Secondary battery

Abstract

The present invention relates to a secondary battery capable of reducing costs and increasing capacity. For example, disclosed is a secondary battery characterized by comprising: an electrode assembly including a first electrode, a second electrode, and a separator; a case accommodating the electrode assembly; and a cap assembly coupled to the upper portion of the case, wherein the first electrode comprises: a first current collector; a first current collecting tab structure extending from the first current collector and having a plurality of bent current collection parts; and a first lead tab electrically connected to the first current collecting tab structure, wherein, in the first current collecting tab structure, the width of the current collection parts increases from the center of the electrode assembly to the outside, and the distance between the current collection parts increases.