MANDREL USED IN MANUFACTURE OF JELLY ROLL-TYPE ELECTRODE ASSEMBLY

摘要

The present invention provides a mandrel used during a rolling process in a manufacture of a jelly roll-type electrode assembly out of a long sheet-type laminate comprising an anode/separator/cathode structure. The mandrel is characterized in that the shape of the vertical cross section of the mandrel with respect to the central rotational axis is elliptical; a length of a long axis is at least 1.5 times a short axis; and in the shape of the vertical cross-section with respect to the central rotational axis, a slope of the surface of the mandrel forms an elliptical structure with a continuous curve from the end of the short axis to the end of the long axis so that a rolling stress exerted, onto the sheet-type laminate, from the end of the long axis, is reduced during the rotation of the mandrel at a fixed speed when an end of the sheet-type laminate is rolled after being inserted into the middle section of the mandrel.