SECONDARY BATTERY

摘要

A secondary battery is provided to improve the welding effectiveness between a uncoated area and a current collector by reducing the loss of heat energy caused by the laser irradiation transmitted by the current collector. A secondary battery comprises an electrode assembly formed by winding a separator between a positive plate and negative plate formed with the uncoated area(111a); a current collector equipped with one or a plurality of slits(170), which is electrically connected to the electrode assembly; a case housing the electrode assembly and current collector; and a cap assembly sealing the case tightly.