Non-aqueous electrolyte solution for lithium secondary battery and lithium secondary battery including the same

A non-aqueous electrolyte solution for a lithium secondary battery, comprising:

• an oligomer represented by Formula 1;
• a lithium salt;
• and
• an organic solvent:
• wherein, in Formula 1,
• R is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
• R′ is an unsubstituted or substituted alkylene group having 1 to 5 carbon atoms,
• R1 to R4 are same or different from each other and are each independently an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms,
• R5 is an unsubstituted or substituted alkylene group having 1 to 5 carbon atoms,
• n is an integer of 1 to 10,
• m is an integer of 1 to 5,
• x is an integer of 1 to 200, and
• E and E′ are same or different from each other and are each independently represented by Formula 2,
• wherein, in Formula 2,
• Ra and Rb are same or different from each other and are each independently hydrogen;
• an alkyl group having 1 to 6 carbon atoms which is unsubstituted or substituted with a halogen group;
• or an alkenyl group having 1 to 6 carbon atoms which is unsubstituted or substituted with a halogen group,
• Rc and Rd are same or different from each other and are each independently hydrogen or an alkyl group having 1 to 5 carbon atoms,
• Rb and Rc may be bonded to each other to form a cycloalkyl group including O, and
• p is an integer of 0 to 4, and
• k is an integer of 1 to 3.