Secondary battery

A secondary battery comprising:

• an electrode assembly;
• a case having the electrode assembly received therein;
• and
• a cap assembly coupled to the case and covering an opening of the case,
• wherein the cap assembly comprises:
• a cap plate comprising a through hole;
• a rivet part comprising a body part and an inner fastening portion, the body part positioned in the through hole and extending toward an outside of the case, and the inner fastening portion extending from the body part between the cap plate and the electrode assembly;
• a base insulating member disposed between the cap plate and the electrode assembly;
• and
• a gasket disposed between the cap plate and the rivet part;
• a current collection plate;
• and
• a current collection protrusion protruding from the current collection plate and positioned within a throughbore defined in the body part,
• wherein at least a part of the base insulating member and at least a part of the gasket contact the inner fastening portion and extend parallel to each other between the cap plate and the inner fastening portion.