A lithium secondary battery is disclosed herein. In some embodiments, a lithium battery includes a positive electrode having a lithium-nickel-cobalt-manganese-based electrode active material wherein nickel has a content of 80 mol % or greater, relative to the other transition metals, a negative electrode including a silicon-based negative electrode active material, a separator, and a non-aqueous electrolyte solution including a non-aqueous organic solvent and a lithium salt, the lithium salt being contained in a concentration of 1.8 M to 5 M, and wherein the lithium salt includes LiPF6 and a lithium bis(fluorosulfonyl)imide.