MANDREL MEMBER OF WINDER FOR SECONDARY BATTERY

A mandrel member (100) of a winder for a secondary battery, which is mounted in a winder configured to manufacture a jelly roll-type electrode assembly by winding a stack of a first electrode plate (21), a separator (22), and a second electrode plate (23), the mandrel member (100) comprising a cylindrical body having a hollow portion (120), wherein the cylindrical body includes a plurality of slits (110) crossing the cylindrical body in a hollow axis direction so that the hollow portion (120) inside the cylindrical body is in fluid communication with the outside of the cylindrical body.