Additive for electrolyte, electrolyte and rechargeable lithium battery

An electrolyte for a rechargeable lithium battery, comprising

• a lithium salt;
• a non-aqueous organic solvent;
• and
• an additive for an electrolyte represented by the following Chemical Formula 1:
• wherein, R1 and R4 are each independently hydrogen or a C1 to C12 alkyl group;
• R2 and R3 are each independently —OR′ or —R″C(O)-OR′″;
• each R′ is a C1 to C12 alkyl group;
• R″ is a C1 to C4 alkylene (alkanediyl) group;
• and
• R′″ is a C1 to C12 alkyl group.

A rechargeable lithium battery, comprising

• a positive electrode including a positive active material;
• a negative electrode including a negative active material;
• and an electrolyte comprising a lithium salt;
• a non-aqueous organic solvent;
• and an additive for an electrolyte represented by the following Chemical Formula 1:
• wherein, R1 and R4 are each independently hydrogen or a C1 to C12 alkyl group;
• R2 and R3 are each independently —OR′ or —R″C(O)—OR′″;
• each R′ is a C1 to C12 alkyl group;
• R″ is a C1 to C4 alkylene (alkanediyl) group;
• and
• R′″ is a C1 to C12 alkyl group.