JPH05129010A - Sealed lead-acid battery - Google Patents

Abstract

PURPOSE:To restrict the mechanical deterioration of films or sheets, and reduce the thermal deformation to improve the reliability of a safety valve part by making resin films or sheets of a safety valve part come close to each other, and bonding the synthetic resin reinforcing material to reinforce the films or the sheets. CONSTITUTION:In a lead-acid battery, the thickness direction of a plate group 4 is pinched to be covered for seal by resin films or sheets 5, 5' having the acid resistance. A small hole 6 is provided at a position, where both the films or the sheets 5, 5' come close to each other, to form a safety valve part. Synthetic resin reinforcing materials 10 are bonded to the films or the sheets 5, 5'. At this stage, the reinforcing material having the heat resistance higher than that of the films or the sheets is used. Mechanical strength of the films or the sheets 5, 5' is thereby increased, and the thermal deformation is reduced to improve the reliability of the operation of the safety valve part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a safety valve portion of a sealed lead acid battery.

[0002]

2. Description of the Related Art In recent years, with the progress of portable devices in particular, the size of a sealed lead-acid battery serving as a power source thereof has come to be restricted. Therefore, as shown in FIGS. The electrode group 4 in which the electrolyte 2 and the negative electrode 3 are arranged on the same plane is sandwiched by resin films or sheets 5 and 5 ′ having acid resistance from both sides and sealed by heat welding at the peripheral joint portion 7, The safety valve is the peripheral joint 7
And a resin film or sheet 5, 5 ′ are brought close to each other by a discontinuous joint portion 8 which is heat-welded without being continuous to this, and silicone oil 9 is injected into this adjacent surface, and a through hole 6 is provided. 1 mm thick sealed lead-acid battery (conventional product) has been proposed. The sealed lead-acid battery having this kind of safety valve part has the above-mentioned resin film or sheet 5,
The positions where the 5's are brought close to each other act to separate and open the valve when the battery internal pressure rises, and close the valve when the battery internal pressure is equal to or lower than the external pressure.

[0003]

In the above-mentioned conventional sealed lead-acid battery, the stress at the time of valve opening / closing of the safety valve portion accumulates in the resin film or the sheet 5, 5 ′ during long-term use, and the proximity of There is a problem that a gap is generated between the resin films or sheets 5 and 5'and the valve closing is incomplete, resulting in poor airtightness. When the peripheral joint portion 7 and the discontinuous joint portion 8 which is not continuous with the peripheral joint portion 7 are formed by heat welding, thermal deformation of the resin film or sheet 5, 5 ′ causes the resin film or sheet 5, 5 close to the safety valve portion. In addition, there is a problem that a gap is formed between the resin films or sheets 5 and 5'and the valve closing is incomplete, resulting in poor airtightness. An object of the present invention is to provide a sealed lead-acid battery provided with a safety valve portion having high operation reliability.

[0004]

To achieve the above object, the present invention relates to a sealed lead acid battery in which the thickness direction of an electrode plate group is sandwiched and sealed by a resin film or sheet having acid resistance, A safety valve portion formed by providing a small hole at a position where the resin films or sheets are brought close to each other, and a synthetic resin reinforcing material on the outer surface of the safety valve portion where the resin films or sheets are brought close to each other. Are joined together, or the synthetic resin reinforcing material has higher heat resistance than the resin film or sheet.

[0005]

The present invention suppresses mechanical deterioration between the resin films or sheets by joining and reinforcing a synthetic resin reinforcing material to the outer surface of the safety valve portion where the resin films or sheets are close to each other. Further, since the synthetic resin reinforcing material has higher heat resistance than the resin film or sheet, it is possible to reduce the influence of thermal deformation and increase the operational reliability of the safety valve portion.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view showing a sealed lead-acid battery as an embodiment of the present invention, and FIG.
It is sectional drawing which follows the A line. For the positive electrode 1 and the negative electrode 3, a paste-like active material material containing lead oxide as a main component is applied by a screen printing method on a current collector made of a lead sheet adhered and fixed onto a resin film or a sheet 5. An active material layer is formed by performing an appropriate treatment. The electrolyte 2 is configured to contain powder or fibers having acid resistance, and is composed of, for example, a gelled substance of silica and an electrolytic solution, and is applied between the positive electrode 1 and the negative electrode 3 by a screen printing method or the like. It is applied. An electrode plate group 4 in which the positive electrode 1, the electrolyte 2 and the negative electrode 3 are arranged on the same plane is sandwiched by a resin film or sheet 5 ′ having an acid resistance from the upper surface and sealed by heat welding at a peripheral joint 7. .. The safety valve portion brings the resin film or the sheets 5 and 5 ′ into close proximity by the peripheral joint portion 7 and the discontinuous joint portion 8 which is heat-welded without being continuous with the peripheral joint portion 7, and the silicone oil 9 is injected onto the adjacent surface. It is formed by providing a through small hole 6.

The resin film or sheet 5, 5'is
Polyethylene terephthalate layer (12μ
m), a polyvinylidene chloride layer (15 μm), a polyethylene terephthalate layer (12 μm), and an unstretched polypropylene layer (60 μm) are used as a laminated film, and a resin film or sheet 5, 5 ′ for a safety valve portion is used. A 1 mm-thick sealed lead-acid battery (invention product 1) having a structure in which a 100 μm-thick synthetic resin reinforcing material 10 made of polyethylene terephthalate is adhered to the outer surface of the positions where the two are in close proximity to each other, and the resin film Alternatively, a sealed lead-acid battery (invention product 2) having a thickness of 1 mm having a structure in which a synthetic resin reinforcing material 10 having a thickness of 100 μm and made of polyimide having heat resistance higher than that of the sheets 5 and 5 ′ is adhered,
Fifty pieces each were made together with the conventional product. In addition, the thermal welding of the peripheral joint portion 7 and the discontinuous joint portion 8 is performed at 200 ° C. for 5 seconds.
The pressure was 3 kg.

Regarding the conventional product, the product 1 of the present invention, and the product 2 of the present invention, the number of the airtight defective states caused by thermal deformation of the peripheral joint portion 7 and the discontinuous joint portion 8 due to heat welding was counted. 10 out of 50, 4 out of 50 of the invention product 1 and 0 out of 50 of the invention product 2 were encountered. Next, among the above-mentioned conventional product, the product 1 of the present invention, and the product 2 of the present invention, the change of the valve opening pressure when the safety valve portion was continuously operated was changed for each of 10 products which did not cause the airtight state. As shown in FIG. The conventional product had a poor airtight state when the number of valve operations was about 500 times, whereas the inventive product 1 and the inventive product 2 had a poor airtight state at about 2000 times. That is, the product of the present invention has about four times the operational reliability of the safety valve portion as that of the conventional product.

[0009]

As described above, the present invention is of great industrial value in that the safety valve portion of the sealed lead-acid battery can be made highly reliable in operation.

[Brief description of drawings]

FIG. 1 is a plan view showing a sealed lead-acid battery (product of the present invention) as an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a plan view showing a conventional sealed lead-acid battery (conventional product).

4 is a sectional view taken along the line BB in FIG.

FIG. 5 is a comparative diagram showing the results of measuring changes in the valve opening pressure of the safety valve portions of the conventional product and the products 1 and 2 of the present invention.

[Explanation of symbols]

1 is a positive electrode, 2 is an electrolyte, 3 is a negative electrode, 4 is an electrode plate group, 5,
5'is a resin film or sheet, 6 is a small through hole, 7 is a peripheral joint, 8 is a discontinuous joint, 9 is silicone oil,
10 is a synthetic resin reinforcement material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hayakawa and others ▲ Ku ▼ Beauty, 2-1-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Within Shin-Kamido Electric Co., Ltd. (72) Inventor Akio Komaki Nishi-Shinjuku, Shinjuku-ku, Tokyo 2-1-1 No. 1 Shinjin Door Electric Co., Ltd. (72) Inventor Keiji Akudo 1-1-6 Uchiyuki-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Tsutomu Ogata 1 Uchi-yuki-cho, Chiyoda-ku, Tokyo 1-6 Nihon Telegraph and Telephone Corporation (72) Inventor Toshio Horie 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. A sealed lead-acid battery in which the electrode plate group is sandwiched and sealed with an acid-resistant resin film or sheet in the thickness direction, and a small hole is formed at a position where the resin film or sheet is close to each other. A sealed lead-acid battery having a safety valve portion provided and formed, wherein a synthetic resin reinforcing material is joined to the outer surface of the safety valve portion at a position where the resin films or sheets are brought close to each other. 2. The sealed lead acid battery according to claim 1, wherein the synthetic resin reinforcing material has higher heat resistance than the resin film or sheet.