Electrolyte for rechargeable lithium battery and rechargeable lithium battery including same

1. An electrolyte for a rechargeable lithium battery, the electrolyte consisting of:

a lithium salt;

an organic solvent;

0.5 wt % to 1.5 wt % of LiPO 2 F 2 ;

1 wt % to 2 wt % of a compound represented by the following Chemical Formula 1 or Chemical Formula 2, in which wt % is based on a total weight of the electrolyte for a rechargeable lithium battery;

fluoroethylene carbonate;

LiBF 4 ;

lithium bisoxalatoborate; and

succinic nitrile,

wherein, in Chemical Formulae 1 and 2,

R 1 is an unsubstituted C1 to C30 alkyl group.

2. The electrolyte as claimed in claim 1 , wherein the organic solvent includes a carbonate-based compound and an ester-based compound.

3. The electrolyte as claimed in claim 1 , wherein the compound represented by Chemical Formula 1 or 2 is represented by one of the following Chemical Formulae 1a to 1g or 2a:

4. A rechargeable lithium battery, comprising

a positive electrode,

a negative electrode, and

the electrolyte as claimed in claim 1 .

5. The rechargeable lithium battery as claimed in claim 4 , wherein the positive electrode includes a positive active material represented by Chemical Formula 4:

Li a Ni b E c G d O 2   Chemical Formula 4

wherein, in Chemical Formula 4,

0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1,

E is Co, Mn, or a combination thereof, and

G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof.