JPS59154742A - Sealed type battery - Google Patents

Abstract

PURPOSE:To exhaust gas from a sealed battery that uses lithium and oxy halide filled with the gas before explosion and hold the contents of the battery by providing an annular groove on the outer periphery of the side of a negative electrode can and covering the entire of the negative electrode can with heat- shrinkable tubing. CONSTITUTION:A negative electrode can 5 is comprised with a deep drawing processing can made of stainless steel and a negative electrode 1 made of lithium, separator 2, positive electrode 3 of a carbon porous molding body, and a positive electrode collecting body 4 are contained internally. A metal cover 6 is welded to the opening section of the can 5 and an electrolyte made of oxy halide is injected from a metal pipe 8 that is welded to the glass seal 7 of the metal 6 and the can is sealed. The capacity of oxy halide occupied in the total amount of the space capacity in the sealed structure and the capactiy of oxy halide is 75 capacity % or more. An annular groove 9 is formed near almost the center in the axial direction of the outer periphery of the side of the can 5 and heat-shrinkable resin tubing 10 that covers the entire of the can 5 is provided.

Description

[Detailed description of the invention]

This invention uses lithium as the cathode active material while oxy...
This invention relates to a sealed battery using a halide as an electrolyte solvent and anode active material. In this type of battery, the cathode can containing the Azuike element is constructed from a stainless steel can with a hollowed-out surface, and a metal lid with a glass seal is inserted into the opening of the can, and the inner circumferential surface of the can and the outer circumference of the metal lid are connected to each other. It uses a hermetically sealed structure in which the surfaces are welded together using a so-called hermetic seal. For this reason, it has the characteristic of not leaking even under severe conditions, and because of this characteristic, it is common to fill the battery with a large amount of liquid oxylogenide, which serves as both the solvent for the electrolyte and the positive electrode active material. In terms of applications, use in high-temperature atmospheres is also being considered. However, when the oxyhalide is filled with a high filling rate of 75% by volume or more, usually up to 95% by volume, which is the total amount of space inside the battery, it expands thermally and can cause internal short circuits. The resulting gas generation causes the battery container to bulge, and there is a risk of a violent explosion due to the sudden rise in internal pressure. In other words, although this type of battery has excellent secondary liquid resistance due to being a sealed type, it is currently impossible to avoid the risk of explosion on the skin due to storage issues and handling issues. . The present invention aims to provide a sealed battery with an explosion-proof structure from the above point of view. A cathode can containing these battery elements as an active material is constructed by processing stainless steel, and a metal lid is welded to the opening of the cathode can to create a sealed structure, and the space within this sealed structure and the above-mentioned In a sealed battery in which the capacity of the oxyhalide in the total amount of the oxyhalide is 75% by volume or more, an annular groove is provided on the outer periphery of the side surface of the cathode can, and , there is provided a sealed battery characterized in that a heat-shrinkable resin tube is provided to cover the entire cathode can. An embodiment of the present invention will be described below with reference to the drawings. In Figures 1 and 2, 1 is a cathode made of lithium, 2 is a separator such as a glass fiber non-woven fabric, and 3 is a carbon porous molded material formed by adding polytetrafluoroethylene as a binder to aceta-plat. Anode like a body, 4
5 is a cathode can made of stainless steel, and 6 is a metal lid made of stainless steel. The outer periphery of this metal lid 6 is inside the opening of the cathode can 5. A glass seal 7 is formed on the inner circumferential side of the metal lid 6, which is completely welded to the circumferential surface, and after injecting electrolyte from the metal pipe 8 which is slightly welded to this seal 7,
The anode current collector 4 and the metal pipe 8 are welded together to form a sealed structure inside the battery. The above electrolyte contains electrolytes such as aluminum chloride and lithium chloride, thionyl chloride (5OC12), sulfuryl chloride (
SO2Ct), phosphoryl chloride (POCta), and other oxyhalides are dissolved therein, and the oxyhalides serve as an electrolyte solvent as well as an anode active material. The capacity of this oxyhalide is defined as 75% by volume or more and up to 95% by volume in the total volume of the six spaces inside the battery, which has a sealed structure.
The energy density of the battery is increased. The above-mentioned space 6 is defined as 'the cathode 1.' from the total internal volume of the pond. Separator 2° Anode 3. The total gt (calculated from true specific gravity and weight) of battery filling materials such as anode current collector 4 and electrolyte is subtracted. 9 is the i! of the above cathode can 5! 111fi is an annular groove formed near the center of the outer periphery in the axial direction. Cutting and press processing such as banbans

[It was formed from this. The depth of the groove portion 9 is determined by assuming that the thickness of the stainless steel forming the cathode can 5 (before drilling) is 0.
In the case of 3 mm, the depth can be cut so that the remaining thickness of the can after forming the groove is 0.1.5 mm or less, and up to 0.05 mm in total. If the remaining thickness becomes too thin, there is a risk that damage may occur from the grooves in the battery manufacturing process. In addition, although the shape of the groove part 9 is triangular in cross section in the drawing, it can be made into arbitrary shapes, such as a semicircle and a rectangle. 10 is a polyvinyl chloride resin or other heat-shrinkable resin tube that covers the entire cathode can 5, and after welding the metal lid 6 and the cathode can opening and welding the metal pipe 8 and the anode current collector 4. After assimilating the insulating material 11 made of resin or rubber to cover the metal lid 6, a label made of paper or aluminum is pasted on the side of the can as necessary, and the tube 10 is covered thereon. It is made by shrinking due to heat shrinkage. As is clear from the above structure, in this invention, the annular groove 9 is provided on the outer periphery of the side surface of the cathode can 5, which is made of stainless steel. As a result, before an explosion occurs due to a sudden increase in the internal pressure of the battery, cracks occur in the grooves, and the gas filled inside is discharged from the grooves. In addition, in the above embodiment, since the annular groove 9 is provided almost at the center of the cathode can 5 in the axial direction, an even internal pressure is applied to this part, which increases the lifespan of the battery based on the cracking strength of the can measured in advance. can be predicted almost accurately. Furthermore, forming the groove in the axially central portion in this manner facilitates cutting or pressing, which is advantageous in battery production. It is preferable to form the groove 9 by cutting or pressing and then subject the entire can to solution heat treatment to eliminate the distortion that occurs during the drilling process of the stainless steel and the process for forming the groove. . In particular, distortion is likely to occur in the axial direction of the can during the digging process, and by eliminating such distortion through the solution heat treatment, the strength in the axial direction of the can can be stabilized, making it possible to ensure that cracks do not occur in the grooves. . For example, when the stainless steel is SUS 3 Q4, the solution heat treatment is generally performed at 1000 to 100° C. for 1 to 4 hours, and then quenched. Next, in the configuration of the present invention, "1 groove portion 9
By providing the heat-shrinkable resin tube 10 that covers the entire cathode can 5 formed with 01, the battery contents discharged together with the gas due to cracks in the groove 9 can be retained from the tube 01. It is possible to effectively prevent adverse effects on external devices, etc. As detailed above, according to the present invention, before the internal pressure of the battery rapidly increases and an explosion occurs, a crack is generated in the groove formed on the outer periphery of the side surface of the cathode can, and the gas filling the inside is released from there. It is possible to provide a sealed battery having an explosion-proof structure in which the battery contents can be discharged in advance and are suspended with a heat-shrinkable plum tube.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing an example of a sealed battery of the present invention, and FIG. 2 is a cross-sectional view showing an enlarged main part of the sealed battery of the present invention. 1... Cathode, 5... Cathode can, 6... Metal lid, 9...
... Groove, 10... Heat-shrinkable resin tube. Patent Applicant Hitachi Maxell Co., Ltd. No. 1 1 o□ -8 □11

Claims (1)

[Claims] tl) Lithium is used as the cathode active material, while oxyhalide is used as the solvent of the electrolyte and the anode active material, (the cathode can containing these battery elements is constructed from a stainless steel machined can with its opening A metal lid is welded to the part to form a sealed structure, and the volume of the oxyhalide is 75% by volume or more in the total volume of the space valley in the sealed structure and the volume of the oxyhalide. 1. A sealed battery comprising: an annular groove provided on the outer periphery of a side surface of the cathode can; and a heat-shrinkable resin tube covering the entire cathode can.