Method for manufacturing lithium secondary battery

Abstract

The present invention relates to a method for manufacturing a lithium secondary battery, the method comprising a step (S1) of producing a preliminary-cell which comprises a positive electrode including a positive electrode active material, a negative electrode, a separator, and an electrolyte, and a step (S2) of activating the preliminary-cell by charging the preliminary-cell to a charging cut-off voltage and then discharging the preliminary-cell to a discharging cut-off voltage, wherein: the positive electrode active material comprises an overlithiated manganese-based oxide that comprises, among the total metal other than lithium, at least 50 mol% manganese (Mn) and in which the mole ratio (Li / Me) of lithium to the total metal other than lithium is greater than 1; the charging cut-off voltage is greater than 4.3V; and the discharging cut-off voltage is at least 2.6V.