Non-aqueous electrolyte including additive for non-aqueous electrolyte, and lithium secondary battery including the non-aqueous electrolyte

A non-aqueous electrolyte comprising:

• a lithium salt;
• an organic solvent;
• a first additive;
• and
• a second additive,
• wherein the first additive is a compound represented by Formula 1;
• and
• the second additive is a polymer comprising a repeating unit represented by Formula 2-1, Formula 2-2, and Formula 2-3:
• wherein, in Formula 1,
• R is a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, and
• R1 to R3 are each independently H, an alkyl group having 1 to 3 carbon atoms, or a nitrile group,
• wherein, in Formula 2-1 above,
• R4 is any one selected from the group consisting of H, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a halogen atom, and a nitrile group,
• wherein, in Formula 2-2 above,
• R4 is an alkyl group having 1 to 10 carbon atoms which is substituted with at least one nitrile group, and
• R5 is any one selected from the group consisting of H, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a halogen atom, and a nitrile group, and
• wherein, in Formula 2-3 above,
• Rb is an fluoroalkyl group having 1 to 10 carbon atoms, and
• R6 is any one selected from the group consisting of H, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a halogen atom, and a nitrile group.