JP3212090U - Lead material - Google Patents

Abstract

Provided is a thin lead member that prevents a burr from penetrating an insulating film fixed to a conductor even when a burr is formed on the conductor of the lead member. Lead members 30 and 40 are formed by bonding two insulating films 51 and 52 having different thicknesses to both surfaces of flat lead conductors 31 and 41 excluding both ends in the length direction. The lead conductors 31 and 41 have burrs only on one surface side, and the thicker insulating film 51 of the two insulating films 51 and 52 is bonded to the surface of the lead conductor having burrs. [Selection] Figure 2

Description

  The present invention relates to a lead member used for a nonaqueous electrolyte battery or the like.

  Non-aqueous electrolyte batteries such as lithium ion batteries are used as power sources for small electronic devices. In this non-aqueous electrolyte battery, a positive electrode plate, a negative electrode plate, and an electrolytic solution are accommodated in an encapsulating bag body (also referred to as a “packaging material”) made of a multilayer film, and lead members connected to the positive electrode plate and the negative electrode plate are sealed. A structure that is sealed and taken out to the outside is known. As the multilayer film forming the encapsulating bag, a multilayer film having a high sealing property in which a metal foil layer made of a metal such as aluminum is sandwiched between at least the innermost layer film and the outermost layer film is used. .

  The lead member uses an aluminum or titanium aluminum alloy lead conductor on the positive electrode side and a copper or nickel copper alloy lead conductor on the negative electrode side. Patent Document 1 discloses a lead member in which the surface of a conductor can be identified by changing the color, surface roughness, and shape of two insulating films provided on the lead conductor.

Utility Model Registration No. 3178499

  When the battery is made thin, it is necessary to make the insulating film and the packaging material provided on the lead conductor thin. Further, as a countermeasure against electrolyte leakage, the pressure applied when sealing the packaging material and the lead member is increasing. When the insulating film provided on the lead member is thinned, the possibility that the burr of the lead conductor penetrates the insulating film and reaches the metal layer of the packaging material increases.

  The present invention has been made in view of the above-described circumstances, and even when burrs are formed on the conductor of the lead member, a thin lead member that prevents the burrs from penetrating through the insulating film fixed to the lead conductor is provided. Its purpose is to provide.

  The lead member according to one aspect of the present invention is a flat conductor having burrs on only one surface side, and two insulating films having different thicknesses on both surfaces except for both ends in the length direction have a thickness of 70 μm or more. A certain thicker insulating film is bonded to the surface of the flat conductor having the burr.

  According to the present invention, even when burrs are formed on the flat conductor of the lead member, the burrs can be prevented from penetrating through the insulating film fixed to the conductor, and the lead member can be thinned.

It is a figure for demonstrating the outline of the nonaqueous electrolyte battery using the lead member which concerns on one Embodiment of this invention. It is a figure for demonstrating the lead member which concerns on one Embodiment of this invention. It is a figure which shows an example of the manufacturing method of the lead conductor of a lead member. It is a figure explaining the test result of the lead member by this invention. It is a figure for demonstrating the lead member which concerns on other embodiment of this invention.

(Description of Embodiment of the Invention)
First, embodiments of the present invention will be listed and described.
The lead member according to one aspect of the present invention is a flat conductor having burrs on only one surface side, and two insulating films having different thicknesses on both surfaces except for both ends in the length direction have a thickness of 70 μm or more. A certain thicker insulating film is bonded to the surface of the flat conductor having the burr.
According to this embodiment, even when burrs are formed on the flat conductor of the lead member, the burrs can be prevented from penetrating through the insulating film fixed to the conductor, and the lead member can be thinned.

As one aspect of the present embodiment, in the above lead member, the thinner one of the two insulating films has a thickness of 30 μm or more and 50 μm or less.
According to this embodiment, since the thickness of the thinner insulating film can be 30 μm or more and 50 μm or less, the thickness of the lead member can be reduced.

(Description of Embodiment of the Invention)
Specific examples of the lead member according to the present invention will be described below with reference to the drawings. The present invention is not limited to the following examples, but is indicated by the scope of the utility model registration request and is intended to include all modifications within the meaning and scope equivalent to the scope of the utility model registration request. Is done. Moreover, in the following description, the structure which attached | subjected the same code | symbol also in different drawing is the same, and the description may be abbreviate | omitted.

  FIG. 1 is a view for explaining an outline of a nonaqueous electrolyte battery using a lead member according to an embodiment of the present invention. FIG. 1A is a view for explaining an assembled form of a non-aqueous electrolyte battery, and FIG. 1B is a view showing its appearance. The nonaqueous electrolyte battery 1 includes an encapsulating bag body 10, a laminated electrode group 20, a positive lead member 30, a negative lead member 40, and an insulating film 50.

  The nonaqueous electrolyte battery 1 includes a nonaqueous electrolyte battery such as a lithium ion battery, a capacitor such as an electric double layer capacitor (EDLC) or a lithium ion capacitor, and the like. In the electric double layer capacitor, aluminum is used for the lead conductors 31 and 41 of the lead members 30 and 40 on both the positive electrode side and the negative electrode side. In a lithium ion battery or a lithium ion capacitor, a high potential is applied to the lead conductor 31 of the lead member 30 on the positive electrode side, so that it is a metal material that does not dissolve in the electrolytic solution at a high potential, and is usually formed of aluminum or a titanium aluminum alloy. . In addition, lithium is deposited on the lead conductor 41 of the lead member 40 on the negative electrode side due to overcharge and the potential becomes high due to overdischarge. Therefore, the lead conductor 41 is less likely to be corroded by lithium, less likely to form an alloy with lithium, and high. Copper that is difficult to dissolve at an electric potential is used. Copper is often used after nickel plating.

  In the nonaqueous electrolyte battery 1, a laminated electrode group 20 in which a positive electrode plate and a negative electrode plate are laminated via a separator and an electrolytic solution are housed in an encapsulating bag body 10 made of a multilayer film including a metal foil, and connected to the positive electrode plate. The lead member 30 and the lead member 40 connected to the negative electrode plate are taken out from the sealing portion 11 of the encapsulating bag body 10 in a hermetically sealed state and configured. As will be described later, the multilayer film of the encapsulating bag body 10 is formed by bonding resin films on both surfaces of a metal foil.

  The encapsulating bag body 10 serves as an outer case of the nonaqueous electrolyte battery, and is sealed by, for example, sealing the sealing portion 11 around two rectangular multilayer films by heat welding. An insulating film 50 is bonded in advance to the portions of the lead members 30 and 40 taken out from the seal portion 11 by heat welding. The insulating film 50 prevents the sealing performance from being deteriorated with respect to the multilayer film of the encapsulating bag 10 and prevents electrical contact between the lead members 30 and 40 and the metal foil in the multilayer film.

  Next, details of the lead members 30 and 40 will be described. FIG. 2 is a view for explaining a lead member according to an embodiment of the present invention. FIG. 2 (A) is a schematic view of the lead member, and FIGS. 2 (B) and 2 (C) are taken out of the lead member. It is a figure which shows a state. Moreover, FIG. 3 is a figure which shows an example of the manufacturing method of the lead conductor of a lead member.

  As shown in FIG. 3, the lead members 31 and 41 are thin conductor pieces 131 and 141 having a thickness of about 0.05 mm to 0.50 mm, which are cut into a rectangular shape to form lead conductors 31 and 41. For the lead conductors 31 and 41, first, a wide conductor foil 130 and 140 as shown in FIG. 3A is finely cut by, for example, a rotary blade 60 rotated by a shaft 61, and FIG. After obtaining the elongated conductor pieces 131 and 141, the elongated conductor pieces 131 and 141 are further cut to obtain individual pieces of flat lead conductors 31 and 41. In the lead conductors 31 and 41 thus obtained, protrusions called burrs are generated at both ends caused by cutting as indicated by A in FIG. The height of this burr may be about 20 μm or more. In the present embodiment, the direction of the rotary blade 60 is adjusted so that burrs appear only on one side of the lead conductors 31 and 41.

  The lead members 30 and 40 are configured by attaching an insulating film 50 to portions where the lead conductors 31 and 41 are taken out from the encapsulating bag body 10. The insulating film 50 is bonded to both surfaces of the lead conductor in alignment. The insulating film 50 is shorter than the length of the lead conductors 31 and 41 and wider than the width of the lead conductors 31 and 41. In the present embodiment, the thickness of the insulating film 51 attached to the surface of the lead conductors 31 and 41 where the burrs are exposed and the insulating film 52 attached to the surfaces of the lead conductors 31 and 41 where the burrs are not exposed. Different thickness. The insulating film 50 is used as a general term for the insulating films 51 and 52.

  More specifically, the thickness d1 of the insulating film 51 attached to the surface of the lead conductors 31 and 41 where the burrs are exposed is set to the insulating film 52 attached to the surface of the lead conductors 31 and 41 where the burrs are not exposed. It is thicker than the thickness d2. As shown in FIG. 2B, the insulating film 51 includes, for example, an inner layer 51a that adheres or welds to the metal surfaces of the lead conductors 31 and 41 and an outer layer 51b that is fused to the encapsulating bag body 10. Similarly, the insulating film 52 is formed of, for example, two layers of an inner layer 52a that adheres or welds to the metal surfaces of the lead conductors 31 and 41 and an outer layer 52b that is fused to the encapsulating bag body 10. Can do.

  The inner layers 51a and 52a are previously brought into close contact with the lead conductors 31 and 41 by heating and melting to form a good hermetic seal at the lead conductor interface. An adhesive material is preferable for the inner layers 51a and 52a. It is preferable that the inner layers 51a and 52a of each insulating film have the same thickness. The outer layers 51b and 52b have a melting point higher than that of the inner layers 51a and 52a, and maintain the shape so that no melting occurs during hermetic sealing with the lead conductors 31 and 41. Then, when sealing with the encapsulating bag body 10, the outer layers 51b and 52b and the encapsulating bag body 10 are fused, so that the metal foil in the encapsulating bag body 10 and the lead conductors 31 and 41 are not electrically short-circuited. it can. It is preferable to vary the thickness of the insulating films 51 and 52 by varying the thicknesses of the outer layers 51b and 52b. As materials for the insulating films 51 and 52, acid-modified polyolefin and acid-modified polypropylene are desirable.

  As shown in FIG. 2 (B), the multilayer film forming the encapsulating bag 10 is composed of a laminate of at least three layers, and the innermost layer film 10a is not dissolved by the electrolytic solution and the electrolytic solution is supplied from the seal portion 6. Polyolefin resins (eg maleic anhydride modified low density polyethylene or polypropylene) are used as suitable for preventing leakage. The metal foil layer 10b is made of a metal foil such as aluminum, copper, and stainless steel, and has improved sealing performance against the electrolytic solution. The outermost layer film 10c is for protecting the thin metal foil layer 10b, and is formed of polyethylene terephthalate (PET) or the like.

  In the present embodiment, the burrs of the lead conductors 31 and 41 are made only on one side, and the thickness d1 of the insulating film 51 attached to the surface of the lead conductors 31 and 41 on which the burrs are protruding is projected. It is made thicker than the thickness d2 of the insulating film 52 attached to the surfaces of the non-lead conductors 31 and 41. For this reason, a burr | flash does not penetrate from the insulating film 51 of the lead conductors 31 and 41, and the whole thickness of the lead members 30 and 40 can be made thin.

(Test results)
FIG. 4 is a diagram for explaining a test result of the lead member according to the present invention. In the test, the thickness of the insulating film to be affixed on both sides of the lead conductor was variously manufactured and tested. In the test, nickel metal was used as the lead conductor, and the resulting lead member was welded by pressing it against the encapsulating bag body using a metal press at a temperature of 200 ° C. and a pressure of 0.1 MPa for 10 seconds, and then the cross-section of the lead member was examined with a microscope. A photograph was taken to confirm whether the lead conductor had broken through the insulating film.

  In the lead member of the conventional example, a 70 μm insulating film having the same thickness is bonded to both surfaces of a 80 μm thick lead conductor, and the lead conductor did not break through the insulating film. In addition, as a comparative example, in a lead member in which the thickness of the insulating film is reduced without changing the thickness of the lead conductor and the 60 μm insulating film having the same thickness is bonded to both sides, the lead conductor breaks through the insulating film. Occurred with a probability of 1 / 10,000. Furthermore, in the lead member of the present invention 2 in which the insulating film on the surface of the lead metal having no burrs is thinned to 50 μm as compared with the conventional example, the lead conductor did not break through the insulating film. Furthermore, the lead conductor did not break through the insulating film even in the lead member of Invention 2 in which the insulating film on the surface of the lead metal with burr was made as thick as 90 μm with respect to the lead member of Invention 1.

  From the above, if the thickness of the thicker insulating film attached to the surface of the lead conductor with burrs is 70 μm or more, the lead conductor does not break through the insulating film. Moreover, if the thickness of the insulating film on the surface of the lead metal that is not burred is 30 μm, the sealing effect with the encapsulating bag body can be obtained. Therefore, in addition to the test result, if the thickness of the thinner insulating film attached to the surface of the lead conductor having no burr is 30 μm or more and 50 μm or less, the sealing effect with the encapsulating bag body is sufficiently obtained. In order to make the lead member thin, the thinner insulating film does not require a thickness of 60 μm.

(Other embodiments)
FIG. 5 is a view for explaining a lead member according to another embodiment of the present invention.
The lead members 30 ′ and 40 ′ shown in FIG. 5A are the same as the above-described embodiment in that insulating films having different thicknesses are bonded to both surfaces of the lead conductors 31 and 41. The lengths of the margin portions of the insulating films 51 and 52 that appear at both ends of the lead conductors 31 and 41 are made different. For this reason, even if the lead members 30 ′ and 40 ′ are supplied as individual pieces, it is possible to easily select the burr-free surface of the lead conductors 31 and 41 by visual observation.

  In the lead members 30 "and 40" shown in FIG. 5B, the outer surface of the thinner insulating film 52 and the outer surface of the thicker insulating film 51 'have different average roughnesses. This facilitates identification of the burred surfaces of the lead members 30 ″, 40 ″. In this way, if the physical characteristics of the two insulating films are made different, it is possible to identify the surface with burrs. The physical characteristics to be made different are not limited to the shape and the average roughness of the outer surface. It may be.

DESCRIPTION OF SYMBOLS 1 ... Non-aqueous electrolyte battery, 5 ... Insulating film, 6 ... Seal part, 10 ... Encapsulated bag body, 10a ... Innermost layer film, 10b ... Metal foil layer, 10c ... Outermost layer film, 11 ... Seal part, 20 ... Laminated electrode Group, 30, 30 ', 30 ", 40, 40', 40" ... lead member, 31, 41 ... lead conductor, 50, 51, 51 ', 52 ... insulating film, 60 ... rotary blade, 61 ... shaft, 130 140, conductor foils, 131, 141, conductor pieces.

A lead member according to an aspect of the present invention is a lead member in which two insulating films having different thicknesses are bonded to both surfaces except for both ends in the length direction of a flat conductor having burrs only on one surface side. The thick insulating film having a thickness of 70 μm or more is bonded to the surface of the flat conductor having the burrs.

(Description of Embodiment of the Invention)
First, embodiments of the present invention will be listed and described.
A lead member according to an aspect of the present invention is a lead member in which two insulating films having different thicknesses are bonded to both surfaces except for both ends in the length direction of a flat conductor having burrs only on one surface side. The thick insulating film having a thickness of 70 μm or more is bonded to the surface of the flat conductor having the burrs.
According to this embodiment, even when burrs are formed on the flat conductor of the lead member, the burrs can be prevented from penetrating through the insulating film fixed to the conductor, and the lead member can be thinned.

Claims (2)

  A flat conductor having burrs only on one surface side, two insulating films having different thicknesses on both surfaces except for both ends in the longitudinal direction, and the thicker insulating film having a thickness of 70 μm or more are connected to the flat conductor. A lead member formed by bonding to the surface having the burr.   2. The lead member according to claim 1, wherein the thinner one of the two insulating films has a thickness of 30 μm to 50 μm.

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