JP2002208395A - Nonaqueous electrolyte solution battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte solution battery with excellent connection characteristics between a conductive connection part made of aluminum and a conductive connection lead for outer circuit connection. SOLUTION: With the nonaqueous electrolyte solution battery, an aluminum face of a cladding with at least one protrusion for projection welding formed on an aluminum face, formed of a conductive connection lead connecting with the outer circuit, an easily weldable metal material and aluminum, is joined to a conductive connection part with an outer circuit of the battery formed of aluminum, with the aluminum face faced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides an excellent connection characteristic between an aluminum battery can or an aluminum conductive connection portion such as an aluminum conductive connection terminal and a conductive connection lead for connection to an external circuit. A non-aqueous electrolyte battery having a conductive connection portion.

[0002]

2. Description of the Related Art Various types of batteries are used as power supplies for small electronic devices, such as lithium-ion secondary batteries, which are small and large-capacity sealed batteries, as power supplies for mobile phones, notebook computers, camcorders and the like. Non-aqueous electrolyte batteries are used. As these non-aqueous electrolyte batteries, batteries having a cylindrical or square structure are used.

[0003] In general, in a battery storage portion of a device having a rectangular parallelepiped shape, there is a problem that an invalid volume is increased with a cylindrical battery. Further, since the diameter of the cylindrical battery is limited by the thickness of the battery storage portion, in a small or thin device, instead of the cylindrical battery,
A prismatic prismatic battery having a small thickness is used.

[0004] A prismatic battery can effectively use a small space in a device that is thinner than a cylindrical battery, and thus a prismatic battery is used in small devices such as mobile phones. ing. In a rectangular nonaqueous electrolyte secondary battery, a battery can in which stainless steel or mild steel is nickel-plated has conventionally been used. However, although battery cans made of these materials have high strength, the specific gravity of the material is high, so the weight of the battery can is large.In thin rectangular batteries for portable equipment, the weight of the battery can is reduced by the weight of the battery. There is a problem that the occupation ratio is large and the weight energy density of the battery is reduced.

Therefore, it has been proposed to use a material such as aluminum or titanium as a metal material having a small specific gravity and a high strength which can be used as a current extraction terminal on the positive or negative electrode side of a battery. In particular, aluminum is a material that is easy to handle and that shows sufficient corrosion resistance when used as a positive electrode in nonaqueous electrolyte batteries.

An aluminum battery can has a lower strength than a mild steel or stainless steel battery can, so it is difficult to attach a battery header by caulking or the like, and an aluminum battery can having an anode terminal attached via an insulator is difficult. Is attached to the battery can by laser welding or the like. In a battery using an aluminum battery can, the battery can was used as a terminal on the positive electrode side, and a positive electrode lead for external circuit connection was directly welded to the conductive connection portion of the battery can.

[0007] The positive electrode lead or the negative electrode lead
All of them are made of a metal material such as nickel, copper, nickel-plated copper, nickel alloy, and copper alloy which have corrosion resistance and can be joined by solder. In joining the nickel positive electrode lead to the aluminum battery lid, that is, the conductive connection provided on the battery header, aluminum and nickel cannot be joined by resistance welding. It was joined by welding and ultrasonic welding. However, both laser welding and ultrasonic welding require large-scale equipment, and in ultrasonic welding in particular, the horn for irradiating ultrasonic waves is severely worn and it is necessary to replace the horn at an early stage. there were.

Further, in a battery using a battery can made of stainless steel or nickel-plated mild steel,
In the conductive connection terminal portion on the positive electrode side, aluminum, which is a metal material that can be used stably on the positive electrode side in a nonaqueous electrolyte battery, is attached to the lid via an insulating member. The nickel positive electrode lead is joined to the positive electrode terminal, but the nickel positive electrode lead is joined to the aluminum positive terminal by resistance welding to the aluminum positive terminal. There was a problem that it could not be done.

In view of this, Japanese Patent Application No. 9-330696 proposes a battery with a lead plate in which a clad material of aluminum and a metal that can be joined to a connection lead is joined to the bottom surface of a battery can. Also, in Japanese Patent Application No. 11-171133, a conductive connection portion with an external circuit provided on a battery header or the like of a battery formed of aluminum is formed of a conductive connection lead with an external circuit, a metal material that is easily welded, and aluminum. A battery has been proposed in which the aluminum surface of the formed clad body is joined face-to-face and joined, and a conductive connection surface made of an easily weldable metal surface is formed, thereby facilitating joining with a positive electrode lead made of nickel or the like. ing.

FIG. 5 is a view for explaining a method of joining the clad body to the battery can. It is a figure explaining the method of welding the clad body 5 to the bottom surface 14 of the battery can 2 by resistance welding. Pressing the welding point using welding rods 7a and 7b,
An example is shown in which the current is concentrated on the portion of the welding rod and the clad body 4 and the bottom surface 14 of the battery can 2 are joined by resistance welding. In order to form a nugget that is effective in increasing the bonding strength with the bottom surface, it is necessary to concentrate the current, and a welding electrode with a small contact area is used to increase the pressing force. . In order to further increase the joining strength, resistance welding has been performed at a plurality of locations. These proposals make it possible to easily join the positive electrode lead to an aluminum battery can.However, a large force was applied to the positive electrode lead during the process of assembling the battery into equipment or using the battery. Even in the case, without breaking at the joint,
In addition, there has been a demand for manufacturing a battery having a stable joint with small variation in strength.

SUMMARY OF THE INVENTION According to the present invention, there is provided a battery formed of aluminum having a conductive connection with an external circuit, a conductive connection lead to the external circuit, a clad formed of an easily weldable metal material and aluminum. It is an object of the present invention to provide a battery in which the aluminum surface of the body is joined to face and joined, and the joining strength is further increased.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a non-aqueous electrolyte battery in which a conductive connection lead to an external circuit of a battery formed of aluminum is connected to a conductive connection lead to the external circuit. Formed from metal material and aluminum,
The problem can be solved by a nonaqueous electrolyte battery in which a conductive connection portion is formed by joining at least one projection welding projection on an aluminum surface with an aluminum surface of a clad body facing the aluminum clad body. The conductive connection portion is the nonaqueous electrolyte battery in which the welding electrode is pressed at a plurality of locations and joined at the plurality of locations. The non-aqueous electrolyte battery described above, wherein all of the welding locations are formed by energization in the same direction. Further, the nonaqueous electrolyte battery described above is one in which a plurality of projection welding projections are formed in a region pressed by one welding electrode.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a method for joining aluminum and a clad body of an easily weldable metal such as nickel to a conductive connection portion of a battery formed of aluminum with an external circuit.
In the case where it is attempted to increase the bonding strength by performing at a location, FIG.
As shown in the above, when a plurality of locations are pressed with welding electrodes and two welding locations are energized in series, the size of the left and right nuggets is different due to the difference in the polarity of the current, making uniform joining difficult. In addition, even when the direction of current flow was the same, sufficient bonding strength could not be formed. However, after forming at least one projection welding projection on the aluminum surface of the clad body, the projection welding projection was formed. It has been found that it is possible to greatly increase the bonding strength between aluminum and a clad body by pressing and welding with a welding electrode while facing the aluminum surface. In the present invention, aluminum means aluminum and its alloy, and nickel means nickel and its alloy. Therefore, the clad body of aluminum and nickel also means a clad body of an aluminum alloy and nickel or a nickel alloy.

The present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a manufacturing process of the battery of the present invention. As shown in FIG. 1 (A), a clad body 5 made of aluminum and nickel is provided on the conductive connection portion 4 of the battery header 3.
A projection 6 for projection welding is formed on the aluminum side of the battery, and the projection 6 for projection welding of the clad body 5 is opposed to the aluminum surface of the battery header 3. Thereby, the clad body is welded and joined to the battery header 3. Next, as shown in FIG. 1 (B), the negative electrode conductive tab 9 attached to the battery element 8 is welded to the negative terminal 10 of the battery header 3 on the back surface of the battery header 3, and the positive electrode conductive tab similarly attached to the battery element 8. The tab 11 is welded to the electrode header 3. Then
As shown in FIG. 1 (C), after the battery header 3 is placed on the upper part of the battery can 2 and laser welding is performed by irradiating the laser 12, the electrolyte is injected from the electrolyte injection port 13. The non-aqueous electrolyte battery 1 is manufactured by closing and sealing the electrolyte inlet 13.

In the nonaqueous electrolyte battery according to the present invention, since the connection portion of the nickel positive electrode lead is formed at the conductive connection portion of the battery header of the aluminum battery, the nickel positive electrode lead is electrically connected. The parts can be joined by resistance welding to form a conductive connection. The clad body used in the present invention can be manufactured by bombarding a plate material of an easily weldable metal such as aluminum and nickel, joining by a hydraulic press or the like, and then rolling to a desired thickness. Cladding body is 0.1mm ~ 0.2
mm, and the ratio of the thickness of the easily weldable metal such as aluminum to nickel is about 1: 1 to 3: 7, and the thickness of the easily weldable metal such as nickel may be slightly increased. Preferably, when the thickness of nickel is reduced, it becomes difficult to secure welding strength in joining by resistance welding. Nickel, copper, and alloys thereof can be used as the easily weldable metal material that forms the clad body with aluminum.

In the above description, the case where the conductive connecting portion made of aluminum is a part of the base of the battery header has been described as an example. It may be a partial wall surface of a can.

FIG. 2 is a diagram for explaining another embodiment of the present invention. FIG. 2A is a perspective view showing a battery of the present invention. The nonaqueous electrolyte battery 1 of the present invention
2 shows a clad body 5 having projections for projection welding joined by resistance welding. FIG.
(B) is a figure explaining the welding process of the projection for projection welding to the battery can of the present invention. In the battery of the present invention, a plurality of projection welding projections are pressed at one time, and the welding electrode 7 is used in such a size as to be energized, and the entire projection welding projection 6 is pressed at once and the facing aluminum is pressed. A sufficient current can flow between them to form a nugget.

FIG. 3 is a diagram illustrating projections for projection welding formed on the clad body. The projection welding projections 6 formed on the clad body 4 form a more sufficient nugget by providing a plurality of projection welding projections at each of the welding locations. The projection welding projections 6 include projection projections 6 shown in FIGS. (E) and the like. In each, A1, B1, C1, D
1 and E1 show examples in which a projection welding portion was provided at one place of the clad body, and A2, B2, C2, D
2 and E2 show examples in which projection welding portions are provided at two locations.

In projection welding, current concentrates and flows on the projections for projection, and depending on welding conditions such as welding current and pressurizing pressure, phenomena such as generation of pores and aluminum popping out in a portion where aluminum is melted may also occur. As can be seen, in the case of FIG. 3 (D) or (E), in which the number of projection welding projections is as small as four, an excellent welded portion can be obtained under a wide range of welding conditions. In particular, as shown in FIG. 3 (E), it is preferable that four projection welding projections are arranged at the vertices of a rhombus, and a nugget is formed in a region surrounded by these projection welding projections so that good joining characteristics are obtained. Things are obtained.

The projection welding projection preferably has a diameter of 0.5 mm to 1.0 mm.
More preferably, it is 7 mm to 0.9 mm. Also,
The projection welding projection height indicated by d in E3 shown in a side view in FIG. 3E is preferably from 0.2 to 0.4 mm, more preferably from 0.25 mm to 0.35 mm. It is preferable that the welding time and the welding current are appropriately adjusted according to the size and number of the formed projection welding projections. For welding at a plurality of locations, a welding current may be applied in series to a plurality of welding electrodes. However, it is preferable to apply an electrical current to the welding locations in the same direction because the size of the nugget is constant.

[0020]

The present invention will be described below with reference to examples and comparative examples. Example 1 Nickel thickness 0.1 mm, aluminum thickness 0.0
5mm, 14mm × 3mm clad body
As shown by E2 in (E), four projection welding projections were arranged at the vertices of a rhombus at two locations. In E2, the size of each part is a = 0.
75 mm, b = 3.0 mm, c = 6.8 mm, d = 0.
3 mm. An aluminum battery header having a thickness of 0.6 mm was placed on a fixed side electrode having a length of 3.7 mm and a width of 26 mm. Next, a welding electrode having a diameter of 8 mm was used as a pressing-side welding electrode.
Bonding was performed by applying a current of 4.8 μA by applying a pressure of N. Next, the obtained battery header was attached to a battery can, and a junction with the battery can was subjected to laser welding, and then an electrolyte was injected to produce a non-aqueous electrolyte battery. At the center of the clad body of the manufactured battery, 4 mm wide and 0.1 mm thick
Were joined by resistance welding.

As shown in FIG. 4A, the nickel tabs 15 were joined by resistance welding as shown in FIG. 4A. When the nickel tab was peeled off and the welding strength was measured for 30 of the manufactured batteries, it was 50 N. In the welding strength test,
Although the clad body was cut and the nickel tab was broken from the welded portion, none of the clad bodies was peeled off from the welded portion of the battery header.

Example 2 A battery was manufactured in the same manner as in Example 1 except that the clad body was joined at only one place. For the 50 batteries manufactured,
As shown in FIG. 4 (B), when the clad body 5 was peeled off and the welding strength was measured, it was 33.3N.

Comparative Example 1 Welding was performed in the same manner as in Example 1 except that welding was performed at two locations using a welding electrode having a diameter of 1.5 mm without forming projections for projection welding on the clad body. When the strength of the joint was measured in the same manner as in Example 1, the strength was 30N.

[0024]

According to the present invention, a non-aqueous electrolyte battery is connected to a conductive connecting portion formed of aluminum by welding with a projection welding projection facing an aluminum surface of a clad body made of aluminum and an easily weldable metal. The strength of the joint is large, and the conductive connection lead can be joined to an easily weldable metal surface such as nickel, so it can be easily joined to an external circuit and peels off even if a force is applied during use. It is possible to perform reliable bonding without any problem.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a process for manufacturing a battery of the present invention.

FIG. 2 is a diagram illustrating another embodiment of the present invention.

FIG. 3 is a diagram illustrating projections for projection welding formed on a clad body.

FIG. 4 is a diagram illustrating a bonding strength test.

FIG. 5 is a diagram illustrating a method of joining a clad body to a battery can.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Non-aqueous electrolyte battery, 2 ... Battery can, 3 ... Battery header, 4
... Conductive connection part, 5 ... Clad body, 6 ... Projection welding projection, 7, 7a, 7b ... Welding rod, 8 ... Battery element,
Reference numeral 9: negative electrode conductive tab, 10: negative electrode terminal, 11: positive electrode conductive tab, 12: laser, 13: electrolyte injection port, 14: bottom surface, 15: nickel tab

Claims (1)

[Claims] In a non-aqueous electrolyte battery, a conductive connection lead to an external circuit of a battery formed of aluminum and a conductive connection lead to the external circuit, at least a metal material easy to weld and aluminum, A non-aqueous electrolyte battery, wherein a conductive connection portion is formed by joining one projection welding projection on an aluminum surface with an aluminum surface of a clad body facing the aluminum alloy surface.