Additives for nonaqueous electrolyte and lithium secondary battery containing the same

An electrolyte composition for a lithium secondary battery, comprising:

• a non-aqueous organic solvent;
• a lithium salt;
• and
• a compound represented by Formula 1:
• wherein,
• R1 is hydrogen or an alkyl group having 1 to 4 carbon atoms,
• R2 includes one or more selected from an alkylene group having 1 to 10 carbon atoms, an oxyalkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 5 to 10 carbon atoms, or
• each of which is are optionally substituted with a fluorine atom,
• R3 is a fluoro group, an alkyl group having 1 to 10 carbon atoms optionally substituted with a fluorine atom, an alkoxy group having 1 to 10 carbon atoms optionally substituted with a fluorine atom, or
• optionally substituted with a fluorine atom, provided when R2 is an alkylene group having 1 to 10 carbon atoms, R3 is not an alkyl group having 1 to 10 carbon atoms substituted with a fluorine atom,
• X is an oxygen atom (O) or —NR4, R4 is hydrogen or an alkyl group having 1 to 4 carbon atoms,
• M comprises one or more selected from the group consisting of one or more selected from the group consisting of lithium, sodium, potassium, tetraalkyl ammonium having 1 to 4 carbon atoms, and tetraalkyl phosphonium having 1 to 4 carbon atoms,
• l is an integer of 1 to 6, and
• each of m and n is an integer of 2 to 20.