JPH0513061A - Thin battery - Google Patents

Abstract

PURPOSE:To provide a thin battery of excellent safety, i.e., no damage to an external apparatus when a gas is generated in the battery due to external shortcircuit, excessive discharging or excessive charging. CONSTITUTION:Terminal plates 4, 5 that also work as collectors, are arranged on the upper and lower parts of a power generation factor for which a positive electrode active material 1, an electrolyte 2, and a negative electrode active material 3 are layered, and the peripheral parts of the terminal plates 4, 5 are sealed by an electrically insulating sealing body 6, and a thin battery is thus formed, for which adhesive power of the sealing body 6 and the terminal plates 4, 5 is locally reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing portion for a thin battery.

[0002]

2. Description of the Related Art In recent years, portable electronic devices and devices using batteries have been rapidly reduced in size and thickness. Along with that, the batteries used as the power source for those electronic devices,
The demand for smaller and thinner products is increasing. In particular, a thin battery using a light metal typified by lithium as a negative electrode active material can be made to have a thickness of 0.1 mm, but it is not possible to provide a safety valve as used in a cylindrical battery. It was For this reason, when the internal pressure of the battery increased, the sealing adhesive part was peeled off and the gas was released to the outside.

[0003]

The peeled portion of the sealing adhesive portion occurs in a portion having a weak adhesive strength due to variations in battery production, and the portion was not specified. Therefore, when the electronic device is built in the vicinity of the portion, there is a problem that the electronic device is damaged by the gas.

The present invention has been made in view of the above problems, and an object thereof is to provide a thin battery excellent in safety.

[0005]

[Means for Solving the Problems] In order to achieve the above object,
According to the present invention, terminal plates 4 and 5 also serving as current collectors are arranged above and below a power generation element in which a positive electrode active material 1, an electrolyte 2 and a negative electrode active material 3 are layered, and peripheral portions of the terminal plates 4 and 5 are arranged. Is a thin battery in which an electrically insulating sealing body 6 is sealed, and the adhesive strength between the sealing body 6 and the terminal plates 4 and 5 is locally reduced. Then, in order to locally reduce the adhesive strength, it is effective that the width dimension W of the adhesive portion is locally reduced so that it can be easily manufactured.

[0006]

[Operation] If the adhesive strength between the sealing body 6 and the terminal boards 4 and 5 is locally reduced beforehand, when the internal pressure of the battery rises,
First, this part is peeled off and gas is released. Therefore, if the passage is provided from this portion to the outside, the electronic device is not damaged.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. 1 is a cross-sectional view of a main part of a battery of the present invention, FIG. 2 is a bottom plan view without a lower terminal plate attached, where 1 is a positive electrode active material, 2 is an electrolyte, 3 is a negative electrode active material, and 4 is a positive electrode current collector. A terminal plate also serving as a body, 5 is a terminal plate also serving as a negative electrode current collector, and 6 is a sealing body.

The positive electrode active material 1 contains manganese dioxide as a main component, and the electrolyte 2 is a solid polymer electrolyte obtained by adding lithium perchlorate to polyethylene oxide. Lithium is used as the negative electrode active material 3. As shown in FIG. 1, a terminal plate 4 made of aluminum foil and a terminal plate 5 made of stainless steel foil are arranged above and below a power generation element in which a positive electrode active material 1, an electrolyte 2, and a negative electrode active material 3 are layered. As the sealing body 6, a thermoplastic resin such as modified polypropylene or modified polyethylene was used, and the peripheral edge portions of the terminal plates 4 and 5 were heated and pressed to perform fusion-sealing. At this time, the temperature and the pressure were changed at predetermined portions to make the adhesive strength weaker than other portions.

As a method of locally reducing the adhesive strength, there is a method of reducing the width dimension W of the sealing body 6 at a predetermined portion 7 as shown in FIG. 2, which ensures the adhesive strength at a predetermined position. It can be made small, and the manufacturing method is simple.

[0010]

Since the present invention is configured as described above, it is designed in advance so as not to damage external equipment when a gas is internally generated due to an external short circuit, overdischarge or overcharge. The safety is ensured because gas is released from a predetermined portion of the charged battery.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a battery of the present invention.

FIG. 2 is a plan view of the battery of the present invention to which a lower terminal plate is not attached as seen from below.

[Explanation of symbols]

1 Positive electrode active material 2 electrolyte 3 Negative electrode active material 4,5 terminal board 6 Sealed body W Adhesive width

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shiro Kato             6-6 Josaimachi, Takatsuki City, Osaka Prefecture Yuasa Battery Co., Ltd.             Inside the company

Claims (2)

[Claims] 1. Terminal plates (4, 5) also functioning as current collectors are arranged above and below a power generation element in which a positive electrode active material (1), an electrolyte (2) and a negative electrode active material (3) are layered. The terminal board (4,
A thin battery in which the periphery of (5) is sealed by an electrically insulating sealing body (6), and the adhesive strength between the sealing body (6) and the terminal plates (4, 5) is locally small. A thin battery characterized by being tightened. 2. The sealing body (6) and the terminal plate (4.
5. The thin battery according to claim 1, wherein the width dimension (W) of the portion bonded to 5) is locally reduced.