Patent ID: 7858227

Claim:
A lithium secondary battery comprising: an electrode assembly including a first electrode plate, a second electrode plate, and a separator interposed between the first electrode plate and the second electrode plate; a battery case containing the electrode assembly; and a cap plate coupled to the battery case to seal the battery case, the cap plate having at least one protrusion formed on an interior-facing surface of the cap plate; and an insulation case disposed on the electrode assembly, the insulation case having at least one recess on a surface facing the cap plate, wherein each of the at least one recess has a bottom surface and has a depth less than a height of the at least one protrusion such that the cap plate is spaced from the insulation case by the at least one protrusion abutting the bottom surface, and wherein each of the at least one recess is coupled to a corresponding one of the at least one protrusion to fix the cap plate to the insulation case.