Secondary battery and device including the same

Abstract

A secondary battery according to one embodiment of the present invention comprises: a jelly-roll-type electrode assembly in which a first electrode sheet, a second electrode sheet, and a separator provided between the first electrode sheet and the second electrode sheet are wound together; and a first electrode tab coupled to the uncoated portion of the first electrode tab and disposed at a central portion of the jelly-roll-type electrode assembly, in which the first electrode tab includes a coupling portion coupled to the uncoated portion and an extension portion extending outwardly from the coupling portion, a width of the coupling portion is wider than a width of the extension portion, and the coupling portion is wound at a center portion of the jelly-roll-type electrode assembly by 3 / 4 turns or more and one turn or less.

Description

technical field [0001] CROSS-REFERENCE TO RELATED APPLICATIONS [0002] This application claims the benefit of Korean Patent Application No. 10-2019-0129946, filed with the Korean Intellectual Property Office on October 18, 2019, the disclosure of which is incorporated herein by reference in its entirety. [0003] The present disclosure relates to a secondary battery and a device including the secondary battery, and more particularly, to a secondary battery including a jelly roll type electrode assembly and a device including the secondary battery. Background technique [0004] Recently, due to rising energy prices due to the depletion of fossil fuels and increasing concerns about environmental pollution, the demand for environmentally friendly alternative energy sources is bound to play an important role in future life. Therefore, research on technologies for generating various power such as nuclear power, solar power, wind power, and tidal power is being conducted, and po...

AI Technical Summary

Problems solved by technology

[0020] When the impact test is performed on the secondary battery housing the electrode assembly 10, there is a problem that different results are obtained depending on the positions of the electrode tabs 21 and 31, and the electrode assembly 10 is not positioned with the electrode tabs 21 and 31 positioned. 31 is pushed in the direction of

This is a problem that secondary batteries can exhibit not only in shock tests but even when exposed to external shocks

In addition, when the electrode assembly 10 is charged and discharged, a phenomenon in which the electrode assembly 10 expands may occur

Due to this asymmetrical shape, there may be a problem that the shape is deformed relative to the portion where the electrode tabs 21 and 31 are not positioned.

[0021] The thickness of the first electrode tab 21 and the second electrode tab 31 may be said to be thin, but since the winding of the first electrode tab 20, the second electrode tab 30, and the separator 40 is usually performed several tens of turns or more Many, so the asymmetry and deformation of the electrode assembly 10 are more prominent, which may eventually lead to problems that cannot be ignored

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