JP2001313012A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack that has no troubles in mounting on and dismounting from equipment nor strength, not affecting the outer thickness of the battery pack even if a nonaqueous electrolyte secondary battery is swollen in use. SOLUTION: The battery pack has a support curved in convex toward an inside face of a packaging body fixed with a bonding or the like between the packaging body orthogonal to the thickness direction of laminated electrodes or in parallel with a flat face of a group of electrode plates with electrodes wound flatly and an outer face of the battery, and this support absorbs the swelling of the battery and endures outer pressure on to the face of the packaging body with the improved strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a battery pack.

[0002]

2. Description of the Related Art Conventionally, a battery pack, particularly a battery pack using a non-aqueous electrolyte secondary battery, is divided into a core pack in which a non-aqueous electrolyte secondary battery, a protection circuit, a protection element, terminals and the like are electrically connected. In general, after being housed in one of the box-shaped plastic cases, it is integrated with the other plastic case by bonding or ultrasonic welding. Non-aqueous electrolyte secondary batteries are subject to
Because it has the property of swelling in the thickness direction of the stacked electrodes and in the direction perpendicular to the flat surface of the electrode group wound flat, the nonaqueous electrolyte A method of providing an extra space inside a plastic case is generally used in consideration of the size of the battery swelling during use of the secondary battery. By providing such an extra space, even if the nonaqueous electrolyte secondary battery swells during use, the external thickness of the battery pack is not affected, and there is no problem in terms of attachment / detachment to / from the main device or appearance. A battery pack can be provided.

[0003]

However, these non-aqueous electrolyte secondary battery packs having an extra space inside the plastic case apply a load of a certain magnitude or more to a portion far from each fulcrum of the plastic case, for example, a box-shaped portion. When applied near the center of the wide side of the battery pack, the plastic is significantly dented, and even though the degree of dent is small, it has a feeling of poor strength, so-called “peco-peco feeling”. There were cases where it was not favorable.

The problem to be solved by the present invention is that even if the nonaqueous electrolyte secondary battery swells during use, the external thickness of the battery pack is not affected, and the battery pack cannot be attached to or detached from the main unit or the strength of the battery pack. It is to provide a battery pack which does not have any problem.

[0005]

In order to solve the above-mentioned problems, a battery pack according to the first aspect of the present invention is an electrode plate group in which the electrodes are orthogonal to the thickness direction of the stacked electrodes or the electrodes are wound flat. Between the outer surface of the battery and the outer surface of the battery,
A support having a shape curved in a convex shape in the direction of the inner surface of the exterior body is arranged.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below, but the present invention is not limited to the following description.

[0007] The battery pack according to the present invention is characterized in that a battery pack is provided between an inner body surface of a battery and an outer surface of a battery, which is perpendicular to the thickness direction of the stacked electrodes or parallel to the uneven surface of the electrode group in which the electrodes are wound flat.
A support having a shape curved in a convex shape in the direction of the exterior body surface is fixed by bonding or the like, and this support absorbs the swelling of the battery and prevents external pressure on the exterior body surface. On the other hand, strength can be improved and endured.

[0008]

Embodiments of the present invention will be described below. FIG. 1 is a sectional view of a main part of a nonaqueous electrolyte secondary battery pack showing one embodiment of the present invention. The nonaqueous electrolyte secondary battery 1 includes a negative electrode in which a negative electrode active material is applied to a copper foil or the like, an electrode plate group in which a positive electrode is applied to an aluminum foil or the like and a positive electrode is flatly wound via a separator, and Each of the stacked electrode groups is housed in an outer package and filled with a non-aqueous electrolyte, and the outer dimensions are 6.2 mm in a thickness direction, 30 mm in a width direction, and 47 mm in a length direction.
Battery.

The thermal fuse 2 is a non-aqueous electrolyte secondary battery 1
When the temperature rise of 98 ° C. is detected, the fusible alloy melts at 98 ° C. to interrupt the current, and is mounted on the outer surface of the non-aqueous electrolyte secondary battery 1. The thermal fuse 2 and the protection circuit 3 are connected by a nickel lead 4.

The protection circuit 3 comprises an IC, a FET, a capacitor, a resistor, etc., and operates under a predetermined condition against overcharge, overdischarge, external short circuit, etc., and cuts off the current, thereby protecting the nonaqueous electrolyte secondary battery 1. Protect. An output terminal 5 is formed on the substrate of the protection circuit 3, and the nonaqueous electrolyte secondary battery 1 supplies power to the device via the output terminal 5.

The non-aqueous electrolyte secondary battery 1, the thermal fuse 2, the protection circuit 3, and the core pack electrically connected to the nickel lead 4 are accommodated in a plastic case (a) 6 having a thickness of 0.5 mm. The core pack is double-sided tape 7
And is fixed to the plastic case (a) 6 via the.

A non-aqueous electrolyte secondary battery 1 is provided between an outer surface of the battery and an outer surface of the battery, which is perpendicular to the thickness direction of the stacked electrodes or parallel to the flat surface of the electrode plate group in which the electrodes are wound flat. Thickness 0.1 with a shape that curves convexly toward the exterior body surface
A support 8 having a thickness of 5 mm and a height of 1 mm is fixed. Support 8
Here, a leaf spring whose surface is coated with a resin is used, but a high-strength plastic material may be used.

In addition, the curved shape is in accordance with the shape when the non-aqueous electrolyte secondary battery 1 is swollen, and is perpendicular to the thickness direction of the stacked electrodes or the flat surface of the electrode plate group in which the electrodes are wound flat. The central part of the inner surface of the parallel exterior body was the most convex, and the shape was gently curved toward the end of the battery. For this reason,
The space between the exterior body surface and the support increases with distance from the central portion of the exterior body.

In this case, the support 8 is adhered to the inner surface of the exterior with double-sided tape, but may be adhered to the battery. A plastic case (b) 9 having a thickness of 0.5 mm was adhered to the assembled product to complete a battery pack.

FIG. 2 shows a conventional embodiment.
The battery pack has the same configuration as that of the embodiment of the present invention shown in FIG. 1 except that the support 8 is not provided.

Next, using 20 battery packs of the present invention and 20 battery packs of the conventional example, a 10 kg / cm
A load of ² was applied to measure the amount of deformation. Thereafter, a complete charge / discharge cycle test of 500 cycles was performed at room temperature using the battery pack used for the load test, and the swelling of the battery pack before and after the test was measured, and the amount of swelling at 500 cycles was obtained. These results are summarized in Table 1.

[0017]

[Table 1]

As is clear from Table 1, the conventional battery had a large amount of deformation when a load of 10 kg / cm ² was applied, and had a feeling of poor strength. However, in the cycle test, the battery swelled. Was absorbed inside the battery pack, so that the battery pack did not swell at all. In contrast, the battery pack of the present invention has a small amount of deformation when a load of 10 kg / cm ² is applied, is excellent in strength, and absorbs swelling of the battery inside the battery pack even in the cycle test. Therefore, the battery pack did not swell at all like the conventional example.

In this embodiment, the non-aqueous electrolyte secondary battery has been described. However, the battery is not limited to the non-aqueous electrolyte secondary battery, and may be any type.

[0020]

As is apparent from the above description, according to the present invention, the outer casing perpendicular to the thickness direction of the stacked electrodes or parallel to the plane of the electrode group in which the electrodes are wound flat. Between the surface and the outer surface of the battery, by fixing a support having a shape curved convexly in the direction of the inner surface of the outer package, the amount of deformation when a load is applied to the center of the battery pack is reduced, In addition, since the curved shape absorbs the swelling of the battery, it is possible to design the battery pack not to swell.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing one embodiment of a battery pack of the present invention.

FIG. 2 is a sectional view of a main part showing one embodiment of a conventional battery pack.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Non-aqueous electrolyte secondary battery 2 Thermal fuse 3 Protection circuit 4 Nickel lead 5 Output terminal 6 Plastic case (a) 7 Double-sided tape 8 Support 9 Plastic case (b)

Claims (1)

[Claims] The direction of the inner body surface between a body outer surface and a battery outer surface that is perpendicular to the thickness direction of the stacked electrodes or parallel to the plane of the electrode group in which the electrodes are flatly wound. A battery pack characterized in that a support having a convexly curved shape is disposed on the battery pack.