A lithium secondary battery includes: a cathode, an anode; and an electrolyte between the cathode and the anode, wherein the cathode includes a cathode active material represented by Formula 1 below, and the electrolyte includes a lithium salt, a non-aqueous solvent, and a compound represented by Formula 2, where x, y, z, M, A, L1, a1, and R1 to R4 are defined as described in the disclosure.