SEPARATOR FOR RECHARGEABLE LITHIUM BATTERY AND RECHARGEABLE LITHIUM BATTERY INCLUDING THE SAME

A separator for a rechargeable lithium battery includes a substrate and a heat-resistant porous layer on at least one side of the substrate. The heat-resistant porous layer includes a crosslinked binder. The crosslinked binder has a cross-linked structure of a crosslinkable compound including a siloxane compound. The siloxane compound includes a siloxane resin including a unit represented by the chemical formula RSiO, where Ris a curable reactive group, or an organic group having a curable reactive group.