METHOD FOR PREDICTING SECONDARY BATTERY PERFORMANCE FROM POSITIVE ELECTRODE ACTIVE MATERIAL, POSITIVE ELECTRODE ACTIVE MATERIAL, POSITIVE ELECTRODE, AND SECONDARY BATTERY

Abstract

The present invention relates to a method for predicting the performance of a secondary battery, the method comprising the steps of: manufacturing a cathode comprising a cathode active material comprising an overlithiated manganese-rich oxide containing 50 mole % or more but less than 100 mole % of manganese based on the total metal content except lithium; preparing a cathode sample by grinding the cathode; obtaining a cross-sectional image by taking photographs of the cathode sample and a cross-section with a scanning electron microscope; selecting a region of cathode active material particles from the cross-sectional image, followed by measuring an average pore area ratio according to a range of ECD values ​​of the cross-sections of the selected cathode active material particles;and predicting the performance of a secondary battery comprising a cathode from an average pore area ratio according to a range of ECD values ​​of the cross-section of the cathode active material particles, wherein the ECD represents the diameter of a circle having an area equal to the cross-sectional area of ​​the particles, and the pore area ratio represents a ratio of the pore area to the cross-sectional area of ​​the cathode active material particles.;