JPS6110881A - Manufacture of sodium-sulfur battery - Google Patents

Abstract

PURPOSE:To facilitate assembly of a sodium-sulfur battery by minimizing the number of spots to be welded in a vacuum by adjusting the position of the upper sealing area of the container to be higher than the liquid level of the positive active material during the last stage of electric discharge are welding said upper sealing area to a positive auxiliary lid, integrated with a solid electrolyte tube, in a vacuum. CONSTITUTION:After a cylindrical positive electrode 8 made of sulfur is installed in a container 7, a negative electrode 11 made of sodium is installed inside the positive electrode 8 with a solid electrolyte tube 1 made of beta-alumina interposed. The position of the upper sealing area 14 of the container 7 is adjusted to be higher than the liquid level of the positive electrode during the last stage of electric discharge. The sealing area 14 is welded to a unified body consisting of a solid electrolyte tube 1, an alpha-alumina ring 2, a negative lid 12, a positive lid 5 and a positive auxiliary lid 6 in a vacuum to produce a completely sealed state. Next, after the sodium 11 is poured into the solid electrolyte tube 1, the terminal 13 in welded in a vacuum. Consequently, it is possible to minimize the number of spots to be welded in a vacuum during assembly. Furthermore, it is also possible to prevent any decrease in the strength of the battery at operation temperatures.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing sodium-sulfur batteries.

Prior art and its problems In a sodium-sulfur battery, molten sodium as a cathode active material and molten sulfur as an anode active material are completely separated by a solid electrolyte tube such as β'-alumina that conducts sodium ions. As shown in the cross-sectional view in the figure, it is housed in a completely sealed battery case that is not affected by air, moisture, etc.

In FIG. 5, reference numeral 1 denotes a solid electrolyte tube made of a material such as r-alumina, and a high-purity α-alumina ring 2 is glass-bonded to the upper end. 6 is stainless steel, Fe-0r-
AI! The cathode cover is made of a material such as alloy or aluminum-coated iron, and α-
It is bonded to the upper surface of the alumina ring 2 by thermopressure. 5 is an anode lid made of the same material as the cathode lid 6; 1 is thermo-pressure bonded to the lower surface of the α-alumina ring 2 via high-purity aluminum M4; 06 is an anode auxiliary lid with a flange at the lower end, made of stainless steel; Fe-Cr-AJ gold alloy Fe-0r-
It is made of a material such as AJ-Y alloy and is welded to the anode cover 5. 7 is a battery case which has a flange extending outward at the upper end, and this flange is welded to the flange extending outward at the lower end of the pole auxiliary cover O. 08 and 9 are impregnated with sulfur as an anode active material. It is an anode conductive material made of multiple layers such as graphite felt, carbon felt, gold, and A felt.

A bottom cover 10 is welded to seal the lower end of the battery case 7. 11 is a synthetic fiber made of stainless steel, iron, aluminum, nichrome, etc. impregnated with sodium as a cathode active material, and the inner diameter is larger than the outer diameter of the cathode current collector terminal 13 to which the cathode auxiliary lid 112 is welded; It is formed into a cylindrical shape smaller than the inner diameter of the solid electrolyte tube 1, and is fitted into the solid electrolyte tube 1.

In order to make the sodium-sulfur battery with the above structure completely sealed, unaffected by air, moisture, etc., everything is welded in a vacuum, but the process is complicated because there are many parts to be welded in a vacuum. There was a drawback.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a sodium-sulfur battery that simplifies the above-mentioned welding process and is less susceptible to damage at battery operating temperatures.

Structure of the Invention The present invention provides a sealing part at the upper part of the container at a position higher than the liquid level of the anode active material at the end of discharge, and stores the anode conductive material in a cylindrical shape in the container to which the bottom cover is welded. After welding the anode auxiliary lid to which the anode lid is welded, the sealing portion is welded and sealed in a vacuum.

Embodiment FIGS. 1 and 2 are partially enlarged vertical cross-sectional views of a sodium-sulfur battery manufactured by the manufacturing method of the present invention, and all numbers are the same as in FIG. 3. In FIG. 1, by providing the sealing part 14 at the upper part of the battery case 7 at a position higher than the liquid level of the anode active material at the end of discharge, the anode conductive material 8 is housed in the battery case 7 to which the bottom cover is welded. After fitting the solid electrolyte tube integrated with @ electrode lid 5, anode auxiliary lid 6, α-alumina ring 2, cathode lid 3, cathode auxiliary lid 12, and cathode current collector terminal 13, the sealing part 14 is inserted. If welded in a vacuum, it can be completely sealed. Moreover, by injecting the cathode active material sodium by impregnation into the upper end of the cathode current collector terminal in a vacuum, and then welding the tip in a vacuum, a completely sealed state can be achieved.

The reason why the anode auxiliary lid 6 in FIG. 1 has a wavy structure and the anode auxiliary lid 6 in FIG. 2 has a bellows structure is because the battery operating temperature is 600.
This is to prevent solid electrolyte tubes from being destroyed due to the increase in internal pressure at -370"C.
This is to prevent solid electrolyte tubes from being destroyed due to an increase in the internal pressure of the battery case, and is intended to give the battery case a flexible structure.

Effects of the Invention As described above, the sodium-sulfur battery produced by the manufacturing method of the present invention can minimize the number of welded parts in vacuum, and is a sodium-sulfur battery that does not easily break under battery operating temperatures.
Sulfur batteries can be provided.

[Brief explanation of drawings]

Figures 1 and 2 are partially enlarged vertical cross-sectional views of a sodium-sulfur battery manufactured by the manufacturing method of the present invention, and Figure 6 is a conventional one.
FIG. 2 is a longitudinal cross-sectional view of an Umu sulfur battery. 1...Solid electrolyte tube 2...α-alumina ring 5...Anode cover 6...@Pole auxiliary cover 7...
Battery container 8, 9... Anode conductive material 16... Cathode current collecting terminal 14... Sealing section applicant Yuasa Battery Co., Ltd. Voluntary procedure amendment

Claims (1)

[Claims] After storing an anode conductive material impregnated with an anode active material in a cylindrical shape in a container, a
- An alumina ring is glass bonded, a cathode cover with a cathode auxiliary cover and a cathode current collector terminal welded to the top surface of the α-alumina ring, and an anode cover with an anode auxiliary cover welded to the bottom surface thereof are bonded by thermo-pressure. In the manufacturing method of a sodium-sulfur battery in which a solid electrolyte tube is inserted, a solid electrolyte tube is inserted, an outwardly expanding flange at the upper end of the battery case, and an outwardly expanding flange at the lower end of the anode auxiliary lid having a wavy or bellows structure. After welding, the cathode active material is injected from the tip of the cathode current collector terminal in a vacuum, and the tip is sealed, and the sealing part provided at a position higher than the liquid level of the anode active material at the end of the discharge at the top of the battery case is sealed. A method for manufacturing a sodium-sulfur battery.