Lithium Secondary Battery

A lithium secondary battery includes a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode includes a positive electrode active material layer having a positive electrode active material containing an overlithiated manganese-based oxide represented by Formula 1 below, and the negative electrode includes a negative electrode active material layer having a silicon-based negative electrode active material, LiNiCoMnMO [Formula 1]