JPS62117256A - Sealed battery - Google Patents

Abstract

PURPOSE:To increase and stabilize the liquid leakage resistance of a sealed battery by determining the positional relationship between the folded section and the expanded section of the sealing plate to maximize the compressibility of the gasket at the upper end of the folded section of the sealing plate. CONSTITUTION:During processing of a sealing plate 8, the dimensional accuracy of the diameter (phi) and the height (h) of the folded section is produced in order to produce the dimensional accuracy of the upper end 8c of the folded section and to make the vertical angle of a cone formed by connecting the upper end 8c and an expanded section 8c at least 90 deg.. As a result, the compression (d) of the gasket at the upper end 8c of the folded section with superior dimensional accuracy and physical strength becomes higher than the compression (e) of the gasket at an expanded section 8b and a compression rate of 65-75% effec tive for liquid leakage resistance can be easily maintained, thereby stably sealing condition is obtained for the battery.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is applicable to mercury batteries, silver oxide batteries, lithium batteries, etc.
It relates to a sealed battery in which the power generation element is liquid-tightly sealed by a battery case, a sealing plate, and a gasket.

(Prior Art) An example of the structure of a conventional sealed battery will be described with reference to FIG. 4, using a silver oxide battery as a representative example.

FIG. 4 shows a cross-sectional view of a conventional silver oxide battery.

At the inner bottom of the bottomed cylindrical metal case l, a positive electrode mixture 2 made by pressure-molding a mixed powder of silver oxide, manganese dioxide, graphite, etc. is arranged. The positive J mixture 2 is held by the positive electrode ring 3, and the semi-9
Impregnating materials 5 impregnated with an electrolytic solution are arranged on each of the rotors 4, and a negative electrode mixture 6 made of a mixed powder of frozen zinc, a thickener, etc. is arranged in the impregnating materials 5. . After injecting an alkaline electrolyte between the positive electrode mixture 2 and the negative electrode mixture 6, a gasket 7 is placed in the positive image case 1 containing the above-mentioned component materials.
The end of the positive electrode case 1 is curved inward using a sealing mold to liquid-tightly seal the positive electrode case 1. The gasket 7 is made of a synthetic comb with excellent elasticity and flexibility, or synthetic resin with excellent aging resistance and mechanical strength, and is ring-shaped with an approximately L-shaped cross section. There is. The sealing plate 8 is a single plate having an approximately inverted dish shape in order to close the opening 1 of the positive electrode coos 1.
It has a U-shaped folded part 8a on its peripheral edge, and a step-shaped bulge 8b on the inside upper part of the folded part 8a.
A folded upper end portion 8c is provided at the outer end of the folded portion 8a.

(Problems to be Solved by the Invention) In the configuration of the conventional sealed battery, if it is stored under high temperature and humidity, for example at 45° C. and 90° C. or 60° C. and 90° C., the sealed battery leaks early during storage. There was a problem that many batteries were generated. In addition, the above-mentioned high temperature and humidity atmosphere is
This is used as one of the acceleration conditions for estimating the storage period under normal temperature and normal humidity.

The cause of the above problem lies in the shape of the sealing plate of the battery sealing part. Since the apex angle of the conical shape connecting the upper end of the folded sealing plate and the bulging part is less than 90°, when the end of the positive electrode case is curved inward, the upper end of the folded sealing plate is smaller than the bulged part of the sealing plate. The cause of the problem was that the compressibility of the Gaskent part was low, and moreover, it was lower than the compression ratio of 65 required to ensure leakage resistance.

In addition, it is well known that the hanging position of the gasket should be at the upper end of the folded sealing plate. is a golden rule.

(Means for Solving the Problem) In order to solve the above-mentioned problem, the present invention determines the positional relationship between the folded part and the folded bulge part of the sealing plate, so that the compression ratio of the gasket is increased at the folded upper end. The present invention provides a sealed battery having a sealing plate shape that increases the height of the battery.

(Function) With the above structure, the tightness of the gasket at the folded upper end of the sealing plate is increased, thus the sealing portion is stabilized, and the storage leakage resistance of the sealed battery under high temperature and high humidity is improved. Become.

It should be noted that achieving dimensional accuracy of the folded upper end is very easy to achieve in terms of press processing, and when the end of the positive electrode case is bent inward, the folding provides strength as an internal resistance force, and the gasket is The best position for tight compression is the folded upper end.

(Example) A sealed battery of the present invention will be described with reference to FIGS. 1 to 3, using a silver oxide battery SR920SW with a diameter of 9.5 m and a height of 2.0 m as an example.

FIG. 1 shows a cross-sectional view of the silver oxide battery of the present invention.

At the inner bottom of the bottomed cylindrical metal case 1, there is a positive electrode mixture 2 made of a pressure-molded mixed powder of silver oxide, manganese dioxide, graphite, etc.
is located. The positive electrode mixture 2 is held by a positive electrode ring 3, a separator 4 is placed on top of the positive electrode mixture 2, and an impregnated material 5 impregnated with an electrolyte is placed on top of the separator 4. The impregnating material 5 is provided with a negative electrolyte mixer 6 made of a mixed powder of frozen zinc, a thickener, etc. LE polar mixture 2
and the negative electrode mixture 6 (after injecting the alkaline electrolyte,
On each component side, combine the sealing plate 8 with the gasket 7 attached to the positive electrode case 1 containing all 14 parts,
Using a sealing mold, the end of the positive electrode case 1 is curved inward and sealed in a liquid-tight manner. In addition, the gasket 7 is elastic,
It is made of synthetic rubber with excellent flexibility or synthetic resin with excellent aging resistance and mechanical strength, and has a ring-shaped cross section. In order to close the opening of the positive electrode case 1, the sealing plate 8 is a single plate having an approximately inverted dish shape.
It has a folded part 8a continuous in a U-shape (d) on its peripheral edge, and a step-shaped bulge 8b on the inside upper part of the folded part 8a.
A folded upper end portion 8c is provided at the outer end of the folded portion 8a.

FIG. 2 shows a cross-sectional view of the sealing plate of the sealed battery of the present invention.

When processing the sealing plate 8, by ensuring the accuracy of the diameter φ and the folding height h, the accuracy of the folded upper end portion 8C is achieved,
The apex angle of the cone connecting the folded upper end portion 8c and the bulging portion 8b is 17° with a shape of 90° or more.

FIG. 3 shows a cross-sectional view of the sealed portion of the sealed battery of the present invention. With the above configuration, the compression of the gasket at the folded upper end portion 8c (a), which has reached a state where both dimensional accuracy and mechanical strength (final strength) have been immediately improved, is made higher than the compression at the folded bulge portion 8b (b). In addition, a compression ratio of 65 to 7596, which is effective for liquid leakage resistance, could be easily maintained, and a stable sealing state could be obtained.

Batteries A and B of the present invention and conventional batteries C and 0610
The number of leaking batteries that occurred when 0 batteries were stored in an atmosphere of 45°C and 90°C is shown in the table below.

In addition, battery A has an apex angle of 90°, a gasket compression rate of 68%,
Battery B had an apex angle of 120' and a gasket compression ratio of 73%, Battery C had an apex angle of 85° and a slit compression ratio of 60%, and Battery D had an apex angle of 60° and a gasket compression ratio of 42%.

As shown in Table V, the folded upper end portion 8c of the sealing plate and the bulging portion 8
It can be seen that it is important to form the apex angle of the cone connecting b to 90 degrees or more in order to stabilize the leakage resistance.

(Effects of the Invention) As described above, according to the present invention, the effect of improving and stabilizing the leakage resistance of a sealed battery can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the silver oxide battery of the present invention, FIG. 2 is a partially cutaway front view of the sealing plate of the battery, FIG. 3 is a sectional view of the sealing part of the battery, and FIG. 4 is a conventional silver oxide battery. FIG. 2 is a cross-sectional view of a silver oxide battery. DESCRIPTION OF SYMBOLS 1... Positive electrode case, 2... Positive electrode mixture, 3... Positive electrode ring, 4... Separator, 5... Impregnation material, 6...
... Negative electrode mixture, 7... Gasket, 8... Sealing plate,
8a... Sealing plate folded part, 8b... Sealing plate bulge part,
8c... Upper end of folded sealing plate. 5+! J1 figure 4, - t bar 8a, i pressure sign evil 8b, - swelling: i, evil 8c,...HT arbitrary LfJml figure 2 figure 3

Claims (1)

[Claims] A gasket made of synthetic resin and synthetic rubber is attached to the side of the sealing plate, and the opening of the battery case is sealed by an assembled sealing body, and the opening of the battery case is tightened toward the periphery of the gasket to seal it. In batteries,
A folded part continuous in a U-shape on the outer peripheral edge of the sealing plate,
A step-shaped bulge is provided at the inner upper part of the folded part, and the apex angle of a cone connecting the bulged part and the outer upper end of the folded part is 90° or more. sealed battery.