Cylindrical lithium secondary battery comprising a contoured center pin

摘要

A cylindrical lithium secondary battery includes: an electrode assembly with a center pin at a center of the electrode assembly; a can accommodating the electrode assembly; and a cap assembly coupled to a top of the can, wherein at least one end of the center pin is contoured to deform during collision between the center pin and a bottom surface of the can or the cap assembly and to absorb the impact so as to prevent the center pin from escaping the cylindrical lithium secondary battery.