JP2022065702A - Secondary battery and method for manufacturing secondary battery - Google Patents

Abstract

To provide a secondary battery and a method for manufacturing a secondary battery, capable of preventing the occurrence of electrolytic corrosion.SOLUTION: A secondary battery 1 according to an exemplary embodiment of the present invention includes a current collector terminal 40 and an external terminal 100 connected to the current collector terminal 40 using a connection 41a which has a head and a body formed of a metal that forms the current collector terminal 40. The external terminal 100 is formed of an inlay clad material 10 containing a first metal, in which a metal forming the current collector terminal 40 is contained, and a second metal different from the first metal. The external terminal 100 has a recess 110 where the head 410 of the connection 41a is arranged and a through hole 120 where the body 411 of the connection 41a is inserted. A portion of the external terminal 100 defining the recess 110 and the through hole 120 is formed of the first metal.SELECTED DRAWING: Figure 5

Description

The present invention relates to a secondary battery and a method for manufacturing the secondary battery.

Currently, in vehicles such as hybrid vehicles, plug-in hybrid vehicles, and electric vehicles that use electric power as a driving force, secondary batteries such as lithium ion batteries and nickel hydrogen batteries are used. The secondary battery has an external terminal and is connected to another adjacent secondary battery via the external terminal. As an example of such a secondary battery, Patent Document 1 discloses a secondary battery including an external terminal connected to a current collector member by a connection terminal.

Japanese Patent No. 5656592

However, on the negative electrode side of the secondary battery disclosed in Patent Document 1, since the body portion of the connection terminal made of copper and the aluminum portion of the crimping and fixing portion of the external terminal are close to each other, water or the like may be placed between them. Liquid may enter and the external terminals may be electrolytically corroded.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a secondary battery and a method for manufacturing a secondary battery capable of preventing the occurrence of electrolytic corrosion.

The secondary battery according to an exemplary embodiment of the present invention is
It is provided with a current collector terminal and an external terminal connected to the current collector terminal using a connection portion having a head and a body made of metal forming the current collector terminal.
The external terminal is formed of an inlay clad material containing a first metal containing a metal forming a current collecting terminal and a second metal different from the first metal.
The external terminal has a recess in which the head of the connection portion is arranged and a through hole into which the body portion of the connection portion is inserted.
The portion of the external terminal that defines the recess and the through hole is formed of the first metal.

Further, the portion of the external terminal located below the head of the connecting portion is made of the first metal.

Further, the height position of the upper surface of the head of the connecting portion is preferably equal to or lower than the height position of the upper surface of the external terminal.

Further, the current collector terminal and the connection portion can be integrally formed.

A current collector terminal according to an exemplary embodiment of the present invention and an external terminal connected to the current collector terminal using a connection portion having a head and a body portion made of metal forming the current collector terminal. The method of manufacturing the secondary battery to be equipped is
Of the inlay clad material containing a first metal containing a metal forming a current collecting terminal and a second metal different from the first metal, the first metal is used as an upper layer and the second metal is used as a lower layer. The step of pressing the laminated portion from the upper layer side to form a recess in which the head of the connecting portion is arranged, and
The process of removing the second metal in the lower layer of the laminated portion located below the recess, and
It includes a step of forming a through hole into which a body portion of a connection portion is inserted in a recess to form an external terminal.

Further, in the step of removing the second metal, the laminated portion to be located below the head when the head of the connecting portion is arranged in the recess is made of the first metal, and the second metal is used. The second metal is removed so that it does not contain metal.

Further, in the step of forming the recess, the recess is formed so that the height position of the upper surface of the head when the head of the connection portion is arranged in the recess is equal to or lower than the height position of the upper surface of the external terminal. Is preferable.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a secondary battery capable of preventing the occurrence of electrolytic corrosion and a method for manufacturing the secondary battery.

It is a perspective view which shows the secondary battery which concerns on one Embodiment of this invention. It is a figure which shows the manufacturing process of the external terminal which concerns on one Embodiment of this invention. It is a figure which shows the manufacturing process of the external terminal which concerns on one Embodiment of this invention. It is a figure which shows the bottom surface of the external terminal which concerns on one Embodiment of this invention. It is a figure which shows the connection process of the external terminal and the current collector terminal which concerns on one exemplary Embodiment of this invention.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a secondary battery 1 according to an exemplary embodiment of the present invention. The secondary battery 1 includes a negative electrode external terminal 100a and a positive electrode external terminal 100b on the upper portion. The negative electrode external terminal 100a is connected to the positive electrode external terminal of a secondary battery (not shown) arranged adjacently via a bus bar (not shown). Similarly, the positive electrode external terminal 100b is connected to the negative electrode external terminal of the secondary battery arranged adjacently via the bus bar.

2 and 3 are views showing a manufacturing process of the negative electrode external terminal 100a included in the method for manufacturing a secondary battery according to an exemplary embodiment of the present invention. First, as shown in FIG. 2, the inlay clad material 10 containing the first metal 11 and the second metal 20 is cut at the cutting position. The first metal 11 is a main metal (for example, copper or the like) forming the negative electrode current collector terminal. The second metal is a metal different from the first metal (for example, aluminum, etc.). The second metal is preferably the same as the metal forming the bus bar to be welded to the negative electrode external terminal 100a.

Next, as shown in FIG. 3, of the cut inlay clad material 10, the laminated portion having the first metal 11 as the upper layer and the second metal 20 as the lower layer is pressed from the upper layer side to form a recess. Form 110. At this time, the pressed portion of the second metal 20 is pressed so as to be extruded below the level of the bottom surface of the inlay clad material 10 which is not deformed by the press working.

In the recess 110, the head of a connecting portion connecting the negative electrode external terminal 100a and the negative electrode current collecting terminal is arranged. In the step of forming the recess 110, the recess 110 is set so that the height position of the upper surface of the head when the head of the connection portion is arranged in the recess 110 is equal to or lower than the height position of the upper surface of the negative electrode external terminal 100a. It is preferable to form. Further, the depth of the recess 110 is preferably equal to or greater than the thickness of the first metal 11. The negative electrode current collector terminal and the connection portion will be described in detail with reference to FIG.

Next, the second metal 20 in the lower layer of the laminated portion located below the recess 110 is removed. At this time, the laminated portion located below the level of the bottom surface of the inlay clad material 10 that is not deformed by the press working is removed. In other words, in the step of removing the second metal 20, the portion located below the head of the connection portion when the head of the connection portion is arranged in the recess 110 does not include the second metal 20. In addition, the second metal 20 is removed. As a result, the portion defining the recess 110 and the through hole 120 is formed of the first metal 11 and not the second metal 20. In addition, the plate thickness of the portion defining the recess 110 becomes thin.

Next, the through hole 120 is formed in the recess 110. Since the body portion of the connection portion is inserted into the through hole 120, the diameter of the through hole 120 is set to be equal to or larger than the diameter of the body portion of the connection portion. The through hole 120 is preferably formed in the center of the recess 110. FIG. 4 shows the bottom surface of the negative electrode external terminal 100a thus formed.

FIG. 5 is a diagram showing a step of connecting the negative electrode external terminal 100a and the negative electrode current collecting terminal 40a included in the method for manufacturing a secondary battery. In the present embodiment, the negative electrode current collecting terminal 40a in which the connecting portion 41a is integrally formed is used. The connecting portion 41a is a member that protrudes from the upper portion of the negative electrode current collecting terminal 40a. The negative electrode external terminal 100a is arranged in the insulator 50 installed in the cover 60 of the secondary battery 1. A gasket 70 for sealing the secondary battery 1 is arranged around the negative electrode current collector terminal 40a. An electrode body (not shown) is connected to the lower portion of the negative electrode current collector terminal 40a.

First, the connection portion 41a of the negative electrode current collecting terminal 40a is inserted into the through hole 120 of the negative electrode external terminal 100a from the bottom surface side of the negative electrode external terminal 100a. Next, the connection portion 41a of the negative electrode current collecting terminal 40a is pressed from the upper surface side of the negative electrode external terminal 100a. As a result, the head 410 of the connecting portion 41a is formed, and the negative electrode external terminal 100a and the negative electrode current collecting terminal 40a are crimped.

As shown in FIG. 5, the portion of the negative electrode external terminal 100a located below the head 410 of the connecting portion 41a is composed of the first metal 11 and does not include the second metal 20. Further, the height position of the upper surface of the head 410 of the connection portion 41a is equal to or lower than the height position of the upper surface of the negative electrode external terminal 100a.

After that, the bus bar is welded to the second metal 20 portion on the upper surface of the negative electrode external terminal 100a.

In the above-described embodiment, the secondary battery 1 is connected to the current collecting terminal 40 by using the current collecting terminal 40 and the metal connecting portion 41a having the head 410 forming the current collecting terminal 40 and the body portion 411. It is provided with a connected external terminal 100. The external terminal 100 is formed of an inlay clad material containing a first metal containing a metal forming the current collecting terminal 40 and a second metal different from the first metal. The external terminal 100 has a recess 110 in which the head 410 of the connection portion 41a is arranged, and a through hole 120 into which the body portion 411 of the connection portion 41a is inserted. The portion of the external terminal 100 that defines the recess 110 and the through hole 120 is formed of the first metal.

As a result, the connecting portion 41a and the portion defining the recess 110 and the through hole 120 in the vicinity of the connecting portion 41a are formed containing the same metal, so that the connecting portion 41a and the recess 110 and the through hole 120 are defined. It is possible to prevent the part to be electrically corroded.

Further, the portion defining the recess 110 and the through hole 120 to which pressure is applied when the external terminal 100 and the current collector terminal 40 are connected is formed of the same metal, and the hardness becomes uniform. Therefore, it is possible to suppress deformation of the portion defining the recess 110 and the through hole 120 of the external terminal 100 due to the pressure.

Further, in the external terminal 100, the plate thickness of the portion of the portion defining the recess 110, which is located directly below the head 410 of the connecting portion 41a, becomes thin. As a result, the length of the body portion 411 of the connecting portion 41a inserted into the through hole 120 of the external terminal 100 can be shortened. Therefore, it is possible to facilitate the molding of the connection portion 41a and reduce the electric resistance generated in the connection portion 41a during charging / discharging.

Further, the portion of the external terminal 100 located below the head 410 of the connecting portion 41a is made of the first metal. As a result, the hardness of the portion of the external terminal 100 located below the head 410 of the connecting portion 41a becomes uniform. Therefore, it is possible to prevent the portion of the external terminal 100 located below the head 410 of the connection portion 41a from being deformed by the pressure applied when the external terminal 100 and the current collector terminal 40 are connected.

Further, the height position of the upper surface of the head 410 of the connection portion 41a is equal to or lower than the height position of the upper surface of the external terminal 100. Thereby, with one end of the flat bus bar arranged above the connecting portion 41a, the other end of the bus bar can be welded to the second metal 20 portion on the upper surface of the external terminal 100. Therefore, the flat bus bar can be arranged on the upper side of the connection portion 41a, and the space of the secondary battery 1 can be saved.

In another embodiment, the negative electrode current collector terminal 40a and the connection portion 41a may be configured as individual parts. Further, in another embodiment, the positive electrode external terminal 100b may be formed by using an inlay clad material having aluminum as the first metal and copper as the second metal. In this case, the bus bar made of copper can be welded to the second metal portion of the positive electrode external terminal 100b.

The present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit of the present invention.

1 Rechargeable battery 10 Inlay clad material 11 First metal 20 Second metal 40 Current collecting terminal 40a Negative electrode collecting terminal 41a Connection part 410 Head 411 Body 50 Insulator 60 Cover 70 Gasket 100 External terminal 100a Negative electrode external terminal 100b Positive electrode external terminal 110 Recess 120 Through hole

Claims (7)

A secondary battery including a current collector terminal and an external terminal connected to the current collector terminal using a connection portion having a head and a body made of metal forming the current collector terminal.
The external terminal is formed of an inlay clad material containing a first metal containing a metal forming the current collector terminal and a second metal different from the first metal.
The external terminal has a recess in which the head of the connection portion is arranged and a through hole into which the body portion of the connection portion is inserted.
A secondary battery in which a portion of the external terminal that defines the recess and the through hole is made of the first metal. The secondary battery according to claim 1, wherein the portion of the external terminal located below the head of the connection portion is made of the first metal. The secondary battery according to claim 1 or 2, wherein the height position of the upper surface of the head of the connection portion is equal to or lower than the height position of the upper surface of the external terminal. The secondary battery according to any one of claims 1 to 3, wherein the current collector terminal and the connection portion are integrally formed. A method for manufacturing a secondary battery including a current collector terminal and an external terminal connected to the current collector terminal using a connection portion having a head and a body made of metal forming the current collector terminal. hand,
Of the inlay clad materials containing a first metal containing a metal forming the current collecting terminal and a second metal different from the first metal, the first metal is used as an upper layer and the second metal is used as an upper layer. A step of pressing a laminated portion having a metal as a lower layer from the upper layer side to form a recess in which the head of the connection portion is arranged.
A step of removing the second metal in the lower layer of the laminated portion located below the recess.
A method for manufacturing a secondary battery, comprising a step of forming a through hole into which a body portion of the connection portion is inserted in the recess to form the external terminal. In the step of removing the second metal, the laminated portion to be located below the head when the head of the connection portion is arranged in the recess is composed of the first metal. The method for manufacturing a secondary battery according to claim 5, wherein the second metal is removed so as not to contain the second metal. In the step of forming the recess, the height position of the upper surface of the head when the head of the connection portion is arranged in the recess is equal to or lower than the height position of the upper surface of the external terminal. The method for manufacturing a secondary battery according to claim 5 or 6, wherein the recess is formed.

Images