CYLINDRICAL SECONDARY BATTERY OF IMPROVED SAFETY

摘要

A cylindrical secondary battery is provided to prevent an internal short caused by the contact between an electrode tab and a beading portion, thereby improving the safety, and to realize a simple manufacturing process. A cylindrical secondary battery comprises an electrode assembly(jelly-roll) having a cathode/separator/anode structure, and a cylindrical can for housing the electrode assembly. In the battery, a gasket(401) is mounted along the outer circumferential surface of a cap assembly so as to mount the cap assembly to the opened top of the can in an electrically insulated state. The gasket extends from the bottom thereof to such a length that the jelly-roll connected to the cap assembly is prevented from being in contact with the beading portion(211) of the can. The extended portion(412) has a thickness smaller than the thickness of the portion that is in contact with the inner indentation(212) of the beading portion, wherein the thickness of the extended portion varies when it is in contact with the jelly roll or insulation member(611) positioned at the lower part thereof while not adversely affecting the jelly-roll or insulation member.