ring 4, both joint surfaces 1
If the above-mentioned method is applied to Nos. 2 and 17, pressure bonding can be simultaneously performed with a desired pressing force.

The present invention is not limited to the configuration of the above-described embodiment, and may be embodied by being arbitrarily modified without departing from the spirit of the present invention.

[0029]

Since the present invention is configured as described above, the area of the joint surface between the end surface of the insulating ring and the flange portion of the tubular metal fitting can be increased without increasing the diameter of the insulating ring. It is possible to increase the life of the active material by corrosion and extend the life of the active material against corrosion. Also, the cathode tubular metal fitting and the anode tubular metal fitting can be pressure-bonded to the insulating ring at the same time, and the bonding area can be selected appropriately, so that the design is free. It has an excellent effect that the degree is high.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a sodium-sulfur battery embodying the present invention.

FIG. 2 is a partial cross-sectional view showing another embodiment of the joining structure of the cathode tubular metal member to the insulating ring.

FIG. 3 is a partial cross-sectional view showing another embodiment of the joining structure of the insulating ring and the cathode tubular metal member.

FIG. 4 is a partial cross-sectional view showing another embodiment of the joining structure.

FIG. 5 is a partial cross-sectional view showing another embodiment of the joint structure.

FIG. 6 is a partial cross-sectional view showing a conventional joint structure between an insulating ring and a cathode tubular metal member.

FIG. 7 is a partial cross-sectional view showing another joint structure of a conventional insulating ring and a cathode tubular metal member.

[Explanation of symbols]

4 ... Insulating ring, 5 ... Solid electrolyte tube, 8 ... Cathode cylindrical metal fitting, 8a ... Cylindrical part, 8b ... Flange part, 12 ... Inclined joint surface, 13 ... Square uneven surface, 14 ... Triangular surface , A circular concavo-convex joint surface, 16 ... an inclined joint surface.

Claims (1)

[Claims] 1. An insulating ring for a sodium-sulfur battery and a cylinder, wherein an insulating ring is joined to an open end of a solid electrolyte tube, and a tubular metal fitting having a cylindrical portion and a flange portion is thermocompression-bonded to an end surface of the insulating ring. In the joint structure with the metal fitting, a joint surface extending in a direction intersecting a surface parallel to the radial direction orthogonal to the axis of the battery is provided between the end surface of the insulating ring and the flange portion of the tubular metal fitting. A joint structure between an insulating ring and a tubular metal fitting in a sodium-sulfur battery characterized by the above.