| 摘要 |
Disclosed herein is a mandrel configured to be used in a winding process for manufacturing a jelly roll type electrode assembly using a long sheet type stack of a cathode/separator/anode structure, wherein the mandrel is oval in a section perpendicular to a rotational central axis of the mandrel, a length ratio of a major axis to a minor axis of the mandrel being 1.5 or more, and a tilt of an outer side of the mandrel is continuously changed from an end of the minor axis of the mandrel to an end of the major axis of the mandrel in the section perpendicular to the rotational central axis of the mandrel in such a manner that the mandrel is configured to have an oval structure so as to reduce wound stress applied from the end of the major axis of the mandrel to the sheet type stack during constant speed rotation of the mandrel when the sheet type stack is wound on the mandrel in a state in which an end of the sheet type stack is fitted in a central region of the mandrel. |
