JP2003051294A - Sealed cell and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed cell improved in sealing property by welding a hermetic sealing plate to an open end of a cell jacket for sealing the cell jacket. SOLUTION: An electrolyte is charged into a cell jacket 1, containing a group 2 of plates, and an open and of the cell jacket 1 is caulked through a gasket 8 to temporally seal the cell jacket 1. After the electrolyte attached to site to be welded is removed by cleaning, since a cell temporally sealed can be subjected to a cleaning step, the cell jacket 1 is welded to its contact site of a hermetic sealing plate 3 by laser welding, whereby a sealed cell welded precisely can be produced, without causing welding failures by attachment of the electrolyte.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery in which a battery can containing a power generating element is completely sealed from the outside air so that stable energy can be taken out for a long period of time, and a method for manufacturing the sealed battery. is there.

[0002]

2. Description of the Related Art A lithium thionyl chloride battery is known as a battery capable of obtaining a stable output voltage over a relatively long period of time. The thionyl chloride used as a reactant in this battery decomposes in the air, so a completely sealed structure that shields it from the outside air is adopted to enable stable use over a long period of time. Further, even in a lithium manganese dioxide battery or the like, in order to be able to stably use the battery for a long period of time, a completely sealed structure is required so as to prevent water from entering the battery.

The completely sealed structure welds the open end of the battery can containing the power generating element so that the open end can be completely sealed by the sealing plate. In addition, an output terminal connected to a power generation element in a battery can, generally a positive electrode terminal, is insulated and fixed from a negative electrode by a glass hermetic seal to improve airtightness.

FIG. 4 is a cross-sectional view showing a conventional structure of a sealed battery, in which a battery can 31 formed in a cylindrical shape with a bottom is insulated by an upper insulating ring 38 and a lower insulating ring 39, and an electrode plate group 3 is formed.
2 is accommodated, and the open end of the battery can 31 is sealed by a hermetic sealing plate 33. Hermetic sealing plate 3
3 is a battery can 3 at the opening part opened in the center of the sealing plate 33a.
1, the positive electrode terminal 34 is disposed so as to penetrate therethrough, and the positive electrode terminal 34 is sealed by filling the opening with glass 40.
It is insulated and fixed to 3a. The hermetic sealing plate 33 is welded to the open end of the battery can 31 around its periphery, and the concave portion is filled with resin on the outer surface side, so that the inside of the battery can 31 has a completely sealed structure that is shielded from the outside air.

In this battery, the positive electrode lead 34 connected to the positive electrode of the electrode plate group 32 is welded to the positive electrode terminal 34 protruding into the battery can 31, and the negative electrode of the electrode plate group 32 is connected to the battery can 31. The battery can 31 constitutes a negative electrode terminal. Since the positive electrode terminal 34 protruding to the outside is cylindrical, the positive electrode connecting lead 41
Are connected by welding so as to be wound around the positive electrode terminal 34. The cylindrical positive electrode terminal 34 is used for the battery can 3
1 was sealed by the hermetic sealing plate 33, then used to inject the electrolytic solution into the battery can 31 from the inner cylinder, and after the injection of the electrolytic solution was completed, the inner cylinder was closed by the sealing plug 35. The inside of the battery can 31 is sealed.

In the sealed battery having the above structure, the cylindrical positive electrode terminal 34 is used so that the electrolytic solution can be injected after sealing, but there are problems that the injection time is long and the liquid injection device is complicated. It was Further, since the amount of protrusion of the positive electrode terminal 34 into the battery can 31 and the amount of protrusion to the outside of the battery are large, the total height of the battery becomes unnecessarily large, and a useless space is formed in the battery can 31 to reduce the battery capacity. There are issues to be reduced. In order to solve this problem, as shown in FIG. 3, a hermetic sealing plate 43 is configured by using a positive electrode terminal 44 having a small height, and after the electrolyte solution is injected into the battery can 31, the open end of the battery can 31 is opened. In addition, a hermetically sealed battery in which the peripheral portion of the hermetic sealing plate 43 is laser-welded is proposed.

In this sealed battery, the positive electrode terminal 44 is formed in a T-shaped cross section, is insulated and fixed to the sealing plate 43a by the glass 45, and is further filled with the resin 47 to improve the sealing performance. The peripheral portion of the sealing plate 43a is connected to the battery can 31.
The battery can 31 is sealed by welding the open end of the battery can 31. With this configuration, the external protrusion amount of the positive electrode terminal 44 is small,
The increase in the total height of the battery can be suppressed. Further, the amount of protrusion of the positive electrode terminal 44 into the battery can 31 is small, and the battery capacity can be increased by increasing the storage amount of the power generation element 42.

[0008]

However, after the electrolytic solution is injected into the battery can 31, the hermetic sealing plate 43 is provided.
When welding the battery to the battery can 31, the electrolytic solution may adhere to the open end of the battery can 31, and if laser welding is performed in that state, the adhered electrolytic solution vaporizes and blowholes are generated in that part. Then, there was a problem of poor welding.

The structure of the hermetic sealing plate 43 in which the height of the positive electrode terminal 44 is made small can not only reduce the total height of the battery and increase the battery capacity, as described above, but can also increase the battery capacity in the battery can 31. Since the positive electrode lead 46 can be joined and the external connection lead can be joined on the flat surface of the positive electrode terminal 44, there is an advantage in workability. Therefore, it is desirable to solve the occurrence of welding failure due to the adhesion of the electrolytic solution as described above. It is rare.

An object of the present invention is to provide a hermetically sealed battery having a high hermeticity by eliminating the occurrence of welding defects due to the adhesion of an electrolytic solution.

[0011]

The first invention of the present application for achieving the above object is to insulate an output terminal from a sealing plate at an opening end of a battery can having a bottomed cylindrical shape and accommodating a power generating element. In a sealed battery in which the opening of the battery can is sealed by welding the fixed hermetic sealing plate, the hermetically sealing plate and the opening end of the battery can are welded closer to the inside of the battery can than the welded part. And a gasket for temporarily sealing the inside of the battery can by being compressed between the battery can and the hermetic sealing plate.

According to the above construction, the gasket disposed between the battery can and the hermetic sealing plate is for contacting the open end of the battery can and the hermetic sealing plate at a predetermined position at the welding site. When pressurized, the battery can be compressed to temporarily seal the inside of the battery can. Since the temporarily sealed battery can be washed, the electrolytic solution adhering to the welding site is removed by washing to prevent the occurrence of welding defects due to the electrolytic solution adhering and to ensure the sealing by welding. Can be

In the above structure, the gasket is formed in a ring shape so as to be compressed by the crimping process in which the open end of the battery can is bent inward and brought into contact with the welded portion of the hermetic sealing plate. By doing so, the gasket can be sufficiently sealed to be temporarily sealed until the gasket is compressed by caulking and is brought into close contact with the hermetic sealing plate and the battery can to be sealed by welding.

Further, the gasket is disposed on the constricted portion in which the open end side of the battery can is projected inward in the circumferential direction,
The hermetically sealed plate is pressed into the open end of the battery can to form a ring shape so as to be compressed between the hermetically sealed plate and the constricted portion, so that the compressed gasket has a hermetically sealed plate and the constricted portion. The inside of the battery can can be sealed to the outside by closely contacting with.

Further, the hermetic sealing plate has a glass hermetic seal structure in which the output terminal is insulated and fixed with glass in the opening formed in the central portion of the hermetic sealing plate so that the mounting portion of the output terminal can be sealed with glass. Therefore, the terminal portion can be sealed.

The hermetic sealing plate can also be constructed by fixing the output terminal to the opening formed in the center of the hermetically sealing plate through a gasket, and the sealing of the terminal portion can be performed more reliably by filling the sealing material. It can be anything.

A second invention of the present application is to form a battery by welding a hermetic sealing plate having an output terminal insulated and fixed to a sealing plate to the open end of a battery can having a bottomed cylindrical shape and containing a power generating element. In a method for manufacturing a sealed battery that seals the opening of a can, by injecting an electrolytic solution into the battery can, and pressing between the battery can and the hermetic sealing plate so that their welding portions contact each other. The gasket inserted between them is compressed to temporarily seal the open end of the battery can, and after a cleaning process is performed, the open end of the battery can and the hermetic sealing plate are welded at the welded portion to form the battery can. It is characterized in that the open end of is sealed.

According to the above-mentioned method for manufacturing a sealed battery, the injection of the electrolytic solution into the battery can is easy and the injection time can be shortened. Since the injection is performed, there is a possibility that the electrolytic solution may adhere to the opening end, and if the electrolytic solution adheres to the welding site at the opening end, it may cause welding failure. However, since this battery is temporarily sealed by the gasket, it is possible to carry out a cleaning step after the temporary sealing, and it is possible to remove the electrolytic solution adhering to the welding site by the cleaning. Therefore, the sealing by welding can be surely performed, and the sealed battery having the completely sealed structure can be manufactured.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The embodiments described below are examples of embodying the present invention and do not limit the technical scope of the present invention.

FIG. 1 shows the structure of a sealed battery according to the first embodiment, which is a battery can 1 having a cylindrical shape with a bottom.
Insulating with the upper insulating plate 4 and the lower insulating plate 5 inside, the electrode plate group 2
And the open end of the battery can 1 is sealed by a hermetic sealing plate 3. The hermetic sealing plate 3 is
A positive electrode terminal (output terminal) 9 formed in a T-shaped cross section is insulated and fixed by glass 10 in an opening formed in the center of the sealing plate 3a. The hermetic sealing plate 3 has a gasket 8 at its peripheral portion. The opening end of the battery can 1 is bent inwardly through the caulking process to form a temporary sealing, and then the opening end of the battery can 1 and the sealing plate 3a are laser-welded to form a completely sealed sealing. .

The hermetic sealing plate 3 has a sealing plate 3a having a cylindrical opening for insulating and fixing the positive electrode terminal 9 in the central portion, and the glass pellet and the positive electrode terminal 9 are positioned in the opening. As shown in FIG. 1, the glass pellets are placed and placed in a heating furnace to melt the glass pellets, and the molten glass pellets are solidified. The positive electrode terminal 9 is insulated and fixed to. Further, below the flange portion formed on the positive electrode terminal 9, the glass 10 and the sealing plate 3a are provided.
The epoxy resin 7 is filled so as to cover the opening of the above, and the insulation fixing by the glass 10 is reinforced.

Further, the battery can 1 accommodates the lower insulating plate 5, the electrode plate group 2, and the upper insulating plate 4 therein, and has a constricted portion 1a projecting inward on the circumference on the opening side. Form the electrode plate group 2
Is fixed in position, and the hermetic sealing plate 3 can be fixed on the constricted portion 1a. The positive electrode lead 6 pulled out from the positive electrode plate constituting the electrode plate group 2 is welded to the lower surface of the positive electrode terminal 9, the electrolytic solution is injected into the battery can 1, and the gasket 8 is arranged on the constricted portion 1 a of the battery can 1. Then, the hermetic sealing plate 3 is arranged such that its peripheral edge portion abuts on the inner surface of the gasket 8. Next, the gasket 8 is attached to the sealing plate 3 by the crimping process of bending the opening side of the battery can 1 inward.
The inside of the battery can 1 is temporarily sealed by compressing to the a side, and at the same time, the open end of the battery can 1 is brought into contact with the sealing plate 3a. As shown in FIG. 1, the sealing plate 3a has a step formed on the outer peripheral side, and the open end of the battery can 1 contacts the corner of the step portion by caulking.

In the sealed battery of this embodiment, since the electrolyte is injected before the opening of the battery can 1 is sealed, the injection time can be shortened and the injection work is easy. Electrolyte may adhere to the parts. If laser welding is performed with the electrolytic solution still attached, the attached electrolytic solution evaporates,
Blow holes are generated in that portion, resulting in poor welding.
Since this battery has a temporary sealing for compressing the gasket 8 by crimping, the battery can be moved, and the electrolytic solution adhering to the welding site is removed in order to prevent the occurrence of welding failure due to the electrolytic solution adhering. A cleaning step can be performed.

After the temporarily sealed battery is sent to the cleaning step to remove the electrolytic solution, as shown in FIG. 1, the laser light L is applied to the entire area where the sealing plate 3a and the open end of the battery can 1 contact each other. And laser welding.

As described above, in the sealed battery according to the present embodiment, the positive electrode terminal 9 is hermetically sealed by glass, and the gasket 8 is sealed by welding in addition to the compression sealing compressed by caulking. Thus, a thionyl chloride lithium battery, a lithium manganese dioxide battery or the like can be operated in a stable state for a long period of time, and a sealed battery that is effective for measurement applications such as gas meters and memory backup is constructed.

Next, the structure of the sealed battery according to the second embodiment will be described with reference to FIG. In addition, the first
Elements common to the configuration of the embodiment are given the same reference numerals, and description thereof will be omitted.

In FIG. 2, a battery can 11 having a cylindrical shape with a bottom has an upper insulating plate 4 and a lower insulating plate 5 inside thereof.
After the electrode plate group 2 is insulated and housed, the constricted portion 11a protruding inward on the circumference is formed on the opening side to fix the electrode plate group 2 in position and on the constricted portion 11a. The hermetic sealing plate 13 can be fixed. The diameter of the open end is slightly bent inward so that it is smaller than the diameter of the sealing plate 13a.

The hermetic sealing plate 13 is constructed by insulatingly fixing the positive electrode terminal 19 to an opening formed in the central portion of a plate-shaped sealing plate 13a having a raised peripheral edge. Insulating and fixing the positive electrode terminal 19, the central gasket 12 formed in a cylindrical shape is fitted in the opening formed in the center of the sealing plate 13a, and the positive electrode terminal 19 is fitted in the inner cylinder of the central gasket 12 to make the positive electrode terminal 19 This is done by fixing the washer 14 to the tip of the. Further, the concave portion formed on the sealing plate 13a is filled with an epoxy resin 17 to reinforce the insulation fixing by the central gasket 12.

After forming the battery can 11 and the hermetic sealing plate 13 as described above, the positive electrode lead 6 drawn out from the positive electrode plate forming the electrode plate group 2 is welded to the lower end of the positive electrode terminal 19 to form a battery can. An electrolyte solution is injected into 11. Next, a ring-shaped outer peripheral gasket 18 is disposed on the constricted portion 1a formed on the battery can 1, and the hermetic sealing plate 13 is press-fitted into the opening of the battery can 11 while bending the positive electrode lead 6 as shown in the figure. To do. By press-fitting the hermetic sealing plate 13, the outer peripheral gasket 18 is compressed onto the constricted portion 11a, and the opening of the battery can 11 is temporarily sealed. Further, as described above, the opening end of the battery can 11 has the sealing plate 13a.
Since it is bent to be smaller than the diameter of
The press-fitted hermetic sealing plate 13 is prevented from popping out of the press-fitted position due to the repulsion of the compressed outer peripheral gasket 18.

When the electrolytic solution is injected with the opening of the battery can 11 being opened, there is a possibility that the spray of the electrolytic solution may adhere to the opening of the battery can 11 although the injection speed is high. As described above, the attached electrolyte causes blow holes during laser welding, resulting in poor welding. Similar to the sealed battery according to the first embodiment, the sealed battery according to the present embodiment also has a temporary sealing port. Therefore, after performing the cleaning step of removing the attached electrolytic solution, as shown in the figure. Laser light L is irradiated between the peripheral portion of the hermetic sealing plate 13, the battery can 11 and the opening end to perform sealing by laser welding.

As described above, in the sealed battery according to the present embodiment, the positive electrode terminal 19 is hermetically sealed by the central gasket 12, and the outer peripheral gasket 18 is hermetically sealed by welding in addition to the compressed sealing. A state is obtained, a lithium thionyl chloride battery, a lithium manganese dioxide battery, and the like can be operated in a stable state for a long period of time, and a sealed battery that is effective for measurement applications such as a gas meter and memory backup is configured.

In the sealed batteries of the first and second embodiments described above, since the temporary sealing is performed, it is possible to perform the cleaning step for removing the electrolytic solution, and as a result, blow holes are generated during welding. Can be prevented, and complete sealing can be performed by laser welding. In order to verify the effect of carrying out this cleaning process, a lithium manganese dioxide battery was prepared by the structure of each of the first and second embodiments and the conventional structure shown in FIG. I confirmed the condition. In the sealed battery according to the first embodiment, the one that has been subjected to the cleaning step is referred to as "configuration A", the one without the cleaning step is referred to as "configuration B", and the sealed battery according to the second embodiment is cleaned. The one that has undergone the steps is referred to as "configuration C", the one without the washing step is referred to as "configuration D", and the sealed battery having the conventional structure shown in FIG. 3 is referred to as "configuration E". The verified results are shown in Table 1.

[0033]

[Table 1] As is clear from Table 1, no blowholes are found in the sealed batteries according to the first and second embodiments that have undergone the cleaning process. In addition, when the cleaning process is omitted, blowholes are generated, but the number is low in view of the generation rate of the conventional structure. This is because even if the electrolyte solution in the battery is vaporized and rises due to heat transfer during laser welding, the gaskets 8 and 18 prevent the electrolyte solution from entering the welding site.

[0034]

As described above, according to the present invention, since a hermetic sealing plate is welded to the open end of the battery can containing the power generating element and the sealing is performed using the gasket, the temporary sealing is performed. The cleaning step can be performed before the sealing by the method described above, and the electrolytic solution adhering to the welding site can be removed when the open end of the battery can is opened and the electrolytic solution is injected into the battery can. Therefore, the injection time can be shortened,
Even if the electrolyte is injected from the open end, the injection process is easy,
It is possible to construct a sealed battery in which there is no welding failure due to the attachment of the electrolytic solution and which is completely sealed by welding.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a sealed battery according to a first embodiment.

FIG. 2 is a cross-sectional view showing a configuration of a sealed battery according to a second embodiment.

FIG. 3 is a cross-sectional view showing a structure of a sealed battery having a conventional structure.

FIG. 4 is a cross-sectional view showing the structure of a sealed battery having a conventional structure.

[Explanation of symbols]

1, 11 battery cans 2 electrode group 3,13 Hermetic sealing plate 3a, 13a Sealing plate 8 gasket 9, 19 Positive electrode terminal (output terminal) 10 glass 12 Central gasket 18 Peripheral gasket

Continued front page    (72) Inventor Takeshi Inui             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yukihiro Gotanda             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Takayuki Tanahashi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yasuhiro Suzuki             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 5H011 AA09 AA17 BB04 DD13 FF03                       FF04 GG02

Claims (6)

[Claims] 1. An opening of a battery can is sealed by welding a hermetic sealing plate having an output terminal insulated and fixed to a sealing plate to the opening end of the battery can having a bottomed cylindrical shape and containing a power generating element. In the sealed type battery, which is arranged closer to the inside of the battery can than the welding part for welding between the hermetic sealing plate and the open end of the battery can, and is compressed between the battery can and the hermetic sealing plate. A sealed battery comprising a gasket for temporarily sealing the inside of a battery can. 2. The gasket is formed in a ring shape covering the peripheral edge of the hermetic sealing plate so that the opening end of the battery can is bent inward and compressed by a caulking process that abuts against a welded portion of the hermetic sealing plate. Claim 1
The sealed battery according to. 3. The gasket is disposed on a constricted portion in which the opening end side of the battery can is projected inward in the circumferential direction, and the hermetic sealing plate is press-fitted into the opening end of the battery can to hermetically seal the battery can. The sealed battery according to claim 1, wherein the sealed battery is formed so as to be compressed between a plate and the constricted portion. 4. The hermetic sealing plate according to claim 1, wherein the hermetic sealing plate has a glass hermetic sealing structure in which an output terminal is insulated and fixed with glass in an opening formed in a central portion of the hermetic sealing plate. Type battery. 5. The hermetically sealed battery according to claim 1, wherein the hermetic sealing plate has an output terminal fixed to an opening formed in a central portion thereof via a gasket. 6. The opening of the battery can is sealed by welding a hermetic sealing plate having an output terminal insulated and fixed to the sealing plate to the opening end of the battery can having a bottomed cylindrical shape and containing the power generating element. In the method for manufacturing a sealed battery, an electrolytic solution is injected into the battery can, and the gasket interposed between the battery can and the hermetic sealing plate is pressed so that their welded portions come into contact with each other. After compressing to temporarily seal the open end of the battery can and performing a washing process, the open end of the battery can is sealed by welding between the open end of the battery can and the hermetically sealing plate at the welding site. A method of manufacturing a sealed battery, comprising: