A rechargeable battery includes an electrode group with a separator, a positive electrode, and a negative electrode in a case, a cap plate for sealing the case and including a terminal hole, an electrode terminal extending through the terminal hole, and a lead tab connecting the electrode terminal to the electrode group. The lead tab includes a horizontal part connected to the electrode terminal, a first vertical part and a second vertical part spaced apart from each other and extending from the horizontal part in a vertical direction along the electrode group, and a connection part connecting the first vertical part and the second vertical part, the connection part being spaced apart from the horizontal part to define a gas outlet that overlaps an end part of the electrode group.