Electrolyte Additive And Non-aqueous Electrolyte Solution For Lithium Secondary Battery Comprising The Same

An electrolyte additive comprising a compound represented by Formula 1:

• wherein, in Formula 1,
• X1 and X2 are phosphorus (P),
• Y1 to Y4 are each independently oxygen (O) or sulfur (S),
• L is a direct bond or a divalent hydrocarbon group having 1 to 10 carbon atoms, and
• R1 to R4 are each independently hydrogen, a halogen atom, a nitrile group, or a monovalent hydrocarbon group having 1 to 20 carbon atoms,
• wherein the divalent hydrocarbon group having 1 to 10 carbon atoms and the monovalent hydrocarbon group having 1 to 20 carbon atoms are substituted or unsubstituted, and the substitution is performed with at least one substituent selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms.