JP2895991B2 - 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 sodium-sulfur battery.

[0002]

2. Description of the Related Art In a conventional sodium-sulfur battery, a cathode chamber and an anode chamber are formed inside and outside a bottomed cylindrical solid electrolyte tube, and a cartridge for containing sodium is arranged in the cathode chamber. The anode chamber contains sulfur as an anode active material. And 30
While being heated to 0 to 350 ° C., molten sodium as a cathode active material is supplied from the inside of the cartridge to the gap between the cartridge and the solid electrolyte tube, and sodium in the cathode chamber and sulfur in the anode chamber are supplied. It is ionized and permeates through the solid electrolyte tube and reacts to discharge.

In this type of sodium-sulfur battery, when the solid electrolyte tube is broken during operation, sodium in the cathode chamber and sulfur in the anode chamber directly react to generate sodium polysulfide with heat generation. I do. The corrosiveness of the sodium polysulfide and the high temperature due to the exothermic reaction may cause the metal container forming the anode chamber to melt. This reaction continued to occur as long as sodium and sulfur were present.

In order to suppress such a reaction, for example, as shown in Japanese Patent Application Laid-Open No. 2-112168, a metal material such as aluminum or stainless steel having corrosion resistance is provided in a gap between a cartridge and a solid electrolyte tube. A sodium-sulfur battery provided with a bottomed cylindrical safety tube has been proposed.

[0005]

However, even in the conventional sodium-sulfur battery, when the degree of destruction of the solid electrolyte tube is large, a large amount of direct reaction between sodium and sulfur cannot be suppressed, so that the safety tube cannot be used. In addition, there is a problem that a hole is partially opened, sodium flows out from the hole, and sodium and sulfur react more violently, and the battery fire is expanded.

The present invention has been made in view of such problems existing in the prior art, and has as its object to destroy the solid electrolyte tube and directly convert sodium and sulfur. When high-temperature sodium polysulfide is generated by the reaction, the amount of the reaction can be suppressed and the sodium polysulfide can protect the cartridge and safety tube from corrosion and melting, and the direct reaction between sodium and sulfur can be prevented. It is an object of the present invention to provide a sodium-sulfur battery which can prevent the battery from spreading by preventing the battery from spreading.

[0007]

According to the present invention, a cathode chamber and an anode chamber are formed inside and outside a bottomed cylindrical solid electrolyte tube, and a cartridge is provided in the cathode chamber. Is disposed in the cartridge from the inside thereof to a gap between the cartridge and the solid electrolyte tube,
In addition, a through hole through which sodium enters and exits from the gap into the cartridge is formed, and a bottomed cylindrical safety tube made of a corrosion-resistant metal material is provided in the gap, and sulfur is further contained in the anode chamber. In the sodium-sulfur battery containing the above, a protective tube made of a material having heat resistance and corrosion resistance is disposed between the safety tube and the solid electrolyte tube or between the safety tube and the cartridge. is there.

[0008]

[Action] In the sodium-sulfur battery constructed as described above, a protective tube made of a heat-resistant and corrosion-resistant material is provided between the safety tube and the solid electrolyte tube or between the safety tube and the cartridge. Since the solid electrolyte tube is broken during the operation of the battery and high-temperature sodium polysulfide is generated by the direct reaction between sodium and sulfur, the protective tube increases the number of cartridges and safety tubes. Protected from corrosion and melting by the action of sodium sulfide. For this reason, it is possible to prevent the direct reaction between sodium and sulfur from expanding, and it is possible to reliably prevent the battery fire from expanding.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of a sodium-sulfur battery embodying the present invention will be described in detail with reference to FIGS.

As shown in FIG. 1, an anode container 1 is formed in a cylindrical shape with a bottom, an anode-side terminal 2 is provided on an outer peripheral upper portion, and a support fitting 3 is fixed on an inner peripheral surface at an upper end. . The insulating ring 4 made of α-alumina is fitted and fixed on the support fitting 3, and the upper outer peripheral surface of a bottomed cylindrical solid electrolyte tube 5 made of β-alumina or the like is joined and fixed to the lower inner peripheral surface. I have. A cathode chamber R1 is defined inside the solid electrolyte tube 5, and an anode chamber R2 is defined outside.

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

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

The cathode lid 8 is fixedly joined to the insulating ring 4, and has a central disk portion 9, a cylindrical portion 10 provided on the outer periphery of the disk portion 9, and a projection on the upper surface of the disk portion 9. And a cathode side terminal 11. Then, the lower end of the cylindrical portion 10 of the cathode lid 8 comes into contact with sodium supplied to the gap between the cartridge 6 and the solid electrolyte tube 5, so that the current is collected on the cathode side.

The bottomed cylindrical safety tube 12 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, respectively, and has corrosion resistance. It is formed from a metal material such as aluminum or stainless steel. Then, sodium N supplied from the small hole 7 of the cartridge 6 at the time of discharging
a is moved upward in the gap between the safety pipe 12 and the cartridge 6, then climbs over the upper end of the safety pipe 12 and moves downward in the gap between the safety pipe 12 and the solid electrolyte pipe 5. After being moved, the ions are transmitted as sodium ions through the solid electrolyte tube 5 and moved to the anode chamber R2 side.

A cylindrical protective tube 1 having an open upper end and a lower end.
Numeral 3 is provided between the safety pipe 12 and the solid electrolyte pipe 5 at a predetermined distance from the safety pipe 12 and the solid electrolyte pipe 5, and is formed of a carbon material having heat resistance and corrosion resistance. During the operation of the battery, the solid electrolyte tube 5
Is destroyed and high-temperature sodium polysulfide is generated by a direct reaction between sodium Na and sulfur S, the protective tube 13 prevents the cartridge 6 and the safety tube 12 from being corroded and melted by the action of sodium polysulfide. Protected.

Next, the operation of the sodium-sulfur battery configured as described above will be described. When the sodium-sulfur battery is fully charged, most of the sodium Na is stored in the cartridge 6.
When the discharge is started in this state, the sodium in the cartridge 6 flows out through the small hole 7 due to the pressure of the inert gas G sealed in the upper space of the cartridge 6, and the space between the safety tube 12 and the cartridge 6 is removed. It is moved upward in the gap. Thereafter, the sodium Na climbs over the upper end of the safety tube 12 and moves downward in the gap between the safety tube 12 and the solid electrolyte tube 5, and further permeates the solid electrolyte tube 5 as sodium ions, It is moved to the anode chamber R2 side.
Then, the sodium Na reacts with the sulfur S in the anode chamber R2 to generate sodium polysulfide.

If the solid electrolyte tube 5 is broken during the operation of the battery, sodium Na in the cathode chamber R1 and sulfur S in the anode chamber R2 directly react to generate high-temperature sodium polysulfide. However, in this embodiment, the safety pipe 12 is provided in the gap between the cartridge 6 and the solid electrolyte pipe 5, and the protection pipe 13 is provided between the safety pipe 12 and the solid electrolyte pipe 5. Has been established,
The protective tube 13 protects the cartridge 6 and the safety tube 12 from being corroded and melted by the action of high-temperature sodium polysulfide. Therefore, it is possible to prevent the direct reaction between sodium Na and sulfur S from expanding, and it is possible to reliably prevent the battery fire from expanding.

Incidentally, the overcharge current of the battery in which the protection tube 13 is disposed between the safety tube 12 and the solid electrolyte tube 5 as in the first embodiment and the conventional battery having no protection tube are provided. When the time until the fire of the battery was measured at a constant of 100 A, the result shown in FIG. 5 was obtained. In the figure, comparing the measurement result of the battery of the first embodiment indicated by a mark with the measurement result of the conventional battery indicated by a mark, the battery of the first embodiment shows that the battery reaches the point of fire. It is clear that the time can be significantly extended.

[0019]

Next, another embodiment of the present invention will be described with reference to FIGS. First, the second shown in FIGS.
In the embodiment, a cylindrical protective tube 13 made of a carbon material having upper and lower ends opened is provided between the safety tube 12 and the cartridge 6.
Are arranged at a predetermined distance from each other. Accordingly, in the battery of the second embodiment, similarly to the battery of the first embodiment, when the solid electrolyte tube 5 is broken during operation of the battery and high-temperature sodium polysulfide is generated, the protective tube 1
3, the cartridge 6 and the safety tube 12 can be protected from being corroded and melted by the action of sodium polysulfide, and the direct reaction between sodium Na and sulfur S can be prevented from expanding.

Incidentally, as in the second embodiment, the battery in which the protection tube 13 is disposed between the safety tube 12 and the cartridge 6 also has a battery fire when the overcharge current is fixed at 100 A. When the time was measured, FIG. 5
The result as shown in FIG. In the same figure, comparing the measurement results of the battery of the second embodiment indicated by □ with the measurement results of the conventional battery indicated by ○, it can be seen that the battery of the second embodiment also has a It is clear that the time can be significantly extended. Also, comparing the measurement results of the battery of the second embodiment indicated by □ with the measurement results of the battery of the first embodiment indicated by Δ, the battery of the second embodiment is more likely to cause a fire. It can be seen that the time can be extended slightly.

In the third embodiment shown in FIG. 6, the protective tube 13 is formed of a carbon material into a bottomed cylindrical shape.
This protective tube 13 is the same as the safety tube 1 in the first embodiment.
2 and the solid electrolyte tube 5 are disposed at a predetermined distance from the safety tube 12 and the solid electrolyte tube 5. Further, in the fourth embodiment shown in FIG. 7, the protective tube 13 is formed in a cylindrical shape with a bottom from a carbon material, and the protective tube 13 is connected to the safety tube 12 and the cartridge 6 in the same manner as in the second embodiment. Between the safety tube 12 and the cartridge 6
Are arranged at a predetermined distance from each other. Therefore, in the third and fourth embodiments, the same operation and effect as those in the first and second embodiments can be expected.

The present invention is not limited to the configuration of the above-described embodiment. For example, the protective tube 13 may be formed of graphite to improve heat insulation, or the safety tube 12 may be formed of an inner wall and an outer wall. The configuration of each part may be arbitrarily changed and embodied without departing from the spirit of the present invention, such as a double wall structure having

[0023]

According to the present invention, since the solid electrolyte tube is broken and direct reaction between sodium and sulfur produces high-temperature sodium polysulfide, the present invention is constructed as described above. Sodium sulfide protects cartridges and safety tubes from corrosion and melting, and prevents the direct reaction between sodium and sulfur from expanding, thus preventing the spread of battery fires. It works.

[Brief description of the drawings]

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

FIG. 2 is an enlarged partial cross-sectional view showing a portion A in FIG. 1;

FIG. 3 is a longitudinal sectional view showing a second embodiment of the sodium-sulfur battery of the present invention.

FIG. 4 is an enlarged partial cross-sectional view showing a portion B in FIG. 3;

FIG. 5 shows the results of measuring the time until the battery fires at a constant overcharge current for the sodium-sulfur battery of the first embodiment, the sodium-sulfur battery of the second embodiment, and the conventional sodium-sulfur battery. FIG.

FIG. 6 is a longitudinal sectional view showing a third embodiment of the sodium-sulfur battery of the present invention.

FIG. 7 is a longitudinal sectional view showing a fourth embodiment of the sodium-sulfur battery of the present invention.

[Explanation of symbols]

5 solid electrolyte tube, 6 cartridge, 12 safety tube,
13 Protection tube, R1 cathode compartment, R2 anode compartment, Na sodium, S sulfur.

Claims (1)

(57) [Claims] 1. A cathode chamber and an anode chamber are formed inside and outside a bottomed cylindrical solid electrolyte tube, and a cartridge is disposed in the cathode chamber. A through hole through which sodium flows in and out of the cartridge through the gap and the inside of the cartridge is formed, and a bottomed cylindrical safety tube made of a corrosion-resistant metal material is provided in the gap. Further, in a sodium-sulfur battery in which sulfur is contained in the anode chamber, between the safety tube and the solid electrolyte tube or between the safety tube and the cartridge, a material having heat resistance and corrosion resistance is used. A sodium-sulfur battery, comprising a protective tube.