JPS59857A - sealed battery - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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.

This relates to lithium batteries, nickel-cadmium batteries, etc.

Structure of a conventional example and its problems A typical example of a conventional sealed battery will be explained with reference to FIGS. 1 and 2. This is an example of a silver oxide battery, and FIG. 2 is an enlarged view of its sealed portion. In the figure, 1 is a steel case whose surface is nickel plated, and has a cylindrical rising portion 2. 3 is a positive electrode mixture consisting of silver oxide and graphite, and 4 is a positive electrode metal ring. 6 is a separator, 6 is nickel on the outside, copper on the inside,
It is a sealing lid whose core is made of stainless steel, its periphery is in the shape of an inverted dish, and its tip is folded back into a U-shape and has a rising portion 7 facing outward and upward. 8 is a negative electrode mixture consisting of zinc hydrate particles and an alkaline electrolyte, 9 is an insulating gasket made of nylon, and the gap between the inner wall of the gasket 9 and the sealing lid rising part is filled with blown asphalt, polyamide, etc. The sealant 10 exists in the form of a thin film. The tip 11 of the rising portion 2 of the metal case 1 is bent inward with the gasket 9 sandwiched between the sealing lid 6 and sealed liquid-tightly.

In general, the leakage resistance of a battery is greatly influenced by the bending angle of the metal case, the uniformity of the bending, the dimensional accuracy of the parts, etc.

In particular, if the dimensional accuracy and shape and positional accuracy (geometrical accuracy) of the parts are not appropriate, the leakage resistance will be extremely poor.

Purpose of the Invention The present invention provides a method for reducing the roundness of the portion of the dish-shaped sleeve portion of the sealing lid where the bent tip of the rising portion of the metal case faces within a certain limit through a gasket.
The present invention provides a sealed battery with excellent leakage resistance.

According to ``Definition and Indication of Accuracy of Shape and Position'', ``Circularity refers to the amount of deviation of a circular part from a geometrical circle.'' The expression is as follows: [Curularity is expressed as the difference in radius between two ends when the distance between the ends is the minimum when a circular part is sandwiched between two concentric geometric circles.'' That is, in Fig. 3, the circularity of circle B with respect to geometrical circle A is determined by the geometrical circle C concentrically inscribed in circle B and the geometrical circle C concentrically circumscribed and circumscribed , is expressed by the radius difference f from the circle.

In the present invention, this f is set to 0.03 wh or less to improve leakage resistance.

DESCRIPTION OF THE EMBODIMENTS In FIG. 2, the electrolytic solution normally passes between the gasket 9 and the sealing lid 6 and leaks to the outside. In that case, there are three points to prevent electrolyte leakage: the lowest end 12 of the sealing lid 6, the tip 13 of the U-shaped raised part, and the band-shaped portion 14 of the sealing lid facing the tip of the metal case. . These three points are the areas where external pressure is applied the most,
In particular, the band-shaped portion 14 is located at the outermost of the three points, and is the final part to prevent liquid leakage, and is extremely important. If the shape of this part deviates significantly from its geometric accuracy, a weak pressure area will occur, and leakage will occur from there.

For machined parts, not only dimensional accuracy but also shape and positional accuracy (geometric accuracy) is extremely important.
The present invention aims to reduce the roundness of the portion of the sealing lid that faces the tip of the two parts of the metal case to within 0.03 degrees. By maintaining it in this manner, the sealing pressure can be made uniform, and the leakage resistance of the battery is improved.

A sealing lid with good roundness can be obtained by selecting the punching and drawing process, maintaining mold precision, and improving the mold separability.

The reason why the roundness was set to within 0.03 wIb was that a battery leakage test revealed that there would be no practical problem if the roundness was within 0.0311711.

Now, silver oxide batteries with an outer diameter of 11.6 m and a height of 6.4 mm were fabricated and tested using sealing lids with different roundness. The test method is to test the battery at a temperature of 46±2℃ and a relative humidity of 90~9℃.
The sample was stored continuously for 1,500 hours in Section 5, and after being taken out and left at room temperature and humidity for 3 days, it was observed under a microscope with a magnification of 1° to determine the presence or absence of leakage. The results are shown in the table below.

0.02M or less 20 pieces O.

O,021~0.03M 2o pieces 0
00.031NL or more 20 pieces 8 pieces
3 Effects of the Invention In this way, making the circularity of the part where the rising end of the metal case of the sealing lid faces each other via the gasket to within 0.03 is extremely significant in improving the leakage resistance of the battery. There is an effect.

[Brief explanation of drawings]

FIG. 1 is a half-sectional view of a button-type silver oxide battery, FIG. 2 is an enlarged sectional view of the main part of the seal, and FIG. 3 is a diagram for explaining roundness. 1... Metal case, 2... Standing part, 3... Positive electrode mixture, 6... Separator, 6... Sealing Lid, 7... Rising part folded in a U-shape, 8... Negative electrode mixture, 9...
...Insulating gasket, 10...Sealant, 11
...Tip of the rising part of the case, 14...
The band-shaped part of the sealing lid that faces the tip of the rising part of the case.

Claims (1)

[Claims] The metal case includes a metal case, a dish-shaped sealing lid having a raised edge folded upward on the outer periphery, an insulating gasket, and a sealant present between at least the rising portion of the sealing lid and the gasket. The battery is formed by bending the rising edge of the metal case inward and sealing it, and the circularity of the sealing lid portion where the rising edge of the metal case faces with a gasket interposed therebetween is 0.0.
A sealed battery that has a patent of 3 words or less.