WO2009151007A1

WO2009151007A1 - Method of manufacturing sealed battery

Info

Publication number: WO2009151007A1
Application number: PCT/JP2009/060340
Authority: WO
Inventors: 渡辺修
Original assignee: 日立マクセル株式会社
Priority date: 2008-06-10
Filing date: 2009-06-05
Publication date: 2009-12-17
Also published as: JP2011192386A

Abstract

A method of manufacturing a sealed battery includes a step of preparing a strip-shaped aluminum plate material consisting of aluminum or an aluminum alloy; a step of preparing a strip-shaped dissimilar metal plate material consisting of dissimilar metal dissimilar from the aluminum or of a dissimilar metal alloy dissimilar from the aluminum alloy and having a smaller width than the aluminum plate material; a compression-bonding step for compression-bonding the dissimilar metal plate material on the aluminum plate material with the dissimilar metal plate material overlaid on the aluminum plate material so as to be aligned in the longitudinal direction of the aluminum plate material; a step of cutting the aluminum plate material together with the dissimilar metal plate material after the compression-bonding step to form an opening sealing plate integral with a dissimilar metal body consisting of the dissimilar metal or the dissimilar metal alloy; and a step of joining the opening sealing plate to an opening of a battery can with the dissimilar metal body facing outward.

Description

Manufacturing method of sealed battery

The present invention relates to a method for producing a sealed battery comprising a battery can and a sealing plate made of aluminum or aluminum alloy that closes the opening of the battery can.

Demand for sealed batteries typified by lithium ion secondary batteries is increasing as a power source for various portable electronic devices, and further weight reduction is required. For this reason, recently, a battery case made of a light metal such as aluminum or an aluminum alloy has been used to reduce the weight of the battery. The battery case includes a battery can and a sealing plate that closes the opening of the battery can. Usually, the sealing plate is formed of nickel or an alloy thereof, iron or an alloy thereof, copper or an alloy thereof, and external leads are connected to the sealing plate.

However, since an oxide thin film is formed on the surface of aluminum or aluminum alloy, an external lead formed of nickel or the like is joined to a sealing plate formed of aluminum or aluminum alloy by welding or soldering with a laser or the like. It is difficult to do.

For this reason, in order to facilitate joining between the external lead and the sealing plate, a different metal body formed of a different metal or a different metal alloy different from aluminum is integrated on the upper surface of the sealing plate made of aluminum or aluminum alloy. It has been proposed.

Examples of sealed batteries using a sealing body in which the different metal bodies are integrated include those shown in Patent Documents 1 to 3, for example. In

Patent Documents

1 and 2, a sealing plate made of aluminum or an aluminum alloy is welded and integrated with a terminal made of a nickel-aluminum clad material with the aluminum surface of the terminal facing the sealing plate. It is described to do. And in

patent document

1 and 2, the external lead connected to the protection circuit or the external apparatus etc. is welded to the said terminal. Patent Document 3 describes that a small piece of nickel is pressed and integrated with a part of an aluminum sealing plate by a cold rolling joining method, and an external lead is welded to the small piece.

JP 2001-6746 A JP 2003-317703 A JP 2006-114272 A

In the sealed batteries disclosed in

Patent Documents

1 and 2, since a terminal made of a nickel-aluminum clad material is manufactured separately from the sealing plate, the terminal is welded to the sealing plate. The manufacturing efficiency of the battery deteriorates by the amount required for the terminal welding work and the like.

Further, in the sealed battery of Patent Document 3, a large number of small pieces of nickel are prepared separately from the sealing plate, and after placing each small piece at a predetermined position on the band-shaped aluminum plate that is the material of the sealing plate, Each small piece is pressed against the aluminum plate with a pair of upper and lower tools and joined. For this reason, parts management for every small piece is needed, and the management takes time and the like. Moreover, it takes time to join nickel to the sealing plate by the amount of work for placing each small piece on the aluminum plate, resulting in poor battery manufacturing efficiency.

A method for producing a sealed battery according to the present invention is a method for producing a sealed battery including a battery can and a sealing plate formed from aluminum or an aluminum alloy that closes the opening of the battery can. A step of preparing the formed strip-shaped aluminum plate, and a strip-shaped dissimilar metal plate formed of a dissimilar metal different from the aluminum or a dissimilar metal alloy different from the aluminum alloy and having a narrower width than the aluminum plate. Cutting the aluminum plate together with the dissimilar metal plate after the step, a crimping step of overlapping and crimping the dissimilar metal plate along the length direction of the aluminum plate on the aluminum plate, and the crimping step. A sealing plate in which different metal bodies formed of the different metal or the different metal alloy are integrated. Forming, by the dissimilar metal member to the outside, the sealing plate, characterized in that it comprises a step of bonding the opening of the battery can.

According to the method for manufacturing a sealed battery of the present invention, it is possible to reduce the time and labor of component management accompanying the joining of dissimilar metals to the sealing plate and improve the manufacturing efficiency of the battery.

FIG. 1A is a longitudinal front view of a main part of a sealed battery according to the present invention, and FIG. 1B is an enlarged view of part B of FIG. 1A. FIG. 2 is an exploded perspective view of the sealed battery according to the present invention. 3 is a cross-sectional view taken along the line II of FIG. 1B. FIG. 4 is a top view of the sealing plate of the sealed battery according to the present invention. FIG. 5 is a perspective view showing a process of joining a nickel plate to an aluminum plate.

The present invention is a method for producing a sealed battery comprising a battery can and a sealing plate formed of aluminum or an aluminum alloy that closes the opening of the battery can. Further, the method for manufacturing a sealed battery according to the present invention includes a step of preparing a strip-shaped aluminum plate formed of aluminum or an aluminum alloy, and a dissimilar metal different from the aluminum or a different metal alloy different from the aluminum alloy. A step of preparing a strip-shaped dissimilar metal plate having a width narrower than that of the aluminum plate, and a pressure-bonding step of superimposing the dissimilar metal plate on the aluminum plate along the length direction of the aluminum plate. Cutting the aluminum plate together with the dissimilar metal plate after the crimping step to form a sealing plate integrated with the dissimilar metal or the dissimilar metal body formed of the dissimilar metal alloy; and the dissimilar metal A step of joining the sealing plate to the opening of the battery can with the body facing outside.

More specifically, in the present invention, a dissimilar metal body formed of a dissimilar metal or dissimilar metal alloy different from aluminum is integrally formed on the upper surface of a sealing plate made of aluminum or aluminum alloy that closes the opening of the left and right horizontally long battery cans. It is a manufacturing method of the sealed battery formed. In addition, the manufacturing method of the present invention provides a strip-shaped aluminum plate made of aluminum or an aluminum alloy and a strip-shaped foreign metal plate made of the above-mentioned different metal or the above-mentioned different metal alloy and having a narrower width than the aluminum plate. A member formed by stacking and press-bonding along the length direction and then cutting an aluminum plate together with a dissimilar metal plate is used as the sealing plate 3.

The dissimilar metal body is made of nickel or nickel alloy, iron alloy such as iron or stainless steel, copper or copper alloy, or the like. For example, an external lead connected to a protective circuit or an external device is joined to the dissimilar metal body by welding or soldering using a laser or the like.

Further, the dissimilar metal plate can be pressure-bonded to the aluminum plate by conveying the aluminum plate obtained by superimposing the dissimilar metal plates between the pair of rolling rollers in the length direction of the aluminum plate while being pressed.

Also, the thickness of the dissimilar metal plate material in a free state before crimping can be in the range of 10 to 25% of the thickness of the aluminum plate material.

In the method for manufacturing a sealed battery according to the present invention, the dissimilar metal plate material can be handled as a single member in a free state before the pressure bonding since the belt-like dissimilar metal plate material is superimposed on the belt-shaped aluminum plate material and pressure bonded. Thereby, for example, compared with a case where different kinds of metal plate materials are cut into a large number of small pieces, and each of the small pieces is placed on an aluminum plate material and crimped, the labor of component management is reduced.

Further, in the present invention, the aluminum plate is cut together with the dissimilar metal plate to form the sealing plate, so that each of the small pieces necessary for crimping the small pieces to the aluminum plate is placed on the aluminum plate. Thus, the battery manufacturing efficiency is improved accordingly.

Further, when the aluminum plate material on which the different metal plate materials are overlapped is conveyed in the length direction of the aluminum plate material while being pressed between a pair of rolling rollers, the aluminum plate material after the pressure bonding is directly conveyed to the cutting process or the like and sealed. The battery manufacturing efficiency is further improved.

In addition, if the thickness of the dissimilar metal plate is in the range of 10 to 25% of the thickness of the aluminum plate in the free state before crimping, the thickness of the dissimilar metal body can be sufficiently secured and different external leads can be secured. The metal body can be appropriately welded, and the thickness of the dissimilar metal body is not excessively increased, so that the use amount of the dissimilar metal body can be suppressed.

That is, if the thickness of the dissimilar metal plate is less than 10% of the thickness of the aluminum plate, for example, the heat when welding the external lead to the dissimilar metal body can easily escape from the dissimilar metal body to the sealing body. There is a tendency that the lead is not properly welded to the dissimilar metal body. Further, if the thickness of the dissimilar metal plate exceeds 25% of the thickness of the aluminum plate, the amount of the dissimilar metal body is increased by the amount that the dissimilar metal body becomes too thick, leading to an increase in battery cost. Tend to occur.

Hereinafter, the manufacturing method of the sealed battery of the present invention will be described with reference to the drawings. As shown in FIGS. 1A, 1B and 2, the sealed battery according to the present invention has a bottomed cylindrical battery can 1 having a horizontally long opening on the upper surface and an electrode body 2 accommodated in the battery can 1. And a non-aqueous electrolyte solution, a horizontally long sealing plate 3 that closes and seals the opening of the battery can 1, and a synthetic resin insulator 5 that is disposed below the sealing plate 3. The left-right width dimension of the battery can 1 is, for example, 34 mm, the vertical height dimension is, for example, 46 mm, and the front-rear thickness dimension is, for example, 4 mm. The sealing plate 3 is formed so that the

sides

6 and 7 are linear and the

sides

6 and 7 are parallel to each other.

In this specification, left and right and front and rear are directions shown in FIG. 2 and FIG. 5 described later.

The battery can 1 is formed by, for example, deep drawing a plate material made of aluminum or an aluminum alloy, and the sealing plate 3 is formed by, for example, pressing and cutting a plate material made of aluminum or an aluminum alloy. As shown in FIG. 3, the outer peripheral edge of the sealing plate 3 has a step shape in which the lower portion is recessed inward, and the bottom surface of the step is placed on the upper edge of the opening of the battery can 1, for example, from the lateral direction. By irradiating the light 8, the sealing plate 3 is seam welded to the battery can 1.

As shown in FIG. 2, the electrode body 2 is formed by winding a strip-shaped positive electrode and a strip-shaped negative electrode in a spiral shape with a strip-shaped separator interposed therebetween, and is formed in a flat shape as a whole. A cleavage vent 9 is formed on the left side of the sealing plate 3. The cleavage vent 9 is cleaved when the battery internal pressure abnormally rises to release the battery internal pressure. A liquid injection hole 10 for injecting a non-aqueous electrolyte into the battery can 1 is formed on the right side of the sealing plate 3, and the liquid injection hole 10 after the injection of the non-aqueous electrolyte is closed with a sealing plug 11. For example, it is sealed by a laser.

As shown in FIG. 1, a through hole 14 is formed in the center of the sealing plate 3 in the left-right direction, and a negative electrode terminal 15 is inserted through the through hole 14 with the insulating packing 12 interposed. Below the sealing plate 3, the insulating plate 13 and the lead plate 16 are arranged vertically, and the lead plate 16 is connected to the lower end of the negative electrode terminal 15. The negative electrode terminal 15 is made of, for example, an iron material whose surface is plated with copper nickel. The insulating packing 12 and the insulating plate 13 are made of a synthetic resin molded product having insulation properties such as polypropylene, and the lead plate 16 is made of a thin plate made of nickel that is horizontally long. The negative electrode terminal 15 is insulated from the sealing plate 3 by the insulating packing 12. The insulating plate 13 extends from the negative electrode terminal 15 side toward the cleavage vent 9 side, and the lead plate 16 extends along the sealing plate 3 from the negative electrode terminal 15 side toward the cleavage vent 9 side in the lateral direction. . The lead plate 16 is insulated from the sealing plate 3 by the insulating plate 13.

The lower end of the negative electrode current collector lead 18 is connected to the negative electrode of the electrode body 2, and the upper end of the negative electrode current collector lead 18 is welded to the lower surface of the lead plate 16. The lower end of the positive electrode current collecting lead 19 is connected to the positive electrode of the electrode body 2, and the upper end of the positive electrode current collecting lead 19 is in the space between the negative electrode terminal 15 and the liquid injection hole 10 on the lower surface of the sealing plate 3. Welded. Thus, the negative electrode terminal 15 has the same potential as the negative electrode of the electrode body 2, and the sealing plate 3 and the battery can 1 have the same potential as the positive electrode of the electrode body 2.

In the space between the negative electrode terminal 15 and the liquid injection hole 10 on the upper surface of the sealing plate 3, as shown in FIG. 1 and FIG. 2, for example, nickel (dissimilar metal) or nickel alloy (dissimilar metal alloy) is formed. A nickel body (dissimilar metal body) 21 is disposed integrally with the sealing body 3. The nickel body 21 is joined to an external lead 27 described later. The nickel body 21 extends in a band shape between the

sides

6 and 7 of the sealing plate 3, and the upper surface of the nickel body 21 is substantially flush with the upper surface of the sealing plate 3. The nickel body 21 has a lateral width dimension of, for example, 5 mm and a thickness dimension of, for example, 0.1 to 0.2 mm. The sealing plate 3 has a left-right width dimension of, for example, 30 mm and a thickness dimension of, for example, 0.8 mm.

The nickel body 21 is integrated with the sealing plate 3 as follows, for example. First, a strip-shaped aluminum plate material 22 made of aluminum or an aluminum alloy, which is a material of the sealing plate 3, is prepared. In addition, a strip-like nickel plate material (dissimilar metal plate material) 23 made of nickel or a nickel alloy, which is the material of the nickel body 21, and narrower than the aluminum plate material 22 is prepared. Next, as shown in FIG. 5, the nickel plate material 23 is superposed along the length direction of the aluminum plate material 22 at a predetermined position in the left-right width direction on the upper surface of the aluminum plate material 22, and a pair of upper and

lower rolling rollers

24, 25 are used. The nickel plate material 23 is pressure-bonded to the aluminum plate material 22 by being conveyed in the length direction of the aluminum plate material 22 while being sandwiched and pressurized.

Thereafter, the aluminum plate material 22 is conveyed to the pressing step and the cutting step, so that the cleavage plate 9, the liquid injection hole 10, and the through hole 14 are formed at predetermined positions in the aluminum plate material 22 to which the nickel plate material 23 is pressure-bonded. And the aluminum plate material 22 is cut | disconnected by the predetermined shape shown in FIG. This completes the production of the sealing plate 3 in which the nickel body 21 is integrated.

When the battery is assembled, the sealing plate 3 formed as described above is used. That is, the negative electrode terminal 15, the insulating packing 12, the insulating plate 13, and the lead plate 16 are assembled to the sealing plate 3 (see FIG. 1A). Next, the electrode body 2 and the insulator 5 are accommodated in the battery can 1, and the negative electrode current collecting lead 18 of the electrode body 2 is welded to the lead plate 16, and the positive electrode current collecting lead 19 of the electrode body 2 is welded to the sealing plate 3. .

Next, after the sealing plate 3 is seam welded to the opening of the battery can 1 with the nickel body 21 facing outward, for example, by laser, the inside of the battery can 1 is evacuated and the non-aqueous electrolyte is supplied from the injection hole 10. inject. After the injection of the nonaqueous electrolyte is completed, the sealing plug 11 is press-fitted into the liquid injection hole 10, and the sealing plug 11 is welded to the peripheral edge of the liquid injection hole 10 of the sealing plate 3 by, for example, a laser (see FIG. 1A). Status). Thereby, the liquid injection hole 10 is sealed with the sealing plug 11 to complete the sealed battery.

Thereafter, as shown in FIG. 4, for example, external leads 26 and 27 for connection to an external device or a protection circuit are connected to the upper surface of the negative electrode terminal 15 and the nickel body 21 by spot welding or the like.

As described above, in the method for manufacturing a sealed battery according to the present invention, since the band-shaped nickel plate material 23 is superimposed on the band-shaped aluminum plate material 22 and pressed, the nickel plate material 23 is handled as a single member in a free state before pressure bonding. Can do. Thereby, for example, compared with a case where the nickel plate member 23 is cut into a large number of small pieces, and each small piece is placed on the aluminum plate member 22 and is crimped, the labor of component management is reduced.

In the present invention, since the aluminum plate 22 is cut together with the nickel plate 23 to form the sealing plate 3, each piece is placed on the aluminum plate 22 as compared with the case where each piece is pressed against the aluminum plate 22. Therefore, the battery manufacturing efficiency is improved accordingly.

In the present invention, the aluminum plate 22 on which the nickel plate 23 is superimposed is conveyed in the length direction of the aluminum plate 22 while being pressed between the pair of rolling

rollers

24 and 25. Therefore, the aluminum plate 22 after the pressure bonding is conveyed. Can be transported to the cutting process or the like as it is to form the sealing body 3, and the manufacturing efficiency of the battery is further improved.

It is desirable that the thickness of the nickel plate material 23 in a free state before crimping is in the range of 10 to 25% of the thickness of the aluminum plate material 22. If the thickness of the nickel plate material 23 is less than 10% of the thickness of the aluminum plate material 22, the nickel body 21 becomes too thin, and when the external lead 27 is welded to the nickel body 21, the heat of the welding is reduced to the nickel body. There is a tendency that the inconvenience that the external lead 27 is not properly welded to the nickel body 21 due to escape from the sealing body 21 to the sealing body 3. Further, if the thickness of the nickel plate member 23 exceeds 25% of the thickness of the aluminum plate member 22, the nickel body 21 becomes too thick, and the amount of use of the nickel body 21 increases, leading to an increase in battery cost. Tend to occur.

The nickel body (different metal body) 21 may be formed of an iron alloy such as iron or stainless steel, or formed of copper or a copper alloy.

The present invention can be implemented in forms other than those described above without departing from the spirit of the present invention. The embodiments disclosed in the present application are merely examples, and the present invention is not limited thereto. The scope of the present invention is construed in preference to the description of the appended claims rather than the description of the above specification, and all modifications within the scope equivalent to the claims are construed in the scope of the claims. It is included.

According to the present invention, it is possible to provide a manufacturing method of a sealed battery that can reduce the labor of component management accompanying the joining of dissimilar metals to the sealing plate and can improve the manufacturing efficiency of the battery, and its industrial value is great. .

DESCRIPTION OF SYMBOLS 1 Battery can 3 Sealing plate 21 Nickel body 22 Aluminum plate material 23

Nickel plate material

24, 25 Rolling roller

Claims

A method for producing a sealed battery comprising a battery can and a sealing plate formed from aluminum or an aluminum alloy that closes the opening of the battery can,
A step of preparing a strip-shaped aluminum plate formed from aluminum or an aluminum alloy;
A step of preparing a dissimilar metal plate that is formed of a dissimilar metal different from aluminum or a dissimilar metal alloy different from the aluminum alloy and is narrower than the aluminum plate; and
A crimping step in which the dissimilar metal plate is overlapped and crimped to the aluminum plate along the length direction of the aluminum plate; and
After the crimping step, cutting the aluminum plate together with the dissimilar metal plate to form a sealing plate integrated with the dissimilar metal or the dissimilar metal body formed from the dissimilar metal alloy;
Bonding the sealing plate to the opening of the battery can with the dissimilar metal body facing outside;
The manufacturing method of the sealed battery characterized by including.
In the crimping step, the aluminum plate material on which the different metal plate materials are overlapped is conveyed in the length direction of the aluminum plate material while being pressed between a pair of rolling rollers, and the different metal plate material is pressure bonded to the aluminum plate material. The method for producing a sealed battery according to claim 1.
The method for manufacturing a sealed battery according to claim 1, wherein the thickness of the dissimilar metal plate in a free state before the crimping step is within a range of 10 to 25% of the thickness of the aluminum plate.
The method for manufacturing a sealed battery according to claim 1, wherein the dissimilar metal is any one metal selected from the group consisting of nickel, iron and copper.
The method for manufacturing a sealed battery according to claim 1, wherein the dissimilar metal alloy is any one alloy selected from the group consisting of a nickel alloy, an iron alloy, and a copper alloy.