JPH0845488A - Sealed type battery - Google Patents

Abstract

PURPOSE:To eliminate danger such as spark generation at the time of resistance welding and prevent welding failure due to the abrasion of an electrode by performing the airtight sealing by a sealing plug for a battery case or a sealing lid plate by ultrasonic welding. CONSTITUTION:This sealed type battery is provided with a battery case 1 incorporated with a power generation element and a sealing lid plate 2 for blocking the opening part of the battery case 1, and a liquid pouring hole 7 is formed on the battery case 1 or the sealing lid plate 2. The liquid pouring hole 7 is airtightly sealed by ultrasonically welding (18: ultrasonic horn) a sealing plug 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery as a power source for driving portable equipment.

[0002]

2. Description of the Related Art In recent years, a large current is supplied to a battery as a power source such as a laptop computer, a portable information device such as a word processor, a camera integrated VTR, an AV device such as a liquid crystal television, a mobile communication device such as a mobile phone and the like. A wide variety of devices that require high output have been developed, and higher energy density is required.

In the meantime, as a method of manufacturing a sealed battery, a positive electrode plate and a negative electrode plate are first wound or laminated with a separator interposed therebetween to form an electrode group, and a positive electrode lead and a negative electrode are attached to a sealing lid plate in advance. The lead is welded to the lead taken out from the positive electrode plate and the negative electrode plate and inserted into the battery case. Then, the electrolytic solution is injected, the opening of the battery case is closed with a sealing lid plate, and laser welding or caulking of the upper part of the battery case is performed inside to seal the battery case.

However, in this method, the electrolytic solution adheres to the opening of the battery case at the time of pouring the electrolytic solution, which causes a pinhole during laser welding between the battery case and the sealing cover plate. Further, also in the case of caulking, the electrolyte solution adheres to the caulking portion, which causes liquid leakage. Therefore, as a solution to this problem, after sealing the battery case with the sealing lid plate, inject the electrolytic solution from the injection hole formed in the battery case or the sealing lid plate, and use resistance welding to fill the liquid. A method has been proposed in which the hole is sealed with an injection plug to be integrated with the battery case or the sealing lid plate.

In this method, there are no pinhole defects during laser welding, and there is no liquid leakage even when caulking, so that an excellent mass production effect is brought about.

[0006]

However, sparks are generated during the resistance welding, and there is a risk that, for example, in an organic electrolyte battery using metallic lithium, the heat of the sparks may cause ignition. Further, since the welding failure occurs due to the abrasion of the electrode rod tip of the resistance welding, it is an issue to obtain a safe and reliable sealing method.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by ultrasonically welding the airtight sealing of a battery case or a sealing lid plate with a sealing plug.

[0008]

According to the battery of the present invention, by using ultrasonic waves, the liquid injection hole can be hermetically sealed by the sealing plug without generating a spark unlike resistance welding, and there is no welding failure due to wear of the electrode.

[0009]

Embodiments of the present invention will be described in detail below with reference to the drawings. [Embodiment 1] FIG. 1 shows a top view and a side sectional view of a main part of a sealed battery according to the present invention. In FIG. 1, 1 is a battery case made of aluminum which also serves as a positive electrode terminal and a power generating element (not shown). Is built in. 2 is a sealing lid plate, 3 is a diameter 1.1
mm spherical stopper plug (not shown in spherical shape in FIG. 1 since it is shown after sealing), both of which are made of aluminum. 7 is a liquid injection hole having a diameter of 1 mm. 4 is an insulating packing made of polypropylene resin, 5 is a stainless steel rivet also serving as a negative electrode terminal, 6 is a stainless steel washer, and the rivet is passed through the through hole of the packing and the tip of the rivet is crushed and fixed by the washer. . The battery case and the sealing lid plate are sealed by caulking the upper end of the battery case opening inward.

After pouring the electrolytic solution through the pouring hole, an aluminum sealing plug 3 was placed in the pouring hole, and the head of the sealing plug was integrated with the sealing lid plate by ultrasonic welding and hermetically sealed.

FIG. 2A is an enlarged view of a welded portion when the sealing plug 3 is welded to the sealing lid plate 2 by ultrasonic waves.
The sealing plug 3 is placed in the liquid injection hole 7, the ultrasonic horn 18 presses the sealing plug 3 using the pressure of air, and the ultrasonic horn 18 laterally vibrates to weld the sealing plug 3 and the sealing lid plate 2. Be integrated.

FIG. 2B is an enlarged view after welding, showing that the sealing lid plate 2 and the sealing plug 3 are integrated. [Embodiment 2] FIG. 3 shows a top view and a side sectional view of a main part of a sealed battery of the present invention. In FIG. 2, 11 is a battery case which also serves as a negative electrode terminal and which contains a power generating element (not shown). A liquid injection hole 17 having a diameter of 1 mm is formed on the side surface of the battery case. Reference numeral 12 is a sealing lid plate, 13 is a spherical sealing plug having a diameter of 1.1 mm (the spherical shape is not maintained because the figure after sealing is shown in FIG. 2), and both are made of aluminum.
14 is an insulating packing made of polypropylene resin, 1
Reference numeral 5 is a stainless steel rivet also serving as a negative electrode terminal, and 16 is a stainless steel washer. The battery case and the sealing lid plate were sealed by caulking the upper end of the battery case opening inside.

Then, after injecting the electrolytic solution through the injection hole, an aluminum sealing plug 13 was pressed into the injection hole, and the head of the sealing plug was integrated with the battery case by ultrasonic welding to hermetically seal it.

In the second embodiment, the liquid injection hole is formed on the side surface of the battery case. However, since the periphery of the liquid injection hole is a curved surface as shown in FIG. 2, the liquid injection plug is welded when the liquid injection plug is welded. If the horn part of the ultrasonic welding machine is flat, it cannot be hermetically sealed, so the horn of the ultrasonic welding machine was processed and welded according to the shape of the curved surface of the battery case.

[0015]

As described above, according to the present invention, a spark like resistance welding is generated by sealing the liquid injection hole formed in the battery case or the sealing cover plate by ultrasonic welding. It is excellent in safety without being used, and there is no welding failure due to wear of the electrode, and its practical value is extremely large.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an upper surface and a side surface of a sealed battery of an embodiment.

FIG. 2 is an enlarged view of a welded portion of the sealed battery of the embodiment.

FIG. 3 is a cross-sectional view of an upper surface and a side surface of a sealed battery of another embodiment.

[Explanation of symbols]

 1 Battery case 2 Sealing lid plate 3 Sealing plug 4 Insulating packing 5 Rivet 6 Washer 7 Injection hole 11 Battery case 12 Sealing lid plate 13 Sealing plug 14 Insulating packing 15 Rivet 16 Washer 17 Injection hole 18 Ultrasonic horn

Claims (2)

[Claims] 1. A battery case containing a power generating element and a sealing lid plate for closing an opening of the battery case, wherein the battery case or the sealing lid plate is provided with a liquid injection hole. The sealed battery is characterized in that the liquid injection hole is hermetically sealed by ultrasonically welding a sealing plug. 2. A method for manufacturing a sealed battery, comprising the step of ultrasonically welding a sealing plug to the liquid injection hole.