Electrolyte for a rechargeable lithium battery, and rechargeable lithium battery including the same

A solvent for an electrolyte for a rechargeable lithium battery including a lithium salt, a non-aqueous organic solvent, and an alkyl benzonitrile compound represented by the following Chemical Formula 1, and a rechargeable lithium battery including the same are provided. In Chemical Formula 1, R is a substituted or unsubstituted C1 to C10 alkyl group.