METHOD FOR PRE-PROCESSING LITHIUM ION SECONDARY BATTERY

摘要

This method for pre-processing a lithium ion secondary battery is provided with: a step for preparing a lithium ion secondary battery containing the cathode active material represented by chemical formula (1); and a step for charging with the upper limit potential of the lithium ion secondary battery being at least 4.5 V and less than 5.0 V in terms of a lithium counter electrode, and discharging with the lower limit potential being less than 4.0 V in terms of a lithium counter electrode. Also, the charging and discharging is characterized by being performed at a current rate of 0.1-1.3 C inclusive. Formula 1: aLi[Li1/3Mn2/3]O2·(1-a)LiMO2 (In the formula: a is a value above 0 and less than 1; and LiMO2 is a lithium complex oxide containing Ni and Mn.)