Battery

Abstract

The present invention provides a battery which can inhibit decreased reliability of a welded portion of a laminated film. The battery (100) includes an exterior body (1) formed of a laminate film, the exterior body (1) having a welded portion (5), a power generating element (4) stored in the exterior body (1), the power generating element (4) being formed by winding electrodes and having an inner circumferential surface and an outer circumferential surface, and a positive electrode terminal (2) and a negative electrode terminal (3) which are connected to the power generating element (4), the terminals being exposed to the outside of the exterior body (1), and in a projected plane with respect to a plane where the welded portion (5) is arranged, the welded portion (5) of the exterior body (1) is arranged in a region (A-B region) between an intermediate point (point A) of an inner circumferential end (4c) and an outer circumferential end (4d) of the power generating element (4), and a side end (2a (3a)) of the positive electrode terminal (2) (negative electrode terminal (3)) (point B).

Description

technical field [0001] The present invention relates to a battery, and more particularly, to a battery provided with an exterior body made of a laminated film. Background technique [0002] Conventionally, a battery including an exterior body made of a laminated film is known (for example, refer to Patent Document 1). [0003] The aforementioned Patent Document 1 discloses a battery including an exterior body having a welded portion where a part of the inner surface and a part of the outer surface of a laminated film are superimposed and welded. This exterior body has sealing portions that are welded by bringing the inner surfaces of the laminated films into contact with each other at both ends in the longitudinal direction of a tubular (tubular) laminated film having welded portions formed thereon. In addition, the battery is provided with a pair of lead terminals so as to be exposed to the outside from the sealing portion on one side of the exterior body. The pair of lea...

AI Technical Summary

Problems solved by technology

[0007] However, in a battery using a flexible laminated film as an exterior body, the exterior body expands and contracts with charge and discharge of the battery, and therefore, the amount of displacement of the exterior body accompanying the expansion and contraction increases in the width direction of the battery. The central part becomes larger

In particular, the expansion and contraction of the central part in the width direction is large in the case housing the wound type power generating element formed by winding the electrode plate.

Here, in the configuration of Patent Document 1, since the welded portion is disposed at the center of the battery, a large force is applied to the welded portion accompanying expansion and contraction, and as a result, the welded portion exists The problem of the reliability reduction of the welded part such as scattering

Such a decrease in the reliability of the welded portion will lead to a shortened life of the battery and a decrease in reliability.

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