The present invention relates to a
lithium secondary battery which includes a positive
electrode including an overlithiated
manganese-based
oxide, in which an amount of
manganese among total metals excluding
lithium is greater than 50 mol% and a ratio (Li / Me) of the number of moles of the
lithium to the number of moles of the total metals excluding the lithium is greater than 1, as a positive
electrode active material; a negative
electrode including a
silicon-based negative electrode active material; a separator disposed between the positive electrode and the negative electrode; and an
electrolyte, and satisfies Equation (1). 0.25A≤B≤0.6A In Equation (1), A is a
discharge curve area in a
voltage range of 2.0 V to 4.6 V of a dQ / dV graph obtained by differentiating a graph of battery
discharge capacity Q and
voltage V after one cycle which are measured while charging the lithium secondary battery at 0.1 C to 4.6 V and then discharging the lithium secondary battery at 0.1 C to 2.0 V, and B is a
discharge curve area in a
voltage range of 2.0 V to 3.5 V of the dQ / dV graph.