JPH02165572A - Sodium-sulfur battery and its connection - Google Patents

Abstract

PURPOSE:To prevent eccentricity of a battery jar and leak-out of active materials during damages by flexibly welding an anode cover and the battery jar via an anode auxiliary cover to provide an anode current-collecting terminal which is connected to the battery jar via an insulating member. CONSTITUTION:An anode cover 4 and a battery jar are welded with a ring anode auxiliary cover (A) which is extended obliquely downward along the outer periphery of a alpha-alumina ring 2 to the upper insidewall of the battery jar. Then, an anode cover 3 has the upper edge provided with a bellows portion 12, and a cathode terminal 5 welded on the upper edge of the bellows portion 12 has the peripheral edge arranged with an insulating member 13, so that a gap is provided in between the insulating member 13 and a ring anode current- collecting terminal 14 which is inversely L-shaped in cross section welded on the upper portion of the battery jar. It is thus possible to prevent leak-out of active materials during damages by the anode current-collecting terminal 14 and eccentricity of the battery jar because the anode current-collecting terminal 14 is not welded on the side of the battery jar.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Use] The present invention relates to an IJ Umu sulfur battery and its connection method, and more specifically, to prevention of damage and improvement of safety thereof.

Conventional technology and its problems Sodium-sulfur batteries have a completely sealed structure in which sodium as a cathode active material and sulfur as an anode active material are separated by a sodium ion conductive solid electrolyte tube such as β'-alumina. This is a high-temperature secondary battery.

The conventional structure of the IJ Umu sulfur battery will be explained with reference to FIG. An a-alumina ring 2 is bonded to the upper end of the solid electrolyte tube 1 by glass soldering, and a cathode cover 3 and an anode cover 4 are bonded to the upper surface and the lower surface of the α-alumina ring 2 and heat pressure, respectively. The cathode *3) This is the cathode terminal 5
is welded, and a cathode vibro serving as a cathode current collector is welded to pass through the center thereof, and the lower part thereof is inserted into the solid electrolyte tube 1.

Inside this solid electrolyte v1, a metal fiber 7 is arranged and about 1
After evacuating the inside of the solid electrolyte tube 1 from the cathode vibro while keeping the temperature at 50°C, it is melted at the same humidity) IJ
In such a cathode chamber structure, a cylindrical sulfur molded body 10 was inserted, and an anode current collector terminal 11 was welded to the cathode chamber structure. Ia
It is inserted into the T tank 9 which also serves as an electrode current collector, and the anode collector 1 terminal 1
1 is bent outward, and its upper end is vacuum welded to the anode lid 4 to completely seal it.

In the IJ Umu sulfur battery having the above structure, the sulfur molded body 10 thermally expands during the process of increasing the temperature to the operating temperature of 550° C., and the solid electrolyte tube 1 is subjected to bending stress. However, since the solid electrolyte tube 1 is firmly bonded to the α-alumina ring 2 by glass solder, the solid electrolyte tube 1 may be damaged at the glass solder joint due to the bending stress. If the solid electrolyte tube is damaged in this way,
Sulfur and sodium react directly, internal pressure increases and the cathode! 5 peels off from the upper surface of the α-alumina ring 2, and the active material leaks out, damaging adjacent normal batteries and causing large-scale damage. In addition, when welding the anode current collector terminal 11 to the battery case 9, there was a problem in that the opening of the VL cypress 9 was eccentric due to the heat, resulting in a defect in welding with the anode fi 4. .

OBJECT OF THE INVENTION The present invention solves the above-mentioned drawbacks.The anode cover and the battery case are welded together with flexibility through the anode auxiliary cover, and a bellows portion is provided on the upper edge of the #electrode cover. By placing an electrically insulating member around the periphery of the cathode terminal that is welded to the upper edge of the WL tank, and providing an anode current collector terminal that is connected to the battery case through this electrically insulating member, the WL tank can be prevented from eccentricity and can be prevented from breaking. In addition to preventing leakage of active materials, etc., the safety of the battery group is improved by separating damaged batteries from the battery group and making connections with adjacent batteries more flexible. In the sodium-sulfur battery of the invention, the anode cover and the battery case are bonded under heat and pressure to the lower surface of the Sa-alumina ring, and extend obliquely downward along the outer peripheral surface of the α-alumina ring to reach the upper inner wall of the battery case. A bellows portion is provided at the upper edge of the cathode cover which is welded to the annular anode auxiliary cover and is thermo-pressure bonded to the upper surface of the α-alumina ring, and a cathode terminal is welded to the upper edge of this bellows portion. An electrically insulating member is arranged around the periphery of the battery case, and the electrically insulating member and the upper part of the battery case are welded to each other. A gap is provided between the terminal and the terminal.

EXAMPLES The present invention will be explained below using examples. FIG. 1 is a sectional view of the main parts of the sodium-sulfur battery of the present invention, and parts common to those in FIG. 2 are given the same reference numerals.

In FIG. 1, a solid electrolyte tube 1 has an outer diameter of 46mm, 11mm, and an open top. Inner diameter 40mm, length 4001mm
The upper open end has an outer diameter of 56 mm and an inner diameter of 406 mm. An α-alumina ring 2 having a thickness of 151 mj1 is bonded with glass solder. A cathode lid 3 is heat-pressure bonded to the upper surface of this α-alumina ring 2, and a bellows portion 12 is welded to the upper edge of this cathode lid 3. Gold R114 fibers 7 made of iron or stainless steel are arranged up to 50 fibers with a porosity of 94.0 to 98.0%. A cathode terminal 5 to which an aluminum cathode vibro having an outer diameter of 8 mm and an inner diameter of 6 mm is fitted or screwed is welded to the open end of the upper edge of the bass part 12, and its tip is connected to the metal fiber 7. It is inserted to a depth of approximately 1 cm from the top surface of the. Then, molten sodium 8 is vacuum-filled into the solid electrolyte tube 1 from the tip of the cathode terminal 5, and after filling, the upper end of the cathode terminal 5 is sealed. An annular a-aluminum member or an annular asbestos member as an electrical insulating member 15 is attached to the periphery of the cathode terminal 5. On the other hand, an anode cover 4 is thermo-pressure bonded to the lower surface of the a-Al hawk ring 2, and a first anode whose one end extends obliquely inwardly and downwardly along the outer peripheral surface of the a-Al hawk ring 2. An annular second anode auxiliary i1B is welded to the upper part of the auxiliary lid at the lower end of this first anode auxiliary lid.
The inner peripheral edge of the cathode chamber is welded to form the cathode chamber structure. Note that the first and second anode auxiliary fiA.

B is made of 0.4 mm thick chromium-diffused iron, stainless steel, aluminum-covered iron, etc. Then, the cathode chamber structure is inserted into the battery case 9 into which the cylindrical sulfur molded body 10 is inserted, and as shown in the 39th enlarged view, the inner wall of the protrusion B provided at the top of the battery case 9 is The outer peripheral edge of the second anode auxiliary lid B is welded to the anode chamber to vacuum-seal the anode chamber. Next, a protrusion provided on the upper outer wall of the battery case 9 has an annular anode current collector terminal 1 with an inverted cross section.
4 is welded to its lower end, and its upper end is positioned above the electrically insulating member 13. This gap is such a distance that the lower end of the cathode vibro separates from the upper surface of the metal fiber 7 when the bellows portion 12 is extended. An anode terminal 15 is attached to the upper surface of this anode current collector terminal 14, and a conductor 16 for connecting to the terminal 17 of an adjacent battery, which is made of six laminated nickel plates with a thickness of 0.2 fin, is attached to connect the batteries. Connecting.

By using a connecting conductor made by laminating multiple metal plates like this, it is possible to provide flexibility in connecting adjacent batteries, and it is possible to absorb thermal strain between batteries at operating temperatures. . Note that the metal plate is not particularly limited as long as it is conductive and oxidation resistant.

10 cells each of the battery of the present invention and the conventional battery as shown in Fig. 2 were manufactured, and a heat cycle test was conducted at room temperature ← 350°C and a temperature increase/decrease rate of 150 to 200 t/h, and the results are shown in the table below. - Shown in 1.

In Table 1, one molecule indicates the number of batteries from which the active material etc. leaked, and the denominator indicates the number of damaged batteries. In addition, when a battery is damaged, the voltage drops rapidly, so the voltage drop causes the damaged battery's ME.
I did it.

Table 1 From Table 1, conventional batteries often break during heat cycle tests up to 10 cycles, and even when they break, active materials leak out and all of them are short-circuited, whereas the present invention Only one cell of the battery was damaged in the heat cycle test up to 10 cycles, and there was no leakage of active material, and no short circuit was observed. A battery broken line test was conducted, and the results are shown in Table 2.

From Table 2, while the conventional battery was damaged and short-circuited, the battery of the present invention had only 17 short-circuited batteries.

Effects of the Invention As detailed in the examples, since the battery of the present invention connects the anode lid and the battery case with the annular auxiliary anode lid, it is possible to absorb bending stress during heat cycle trials and battery operating temperatures. Can be done. Even in the event of damage, the anode current collector terminal can prevent leakage of the active material, and the increase in internal pressure within the cathode chamber allows the cathode pipe and gold B fibers to be separated and insulated, thereby preventing any effects on adjacent batteries. And since this anode current collector terminal is not welded to the side of the N oak,
Eccentricity of the battery container can be prevented. Furthermore, since such sodium-sulfur batteries are connected by a connecting conductor made of a plurality of laminated metal plates, the safety of the battery group can be improved.

In addition, in order to enhance the effect of increasing the internal pressure of the cathode guide,
If an appropriate amount of a substance that gasifies above the battery operating temperature, preferably 450°C or above, e.g., a substance that generates nitrogen such as diiron nitride or thallium azide, is sealed in the cathode chamber, insulation in the event of damage will be more secure. It can be done.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of the sodium-sulfur battery of the present invention,
FIG. 2 is a sectional view of a conventional battery, and FIG. 3 is an enlarged view of a welded part. 1...Solid electrolyte tube 2...A-alumina ring 5...Cathode M4...#J electrode lid 5...Cathode terminal 6...#Pole vibe 11.
14... Anode current collector terminal 12... Bellows part 13
... Electrical insulation member 15 ... Anode terminal 16.
...Connection conductor A...First anode auxiliary cover B...Second anode auxiliary cover a, b...Protrusion Applicant fJIj Asa Battery Co., Ltd. Figure 3

Claims (3)

[Claims] (1) An α-alumina ring is bonded to the upper end of a solid electrolyte tube that conducts sodium ions, and a cathode cover is heat-pressure bonded to the top surface of this α-alumina ring, and an anode cover is bonded to the bottom surface of the α-alumina ring, and welded to this anode cover. In the sodium-sulfur battery, the battery has a battery case that covers the solid electrolyte tube from below, the inside of the solid electrolyte tube is a cathode chamber, and the gap between the solid electrolyte tube and the battery case is an anode chamber, and the battery case are welded by an annular anode auxiliary cover that extends diagonally inward and downward along the outer peripheral surface of the α-alumina ring to reach the upper inner wall of the battery case, and a bellows portion is attached to the upper edge of the cathode cover. An electrically insulating member is arranged around the periphery of the cathode terminal that is welded to the upper edge of the bellows portion, and an annular anode current collector having an inverted L-shaped cross section is welded to the electrically insulating member and the upper part of the battery case. A sodium-sulfur battery characterized by having a gap between the terminal and the terminal. (2) A sodium-sulfur battery according to claim 1, characterized in that a metal fiber impregnated with a cathode active material is arranged in the cathode chamber, and the lower end of the cathode terminal is inserted into the upper part of the metal fiber. . (3) A sodium battery characterized in that an anode terminal is provided on the upper surface of the anode current collector terminal, and the anode terminal and the terminal of an adjacent battery are connected by a connecting conductor made of a plurality of laminated metal plates. How to connect a sulfur battery.