JP2001160317A - Ni-plated rectangular copper wire - Google Patents

Abstract

(57) [Problem] To provide a Ni-plated rectangular copper wire having no burr at both ends and high conductivity. SOLUTION: This is a Ni-plated rectangular copper wire having a core material 2 mainly composed of copper and a Ni-based plating layer 1 formed on the core material. It is obtained by forming the Ni-based plated core material into a rectangular shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Ni-plated rectangular copper wire.

[0002]

2. Description of the Related Art A lithium ion battery as shown in FIG. 3 is known. This battery is obtained by winding a battery with a separator 12 interposed between a positive electrode 10 and a negative electrode 11, for example.
An electrode lead 13 for extracting a current is joined to each of the electrodes 10 and 11.

Conventionally, this electrode lead 13 has a wide Ni
A (plate) foil was prepared, and a Ni wire formed by slitting the foil and forming a strip having a predetermined width was used.

[0004]

However, as shown in FIG. 4, the Ni wire manufactured by the slit has burrs at both ends.
20 occurs and causes problems such as breaking through the separator when used as an electrode lead.

Further, since all are made of Ni material, the conductivity is as low as about 16 (% IACS), which is a factor of increasing the internal resistance of the battery.

Accordingly, the main object of the present invention is to eliminate burrs,
Another object of the present invention is to provide a Ni-plated rectangular copper wire having high conductivity.

[0007]

According to the present invention, the above object is achieved by forming a rectangular copper wire by molding such as rolling instead of cutting a slit or the like, and using copper as a core material.

That is, a first feature of the present invention is a Ni-plated rectangular copper wire having a copper-based core material and a Ni-based plating layer formed on the core material, wherein the core material is It is obtained by forming into a rectangular shape and applying a Ni-based plating to the core material formed into a rectangular shape.

A second feature is a Ni-plated rectangular copper wire having a core material mainly composed of copper and a Ni-based plating layer formed on the core material, wherein the Ni material is plated on the core material. And forming the Ni-plated core material into a rectangular shape.

The difference between the first feature and the second feature is that the core material is formed into a rectangular shape and then plated, or the plated material is formed and then the core material is formed into a rectangular shape. It is in. In any configuration, a round wire can be used as a core material before being formed into a rectangular shape.

As the core material, pure copper or a copper alloy can be used. In particular, oxygen-free copper is optimal in terms of conductivity. When strength is required, a copper alloy is preferred. Rolling is the most suitable means for forming the core into a rectangular shape.

It is desirable that the Ni-based plating layer be made of pure Ni in consideration of corrosion resistance. Of course, Ni alloy plating may be used. As a plating method, electrolytic plating, chemical plating and the like can be used.

As described above, by using the core material mainly composed of copper, the conductivity can be remarkably improved as compared with the conventional Ni wire, and when used as a battery electrode lead,
A battery with low internal resistance can be configured. Also,
Since it is obtained without going through a cutting step such as a slit, there is no burr, and the problem of breaking through the separator when used as an electrode lead of a battery can be solved.

Here, in the first and second configurations, it is desirable to apply the following requirements individually or in combination.

The “width / thickness” of the Ni-plated rectangular copper wire is set to 20 or more. In particular, 40 or more is preferable. Usually, when this ratio is high, it is often manufactured with slits,
A flat copper wire free of burrs can be obtained by multi-stage rolling. Such a thin rectangular copper wire is most suitable as a lead for a battery electrode.

The conductivity is set to 50 (% IACS) or more. A more preferred conductivity is 60% or more, and further preferably 80% or more. If the thickness of the Ni plating layer is increased, the electrical conductivity decreases. Therefore, the electrical conductivity can be adjusted mainly by reducing the thickness of the Ni plating layer.

The thickness of the Ni plating layer in the middle of the Ni-plated rectangular copper wire is 10 μm or less. This is because if the thickness of the Ni plating layer is too large, the conductivity is reduced.

The thickness of the Ni plating layer in the middle portion of the Ni-plated rectangular copper wire is made smaller than the thickness of the Ni plating layer at both ends. When the core material is formed into a rectangular shape after being subjected to Ni plating, a structure in which the Ni plating layer at the middle portion is thin and the Ni plating layers at both ends are thick is realized.

[0019]

Embodiments of the present invention will be described below. (Trial Production Example 1) A Ni-plated copper wire of the present invention was produced using an oxygen-free copper wire having a circular cross section of 1.2 mmφ as a core material. The manufacturing steps are as follows. The oxygen-free copper wire is plated with Ni, and the plated core is rolled (Example 1). An oxygen-free copper wire is rolled into a rectangular shape, and plated on a rectangular core material (Example 2).

In each of the procedures, rolling is performed in multiple stages, and the “width / thickness” of the finally obtained Ni-plated rectangular copper wire is obtained.
Was 40. The plating was performed by electrolytic plating.

Further, as a comparative example, a Ni plate was prepared by rolling a Ni plate and slitting it to form a strip.

The size of the obtained rectangular copper wire of the example and the comparative example is 4.0 mm in width and 1.0 mm in thickness. The presence or absence of burrs, tensile strength, elongation, conductivity, and plating thickness of each of the examples and comparative examples were measured. The plating thickness was measured at both the end and the middle in the width direction of the rectangular copper wire.
The results are shown in Table 1.

[0023]

[Table 1]

As shown in Table 1, all the examples show higher conductivity in each stage than the comparative example. In addition, mechanical properties such as tensile strength and elongation are comparable to those of the comparative examples in both examples.

FIG. 1 is a sectional view of the first embodiment, and FIG. 2 is a sectional view of the second embodiment. Both figures show one end, the middle, and the other end in the width direction of the rectangular copper wire. In Example 1 in which plating was performed and then rolling was performed, the plating layers 1 at both ends were thick, and the plating layer at the intermediate portion was thin. On the other hand, in Example 2, in which the core material 2 was rolled into a rectangular shape and then plated, the thickness of the plating layer 1 at both end portions and the intermediate portion was substantially uniform. In each of the examples, both ends were formed with curved surfaces, and no burrs were observed.

(Trial Production Example 2) Next, Examples 3 to 9 were produced by the manufacturing steps shown in Table 2. Then, the plating thickness, hardness and conductivity of the obtained rectangular copper wire were measured. "Plating thickness" of rectangular copper wire obtained by "rolling after plating"
Indicates variations in the end portion and the middle portion in the width direction of the rectangular copper wire. Also, "softening" in the manufacturing process
Is. This is performed by maintaining the temperature at a predetermined temperature for a predetermined period of time by heating in a batch furnace or heating by energization. Table 2 also shows the measurement results.

[0027]

[Table 2]

As shown in Table 2, an embodiment having a thick plating thickness
6 and 8 show that the conductivity is lower than those of Examples 5 and 7 where the plating thickness is thin. In addition, Examples 3 and 4 obtained by “rolling after plating” have larger end plating thicknesses and lower conductivity than Examples 5 to 9 obtained by “post-rolling plating”. .

[0029]

As described above, according to the present invention,
By using a core material mainly composed of copper, the conductivity can be
It can be dramatically improved compared to the line. Therefore, when used as a battery electrode lead, a battery with low internal resistance can be configured.

Further, since it is obtained without going through a cutting step such as a slit, there is no burr. for that reason,
When used as a battery electrode lead, problems such as breaking through the separator can be solved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a rectangular copper wire of the present invention that has been plated and rolled.

FIG. 2 is a cross-sectional view of a rectangular copper wire of the present invention that has been rolled and then plated.

FIG. 3 is a configuration diagram of a lithium ion battery (cylinder type).

FIG. 4 is conventionally used for a battery electrode lead.
FIG. 3 is a cross-sectional view of the Ni line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plating layer 2 Core material 10 Positive electrode 11 Negative electrode 12 Separator 13 Electrode lead 20 Burr

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Masayoshi Numano 1-3-1 Shimaya, Konohana-ku, Osaka Sumitomo Electric Industries, Ltd. Osaka Works F-term (reference) 4K024 AA03 AB01 BA09 BB09 BC03 CB21 GA16 5G307 BA03 BB02 BC09 5H022 AA09 BB22 CC08 CC11 CC16 CC21 EE01 EE03

Claims (7)

[Claims] 1. A Ni-plated rectangular copper wire having a copper-based core material and a Ni-based plating layer formed on the core material, wherein the core material is formed into a rectangular shape, A Ni-plated rectangular copper wire obtained by applying a Ni-based plating to a core material molded into a rectangular shape. 2. A Ni-plated rectangular copper wire having a core material mainly composed of copper and a Ni-based plating layer formed on the core material, wherein the Ni material is plated on the core material. A Ni-plated rectangular copper wire obtained by forming the applied core material into a rectangular shape. 3. The Ni according to claim 1, wherein the “width / thickness” of the Ni-plated rectangular copper wire is 20 or more.
Plated rectangular copper wire. 4. The Ni-plated rectangular copper wire according to claim 1, wherein the electrical conductivity is 50 (% IACS) or more. 5. The Ni-plated rectangular copper wire according to claim 1, which is used as a battery electrode lead. 6. The Ni-plated rectangular copper wire according to claim 1, wherein a thickness of the Ni-plated layer at an intermediate portion of the Ni-plated rectangular copper wire is 10 μm or less. 7. The Ni-plated rectangular copper wire according to claim 1, wherein the thickness of the Ni-plated layer at an intermediate portion of the Ni-plated rectangular copper wire is smaller than the thickness of the Ni-plated layer at both ends.