JP5261991B2 - battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery without any risk of displacement at the time of connection of leads with an electrode by ultrasonic welding or the like, by integrating the leads and a core body with a gap. <P>SOLUTION: A core body 2 (an insulating member) with recessed parts 2a, 2b formed and leads 3, 4 are provided inside or at a side face of a power generating element 1. The leads 3, 4 are integrated with the core body 2 by bonding an adhesive tape on a gap opened at either part in the recessed parts 2a, 2b. The leads can be surely positioned by the recessed parts of the insulating member. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

The present invention relates to a battery in which an insulating core is disposed as a core inside or on a side surface of a power generation element.

  In a nonaqueous electrolyte secondary battery in which a power generation element is housed in a flexible aluminum laminate film, a core body is disposed inside the power generation element, and electrodes of the power generation element are ultrasonically welded to leads integrated with the core body. There are some (for example, refer to Patent Document 1).

  An example of the structure of a conventional non-aqueous electrolyte secondary battery using a resin plate as the core is shown in FIGS. As shown in FIG. 6, the power generation element 1 of this battery is obtained by winding a positive electrode 1a and a negative electrode 1b into a long cylindrical shape via a separator 1c. Further, an aluminum foil that is a current collector of the positive electrode 1a protrudes from the front end portion of the power generation element 1, and a copper foil that is a current collector of the negative electrode 1b protrudes from the rear end portion.

  A core body 2 is inserted and arranged in the center of the winding of the power generating element 1. As shown in FIGS. 6 and 7, the core body 2 is an insulating substantially rectangular resin plate, and concave portions 2 a and 2 b are formed at the center portions of the front end side and the rear end side of the square shape, respectively. ing. Further, a positive electrode lead 3 and a negative electrode lead 4 made of a metal plate are fitted into these concave portions 2a and 2b, and are integrated by an adhesive tape (not shown).

  As shown in FIG. 6, the core body 2 in which the leads 3 and 4 are integrated is inserted and disposed at the center of winding of the power generation element 1. The leads 3 and 4 protruding from the front and rear end faces of the power generation element 1 are connected to the aluminum foil and copper foil of the electrodes 1a and 1b protruding from the front and rear ends of the power generation element 1 by ultrasonic welding.

  The power generating element 1 is covered with an aluminum laminate film (not shown) and thermally welded around it, and is filled with a nonaqueous electrolyte solution to form a nonaqueous electrolyte secondary battery. Further, the leads 3 and 4 protruding from the front and rear end faces of the power generation element 1 protrude to the outside from between the heat-welded portions of the aluminum laminate film, respectively, and become the positive electrode terminal and the negative electrode terminal of the nonaqueous electrolyte secondary battery.

  However, in the non-aqueous electrolyte secondary battery, since the leads 3 and 4 are fitted into the recesses 2a and 2b of the core body 2 without any gap, the leads 3 and 4 and the electrodes 1a and 1b of the power generation element 1 are connected. When ultrasonic welding is performed, ultrasonic vibration is transmitted from the leads 3 and 4 to the contact surface of the core body 2 with the recesses 2a and 2b, which may cause misalignment of the leads 3 and 4. That is, the positions of these leads 3 and 4 are often shifted in the direction of exiting from the recesses 2a and 2b. Moreover, the amount of the positional shift varies, and the leads 3 and 4 are bent in an oblique direction. There was also.

For this reason, in the conventional nonaqueous electrolyte secondary battery, there is a possibility that the leads 3 and 4 may be misaligned during the ultrasonic welding, so that the connection with the electrodes 1a and 1b becomes insufficient, or the power generation element 1 As a result of variations in the protruding amount and inclination of the leads 3 and 4 protruding from the end face of the battery, there is a problem that the possibility of occurrence of defects during the battery assembly operation increases.
JP 2004-178862 A

In the present invention, when the lead is connected to the electrode by ultrasonic welding or the like, the lead is attached to and integrated with the insulating core via an adhesive tape with a gap between the lead and the insulating core. It is an object of the present invention to provide a battery that is free from misalignment.

The battery of claim 1 includes an insulating core and a lead inside or on the side of a power generation element wound in a long cylindrical shape, and the power generation element and the lead are connected by ultrasonic welding, The lead is attached to the insulating core via an adhesive tape in a state where there is a gap in at least a part between the insulating core and the lead.

According to the first aspect of the present invention, since the lead is integrated with a gap between the lead and the insulating core , no positional deviation occurs when the lead is connected to the electrode of the power generation element. Therefore, the connection between the lead and the electrode is not inadequate, and the assembly failure does not occur due to the variation in the position of the lead.

In many cases, the lead and the electrode of the power generation element are connected by ultrasonic welding. In this case, in particular, since the lead vibrates ultrasonically during ultrasonic welding, it is possible to reliably prevent the positional deviation from the insulating core due to the vibration.

Further, it is preferable that the insulating core is provided with a recess, and the lead is integrated by inserting a gap in the recess at any part. In this way, positioning of the lead is ensured by the recess of the insulating core, and no positional deviation occurs when the lead is connected to the electrode of the power generation element, so that there is less variation in the position of the lead. can do.
Moreover, it is preferable that a lead | read | reed and an insulating core are integrated by sticking an adhesive tape. In this way, since the lead and the insulating core are integrated via the adhesive tape, it is possible to suppress the vibration applied to the lead from being transmitted to the insulating core by the buffering property of the adhesive tape. it can.

  Hereinafter, the best embodiment of the present invention will be described with reference to FIGS. In these drawings, the same reference numerals are given to constituent members having functions similar to those of the conventional example shown in FIGS.

  In the present embodiment, a non-aqueous electrolyte secondary battery similar to the conventional example shown in FIG. 6 will be described. As shown in FIG. 1, a power generation element 1 of this nonaqueous electrolyte secondary battery is obtained by winding a positive electrode 1a and a negative electrode 1b into a long cylindrical shape via a separator 1c.

  The positive electrode 1a has a positive electrode active material supported on the surface of a strip-shaped aluminum foil that is a current collector, and the negative electrode 1b has a negative electrode active material supported on the surface of a strip-shaped copper foil that is a current collector. Is. However, the positive electrode 1a is provided with an uncoated portion to which the positive electrode active material is not applied at the front side end portion of the strip-shaped aluminum foil, and the negative electrode 1b is coated with the negative electrode active material at the rear side end portion of the strip-shaped copper foil. There is no uncoated part. Further, since the positive electrode 1a and the negative electrode 1b are wound with the positive electrode 1a shifted forward and the negative electrode 1b shifted backward, the power generation element 1 has an uncoated portion of the positive electrode 1a at the front end thereof. Only the aluminum foil protrudes from the separator 1c, and only the copper foil of the uncoated part of the negative electrode 1b protrudes from the separator 1c at the rear end. The separator 1c is formed of a band-like PE (polyethylene) microporous film that is slightly narrower than the electrodes 1a and 1b.

A core body 2 (insulating core body ) is inserted and disposed in the central portion of the winding of the power generating element 1. As shown in FIGS. 1 and 2, the core body 2 is an insulating substantially square resin plate made of PET (polyethylene terephthalate), PP (polypropylene), or the like, and has a front end side and a rear end side of the square. Recesses 2a and 2b are respectively formed in the central part.

  A positive electrode lead 3 and a negative electrode lead 4 are fitted into the recesses 2 a and 2 b of the core body 2 with a gap therebetween. The positive electrode lead 3 is a rectangular strip-shaped aluminum plate, and the negative electrode lead 4 is a rectangular strip-shaped copper plate. As shown in FIG. 2, these leads 3 and 4 are fitted in the recesses 2 a and 2 b of the core body 2 with not only a gap in the left-right direction but also a sufficient gap G in the front-rear direction.

  Such a fitting operation of the leads 3 and 4 can be performed using a jig 5 as shown in FIG. The jig 5 includes a mounting surface on which the core body 2 and the leads 3 and 4 (only the positive electrode lead 3 is shown in FIG. 3) are arranged, and a protrusion 5 a is provided between the core body 2 and the leads 3 and 4. Formed. Accordingly, since the leads 3 and 4 are blocked by the protrusion 5 a, the leads 3 and 4 can be easily fitted into the recesses 2 a and 2 b of the core body 2 without making contact with the core body 2. Then, when the leads 3 and 4 are fitted into the recesses 2a and 2b of the core body 2, the leads 3 and 4 are attached to the core body 2 with a gap therebetween by applying the adhesive tape 6. Integrated.

  As shown in FIG. 1, the core body 2 integrated with the leads 3 and 4 as described above is disposed by being inserted into the central portion of the winding of the power generation element 1. The positive electrode lead 3 protruding further forward from the front end surface of the power generation element 1 is connected and fixed to the aluminum foil of the positive electrode 1a protruding to the front end portion of the power generation element 1 by ultrasonic welding, and the rear of the power generation element 1 The negative electrode lead 4 protruding further rearward from the end face is connected and fixed to the copper foil of the negative electrode 1b protruding to the rear end portion of the power generation element 1 by ultrasonic welding.

  The power generating element 1 is covered with an aluminum laminate film (not shown) and thermally welded around it, and is filled with a nonaqueous electrolyte solution to form a nonaqueous electrolyte secondary battery. Further, the leads 3 and 4 protruding from the front and rear end faces of the power generation element 1 protrude to the outside from between the heat-welded portions of the aluminum laminate film, respectively, and become the positive electrode terminal and the negative electrode terminal of the nonaqueous electrolyte secondary battery.

  According to the nonaqueous electrolyte secondary battery having the above-described configuration, the leads 3 and 4 fitted in the recesses 2a and 2b of the core body 2 are integrated with a gap between the core body 2 and therefore, these Even if the leads 3 and 4 are ultrasonically vibrated during the ultrasonic welding, the leads 3 and 4 are not in contact with the core body 2 at all, and there is no possibility of positional deviation. In addition, since the leads 3 and 4 and the core body 2 are attached via the adhesive tape 6, the shock absorbing property of the adhesive tape 6 reliably prevents the ultrasonic vibration of the leads 3 and 4 from being transmitted to the core body 2. can do. Accordingly, the connection between the leads 3 and 4 and the electrodes 1a and 1b are not sufficiently fixed and the assembly of the leads 3 and 4 is not changed.

  In the above embodiment, the case where the leads 3 and 4 have a gap in all of the left and right directions and the front and rear directions in the recesses 2a and 2b of the core body 2 is shown. If there is a gap in the part, positional deviation due to ultrasonic vibration can be reduced. For example, as shown in FIG. 4 (a), the leads 3 and 4 may be formed with a gap only in the left and right directions within the recesses 2a and 2b, or as shown in FIG. The gap may be opened only in the right direction in 2b, or the gap may be opened only in the front-rear direction in the recesses 2a and 2b as shown in FIG. However, in FIGS. 4A to 4C, only the positive electrode lead 3 and the recess 2a are shown.

  Further, the core body 2 is not necessarily formed with the recesses 2a and 2b. For example, as shown in FIG. 4D, the core body 2 is a simple rectangular resin plate in which the recesses 2a and 2b are not formed. In some cases, the leads 3 and 4 may be arranged close to each other with a gap from the core body 2. However, in FIG. 4D, only the positive electrode lead 3 is shown.

Moreover, although the case where the core body 2 is a substantially square resin plate was shown in the said embodiment, the shape of this core body 2 is arbitrary, and a material will also be arbitrary if it is an insulating core body which has insulation . is there.

  Moreover, in the said embodiment, although the case where the leads 3 and 4 were attached and integrated with the core body 2 via the adhesive tape 6 was shown, since the leads 3 and 4 are integrated with the core body 2 with a gap. If there is, for example, a thin sheet material, a net material, or the like may be bonded with an adhesive or thermally welded.

  Moreover, in the said embodiment, although the case where the core body 2 was inserted and arrange | positioned inside the electric power generation element 1 was shown, for example, the core body 2 which attached the leads 3 and 4 was used as a winding core, The electrodes 1a and 1b and the separator 1c can be wound directly.

  Moreover, in the said embodiment, although the case where the core 2 and the leads 3 and 4 are arrange | positioned inside the electric power generation element 1 was shown, as shown, for example in FIG. It may be arranged on the side of element 1.

  Moreover, in the said embodiment, although the electric power generation element 1 wound by the long cylindrical shape was shown, the winding shape of this electric power generation element 1 is arbitrary, for example, even if it is the electric power generation element 1 wound by cylindrical shape, it is the same. Can be implemented. And when the electric power generation element 1 is cylindrical, the core 2 can also use a cylindrical thing. Furthermore, even if this power generation element 1 is a laminated type, it can be similarly implemented.

  Moreover, although the said embodiment demonstrated the nonaqueous electrolyte secondary battery which accommodated the electric power generation element 1 in the aluminum laminate film, the material and shape of a battery container are arbitrary. Furthermore, in the said embodiment, although shown about the nonaqueous electrolyte secondary battery, the kind of battery is also arbitrary.

  The nonaqueous electrolyte secondary battery of the conventional example in which the recesses 2a and 2b, the leads 3 and 4 and the gap G of the core body 2 shown in FIG. 2 are 0 mm, and Examples 1 to 1 in which the gap G is 0.5 mm to 7 mm. A plurality of non-aqueous electrolyte secondary batteries 5 were prepared, and the results of examining the variation in the distance D between the terminals 3 and 4 and the variation in resistance when measuring the 1 kHz AC resistance were obtained. Table 1 shows.

  According to Table 1, in Examples 1 to 3 where the gap G is 0.5 mm to 3 mm, it is understood that the variation in the inter-terminal distance D can be suppressed more than in the conventional example. In Examples 4 and 5 in which the gap G is 5 mm to 7 mm, the variation in the inter-terminal distance D may be larger than in the conventional example. This is because, since the gap G becomes too large, the portions of the leads 3 and 4 that fit into the recesses 2a and 2b of the core body 2 are almost eliminated, so that these leads 3 and 4 are not related to the core body 2. This is considered to be because the position was shifted in an arbitrary direction by ultrasonic vibration.

  Further, in all of Examples 1 to 5 where the gap G was 0.5 mm to 7 mm, variation in AC resistance could be suppressed as compared with the conventional example. Therefore, it can be seen that the connection and fixing between the leads 3 and 4 and the electrodes 1a and 1b are sufficiently ensured by the present invention.

1 is a perspective view showing a core body and leads inserted and arranged inside a power generation element according to an embodiment of the present invention. 1 is a plan view showing a core body and leads according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view illustrating an embodiment of the present invention and illustrating an operation process for integrating a core body and a lead. FIG. 10 is a plan view showing various gaps between a core body and a lead according to another embodiment of the present invention. FIG. 10 is a perspective view showing another embodiment of the present invention and showing a core body and leads arranged on the side surface of the power generation element. It is a perspective view which shows a prior art example, Comprising: The core and lead | read | reed inserted in the inside of an electric power generation element are shown. It is a top view which shows a prior art example and shows a core and a lead | read | reed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power generation element 1a Positive electrode 1b Negative electrode 1c Separator 2 Core 2a Recess 2b Recess 3 Positive electrode lead 4 Negative electrode lead 5 Jig 5a Protrusion 6 Adhesive tape

Claims (1)

The power generating element wound in the shape of a long cylinder is provided with an insulating core and a lead inside or on the side surface, and the power generating element and the lead are connected by ultrasonic welding, and the insulating core and the lead The battery is characterized in that the lead is attached to the insulating core via an adhesive tape in a state where there is a gap in at least part of the battery.

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