Terminal component

Abstract

To provide a terminal component having excellent electrical conductivity, which is made by joining dissimilar metals.SOLUTION: A terminal component 1 includes a first metal 10 having a convex portion 11 and a second metal 20 having a concave portion 21, and is formed by joining the two metals together by fitting the convex portion of the first metal into the concave portion of the second metal, the opening edge 21a of the concave portion of the second metal is positioned outside the bottom 21c, and the terminal component is formed by joining the two metals together by filling the concave portion with the convex portion of the first metal by plastic deformation.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a terminal component used for the negative electrode external terminal of a secondary battery.

Background Art

[0002] Conventionally, as the negative electrode external terminal of a lithium-ion secondary battery, there is one shown in Patent Document 1. This negative electrode external terminal is configured by joining both members by press-fitting a rod-shaped member made of a copper material into a concave portion of a plate-shaped body made of an aluminum material.

[0003] Further, as an improved version of the above negative electrode external terminal, there is a terminal component shown in Patent Document 2. This terminal component is configured such that the edge of the opening of the concave portion provided in the second metal forms a trapezoidal shape that protrudes inward from the bottom of the concave portion, and the first metal is bitten into this to exert a retaining effect.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the terminal component shown in Patent Document 2, since the opening edge of the concave portion of the second metal is narrower than the bottom, when the first metal is caused to flow by plastic deformation and joined here, the first metal may not be able to fill every corner of the concave portion of the second metal. In particular, it is difficult to fill the corners at the bottom of the concave portion and voids are generated, which becomes a resistance and causes a decrease in conductivity as a terminal component.

[0006] The present invention was created in view of the above problems, and an object thereof is to provide a terminal component formed by joining dissimilar metal components, the terminal component being excellent in adhesion and conductivity between dissimilar metals.

Means for Solving the Problems

[0007] In a terminal component formed by joining a first metal having a convex portion and a second metal having a concave portion, and fitting the convex portion of the first metal into the concave portion of the second metal, the concave portion of the second metal has an edge of its opening located outside the bottom, and the problem can be solved by a terminal component formed by joining both metals by filling the convex portion of the first metal into the concave portion by plastic deformation.

[0008] Note that the concave portion of the second metal preferably has a middle swelling shape.

Effects of the Invention

[0009] According to the present invention, since the edge of the opening of the concave portion of the second metal is located outside the bottom, it is easy to flow the convex portion of the first metal into the concave portion by plastic deformation and fill it without gaps. Therefore, in a terminal component formed by joining dissimilar metals, a terminal component with high adhesion and excellent conductivity between both metals can be provided.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0011] Hereinafter, modes for carrying out the terminal component of the present invention will be described with reference to the drawings.

[0012] In FIG. 1, reference numeral 1 denotes a terminal component, which is used for the negative electrode external terminal of a lithium-ion secondary battery. This terminal component 1 is composed of a first metal 10 having a convex portion 11 and a second metal 20 having a concave portion 21.

[0013] The first metal 10 is an aluminum material formed in a plate shape, and a bus bar (not shown) is connected to its upper surface.

[0014] The second metal 20 is a copper member composed of a head portion 22 and a shaft portion 23. The first metal 10 is joined to the upper surface of the head portion 22, and a current collector (not shown) inside the lithium-ion battery is connected to the shaft portion 23.

[0015] Further, a concave portion 21 is formed on the upper surface of the head portion 22 of the second metal 20. This concave portion 21 has a middle-bulged shape. The edge 21a of the opening of the concave portion 21 is located outside the bottom portion 21c, and the central portion 21b of the concave portion projects outside the edge 21a of the opening.

[0016] The first metal 10 and the second metal 20 are joined by fitting the convex portion 22 of the first metal 10 into the concave portion 21 of the second metal 20. As the joining method, with the second metal 20 held in a receiving mold, the plate-shaped first metal 10 is placed on the head portion 22 of the second metal 20, and the first metal 10 is compressed from above by a press machine (not shown). Then, the first metal 10 flows and fills into the concave portion 21 of the second metal 20 due to plastic deformation, thereby forming the convex portion 11 of the first metal 10.

[0017] According to the above terminal component, since the edge 21a of the opening of the concave portion 21 of the second metal 20 is located outside the bottom portion 21c, it becomes easier to flow the convex portion 11 of the first metal 10 into the concave portion 21 by plastic deformation, and thus it is uniformly filled. For this reason, the adhesion between the first metal and the second metal is high, and the voids that cause resistance are also reduced, resulting in excellent conductivity. Further, since the concave portion 21 of the second metal 20 has a middle-bulged shape, this serves as a retaining means, and thus the terminal component 1 also has excellent pull-out strength.

[0018] Note that the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention. For example, in the embodiment of FIG. 1, the recess 21 of the second metal 20 is rhombic, but in the terminal component 101 shown in FIG. 2, the recess 121 of the second metal 20 may be barrel-shaped.

[0019] 1 Terminal component 10 First metal 11 Protrusion 20 Second metal 21 Recess 21a Edge 21b Central part 21c Bottom 22 Head 23 Shaft part

Claims

1. A terminal component comprising a first metal having a convex portion and a second metal having a concave portion, the two metals being joined by fitting the convex portion of the first metal into the concave portion of the second metal, wherein the concave portion of the second metal has an edge of its opening located outside the bottom, and the convex portion of the first metal is filled into the concave portion by plastic deformation to join the two metals.

2. The terminal component according to claim 1, wherein the concave portion of the second metal has a middle swelling shape.

Images