Rechargeable Lithium Battery

Disclosed is a rechargeable lithium battery that includes a positive electrode including a positive active material, a negative electrode including a silicon-based negative active material, an electrolyte including a lithium salt and a non-aqueous organic solvent, and a separator including a polymer substrate and a ceramic-containing coating layer on the polymer substrate. The ceramic-containing coating layer has a porosity at or between about 50% and about 90%, and a thickness at or between about 2µm and about 6µm. The rechargeable lithium battery has a capacity per volume of more than or equal to about 700Wh/ .