JP2535040Y2 - Sealed batteries and electronic devices incorporating the sealed batteries - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a sealed battery of a primary battery system such as a manganese battery, an alkaline battery, and a lithium battery, and a secondary battery system such as a nickel-cadmium battery, a lead storage battery, and a lithium battery. Related to a safety valve device.

[Conventional technology]

A safety valve device used in a conventional sealed battery is disclosed in Japanese Utility Model Publication No. 59-15398. That is, as described with reference to FIG. 3, the assembled sealing unit A 'provided with the safety valve device has a cover plate 7 having a valve hole 7a and a gas vent hole 1a at the center, and the bent edge of the cover plate 7 A terminal plate 1 to be crimped, and a valve body 6 made of a flexible thin plate whose peripheral edge is sandwiched between the lid plate 7 and the terminal plate 1 and always closes the valve hole 7a.
And a part of the terminal plate 1 is bent inward to form a cutting blade 1b facing the valve body 6. Further, the flexible thin plate is formed of a metal plate, a synthetic resin, or a composite member thereof. An assembled sealing unit A 'is incorporated into an opening of a metal case 8 also serving as a terminal in which the power generating element B is mounted via an insulating gasket 9 and is sealed with the machine. In the battery, when the electrolyte is decomposed and gas is generated due to some abnormality such as an internal short circuit or external charging, the internal pressure of the battery increases. When the battery internal pressure reaches a predetermined pressure, the valve element 6 expands upward by gas pressure through the valve hole 7a, the valve element 6 is broken by the cutting edge 1b or the gas pressure, and gas in the battery passes through the valve hole 7a. As a result, the battery is exhausted into the atmosphere through the gas vent hole 1a of the terminal plate 1 to prevent the battery from being broken.

[Problems to be solved by the invention]

However, in the case of the above method, after the valve is ruptured, the inside of the battery and the atmosphere are kept open through the rupture of the valve, so that the electrolyte leaks and the equipment used is corroded. cause. In addition, in primary and secondary batteries using lithium for the negative electrode, there is a problem of secondary damage, such as a risk of air components entering and active lithium reacting with oxygen to generate heat and ignite.

[Means for solving the problem]

In order to solve the above-mentioned problems, the present invention always closes the valve hole in the assembled sealing unit with the valve body, and furthermore, breaks the sealing plate so as to close the gas vent hole in the upper part of the valve body. The sealing plate is disposed via a breaking member provided with a cutting blade for pressing, and the sealing plate is pressed and held toward the inside of the battery by an elastic body which operates at a lower pressure than that for breaking the valve body. That is, when the gas pressure in the battery abnormally increases, the valve body swells above the battery,
The valve is destroyed by the cutting blade. Further, the elastic body is compressed and the sealing plate is pushed up to be discharged into the atmosphere from the gas vent hole of the terminal plate. When the gas is discharged and the pressure inside the battery falls below the operating pressure of the elastic body, the sealing plate again closes the gas vent hole due to the repulsive force of the elastic body and shuts off the atmosphere from the inside of the battery.

[Action]

By shutting off the inside of the battery and the atmosphere after the gas is discharged by the sealing plate, it is possible to prevent the electrolyte from leaking out even when the valve element is broken. In addition, in the case of a lithium battery, the penetration of atmospheric components is slowed down by shutting off by a sealing plate, and a rapid reaction between active lithium and oxygen is suppressed.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples.
FIG. 1 is a sectional view of a main part of a sealed battery using an assembled sealing unit provided with a safety valve device according to the present invention, and FIG. 2 is a plan view of a sealing plate. In the figure, A is an assembled sealing unit, which has a SUS dish-shaped lid plate 7 provided with a valve hole 7a, a valve body 6 made of a SUS thin metal plate which always closes the valve hole 7a, and a gas vent hole 5a. Polypropylene resin ring 5, valve body 6
A breaking member 4 made of SUS having a sharp cutting edge 4b opposed to a gas vent hole 5a and a gas vent hole 4a smaller than the inner diameter of the resin ring 5, a plurality of notches 3b on the outer periphery, It has a notch inner diameter 3a larger than the inner diameter of the gas vent hole 4a, a SUS sealing plate 3 placed to close the gas vent hole 4a, an elastic body 2 made of silicone rubber, and a gas vent hole 1c. It is composed of a terminal plate 1 made of SUS. B is a power generating element in which a sheet-shaped positive electrode and a sheet-shaped negative electrode are spirally wound via a separator made of a microporous polypropylene sheet. Manganese dioxide was used as a positive electrode main active material, carbon powder was used as a conductive material, a fluororesin emulsion was used as a binder, a net made of SUS was used as a core material, and metallic lithium was used as a negative electrode active material. The assembled sealing unit A is inserted through an insulating gasket 9 made of polypropylene into the opening of the metal case 8 in which the power generating element B is mounted and the outer periphery of which is provided with a horizontal U-shaped annular restrictor 8a. It was caulked inside and hermetically sealed. In the present embodiment, a synthetic resin elastic body made of silicone rubber was used as the elastic body, but since it does not come into contact with the electrolyte solution in the battery, it is not necessary to consider alkali resistance and organic solvent resistance so much, and other polymer resins and Any material having elasticity such as rubber may be used. Further, a coil spring made of metal or the like may be used. The sealing plate may be made of a synthetic resin or a composite material thereof in addition to a metal. The sealing plate may have various shapes such as a circle, an ellipse, and a polygon, but as shown in FIG. Preferably, a plurality of notches are provided. Further, in the embodiment, in order to increase the contact area between the sealing plate 3 and the breaking member 4 and to improve the sealing property, the inside diameter of the gas vent hole 4a of the breaking member 4 is smaller than the inside diameter of the gas vent hole 5a of the resin ring 5. However, the inside diameter of the gas vent hole 4a may be the same as or larger than the inside diameter of the gas vent hole 5a. Further, in the embodiment, only the case of a cylindrical battery is shown, but the present invention is not limited to a cylindrical battery, and can be applied to batteries of any shape such as a square battery, an elliptical battery, a sheet battery, and a flat battery. .

[Effect of the invention]

As described above in detail, the safety valve device according to the present invention can provide a highly reliable sealed battery. Further, since the sealing plate of the present invention is disposed between the valve body and the terminal plate, it has an excellent effect of preventing the electrolyte from flowing out even if the valve body is broken.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part of a sealed battery using a safety valve device according to the present invention, FIG. 2 is a plan view showing an example of a sealing plate according to the present invention, and FIG. 3 is a sealing device using a conventional safety valve device. FIG. 3 is a cross-sectional view of a main part of the battery. A, A ': Assembled sealing unit B: Power generation element 1: Terminal plate 1a, 1c: Gas vent hole 1b: Cutting blade 2: Elastic body 3: Sealing plate 3a: Notch inner diameter 3b Notch 4 Breaking member 4a Gas vent hole 4b Cutting blade 5 Resin ring 5b Gas vent hole 6 Valve body 7 Cover plate 7a Valve hole 8 Metal case 8a …… Circular aperture 9 …… Insulating gasket

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kensuke Tahara 5-30-1, Nishitaga, Taihaku-ku, Sendai City, Miyagi Prefecture Inside Seiko Electronic Components Co., Ltd. (72) Inventor Hideki Ishikawa 5--30 Nishitaga, Taihaku-ku, Sendai City, Miyagi Prefecture No. 1 Inside Seiko Electronic Components Co., Ltd. (56) References JP-B-47-4216 (JP, B1) JP-B-45-39149 (JP, B1)

Claims (1)

(57) [Scope of request for utility model registration] 1. A battery having a diaphragm-type safety valve device that breaks a valve body made of a flexible thin plate sensitive to the internal pressure of the battery with a cutting blade, wherein a cutting blade (6) is provided above the diaphragm valve body (6). 4b), the gas vent hole (4a) at the upper part of the cutting blade (4b) is closed, and a plurality of notches (3b) are provided on the outer periphery, and the cutout is larger than the inner diameter of the gas vent hole (4a). An elastic body (2) having a sealing plate (3) having a notched inner diameter (3a), and pressing the sealing plate (3) inward of the battery, and a terminal plate on the elastic body (2) A battery comprising (1).