JP2003257414A - Sealed battery and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a sealed battery by pouring an electrolyte without installing an electrolyte poring port formed by removing a member. <P>SOLUTION: This sealed battery has an electrolyte pouring port formed by cutting a plate body forming a wall surface of a battery can and deforming the cut part without removing the member from the plate body and an electrolyte pouring port formed from an electrolyte pouring cover part, and after the electrolyte is poured, the electrolyte pouring ports and the electrolyte pouring cover part are welded in one body. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed battery in which a lid placed at the opening of a battery can is sealed by welding, and particularly to a hermetically sealed battery characterized by an electrolyte solution inlet and a method of manufacturing the same. Regarding

[0002]

2. Description of the Related Art In a sealed battery, a lid is attached to the opening of a battery can through a gasket and caulked integrally with the battery can to seal it, or a lid is placed on the opening of the battery can. There is known a sealed battery which is sealed by a method such as laser welding.

As a sealed battery used as a power source for a small electronic device or the like, a rectangular sealed battery which can effectively use a battery storage space is widely used. For example, a prismatic lithium-ion battery for small electronic devices is a positive electrode current collector and a negative electrode current collector each having a positive electrode and a negative electrode manufactured by applying an active material and laminated with a separator interposed therebetween. After storing the wound battery element in the battery can, put a lid on the opening of the battery can to seal it, and inject the electrolyte from the electrolyte injection port provided on the lid or the battery can. After that, a sealing piece is provided at the electrolyte solution injection port, and the sealing piece and the wall surface of the injection port are sealed by welding.

FIG. 6 is a diagram for explaining a conventional process for assembling a sealed battery. As shown in FIG. 6 (A), in the sealed battery 1, the battery element is housed in the battery can 2, and
Welding a battery header 5 having an electrolyte injection port 3, an external electrode lead-out terminal 4, and a pressure release valve for preventing the battery from bursting when the pressure inside the battery rises by irradiating a laser 6 After installing by the method such as
As shown in FIG. 6 (B), after injecting the electrolyte solution into the electrolyte solution injection port 3 from the electrolyte solution injection device, the metal piece 7 is attached, and then,
As shown in FIG. 6C, the metal piece 7 is welded by the laser 5 to seal the electrolyte solution injection port. However,
In such a sealed battery, in order to seal the electrolyte injection port, the step of mounting metal pieces of various shapes such as plate, rod, and sphere on the electrolyte injection port was indispensable. . It is required that after these metal pieces are prepared, they are conveyed by a high-speed conveying means that is suitable for mass production, and that they are accurately attached to the liquid injection port.

However, it was difficult to convey a small metal piece at a high speed and accurately attach it to a predetermined liquid injection port.
In addition, if a small metal piece falls in the manufacturing process, it may have a serious effect on the transport device or the manufacturing device. Further, due to the difference in height between the mounted metal piece and the surrounding metal plate, the focal point may be deviated during laser welding, resulting in defective welding. Alternatively, a method of temporarily fixing the metal piece or adjusting the irradiation direction of the laser to be irradiated at the time of sealing has been proposed, but it does not solve the problem caused by using the metal piece for sealing. There wasn't. In particular, in small batteries, the electrolyte injection port is small and the metal pieces are also small.However, in the automatic conveyance of small metal pieces such as pins and spheres, it is easy to cause conveyance failure and the metal pieces are electrolyzed. It was also necessary to confirm whether or not the liquid was properly attached to the liquid injection port.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a sealed battery for pouring an electrolytic solution into a sealed battery by removing a member from a lid or a battery can without providing an electrolytic solution inlet. It is an object of the present invention to provide a sealed battery that does not require a series of processes such as a process of transporting and mounting a metal piece to a small injection port, confirmation of mounting, and a sealing process by welding a metal piece. It is an object to provide a manufacturing method thereof.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to form a sealed battery without cutting a member from the plate by cutting the plate forming the wall surface of the battery can and deforming the cut portion. It has a liquid injection port and a liquid injection port formed from the liquid injection lid, and the liquid injection port and the liquid injection lid are welded and integrated after the electrolyte is injected. it can. Further, in the above sealed battery, the liquid injection port is formed between the wall surface and a member protruding to the outer surface by cutting the plate-like body while leaving a part of the joint with the wall surface. The injection port is
The sealed battery is formed by a cutting jig that does not form a closed cutting line. In the method for manufacturing a sealed battery, the plate-like body of the lid body attached to the opening of the battery can is cut with a cutting jig having a cutting portion that does not form a closed cutting line, and the plate-like body and a part thereof are joined. After forming the liquid injection lid part, press the liquid injection lid part to the outside of the battery can to form the liquid injection opening with the plate, and then attach it to the opening of the battery can. After welding the contact part with and after sealing the opening of the battery can, after pouring the electrolyte from the pouring opening, press the pouring lid toward the plate side to plate the top of the pouring lid. This is a method for manufacturing a sealed battery, which has the same plane as that of the sheet-like body, and seals the meeting portion between the liquid injection lid portion and the plate-like body by welding.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The sealed battery of the present invention is a battery can,
Alternatively, the member forming the wall surface of the battery header may be partially joined to form an opening for the liquid injection port without completely removing the member from the wall surface, and a metal piece for sealing the opening after the liquid injection. It is one that is fused and integrated without mounting. In the present invention, the opening formed without removing the member in the state where the members forming the wall surface are partly joined together is formed by cutting a part of the wall surface and then deforming the opening to widen the opening. It is formed and means an opening provided from the member forming the wall surface without substantially reducing the mass. Then, using the opening formed in this way as the injection port, the injection port is injected with the electrolytic solution, and then the injection port is fused and integrated to manufacture a sealed battery that does not need to be attached with a metal piece or the like at the time of sealing. It was found that it is possible to do.

The present invention will be described below with reference to the drawings.
FIG. 1 is a diagram for explaining an embodiment of the sealed battery of the present invention, and FIG. 1 (A) is a partially cutaway perspective view showing a state before the liquid injection port is sealed. FIG. 1B is a perspective view illustrating a sealing process. The sealed battery 1 is formed by cutting the battery header 5 while leaving a part of the metal material to form the liquid injection port 3. A circular or horseshoe-shaped injection lid 11 formed from the battery header is connected to the battery header 5 at the injection port 3 by a connecting portion 12, and the injection lid 11 is an outer surface of the battery header 5. With protruding to
The injection port 3 is formed. After injecting the electrolytic solution from the injection port 3, the injection lid portion 11 is pressed to make the surface of the injection lid portion 11 have the same height as the surface of the battery header 5 as shown in FIG. 1 (B). After that, the liquid injection lid 11 can be welded and integrated with the battery header 5 by irradiating the laser 6. As described above, in the sealed battery of the present invention, since it is not necessary to attach a metal piece to the liquid injection port 3, it is not necessary to prepare a small size metal piece for sealing and to supply them. Becomes

FIG. 2 is a diagram for explaining the shape of the liquid injection port provided in the battery header. FIG. 2 (A) is a diagram for explaining the liquid injection port shown in FIG. 1, and is a plan view with a part cut away. Further, FIG. 2B is a cross-sectional view. The liquid injection port 3 is formed between the liquid injection lid part 11 protruding outward from the battery header 5 surface and the battery header 5 surface, and the liquid injection port 3 is formed between the liquid injection lid part 11 and the battery header 5. Has been formed. Also,
The injection port 3 and the injection lid part 11 can be formed by punching from the side of the battery header located on the inner surface side of the battery can using a tool having no cutting blade for the connecting part 12. it can. The diameter A of the opening formed in the battery header 5 of the present invention is preferably 2 / 3d ≦ B ≦ A between the width B of the coupling portion 12 and the width d of the header. Also, the length a of the joint
Is preferably 1 mm or less.

Further, if the angle θ for deforming the liquid injection lid portion 11 from the surface of the battery header 5 to form the liquid injection port becomes too small, the opening of the liquid injection port becomes small, so that the time for injecting the electrolytic solution is reduced. Since there is a problem that it will be longer, 90 ° in consideration of the required size of the injection port, viscosity of the electrolytic solution, etc.
Can be set to a smaller angle.

FIG. 3 is a view for explaining another embodiment of the present invention, and is a view for explaining a cross section of the liquid injection port. Injection port 3
Is the liquid injection lid portion 11 protruding outward from the surface of the battery header 5.
Formed between the battery header 5 and the battery header 5.
Side 11A and side 3A of the liquid inlet 3 of the battery header
Has an inclined surface that is perpendicular to the surface or has a diameter that increases toward the outside. Further, the injection port 3 and the injection lid part 11 are formed by punching out from the side of the battery header located on the inner surface side of the battery can with a tool having no cutting blade at the connecting part 12 and then facing outward. It can be manufactured by pressing and deforming the lid body.

FIG. 4 is a view for explaining another embodiment of the present invention and is a plan view in which a part of the battery header is cut.
In FIG. 4A, a liquid injection port is formed in the battery header 5 in the space between the mountain-shaped liquid injection lid part 11 protruding outward and the surface of the battery header 5, and one side of the triangle forms the connecting part 12. The liquid injection lid 11 is formed and is connected to the battery header 5. The maximum width C of the opening is preferably larger than 1/3 of the width d of the battery header. In addition, in FIG. 4B, a liquid injection port is formed in a space between the battery header 5 and a rectangular liquid injection lid portion 11 protruding to the outside, and one side of the square is the connecting portion 12. And the liquid injection lid portion 11 is connected to the battery header 5. The maximum width C of the opening is preferably larger than 1/3 of the width d of the battery header.

As the liquid injection port provided in the sealed battery of the present invention, various liquid injection ports can be used as long as they are formed without removing the metal plate. Particularly, it is preferable that a part of the metal plate on the wall surface is formed by deforming in a right angle direction,
The surface can be easily made flat by simply pressing from the direction perpendicular to the wall surface after the liquid injection. Further, the cutting line formed in the opening can be of any shape such as a straight line or an arc, but if many cutting lines are formed, it will be possible to use laser welding to integrate the cutting lines. The laser irradiation trajectory becomes complicated and becomes long, which is not preferable.

In the sealed battery of the present invention, the liquid injection port can be formed on any wall surface, but it is preferable to provide it on the battery header. When the battery header is manufactured by press molding a metal plate, It is preferable to manufacture them at the same time. The sealed battery of the present invention can be equipped with a liquid injection means at the liquid injection port to inject a predetermined amount of electrolytic solution,
The liquid injection may be performed by changing the pressure in the battery.

FIG. 5 illustrates a liquid injection method using a liquid injection device that injects liquid according to changes in pressure. Electrolyte injection device 21
Has a liquid injection chamber 24 in which a liquid injection tank 23 having a plurality of unit liquid injection tanks 22 is provided. In the liquid injection chamber 24, a pressure adjusting means 25 capable of arbitrarily adjusting the pressure in the liquid injection chamber is provided. Are combined. The pressure adjusting means 25 has an exhaust means 26 and an atmosphere opening valve 27 capable of reducing the pressure in the liquid injection chamber 24 to a pressure below atmospheric pressure. A plurality of battery cans 2 each provided with a liquid injection port 3 formed by cutting and deforming a part of a plate-shaped body of a battery header are filled with an electrolyte solution 9 with the liquid injection port 3 at the bottom. After accommodating in the unit liquid injection tank 22 provided in the liquid tank 23, the pressure in the liquid injection chamber 24 is set to a predetermined value by operating the exhaust means 26 of the pressure adjusting means 25 to reduce the pressure in the liquid injection chamber 24. Hold for a long time.

Then, the atmosphere release valve 27 is opened, the pressure in the liquid injection chamber 24 is kept at atmospheric pressure, and the pressure is maintained for a predetermined time.
Further, after the pressure in the liquid injection chamber 24 is reduced by operating the exhaust means 26 of the pressure adjusting means 25, the atmosphere release valve 27 is opened to increase the pressure in the liquid injection chamber 24. Hold as atmospheric pressure for a predetermined time. in this way,
By changing the pressure in the liquid injection chamber 24, the electrolytic solution is injected from the liquid injection port 3 into the depressurized battery can 2. After removing the battery can from the filling chamber after the electrolytic solution has been filled, wash the attached electrolytic solution with an organic solvent, etc., and then press the filling lid toward the battery header side, and then the filling lid. Can be sealed by laser welding.

[0018]

EFFECTS OF THE INVENTION The sealed battery of the present invention does not need to be equipped with a metal piece or the like when sealing the liquid inlet of the battery can, and the step of preparing and transporting the metal piece is unnecessary. Since the equipment in the battery manufacturing process can be simplified, there is no risk that the metal piece will fall out of the injection port before welding, and the step of confirming that the metal piece is correctly attached to the injection port is also unnecessary. This enables more stable production of sealed batteries.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of a sealed battery of the present invention.

FIG. 2 is a diagram illustrating the shape of an opening provided in a battery header.

FIG. 3 is a diagram for explaining another embodiment of the present invention and is a diagram for explaining a cross section of the opening.

FIG. 4 is a diagram for explaining another embodiment of the present invention.

FIG. 5 is a diagram illustrating a liquid injection method using a liquid injection device that injects liquid according to a change in pressure.

FIG. 6 is a diagram for explaining an assembly process of a conventional sealed battery.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sealed battery, 2 ... Battery can, 3 ... Liquid injection port, 4 ... External electrode extraction terminal, 5 ... Battery header, 6 ... Laser, 7
... metal piece, 11 ... injection lid part, 12 ... coupling part, 21 ... electrolyte injection device, 22 ... unit injection tank, 23 ... injection tank, 24 ...
Liquid injection chamber, 25 ... Pressure adjusting means, 26 ... Exhaust means, 27 ...
Atmosphere release valve, 28 ... Atmosphere gas supply means, 29 ... Atmosphere gas supply valve, 30 ... Pressurizing means, 31 ... Partition plate, 32 ...
Bottom portion, 33 ... Side wall surface, 34 ... Meeting portion, 35 ... Recessed portion

Continued front page    F term (reference) 5H011 AA09 CC06 DD06 DD07 DD13                       FF02 HH08 JJ12 JJ25                 5H023 AS01 BB01 BB10 CC01 CC11                       CC14                 5H029 AJ14 BJ02 BJ14 CJ04 CJ05                       DJ02 DJ03 EJ01

Claims (2)

[Claims] 1. In a sealed battery, a plate-like body forming a wall surface of a battery can is cut and a cut portion is deformed to remove a member from the plate-like body, thereby forming a filling port and a filling lid. A sealed battery having a formed injection port, wherein the injection port and the injection lid are welded and integrated after injection of the electrolytic solution. 2. A method for manufacturing a sealed battery, wherein a plate-like body of a lid mounted on an opening of a battery can is cut with a cutting jig having a cutting portion that does not form a closed cutting line, And a part of the liquid injection lid are formed, and the liquid injection lid is pressed outward from the battery can to form the liquid injection opening between the plate and the battery can. After mounting and welding the joint with the battery can, after sealing the opening of the battery can, after pouring the electrolyte from the pouring opening, the pouring lid is pressed against the plate-shaped body side to close the pouring lid. A method of manufacturing a sealed battery, wherein the top of the part is formed in the same plane as the plate-like body, and the meeting portion between the liquid injection lid and the plate-like body is sealed by welding.