JPS59171457A - Sealed type battery - Google Patents

Abstract

PURPOSE:To obtain a sealed type battery with excellent leakage by limiting the lowermost end of the external folding section of a sealing cover or the degree of flatness of the peripheral lowermost end. CONSTITUTION:The lowermost end of the peripheral folding section 4 of a sealing cover 3 or the degree of flatness of the lowermost end of a sleeve when the folding section is not provided is limited to 0.03mm. or less. As a result, the pressure applied to the lowermost end of the sealing cover can be uniformalized and the leakage of a battery can be improved. The sealing section with the degree of good flatness is obtained by selecting the process of cutting and contraction of area and maintaining the accuracy of a mold. The degree of flatness of the lowermost end is improved by striking the upper end of the folding section especially in the process of contraction of area using the mold when the folding section is provided.

Description

[Detailed description of the invention] Industrial applications The present invention is a sealed silver oxide battery containing an electrolyte.

Mercury batteries, alkaline manganese batteries, zinc air batteries.

2” for lithium batteries, nickel cadmium batteries, etc. It is related to

Structure of a conventional example and its problems An example of a conventional sealed battery will be explained with reference to FIGS. 1 and 2. All of these batteries use lithium as a negative electrode.

1 in the figure is a steel battery case whose surface is coated with nickel.
For example, a cathode material 2 such as manganese dioxide or carbon fluoride is contained therein. 3 is a special steel sealing lid, which is dish-shaped, and its edge has an upwardly folded part 4 in Figure 1, and a cup-shaped opening outward in Figure 2. The edge is 6. Alternatively, the cut may be made vertically downward. 6 is a negative electrode lithium plate inscribed in the sealing lid, and 7 is a separator impregnated with a non-aqueous electrolyte. Reference numeral 8 denotes a polypropylene gasket, and a sealant such as Pro/Asphalt is usually applied to the contact surface 9 between the gasket and the sealing lid and the contact surface 1o between the gasket and the case.

As is clear from Figure 1, the battery constructed in this way is 3''' liquid-tight, depending on the sealing bending angle and uniformity of the bending at the rising end of the metal case, and the dimensional accuracy of the parts. In other words, the leakage resistance of the battery is greatly affected.In particular, if the dimensional accuracy of parts and the accuracy of shape and position (geometric accuracy) are not appropriate, leakage resistance will be affected no matter how the seal is sealed. Improving sexuality is difficult.

OBJECTS OF THE INVENTION The present invention is directed to, among these parts, the lowermost end of the outer circumference folded part of the sealing lid, or the lowermost part of the circumferential edge if there is no folded part.

Structure of the Invention In order to achieve the above object, the present invention has the flatness of the lowermost edge of the sealing lid set to 0.03++ over the entire circumference of the sealing lid.
It is characterized in that it is less than lIl+. Flatness is determined by ■Technical 5B0621 “Definition of shape and position accuracy”
According to ``Flatness is defined as the amount of deviation of a flat part from a geometric plane.''

In the present invention, the flatness of the lowest end of the folded part of the sealing lid or the lowest end of the peripheral edge when there is no folded part means that when the circumferential sleeve part is sandwiched between two geometric planes parallel to each other, the flatness of both halves It refers to the size of the gap between the two halves when the gap is the minimum, and this should be within 0.03 mm.

DESCRIPTION OF EMBODIMENTS FIG. 3 shows an example in which the lowermost end of the sealing lid 3 having a folded part has poor flatness, and FIG. 4 shows an example in which the lowermost end of the sleeve of the sealing lid 3 without a folded part 4 has poor flatness. are shown respectively.

In this way, if the flatness of the bottom end of the sealing lid 3 is poor, even if the edge of the metal case 1 is bent, the pressure applied to the bottom end of the sealing lid will not be equalized, and the electrolyte will leak from the area where the pressure is low. .

In recent years, mechanically processed parts require not only dimensional accuracy but also
Although the accuracy of shape and position (geometric accuracy) is often discussed, the present invention concerns the flatness of the lowermost end of the circumferential folded part of the sealing lid, or the lowermost end of the sleeve if it does not have a folded part. This is to be within 0.03 mm. By setting the pressure to 5 degrees as described above, the pressure applied to the lowermost end of the sealing lid can be made uniform, and the leakage resistance of the battery is improved.

A sealing lid with good flatness can be obtained by selecting the punching and drawing processes and by maintaining mold precision. When a folded part is provided, the flatness of the lowermost end can be improved by hitting the upper end of the folded part with a mold especially during the drawing process.

The reason for setting the flatness within 0.03 mm is that it goes without saying that the smaller the flatness, the better, but as a result of the battery leakage test, as long as it is within 0.03 mm, there is no problem in practical use as a battery. This is because it has become clear that A fluorocarbon lithium battery with an outer diameter of 23mm and a height of 2.0mm was tested.

The test method was to store the battery at 60''C for 1 hour, then immediately store it at -10''C for 1 hour, which was repeated for 30 consecutive days, and then observe the presence or absence of leakage under a 10x microscope.

(1) If there is a fold, 6"' Flatness classification Number of tests Leakage number 0.02w or less 20 0 0.021-0.030 Cylinder 20 00.
031~0.040ran 20 5
0.041 questions or more 20 11 (2) Flatness classification when there is no folded part Number of tests Number of leaks Loveness 0.02
Below the torso 20 00.021~0.030
Tomo 20 2 Extremely minute 0.031~0.
Between 040 2o 110.041mm or more
2o 20 Effects of the Invention As described above, maintaining the flatness of the bottom end of the folded part of the sealing lid, or the bottom end of the periphery of the sealing lid without a folded part, within 0.03 m is important for the leakage resistance of the battery. It has extremely excellent effects.

Although FIGS. 1 and 2 show an example in which the lower surface of the gasket is in direct contact with the inner peripheral edge of the battery case, the same effect was also observed in a configuration in which the lower surface of the gasket is in contact with the mixture.

[Brief explanation of drawings]

Figure 1 is a half-sectional view of a battery that has a folded part on the periphery of the sealing lid, Figure 2 is a half-sectional view of a battery that uses a sealed lid without a folded part on the periphery, and Figures 3 and 4 show flatness. It is a side view which shows a bad sealing lid. 1... Battery case, 2... Positive electrode material, 3...
・- Sealing lid, 4... Folded portion, 5... One edge, 6... Negative electrode, 7... Separator, 8...
...Insulating gasket. Name of agent Patent attorney Toshio Nakao and one other person Procedural amendment (method) 1 Description of the case Patent application No. 46207 filed in 1982 2 Name of the invention Sealed battery 3 Person making the amendment Relationship to the case Patent issue Colonel Wan Address 1006 Kadoma, Kadoma City, Osaka Prefecture Name
(582) Matsushita Electric Industrial Co., Ltd. Representative Yama
Toshihiko Shimo 4 Agent 571 Address Matsushita Electric Industrial Co., Ltd. 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture All drawings are attached to JWA Toshipoto 0 Figure 1 Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) A battery in which a power generation element is sealed by a metal battery case, a metal sealing lid, an insulating gasket, and a sealant liquid-tightly filled between these, and the area around the sealing lid is sealed. A sealed battery whose flatness at the lowest end of the conductor is within 0.03 mm over the entire circumference. (2) The sealed battery according to claim 1, wherein the sealing lid has an upwardly folded rising portion on its periphery. (3) The sealed battery according to claim 1, wherein the sealing lid has no folded portion on the periphery and is cut off at the lowermost end.