A secondary battery including: an electrode assembly including a first electrode plate that includes an uncoated portion, a second electrode plate that includes an uncoated portion, and a separator that is interposed therebetween, wherein the first and second electrode plates and the separator are wound so that the uncoated portion of the first electrode plate and the uncoated portion of the second electrode plate are arranged in different directions; a groove formed in at least one of the uncoated portions of the first and second electrode plates; and a current collector including a lead tab that is bent passing the groove in such a way that a portion of the lead tab contacts a side surface of at least one first uncoated portions and another portion of the lead tab contacts another side surface of the at least one uncoated portion.