SECONDARY BATTERY AND ELECTRODE LEAD APPLIED FOR THE SAME

摘要

A secondary cell according to the present invention includes: an electrode assembly which includes an electrode tap; a case which accommodates the electrode assembly; and a pair of electrode leads which are coupled to the electrode tap and protrude outside the case. At least one among the two electrode leads includes: a first metal plate which is placed outside the case; a second metal plate which is separated from the first metal plate with a gap and is coupled to the electrode tap; a coating layer which is formed on a part of the surfaces of the first and the second metal plates and more specifically, on the surfaces of the ends of the first and the second metal plate facing each other and the surface inside the case except for at least the area coupled to the electrode tap; and a metal bridge which is made of material which has a lower melting point than the first and the second metal plate and is buried in the gap not to expose the ends. According to the present invention, if an over current flows through the electrode leads, the area of the metal plates where the metal bridge is formed is fractured and the over current flowing inside the secondary cell is blocked irreversibly so that the coupling strength between the electrode leads and the electrode tap can be enhanced and the contact resistance can be reduced.