sealed battery

Abstract

The present invention provides a sealed battery capable of securing a welding margin of a predetermined length and obtaining laser welding strength even if the cover plate is made thin. Since the perimeter of the cover plate is provided with a frame piece perpendicular to the plane of the cover plate, even if the thickness of the cover plate is reduced to reduce the weight of the sealed battery, rigidity that is difficult to bend outward due to internal pressure can be obtained. When the cover plate is fitted into the opening of the case body, the outer shape of the cover plate is maintained with high accuracy without being bent, so that the cover plate can be strongly fitted to the opening. Since the cover plate is strongly fitted to the opening and is laser welded with a sufficient welding margin between the inner wall surface of the opening and the frame piece, it is firmly fixed to the casing body without gaps.

Description

technical field [0001] The present invention relates to a sealed battery in which the opening of the case main body accommodating a power generating element is sealed with a cover plate. A sealed battery in which the opening is sealed by the cover plate. Background technique [0002] A sealed battery is a battery in which power generating elements such as an electrolytic solution and a wound electrode body are accommodated in a metal bottomed cylindrical case body, and the opening of the case body is sealed with a cover plate made of a metal plate. For example, sealed batteries such as lithium-ion secondary batteries and nickel-metal hydride secondary batteries are mounted on electrical appliances such as vehicles and portable communication devices that use electric power as a driving source, and are used as their power sources. [0003] The opening of the case main body needs to be completely sealed by the cover plate so that the electrolyte contained in the case main body...

AI Technical Summary

Problems solved by technology

In addition, in the cover plate of such a sealed battery, in order to prevent accidents caused by rupture, although an explosion-proof valve having a thin-walled portion that ruptures due to a predetermined internal pressure rise in the case main body is provided, when the cover plate When the thickness of the plate 103 becomes thicker, the processing load for stamping the thin-walled part with the cover plate 103 reaches the limit of processing with the stamping model, and it cannot be processed integrally from the cover plate 103

Furthermore, when the thickness of the cover plate 103 increases, the cost of materials and processing increases, resulting in high manufacturing costs, which is not ideal from an economic point of view.

[0005] On the other hand, when the thickness of the cover plate 103 is reduced, since a sufficiently long welding margin with the case body 101 cannot be ensured, the welding strength with the case body 101 cannot be obtained. Since the strength of the cover plate 103 itself cannot be obtained, there is a danger of bending outwards due to the internal pressure of the housing body 101.

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