| 摘要 |
PURPOSE: A lithium secondary battery having a protection plate with a knurled section with a certain range of dimension is provided to improve the weldability of the protection plate to the can. CONSTITUTION: The lithium secondary battery comprises: a battery section; a can(21) which provides a receiving space for the battery section; a cap assembly which is mounted on the upper part of the can, and comprises a cap plate and an electrode terminal having a gasket on its exterior side for insulation with the cap plate; a safety vent which is formed on the bottom of the can, and provides a gas exhaust passage when the inner pressure is elevated; and a protection plate(270) formed on the upper part of the safety vent, which has a knurled section with a certain pattern and dimension to be welded to the can by ultrasonic wave horn(30) having flat(31) and projected(32) parts. |
