A lithium secondary battery is disclosed herein. In some embodiments, a lithium secondary battery which includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte solution, wherein the positive electrode includes a positive electrode active material represented by Formula 1, and the non-aqueous electrolyte solution includes a non-aqueous organic solvent, a first lithium salt, lithium bis(fluorosulfonyl)imide as a second lithium salt, and an additive, wherein a molar ratio of the first lithium salt to the second lithium salt is in a range of 1:0.01 to 1:1, and the additive is a mixed additive which includes fluorobenzene, tetravinylsilane, and tertiary butylbenzene in a weight ratio of 1:0.05:0.1 to 1:1:1.5. Li(NiaCobMnc)O2  [Formula 1] (in Formula 1, 0.65