A secondary battery comprising: an electrode assembly comprising a positive electrode plate having a positive electrode non-coating portion, a negative electrode plate having a negative electrode non-coating portion, and a separator between the positive electrode plate and the negative electrode plate, the positive electrode non-coating portion and the negative electrode non-coating portion being exposed at opposite sides of the electrode assembly; a case having a top opening and an internal space accommodating the electrode assembly; a cap plate sealing the top opening of the case; a positive electrode current collector plate perpendicular to the positive electrode non-coating portion and welded to the positive electrode non-coating portion; a negative electrode current collector plate perpendicular to the negative electrode non-coating portion and welded to the negative electrode non-coating portion; a positive electrode terminal on the cap plate and electrically connected to the positive electrode current collector plate; a negative electrode terminal on the cap plate and electrically connected to the negative electrode current collector plate, wherein the electrode assembly further comprises a second separator, and the positive electrode plate, the separator, the negative electrode plate, and the second separator are sequentially stacked along a Y-axis direction, and wherein a laser welding line joining the positive electrode current collector plate to the positive electrode non-coating portion is formed along the Y-axis direction, and a laser welding line joining the negative electrode current collector plate to the negative electrode non-coating portion is formed along the Y-axis direction, and wherein the positive electrode non-coating portion is in line-contact with the positive electrode current collector plate and the negative electrode non-coating portion is in line-contact with the negative electrode current collector plate. an electrode assembly comprising a positive electrode plate having a positive electrode non-coating portion, a negative electrode plate having a negative electrode non-coating portion, and a separator between the positive electrode plate and the negative electrode plate, the positive electrode non-coating portion and the negative electrode non-coating portion being exposed at opposite sides of the electrode assembly; a case having a top opening and an internal space accommodating the electrode assembly; a cap plate sealing the top opening of the case; a positive electrode current collector plate perpendicular to the positive electrode non-coating portion and welded to the positive electrode non-coating portion; a negative electrode current collector plate perpendicular to the negative electrode non-coating portion and welded to the negative electrode non-coating portion; a positive electrode terminal on the cap plate and electrically connected to the positive electrode current collector plate; a negative electrode terminal on the cap plate and electrically connected to the negative electrode current collector plate, wherein the electrode assembly further comprises a second separator, and the positive electrode plate, the separator, the negative electrode plate, and the second separator are sequentially stacked along a Y-axis direction, and wherein a laser welding line joining the positive electrode current collector plate to the positive electrode non-coating portion is formed along the Y-axis direction, and a laser welding line joining the negative electrode current collector plate to the negative electrode non-coating portion is formed along the Y-axis direction, and wherein the positive electrode non-coating portion is in line-contact with the positive electrode current collector plate and the negative electrode non-coating portion is in line-contact with the negative electrode current collector plate.