JPS5821073Y2 - organic electrolyte battery - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of the sealing part of an organic electrolyte battery, and its purpose is to improve leakage resistance.

Organic electrolyte batteries that use light metals such as lithium as negative electrodes have high energy density and are expected to be used as practical battery systems.

Although this battery is said to have less leakage than batteries using alkaline electrolyte, it may leak when stored at high temperatures, and there is a risk of damage to equipment using the battery.

In this type of battery as well, the sealing portion is usually configured such that the opening of the battery case is caulked to the peripheral edge of the sealing plate via a gasket to seal the opening.

However, because organic solvents such as glopylene carbonate, γ-butyrolactone, 1,2-dimethoxyethane, and tetrahydrofuran are used in the electrolyte, gasket materials are currently not used in silver oxide batteries or mercury batteries. If nylon or rubber elastic material is used, it will dissolve or swell in the electrolyte, making it unusable.

Therefore, olefin polymers such as polyethylene and polypropylene, which have electrolyte resistance, are used as gaskets.

However, the olefin polymers generally have a low elastic limit, and even if they are caulked and sealed under high pressure, they will remain deformed and the caulked portion will loosen over time, allowing the electrolyte to leak out. It may be extruded, especially when stored in a so-called heat cycle (-10 to 600C)
) had the disadvantage that this tendency was remarkable.

Measures to prevent liquid leakage include doubling the sealing plate, folding back the ends of the swinging plate, increasing the contact area between the gasket, case and sealing plate, and sealing with adhesive. Until now, various improvements have been made, but none of these improvements improve the drawbacks of the gasket itself, and it cannot be said that leakage of electrolyte solution is sufficiently prevented.

The present invention improves the leakage resistance of organic electrolyte batteries by improving the gasket itself.

In other words, by using a composite gasket in which a gasket made of an olefin polymer is provided with a groove that opens on the end surface exposed to the outside of the battery, and a rubber-like elastic material is inserted into this groove, the electrolyte resistance of the gasket itself is reduced. It imparts elasticity and improves the sealing effect.

Note that the depth of the groove provided in the gasket should be at least as far as the portion facing the edge of the sealing plate; if it is shallower than this, a sufficient sealing effect cannot be expected.

Hereinafter, the present invention will be explained in detail with reference to its embodiments.

FIG. 1 shows a partial cross-sectional view of a battery using a gasket according to the present invention.

1 is a stainless steel battery case that also serves as a positive electrode terminal, 2 is a positive electrode whose active material is a metal halide, oxide, or carbon fluoride inserted into the case, and 3 is a positive electrode fixed to the bottom of case 1. 4 is a separator made of a polypropylene nonwoven fabric, and 5 is an electrolyte-impregnated material also made of a polypropylene nonwoven fabric.

Reference numeral 6 denotes a sealing plate made of the same material as the case and serving as a negative electrode terminal.A metal collector 7 such as nickel net or nickel sponge is fixed to the inner surface of the sealing plate by spot welding, and a disk-shaped metal lithium 8 is attached to the surface of the sealing plate. are crimped together to form the negative electrode.

9 is a gasket.

The electrolyte contains lithium perchlorate and lithium fluoroborate. A solvent or mixed solvent such as carbonate, γ-butyrolactone, 1,2-dimethoxyethane, tetrahydrofuran, etc. is used.

After the positive electrode, separator, electrolyte-impregnated material, and negative electrode bonded to the sealing plate 6 assembled in the case 1 are vacuum-impregnated with electrolyte, the sealing plate 6 with the gasket 9 fitted around the periphery is placed over the case 1, and the case is opened. The ends are caulked to form a sealed battery.

As shown in FIG. 2, the gasket 9 includes a gasket body 1 made of an olefin polymer, for example, polypropylene.
0, and a rubber-like elastic body 11 having strong elasticity, such as styrene-butadiene rubber or butyl rubber.

In this example, the main body 10 has a cross-sectional shape, and is made by injection molding into a shape having a groove 13 that opens at the end face exposed to the outside of the battery, that is, the upper end of the rising part 12 when assembled into the battery. It is rare.

The depth of the groove 13 is equal to the depth of the portion 15 in contact with the end surface 14 of the sealing plate 6.
The rubber-like elastic body 11 is inserted into this groove 13.

Note that the thickness of the rubber-like elastic body 11 is preferably set to a thickness that occupies 50 degrees or more of the rising portion of the gasket 9 in order to fully exhibit its effect.

Since this elastic body 11 does not come into contact with the electrolyte, there is no need to consider electrolyte resistance, and if it has strong elasticity,
The selection is arbitrary.

As explained above, in the battery of the present invention, the rubber-like elastic body inserted into the groove of the gasket body constantly presses the case and sealing plate through the gasket body with high pressure, and the outside is made of an olefin polymer. Therefore, it has appropriate strength and electrolyte resistance, has high elasticity, does not loosen its caulking force, and exhibits excellent leakage resistance even during long-term storage and heat cycle storage.

Next, in order to confirm the effects of the present invention, we compared the leakage resistance performance of the battery A of the present invention according to the above-mentioned example and the battery B using a conventional polypropylene gasket in the size of a button battery. I got similar results.

The test used 100 samples for both A and B, and -1
A heat cycle of storage at 00C for 4 hours and then at 600C for 4 hours was repeated, and the number of batteries with leakage was compared.

As described above, according to the present invention, a highly reliable organic electrolyte battery with excellent leakage resistance can be obtained.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of the main parts of an embodiment of the battery of the present invention;
FIG. 2 is a longitudinal sectional view of the main part of the gasket. 1...Battery case, 6...Sealing plate, 9
... Gasket, 11 ... Rubber-like elastic body, 13 ... Groove.

Claims (1)

[Scope of utility model registration request] In a battery in which the opening of the battery case is caulked to the peripheral edge of a sealing plate through a gasket made of an olefinic polymer, the gasket has an opening on the end surface exposed to the outside of the battery and a sealing plate with an opening on the edge of the sealing plate. Provide grooves with opposing depths,
An organic electrolyte battery is made by inserting a rubber-like elastic material into this groove.