JPH11176418A - Sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed battery having a structure in which apertures such as an electrolyte inlet, etc., of the battery can be sealed easily, safely and surely. SOLUTION: A member having a structure which can be inserted into an aperture is used as a sealing member 8 for sealing an aperture. In an area between an aperture forming member and the sealing member 8, a portion between both of them that can be directly heated from the outside is welded or soldered to be sealed, and the sealing member 8 is moored mechanically to the aperture forming member of the battery by a mooring projection 85 formed on the side wall and/or the bottom of the member 8. Thus, the aperture can be sealed safely and surely. Furthermore, there is no fear of fire occurring because the inside of a battery can is not heated at sealing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery having a built-in electrolyte, and more particularly to a sealed battery characterized by a structure for sealing an opening such as an electrolyte inlet of the sealed battery.

[0002]

2. Description of the Related Art A sealed battery such as a lithium ion secondary battery containing an electrolytic solution contains a power generating element together with an electric insulating plate in a bottomed battery can made of a conductive metal such as iron or aluminum. Positive and negative electrode tabs derived from the power generating element body are electrically connected to predetermined positions, respectively, and the upper opening of the bottomed battery can is covered with a lid member having an electrolyte inlet, and the electrolyte is injected. It is manufactured by degassing the inside of the battery can from the inlet, injecting the electrolyte from the electrolyte inlet, impregnating the power generating element body with the electrolyte, and finally sealing the electrolyte inlet by welding or the like. . Conventionally, various techniques have been proposed for sealing a battery can opening such as an electrolyte inlet.

For example, Japanese Patent Application Laid-Open No. 8-315786 discloses that in the manufacture of a rectangular sealed battery, a hollow rivet is fitted to an opening of a lid member of a bottomed battery can via a gasket, and a lower end of the rivet is attached. There is disclosed a structure in which a rivet is attached to a lid member in a liquid-tight and air-tight manner by caulking to the periphery of a washer, and a rubber stopper is provided on the top of the rivet, and a metal cover is provided thereon to seal the rivet. However, this structure has a problem that the rubber stopper is damaged by the electrolyte and it is difficult to keep the battery in a sealed state for a long time.

On the other hand, Japanese Patent Application Laid-Open No. Hei 6-68861 discloses that an opening provided in an upper lid of a battery can is closed with a metal thin film having an outer diameter larger than the diameter of the opening, and the thin film is sealed with a battery can. A technique for welding to an upper lid is disclosed.

[0005] By the way, a sealed battery is industrially manufactured by an assembly process. At this time, a precise assembling apparatus is required to correctly install a thin film at a predetermined position on an opening. Welding with the battery can lid is usually performed by laser welding that can be locally heated in many cases,
There is a problem that the inside of the battery can is heated by the laser beam due to the displacement of the thin film due to wind pressure or external force, and in some cases, a temporary fixing work of the thin film is required. If the thin film is welded with its position shifted, there is a risk that the welding will be insufficient and the electrolyte will leak during use of the battery. If the inside is heated by laser light, there is a concern that a fire may occur.

[0006]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a sealed battery in which an opening such as an electrolyte inlet provided in the battery is easily and safely closed. .

[0007]

The object of the present invention is solved by the following means.

(1) A sealing member is inserted into the opening of the battery,
The sealing member is mechanically anchored to a member forming an opening of the battery by an anchoring protrusion formed on a side wall and / or a lower end of the member, and the member forming the opening and the sealing member A sealed battery, wherein a portion between the two members, which can be directly heated from the outside, is closed by welding or soldering by direct heating from the outside. (2) The side wall of the opening is tapered, the sealing member has a frusto-conical shape that can fit into the tapered opening, and the portion between the two members that can be directly heated from the outside is used for sealing. Between the peripheral edge of the upper surface of the member and the tip of the member forming the opening;
(1) The sealed battery according to (1). (3) The above-mentioned (1) in which the mooring projection is immersed in the side wall of the opening.
Or the sealed battery according to (2). (4) The mooring projection formed at the lower end of the sealing member is moored at the lower end of the member forming the opening (1) or
(2) The sealed battery according to (2). (5) The sealed battery according to any one of the above (1) to (4), wherein the welding is laser welding. (6) The battery according to the above (1), wherein the battery has a structure in which a lid member is provided on an upper part of a bottomed rectangular battery can, and an opening is provided in the lid member.
The sealed battery according to any one of (1) to (5). (7) The sealed battery according to any one of (1) to (6) above, wherein the opening is an electrolyte inlet. (8) The battery is a lithium ion secondary battery (1) to
The sealed battery according to any of (7).

[0009]

As the sealing member for the opening, a member which can be inserted into the opening, particularly a member having a non-thin film structure, for example, a block-shaped member is used. Since the sealing member is inserted into the opening before welding or the like, the positioning of the sealing member is easy,
Further, even if the sealing member is not temporarily fixed as in the related art, the sealing member does not displace due to wind pressure or external force. Since the sealing member is not displaced, it can be locally heated directly from the outside, between the two members of the member forming the opening and the sealing member. By welding or soldering a portion between both members that can be heated without difficulty, the opening can be sealed safely and reliably. Further, the sealing member has an anchoring projection on a side wall and / or a lower end of the member, and is mechanically anchored to a member forming an opening of a battery by the anchoring projection. The connection strength and sealing between the members are improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic sectional view of an embodiment of the present invention,
FIG. 2 is an enlarged sectional view of the portion of the electrolyte injection port 7 in FIG. 1, and FIGS. 3 to 5 are each an enlarged sectional view of the portion of the electrolyte injection port 7 in another embodiment of the present invention. .

1 to 5, reference numeral 1 denotes an iron battery can, 2
Is a negative electric insulating plate, 3 is a power generating element body, 31 is a negative electrode lead exposed from the lower part of the power generating element body 3, 32 is a power generating element body 3
The positive electrode lead exposed from the top of the battery, 4 is a donut-shaped positive electrical insulating plate, 5 is a positive electrode, 6 is an upper lid of a battery can, and 7 is an upper lid 6
, A sealing member for sealing the electrolyte injection port 7, 85 a mooring projection provided on the sealing member 8, and 9 having a rupture function. It is an electrically insulating gasket incorporating a safety mechanism (not shown). The upper lid 6 has the positive electrode 5 at an approximate center via an electric insulating gasket 9, and further has an electrolyte inlet 7 at a position slightly away from the electric insulating gasket 9.

In manufacturing the embodiment shown in FIGS. 1 and 2, the tip of a negative electrode lead 31 is welded to the inner bottom surface of a square or round battery can 1 having a bottom and an open top, and then the negative electrode is electrically insulated. These are housed in the battery can 1 in the order of the plate 2, the power generating element 3, and the positive electric insulating plate 4. On the other hand, the upper lid 6 having the electric insulating gasket 9, the positive electrode 5, and the electrolyte inlet 7 is manufactured in a separate step, and the upper lid 6 is attached to the battery can 1 after the above components are accommodated in the battery can 1. The positive electrode lead 32 guided over the upper opening and exposed from the upper part of the power generating element body 3
Is welded to the back surface of the positive electrode 5 via the central hole of the positive electrode insulating plate 4. After this welding, the upper lid 6 is attached to the battery can 1
And welded to the battery can 1. Finally,
The inside of the battery is evacuated using the electrolyte injection port 7 to inject the electrolyte, and the electrolyte injection port 7 is sealed with the sealing member 8 to obtain the sealed battery of the embodiment.

In FIG. 2, the electrolyte injection port 7 is formed in a trumpet-shaped member 61 formed by deep drawing an iron plate constituting the upper lid 6, and the inner surface of the member 61 is tapered. ing. The sealing member 8 has a frusto-conical shape fitted to the inner surface of the member 61, and further has a ring-shaped mooring projection 85 at the lower end thereof and a notch 8 at the periphery of the upper surface thereof.
One. The outer diameter D1 of the mooring projection 85 is, for example, 0.03 to 0.2 mm from the inner diameter D2 of the lower end of the electrolyte inlet 7.
Therefore, the sealing member 8 is connected to the electrolyte injection port 7.
The mooring protrusion 85 is forcibly passed through the lower end of the electrolyte injection port 7 and mechanically moored to the edge of the lower end as shown in the drawing.

When the sealing member 8 is inserted into the electrolyte inlet 7, the notch 81 and the member 61 are formed between the member 61 forming the electrolyte inlet 7 and the sealing member 8. The portion between the two members with the front end portion 611 is externally provided by, for example, a welding unit or a soldering unit installed immediately above the region between the two members.
That is, since heating can be performed directly from the direction of arrow A,
The portion between the two members is welded by laser welding or the like. Reference numeral 10 denotes a weld. Notch 81 of sealing member 8
Is not necessary, but if it is provided, the weld 10
The contact area of the battery is increased, and the strength of welding and the sealing performance of the battery are improved.

The embodiment shown in FIG. 3 is different from the embodiment shown in FIGS. 1 and 2 only in the state of anchoring of the sealing member 8 to the member 61 by the anchoring projection 85. That is, although the sealing member 8 has a ring-shaped mooring projection 85 at its lower end, the length of the sealing member 8 (height of a truncated cone) is used in the embodiment shown in FIG. Therefore, the mooring projection 85 is immersed in the side wall of the member 61 and is moored. The outer diameter D1 of the ring-shaped mooring protrusion 85 is, for example, 0.03 to 0.3 mm larger than the inner diameter D3 of the electrolyte injection port 7 at the mooring position.
For this purpose, the sealing member 8 is inserted into the electrolyte injection port 7 by driving, and the mooring projection 85 is immersed in the side wall of the electrolyte injection port 7 as shown in the drawing. To be moored mechanically.

The embodiment shown in FIG. 4 is different from the embodiment shown in FIGS. 1 and 2 only in the shape of the electrolyte injection port 7 and the shape of the sealing member 8 and the welding portion. The member 61 forming the electrolyte injection port 7 is cylindrical, and the sealing member 8
Has a structure in which a head 83 having an outer diameter larger than the inner diameter of the member 61 and a cylindrical portion 82 fitted to the inner surface of the member 61 are integrally formed.
It is locked to. In this way, of the member between the member 61 forming the electrolyte inlet 7 and the sealing member 8, the above-mentioned locking portion is formed by, for example, a welding means or a soldering device installed diagonally above the portion between the two members. Heating can be performed directly from the outside by means, that is, from the direction of arrow B. Reference numeral 10 denotes a weld. The sealing member 8 further has a ring-shaped mooring projection 85 at its lower end. The outer diameter D1 of the mooring projection 85 is, for example, 0.03 to 0.2 from the inner diameter D2 of the lower end of the electrolyte inlet 7.
For this purpose, the sealing member 8 is inserted into the electrolyte injection port 7 by driving and mechanically anchored to the edge at the lower end as in the case of FIG.

The embodiment shown in FIG. 5 differs from the embodiment shown in FIG. 4 in that the embodiment shown in FIGS. 1 and 2 and the embodiment shown in FIG. The only difference is the anchoring state of the member 85 to the member 61. That is, the sealing member 8 is
Although the lower end has a ring-shaped mooring projection 85, the length of the sealing member 8 (the height of the cylindrical portion 82) is shorter than that used in the embodiment of FIG. Member 61
It is immersed in the side wall and moored. The outer diameter D1 of the ring-shaped mooring protrusion 85 is larger than the inner diameter D3 of the electrolyte injection port 7 at the mooring position by, for example, 0.03 to 0.2 mm,
For this purpose, the sealing member 8 is inserted into the electrolyte injection port 7 by driving, and the anchoring projection 85 is immersed in the side wall of the electrolyte injection port 7 by mechanical insertion as shown in the drawing. Will be moored.

In the present invention, the sealing member is mechanically anchored to the member forming the opening of the battery by the anchoring projection. The mechanical anchoring at this time is as shown in FIG. 2 and FIG. The mooring projection 85 may be hooked on the lower edge of the electrolyte injection port 7, or the mooring projection 85 may be immersed in the side wall of the electrolyte injection port 7 as shown in FIGS. 3 and 5. Good.

In each of the embodiments shown in FIGS. 1 to 5, a ring-shaped mooring projection is exemplified. However, in the present invention, the mooring projection does not need to be ring-shaped, With many notches, sealing member 8
One or several independent projections formed on the side wall and / or lower end of the sealing member 8, a large number of independent projections formed randomly on the side wall of the sealing member 8, and the like.

The mooring protrusion 85 or the mooring protrusion of the other modified embodiment described above is provided at least in part between the two members 61 and 8, or as shown in FIGS. Only at the lower end of the sealing member, the connection strength between the two members is improved. As a result, even if an external force acts on the sealing member 8 during operation of the sealed battery, the external force is not And the mooring force of the mooring projections
The possibility of breakage of the weld 10 is reduced, and the stability of the sealing function is increased. On the other hand, when the mooring protrusion is present between both members so as to block the entire passage from the inside of the sealed battery to the welded portion 10 as shown in FIGS. In addition to the above, it has a function to further stably improve the sealing performance between the two members together with the welded portion 10.

Fundamentally different from the case of welding a metal thin film in the above-mentioned conventional example, FIG.
When each of the sealing members 8 is inserted as shown in FIG.
Is stably fixed at the insertion position. Therefore, without any concern about the displacement of the sealing member 8, and further without substantially heating the flammable electrolyte, in other words,
The welded portion 10 can be accurately and precisely welded without any concern about the occurrence of a fire. Further, at this time, sealing can be performed not only by laser welding but also by various welding methods and soldering methods.

The present invention is suitable for sealing various openings in a lithium ion secondary battery or other various sealed batteries. At this time, the position of the opening to be sealed is not limited to the upper lid 6 shown in FIGS. 2 to 5, but may be at any position such as the side wall of the battery can 1.

[0023]

The present invention has the following various effects as compared with a conventional sealed battery. Handling of the sealing member is easy. Since the sealing member is inserted into an opening to be sealed such as an electrolyte injection port before welding or the like, the positioning of the sealing member is easy. Even when the sealing member is not temporarily fixed as in the related art, there is no displacement of the sealing member due to wind pressure or external force. Since the sealing member is not displaced, the opening between the member forming the opening and the member for sealing can be welded or soldered to a portion between the two members that can be directly heated from the outside. Can be sealed safely and reliably. In addition, since the mooring force of the mooring projection acts at least at a part between the two members other than the portion to be welded or soldered or at the lower end of the sealing member, the connection strength and sealing property between the two members are improved. I do. Since the inside of the battery can is not heated, there is no risk of fire even if the electrolyte is flammable.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a portion of an electrolyte injection port 7 in FIG.

FIG. 3 is an enlarged sectional view of a portion of an electrolyte injection port 7 according to another embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a portion of an electrolyte injection port 7 in another embodiment of the present invention.

FIG. 5 is an enlarged sectional view of a part of an electrolyte injection port 7 in another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 battery can 3 power generating element body 6 top lid of battery can 61 member forming electrolyte solution inlet 7 electrolyte solution inlet 8 sealing member 85 mooring protrusion 9 electrical insulating gasket 10 welded part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01M 10/40 H01M 10/40 Z

Claims (8)

[Claims] 1. A sealing member is inserted into an opening of a battery, and the sealing member is mechanically attached to a member forming an opening of the battery by an anchoring projection formed on a side wall and / or a lower end of the member. Of the members that are moored, and between the member forming the opening and the sealing member, the portion between the two members that can be directly heated from the outside is closed by welding or soldering by direct heating from the outside. A sealed battery characterized in that: 2. A side wall of the opening is tapered, a sealing member has a frusto-conical shape capable of fitting into the tapered opening, and a portion between both members which can be directly heated from the outside is a sealing member. 2. The sealed battery according to claim 1, wherein the distance between the peripheral portion of the upper surface of the stopping member and the tip of the member forming the opening. 3. The sealed battery according to claim 1, wherein the mooring projection is immersed in a side wall of the opening. 4. The sealed battery according to claim 1, wherein the anchoring projection formed at the lower end of the sealing member is anchored at the lower end of the member forming the opening. 5. The method according to claim 1, wherein the welding is laser welding.
5. The sealed battery according to any one of 4. 6. The sealed battery according to claim 1, wherein the battery has a structure in which a lid member is provided on an upper portion of a bottomed rectangular battery can, and an opening is provided in the lid member. 7. The method according to claim 1, wherein the opening is an electrolyte inlet.
7. The sealed battery according to any one of 6. 8. The sealed battery according to claim 1, wherein the battery is a lithium ion secondary battery.