SEPARATOR FOR RECHARGEABLE BATTERY, METHOD OF PREPARING THE SAME AND RECHARGEABLE LITHIUM BATTERY INCLUDING THE SAME

A separator for a rechargeable battery includes a porous substrate; and a coating layer on the porous substrate, the coating layer includes a fluorine-containing binder, a filler, and an additive, the additive is included in an amount of 0.35 wt % to 1.25 wt %, an infrared spectral intensity of a C-F group of the fluorine-containing binder is greater than 0.0030 to less than 0.0050, the infrared spectral intensity of the C-F group of the fluorine-containing binder is measured as a functional group of the fluorine-containing binder to evaluate a distribution of the fluorine-containing binder when separator specimens are mounted on an ATR crystal of a FT-IR spectroscopy and infrared rays are entered at a 45 degree angle, the additive includes a hydrocarbon polymer compound that includes a carboxyl group, and the hydrocarbon polymer compound has a weight average molecular weight of about 5,000 g/mol to about 15,000 g/mol.