JPH09265973A - Terminal structure for flat battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat battery with high corrosion resistance, high mechanical strength, low contact resistance, and easy soldering capability by reinforcing positive and negative terminals with a covering material. SOLUTION: A battery is inserted between a laminated film 1 folded in two so that only a positive terminal 2 and a negative terminal 3 are exposed 5-10mm from the outside, and the surrounding of the laminated film 1 is heat- sealed with a part of each of the terminals 2,3 interposed. Covering materials 4,5 are placed so that the exposed terminals 2, 3 and the periphery parts of the laminated sheet 1 between which the terminals 2, 3 are interposed are covered, and the covering materials 4, 5 and the terminals 2, 3 are spot-welded to complete a battery. The terminals 2, 3 are reinforced with the covering materials 4, 5, mechanical strength is increased, damage is prevented, and corrosion is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat battery terminal structure having flaky terminals.

[0002]

2. Description of the Related Art Conventionally, as one of the sealing structures for flat type batteries, there has been one in which a power generating element such as a positive electrode, a negative electrode and a separator is enclosed in a package film as disclosed in Japanese Patent Publication No. 59-38708. . As the package film, a laminated film made of a resin film that can be heat-sealed with a metal foil such as aluminum is often used, and after the power generation element is inserted, the periphery is heat-sealed.

In such a flat battery, generally, the ends of the current collector are penetrated through the sealing portion of the laminate film and are exposed to the outside to serve as positive and negative terminals. The requirements for the current collector are not only good electrical conductivity, but also corrosion resistance, light weight and small volume, and low cost. Taking a lithium battery as an example, in the case of a primary battery, SUS (stainless steel) is generally used for both the positive and negative electrodes. In the case of a secondary battery, aluminum or SUS is generally used for the positive electrode and copper is generally used for the negative electrode. Further, since the thinner one is advantageous because it occupies less volume, it is common to use an extremely thin foil having a thickness of several tens of μm or less. In a conventional flat battery, a part of these current collectors is directly configured as a battery terminal.

[0004]

As described in the prior art, the configuration in which the positive electrode terminal is made of aluminum or SUS and the negative electrode terminal is made of copper or SUS has the following problems. That is, aluminum or copper exposed to the outside has poor corrosion resistance, and resistance welding such as spot welding is difficult, and in SUS, contact resistance is large and soldering is difficult. Furthermore, since the thickness is as thin as several tens of μm or less, the mechanical strength is insufficient, and there is a risk of breaking when bent.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks, the present invention uses a metal for which the positive and negative terminals 2 and 3 are excellent in mechanical strength and corrosion resistance and which is easy to weld or solder. It is characterized in that the coatings 4 and 5 are coated and the coatings 4 and 5 are fixed to the terminals 2 and 3 by welding. The battery peripheral portion 1a, in which the coatings 4 and 5 are made of a folded metal foil, and the terminals 2 and 3 are projected
Is preferably sandwiched between the coatings 4 and 5.

From the above, it is needless to say that the corrosion of the terminals 2 and 3 is prevented, and the terminals 2 and 3 are prevented from breaking by preventing the bending force from being applied to aluminum or copper. For example, nickel is suitable as the material of the metal. Compared to aluminum and copper, nickel is easier to perform resistance welding such as spot welding and soldering, and can be easily connected to the device side circuit.

[0007]

1 is a plan view showing an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 (A) is a perspective view showing an embodiment of a coating according to the present invention. FIG. 3 (B) is a perspective view showing another embodiment of the same coating, and 1 is polyolefin / aluminum / nylon or polyolefin / aluminum / polyethylene having a heat-fusible polyolefin resin layer on its inner surface. Laminated film such as terephthalate (PET), 2 made of aluminum foil has a width of 3 to 5 μm
Positive electrode terminal, 3 is a negative electrode terminal made of copper foil and having a width of 3 to 5 μm, 4 is a coating material that covers the positive electrode terminal 2, and 5 is a negative electrode terminal 3.
And 6 is a power generation element.

The coatings 4 and 5 are, for example, as shown in FIG.
As shown in FIG. 3, a nickel cap-shaped drawn product having a thickness of 100 to 300 μm is provided with a notch 7 for holding the terminals 2 and 3, or as shown in FIG. A 300 μm nickel strip is folded in two, and a gap 8 for sandwiching the terminals 2 and 3 is provided between these strips.

The coatings 4, 5 and the terminals 2, 3 are fixed by resistance welding, for example spot welding. Although the terminals 2 and 3 are made of metal (aluminum or copper) which is not suitable for resistance welding, the terminals 2 and 3 can be welded easily and surely by being sandwiched between the coatings 4 and 5 and welded. In addition, the coatings 4 and 5 are laminated films 1 of the terminals 2 and 3.
In addition to covering the surface 3 exposed to the outside, the peripheral portion 1a of the battery also clamps the portion sandwiched by the laminate film 1. In this way, since the ends of the battery are also sandwiched by the coatings 4 and 5 together with the terminals 2 and 3, the terminals 2 and 3 are
Almost no bending force is applied to the terminal, the terminals 2 and 3 break,
Damage can be prevented.

[0010]

EXAMPLES Next, the manufacturing method of the present invention will be explained.
First, a positive electrode current collector made of an aluminum foil having a thickness of 20 to 50 μm, in which a rectangular terminal 2 is projected from one side surface of the rectangle,
A positive electrode mixture is prepared by coating lithium cobalt oxide with a carbon powder and a binder resin to prepare a positive electrode. Then, the positive electrode is treated with IMLiPF ₆ -PC (propylene carbonate).
The positive electrode is impregnated with the electrolytic solution by immersing the positive electrode in the electrolytic solution. Similarly, a negative electrode mixture made by mixing carbon powder and a binder resin is applied to a negative electrode current collector made of a copper foil having a thickness of 20 to 50 μm in which a rectangular terminal 3 is protruded from one side surface of the rectangle to form a negative electrode. To make. Then, the negative electrode is immersed in the electrolytic solution to impregnate the negative electrode with the electrolytic solution. The separator impregnated with the electrolytic solution is sandwiched between the positive electrode and the negative electrode to assemble the power generation element 6.

Next, the power generating element 6 is inserted between the two folded laminate films 1 so that only the terminals 2 and 3 are exposed to the outside of 5 to 10 μm, and the terminals 2 and 3 are partially sandwiched. In this state, the peripheral portion 1a of the laminated film 1 is heat-sealed. Next, the peripheral portions 1a of the laminated film 1 sandwiching the exposed terminals 2 and 3 and the terminals 2 and 3
The coatings 4 and 5 shown in FIG. 3 are covered so as to cover and, and the coatings 4 and 5 and the terminals 2 and 3 are spot-welded to complete the battery of the present invention. When spot-welding the coatings 4 and 5 and the terminals 2 and 3, it is desirable to weld the tips and both sides of the coatings 4 and 5 protruding from the terminals 2 and 3.

[0012]

As described in detail above, the present invention has the following effects. (1) According to claim 1, the thin terminals 2 and 3 are covered with the coating 4.
Since it is reinforced by 5, it has excellent mechanical strength. (2) According to the first aspect, since the terminals 2 and 3 are covered with the coatings 4 and 5, they are not damaged and corrosion can be prevented. (3) According to the first aspect, the coatings 4, 5 and the external device can be resistance-welded, so that the connection is excellent in reliability. (4) According to the second aspect, the coatings 4 and 5 cover the terminals 2 and 3 and also sandwich the peripheral portion 1a of the battery.
The mechanical strength of the terminals 2 and 3 can be further increased.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 (A) is a perspective view showing an embodiment of a coating according to the present invention, and FIG. 3 (B) is a perspective view showing another embodiment of the coating.

[Explanation of symbols]

 1a Battery peripheral part 2 Positive electrode terminal 3 Negative electrode terminal 4, 5 Coating

Claims (2)

[Claims] 1. A positive electrode terminal (2) and a negative electrode terminal (3) are coated with a coating (4,5) which is excellent in rust resistance and can be soldered or welded, and the coating (4,5). ) And the terminals (2, 3) are fixed to each other by welding. 2. The coating (4, 5) according to claim 1 is made of a folded metal foil, and the battery peripheral portion (1a) having the terminals (2, 3) protruding therefrom is covered with the coating (4, 5). A terminal structure for a flat battery, characterized in that it is sandwiched by 5).