JPH0587814U - Square sealed battery - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a square sealed battery in which there is no risk of the battery exploding even when the internal pressure of the battery rises and the swelling of the battery is slight. [Structure] A prismatic metal sealing lid of a prismatic sealed battery is provided with a thin groove portion along the width direction of the battery.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rectangular sealed battery in which the inside of the battery is sealed by using an airtight terminal, and provides a battery structure having excellent safety.

[0002]

[Prior Art]

 In recent years, large currents and large outputs are required for batteries as power sources such as laptop computers, portable information devices such as word processors, camera-integrated VTRs, AV devices such as LCD TVs, mobile communication devices such as mobile phones, etc. There is a wide variety of developing devices and there is a demand for batteries with higher energy density. Furthermore, as equipment becomes thinner and smaller, batteries are also required to be thinner and smaller.

Generally, the shape of the device is rectangular, and it is desirable that the shape of the battery is also rectangular in order to effectively use the space of the device.

Then, in order to meet the demand, various new batteries have been proposed.

However, in order for the battery to be used stably over a long period of time, the battery is caused by a reaction with a battery active material, an electrolyte or the like due to leakage of an electrolytic solution or intrusion of water in the atmosphere into the battery. In order to prevent deterioration of performance, it is necessary to completely seal the battery in terms of both air-tightness and liquid-tightness, and a seal with extremely high airtightness is required.

Conventionally, in this type of battery, as shown in FIG. 5, a hermetic structure using an insulating member (23) such as a glass seal or a ceramic seal has been adopted, and an outer can (21) also serving as a unipolar terminal. The metal sealing lid (22) and the metal sealing lid (22) are welded together by laser welding or the like, and the other polarity terminal pin (24) is fixed through the insulating member (23).

[0007]

[Problems to be solved by the device]

 On the other hand, this type of battery may be exposed to high temperatures, or may experience a sudden temperature rise due to external short circuit or deterioration of electrodes or separators, internal short circuit due to shape change, or forced overcurrent discharge from external power source. If there is, or when the secondary battery is overcharged due to excessive voltage, the electrolytic solution volatilizes or decomposes to generate gas, which is trapped in the battery and the internal pressure of the battery is significantly increased. As it rises, the battery's outer can expands and deforms, damaging the equipment in which the battery is mounted, and sometimes causing the battery to burst, which is a serious safety concern.

In order to prevent the battery from bursting, the insulating member (23) is destroyed when the internal pressure of the battery rises. If the insulating member (23) and the metal sealing lid (22) or the insulating member ( The adhesion between 23) and the terminal pin (24) must be weakened, which causes electrolyte leakage.

Therefore, the present invention has been proposed in view of the above situation, and an object thereof is to provide a battery capable of preventing the outer can of the battery from swelling and bursting when the internal pressure of the battery rises. It is a thing.

[0010]

[Means for Solving the Problems]

 The present invention is intended to obtain a prismatic sealed battery equipped with a safety mechanism capable of preventing the outer can from swelling and bursting. A prismatic metal sealing lid is provided along the width direction of the battery. It is characterized in that a thin groove portion is provided.

[0011]

[Action]

 Generally, in a rectangular battery, the outer can expands in the thickness direction, that is, in the directions (E) and (F) as shown in FIG. 4, when the internal pressure of the battery rises.

Therefore, according to the prismatic sealed battery according to the present invention, since the metal sealing lid is provided with the thin groove portion along the width direction of the battery, the outer can is slightly expanded when the internal pressure of the battery rises. As a result, the thin-walled groove is cracked and the gas inside the battery is easily released to the outside, so that the battery can be prevented from bursting and safety can be improved.

Further, since the swelling of the battery is slight, there is no possibility of damaging the device in which the battery is mounted.

[0014]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a top external view of a prismatic sealed battery according to an embodiment, and FIG. 2 is a cross-sectional view of a main part taken along the line A-A ′ shown in FIG. In FIGS. 1 and 2, (1) is an outer can that also serves as a unipolar terminal, in which a power generation element (not shown) is incorporated.

The outer can (1) is made of a material having excellent conductivity, such as iron, and is drawn into a square shape by a press or the like. The surface of the outer can (1) is usually plated with nickel.

Further, in the present embodiment, the outer dimensions of this outer can (1) were 6.4 mm in thickness, 22.2 mm in width, 77.5 mm in height and 0.4 mm in plate thickness. (2) is a metal sealing lid having a through hole, which is pressed from iron having a plate thickness of 0.4 mm, is inserted inside the outer can (1), and is welded by laser welding. (3) is an insulating member of a glass seal filled in the through hole of the metal sealing lid. (4) is another polarity terminal pin, which is fixed through the insulating member (3). In this embodiment, the terminal pin (4) is made of stainless steel SU S447, which has good adhesion to the glass insulating member (3). (5) is a V-shaped thin groove portion along the width direction of the battery installed in the metal sealing lid (2). The thin groove portion (5) is formed by pressing.

In this embodiment, as shown in FIG. 3, the thin groove portion (5) has a length of 15 mm, a V-shaped angle (C) of 60 °, and a groove depth (D) of 0. It was set to 31 mm.

Next, the cut opening pressure of the thin groove portion (5) was measured. The measuring method is shown below.

First, after laser welding the empty outer can (1) and the metal sealing lid (2) without incorporating the power generation element, a thin copper tube was brazed to the inside of the outer can by silver brazing. Nitrogen gas was injected, and the pressure when the thin-walled groove was opened was measured. The tear opening pressure at this time is 22. It was 4 kg / cm ² .

Further, the swelling of the outer can when the thin groove portion cracked was 7.9 mm at the thickest portion, and the swelling amount was 1.5 mm.

FIG. 5 shows a cross-sectional view of a main part of a conventional rectangular sealed battery.

As a comparative example, in a conventional rectangular sealed battery, as in the example, a thin copper tube was brazed with silver on the side surface of an outer can in which no power generation element was incorporated, and nitrogen gas was press-fitted inside, When the pressure at the time of breaking was measured, when the pressure reached 51.3 kg / cm ² , the laser welded portion between the outer can and the metal sealing lid was cracked and ruptured. The blister of the outer can at this time was 12.7 mm at the thickest part.

In the present embodiment, the thin groove portion is V-shaped, but the same effect can be obtained even if it is U-shaped.

[0025]

As is clear from the above description, according to the prismatic sealed battery of the present invention, when the internal pressure of the battery rises, a slight bulge of the battery causes a crack in the thin-walled groove portion, and the crack causes the battery Since the gas inside is released to the outside, there is no danger of the battery exploding and it is highly safe.Because the battery swells only slightly, the portable equipment equipped with the battery is not damaged and its industrial The value is extremely large.

[Brief description of drawings]

FIG. 1 is a top view of a rectangular sealed battery according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part taken along the line AA ′ shown in FIG. 1 in the embodiment of the present invention.

FIG. 3 is a sectional view of a thin groove portion of the present invention.

FIG. 4 is a schematic diagram of a swollen battery when the internal pressure of the battery rises in a conventional rectangular sealed battery.

FIG. 5 is a sectional view of a main part of a conventional rectangular sealed battery.

[Explanation of symbols]

1 Exterior Can 2 Metal Sealing Lid 3 Glass Seal Insulating Member 4 Terminal Pin 5 Thin Groove 21 Exterior Can 22 Metal Sealing Lid 23 Insulating Member such as Glass Seal or Ceramic Seal 24 Terminal Pin AA 'Thickness Section C Thin Angle of V-shape of groove D Depth of thin wall groove E Direction of expansion of outer can F Direction of expansion of outer can

Claims (1)

[Scope of utility model registration request] 1. An outer can (1) and a metal sealing lid (2), wherein the outer can has a built-in power generating element, doubles as a unipolar terminal, and has a rectangular shape, and the metal sealing lid (2). Is provided with another polarity terminal pin (4) that is welded to the opening of the outer can (1) and electrically conductively fixed, and penetrated and fixed to a through hole formed in the sealing lid through an insulating member (3). A prismatic sealed battery, wherein a thin groove portion (5) is provided in the sealing lid along the width direction.