Rechargeable lithium battery

A rechargeable lithium battery, comprising:

• a negative electrode comprising a negative active material which comprises an active element selected from the group consisting of Si, Sn, Ga, Cd, Al, Pb, Zn, Bi, In, Mg, and Ge;
• a lithium electrolyte comprising a non-aqueous organic solvent, a lithium salt, and an additive;
• a positive electrode comprising a positive active material comprising a component that can reversibly intercalating and deintercalating lithium ions;
• and wherein
• the negative electrode reacting with the lithium electrolyte, and reversibly forming a lithium-included compound;
• and
• the additive comprises an ethylene carbonate-based compound represented by Chemical Formula 1 and a silicon-included compound represented by Chemical Formulae 2 and 4,
• chemical Formula 1
• wherein X and Y are each independently substituents selected from the group consisting of hydrogen, a halogen group, and a fluoroalkyl group with 1 through 5 carbons, X and Y are not hydrogen at the same time, and at least one of X and Y is selected from the group consisting of a halogen group and a fluoroalkyl with 1 through 5 carbons;
• and
• wherein R1 through R6 are either the same or different, and are independently selected from the group consisting of hydrogen, a halogen group, and a substituted or unsubstituted alkyl group with 1 through 10 carbons.