JPH11288703A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress increment in contact resistance even if a vibration is received, and prevent increase in internal resistance by fixing and housing the generating element of a battery which is connected by bringing an electrode wound on the outermost circumference into contact with the inner surface of a metal case into the metal case with an adhesive. SOLUTION: A generating element 2 is formed of a stripe positive electrode 2a and negative electrode 2b wound in a long cylindrical formed through a strip separator 2c. In the positive electrode 2a, an aluminum foil is exposed on the winding end circumferential side of one round length without applying a positive electrode active material thereto, and this is wound on the outermost side of the generating element 2 and fixed by a tape. When the generating element 2 is inserted and housed into a flat box-shaped battery case 1, the outermost circumferential aluminum foil of the positive electrode 2a makes contact with the inner surface on both sides of the battery case l to form a positive electrode terminal. An adhesive 4 is preliminarily applied to the aluminum foil surface of the positive electrode 2a corresponding to the inserting side tip of the generating element 2, and the generating element 2 is fixed to the bottom of the battery case 1 by use of this adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte secondary battery in which a long cylindrical winding type power generating element is housed in a metal case, and one electrode is connected by contacting the inner surface of the metal case. The present invention relates to a battery such as a battery.

[0002]

2. Description of the Related Art As shown in FIG. 3, a non-aqueous electrolyte secondary battery has a battery case 1 in which an aluminum plate is box-shaped.
There is one in which a long cylindrical winding type power generating element 2 is housed. As shown in FIG. 4, the power generating element 2 is formed by winding a strip-shaped positive electrode 2a and a strip-shaped negative electrode 2b into a long cylindrical shape via a strip-shaped separator 2c slightly wider than these. The positive electrode 2a is obtained by applying a positive electrode active material such as a lithium-cobalt composite oxide to the surface of a belt-shaped aluminum foil, and the negative electrode 2b is obtained by applying a negative electrode active material such as graphite to the surface of a band-shaped copper foil. is there. The separator 2c is
A strip-shaped microporous resin film is used.

As shown in FIG. 5, the power generating element 2 has an aluminum foil exposed at the end of winding of the positive electrode 2a, and the positive electrode 2a is wound around the outermost periphery and fixed by a tape 3 to fix the winding. I do. Then, as shown in FIG. 3, by storing the power generation element 2 in the battery case 1, the aluminum foil of the positive electrode 2a is brought into contact with and connected to the inner surface of the battery case 1, and the entire battery case 1 is connected to the positive electrode terminal. So that A non-aqueous electrolyte is injected into the battery case 1 in which the power generation element 2 is housed as described above.
As shown in (2), the battery cover 5 is attached to the opening and sealed. At this time, the negative electrode 2b of the power generation element 2 is connected to the battery cover 5
Is connected and fixed to the negative electrode terminal 6 attached at the center of the device by caulking or ultrasonic welding on the inside.

[0004]

However, the power generating element 2
The positive electrode 2a of the positive electrode 2a is connected only to the inner surface of the battery case 1 serving as a positive electrode terminal by contact. Therefore, when the power generation element 2 is displaced or moves in the battery case 1 due to vibration or impact, the aluminum foil of the positive electrode 2a A non-aqueous electrolyte infiltrates the contact interface between the battery and the inner surface of the battery case 1 to increase the contact resistance, thereby increasing the internal resistance of the battery and deteriorating the battery performance. Moreover, particularly when aluminum is used for the battery case 1 and the positive electrode 2a as described above, the contact resistance tends to increase due to the formation of an insulating oxide film on the surface.

Further, in order to solve the above-mentioned problem, there has been a case where the positive electrode 2a is conventionally securely connected and fixed to the positive electrode terminal via a lead or the like by caulking or welding.
However, when the positive and negative electrodes are connected and fixed to the terminals in this manner, a new problem occurs in that the number of assembling steps increases and the manufacturing cost increases.

In a non-aqueous electrolyte secondary battery, an iron plate or a stainless steel plate may be used for the battery case 1, and the inner surface of the battery case 1 may be connected to the negative electrode 2b by contacting the copper foil. However, in this case as well, although not as remarkable as aluminum, there is a problem that the contact resistance increases. Similar problems may occur when metals other than these materials are used, or when batteries other than non-aqueous electrolyte secondary batteries are used.

[0007] The present invention has been made in view of such circumstances, and by fixing a power generating element in a metal case with an adhesive to accommodate the power generating element, the contact resistance can be increased even when subjected to vibration. Not intended to provide batteries.

[0008]

According to a first aspect of the present invention, there is provided a battery in which a winding type power generating element is housed in a metal case, and an electrode substrate wound around the outermost periphery of the power generating element is brought into contact with an inner surface of the metal case. Wherein the power generating element is fixed to the inner surface of the metal case by a fixing member.

According to the battery of the first aspect, since the power generating element is fixed to the inner surface of the metal case with the adhesive, the position of the power generating element does not shift or move even when vibration is applied. Therefore, the electrolyte does not enter the contact interface between the outermost electrode of the power generating element and the inner surface of the metal case.

The adhesive may be insulating, but may be conductive. However, it is limited to those having electrolytic solution resistance. Further, since it is sufficient that the power generation element can be fixed, the adhesive herein includes a pressure-sensitive adhesive.

According to a second aspect of the present invention, the winding type power generating element is formed by winding a long cylindrical shape, and the fixing means is an adhesive.

According to the battery of the second aspect, the connection state at this interface is maintained, and it is possible to prevent the contact resistance from increasing.

According to a third aspect of the present invention, the battery case is of a flat type with one side open, and the winding axis of the power generating element is the battery case.
And the opening portion of the battery case is arranged so as to be perpendicular to the opening portion of the battery case.

According to the third aspect of the present invention, since the bonding area between the power generation element and the battery case increases, the position of the power generation element shifts within the case even if vibration or impact is repeatedly applied to the specification. No movement or movement.

According to a fourth aspect of the present invention, the battery is a non-aqueous electrolyte secondary battery, the metal case is made of aluminum, and the base of the electrode wound around the outermost periphery of the power generating element is an aluminum foil. And

According to the battery of the fourth aspect, when the metal case of the non-aqueous electrolyte secondary battery is made of an aluminum plate for weight reduction, the contact resistance between the positive electrode of the power generation element and the aluminum foil increases. It can be prevented from becoming easy.

As an adhesive for a non-aqueous electrolyte secondary battery, an epoxy resin-based adhesive having resistance to a non-aqueous electrolyte is most suitable.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the battery of the present invention. FIG. 1 is a longitudinal sectional view showing the structure of a non-aqueous electrolyte secondary battery, and FIG. 2 is a non-aqueous electrolyte secondary battery. FIG. 7 is a diagram comparing a change in internal resistance when a vibration is applied to a conventional example.
Components having the same functions as those of the conventional example shown in FIGS. 3 to 6 are denoted by the same reference numerals.

In the present embodiment, a non-aqueous electrolyte secondary battery similar to that shown in FIGS. 3 to 5 will be described. However,
The present invention can be similarly applied to a nonaqueous electrolyte secondary battery in which the negative electrode 2b is wound on the outermost periphery with the copper foil exposed and brought into contact with the inner surface of the battery case 1 made of iron or stainless steel. Also,
In this case, the battery case 1 may be made of, for example, a clad metal using an aluminum plate on the outside and a copper plate on the inside to reduce the weight of the battery. Further, the present invention is a battery in which a long cylindrical wound type power generating element is housed in a metal case and the outermost electrode is connected by contact, and other non-aqueous electrolyte secondary batteries and other non-aqueous electrolyte batteries It can be applied to batteries.

The power generating element 2 of this non-aqueous electrolyte secondary battery
Similarly to the one shown in FIG. 4, a strip-shaped positive electrode 2a and a negative electrode 2b
Is wound into a long cylindrical shape via a band-shaped separator 2c. Then, the positive electrode 2a is exposed on the aluminum foil so as not to be applied to the positive electrode active material on at least the outer peripheral surface side of one end of the winding end, and is wound around the outermost periphery of the power generating element 2. The winding is fixed by fastening with tape 3. Then, as shown in FIG. 3, a flat box-shaped battery case 1 in which the power generation element 2 is open on one side.
Insert and store inside. At this time, the width inside the battery case 1 is set to be slightly smaller than the thickness of the power generation element 2 so that the aluminum foil of the outermost positive electrode 2a is pressed against the inner surfaces on both sides of the battery case 1 and can be securely contacted. To

The adhesive 4 is applied in advance to the surface of the aluminum foil of the positive electrode 2a which is the tip of the peripheral side of the power generating element 2 on the insertion side. Alternatively, the adhesive may be applied to the bottom of the inner surface of case 1. Thus, as shown in FIG. 1, the housed power generating element 2 is firmly fixed to the bottom surface of the battery case 1 by the adhesive 4. The adhesive 4
Here, an epoxy resin adhesive having resistance to the non-aqueous electrolyte is used. The adhesive 4 only needs to have resistance to the electrolytic solution, so that an arbitrary adhesive such as an acrylic resin can be selected according to the type of the battery. Further, since it is sufficient that the power generation element 2 can be fixed to the battery case 1, an adhesive may be used. Furthermore, this adhesive 4
As long as the power generating element 2 can be fixed to the inner surface of the battery case 1, the power generating element 2 may be applied anywhere and in any number of places. However, when an insulating material such as an epoxy resin-based adhesive 4 is used, the long side of the long cylindrical power generating element 2 is used in order to avoid a decrease in the contact area with the inner surface of the battery case 1. It is preferable not to apply it on the peripheral side surface along. However, when the conductive adhesive 4 is used, there is no such limitation.

When the power generating element 2 is housed in this manner, a non-aqueous electrolyte is injected into the battery case 1, and a battery cover 5 is attached to the opening of the battery case 1 to seal the inside. Complete the water electrolyte secondary battery. At this time, the negative electrode 2b of the power generating element 2 is connected and fixed to the negative electrode terminal 6 which is insulated and sealed at the center of the battery lid 5 by penetrating or ultrasonic welding inside. Therefore, in this nonaqueous electrolyte secondary battery, the entire battery case 1 serves as a positive electrode terminal, and the negative electrode terminal 6 protrudes from the center of the battery cover 5.

With the above configuration, in the non-aqueous electrolyte secondary battery of the present embodiment, since the power generating element 2 is fixed to the bottom surface of the battery case 1 with the adhesive 4, even if it is repeatedly subjected to vibration or impact during use, The position of the power generating element 2 does not shift or move inside the battery case 1. For this reason, the connection state due to the contact between the aluminum foil of the positive electrode 2a of the power generation element 2 and the inner surface of the battery case 1 is not impaired by the infiltration of the non-aqueous electrolyte or the like, and the contact resistance is increased. Can be prevented.

FIG. 2 shows a change in internal resistance when a vibration is applied to the non-aqueous electrolyte secondary battery of this embodiment in comparison with a conventional example. In a conventional nonaqueous electrolyte secondary battery, when vibration is repeatedly applied, the internal resistance gradually increases until the internal resistance reaches a certain large value. On the other hand, in the nonaqueous electrolyte secondary battery of the present embodiment, even when the vibration was repeatedly applied, the internal resistance hardly increased. Therefore, even if the non-aqueous electrolyte secondary battery of the present embodiment is used for an application in which vibration or impact is severe, the internal resistance does not increase and the battery performance does not deteriorate.

In the above embodiment, the winding axis of the power generating element 2 is parallel to the opening of the battery case 1, and the plane portion of the power generating element 2 and the opening of the battery case 1 are perpendicular to each other. Although the case of the vertical winding type inserted so as to be positioned has been described, the case of the horizontal winding type inserted into the battery case 1 along the axial direction of the power generating element 2 can be similarly implemented. In the above embodiment, the case where the battery case 1 has a rectangular box shape has been described. However, the case where the battery case 1 has a long cylindrical shape similar to the power generation element 2 can be similarly implemented.

[0027]

As is apparent from the above description, according to the battery of the present invention, the power generating element does not shift or move even when vibration is applied, and the outermost electrode of the power generating element is not moved. The connection at the contact interface with the inner surface of the metal case is maintained, thereby preventing the contact resistance from increasing. Therefore, even when the battery is used in an application that is susceptible to vibration or the like, it is possible to prevent the internal resistance from increasing and the battery performance from being reduced. In addition, the present invention
This is particularly suitable for a non-aqueous electrolyte secondary battery in which a metal case is formed of an aluminum plate for weight reduction.

[Brief description of the drawings]

FIG. 1, showing one embodiment of the present invention, is a longitudinal sectional view illustrating a structure of a nonaqueous electrolyte secondary battery.

FIG. 2 illustrates one embodiment of the present invention, and is a diagram in which a change in internal resistance when a vibration is applied to a nonaqueous electrolyte secondary battery is compared with a conventional example.

FIG. 3 is a perspective view showing a conventional example and showing a step of inserting a power generating element into a battery case of a nonaqueous electrolyte secondary battery.

FIG. 4 is a perspective view showing a conventional example and showing a winding step of a power generating element.

FIG. 5 shows a conventional example and is a perspective view of a power generating element.

FIG. 6 shows a conventional example, and is a longitudinal sectional view showing a structure of a non-aqueous electrolyte secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery case 2 Power generation element 2a Positive electrode 2b Negative electrode 4 Adhesive

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroki Ozaki 5 in Kichijo-in, Nitta Ichidandancho, Minami-ku, Kyoto-shi S-Melcotec Co., Ltd. (72) Inventor Minoru Mizutani Minami-ku, Kyoto 1 Shoinomaba-cho, Japan Battery Co., Ltd.

Claims (4)

[Claims] 1. A battery in which a winding type power generating element is housed in a metal case and a base of an electrode wound around the outermost periphery of the power generating element is brought into contact with an inner surface of the metal case to connect the power generating element. A battery fixed on the inner surface of a metal case. 2. The battery according to claim 1, wherein the wound power generating element is wound in a long cylindrical shape, and the fixing means is an adhesive. 3. The battery case is of a flat type having one side open, and the winding axis of the power generating element is formed by closing the battery case opening surface, closing the flat surface of the power generating element, and opening the battery case. The battery according to claim 1 or 2, wherein the batteries are arranged at right angles. 4. The battery according to claim 1, wherein the battery is a non-aqueous electrolyte secondary battery, the metal case is made of aluminum, and the base of the electrode wound around the outermost periphery of the power generating element is an aluminum foil. The battery according to claim 2 or claim 3.