POSITIVE ELECTRODE ACTIVE MATERIAL FOR SECONDARY BATTERY COMPRISING LITHIUM COBALT-BASED OXIDE OF IMPROVED PERFORMANCE AND LITHIUM SECONDARY BATTERY COMPRISING THE SAME

摘要

PURPOSE: A positive electrode active material for a secondary battery is provided to provide a lithium secondary battery capable of improving capacity and high temperature storage performance and low temperature storage performance. CONSTITUTION: A positive electrode active material for a secondary battery comprises active material particle(A) with a relatively large average particle size, and active material particle(B) with a relatively small average particle size. The active material particle(A) and the active material particle(B) are independently comprises a composition in chemical formula 1: Li_aCo_(1-x-y)Mg_xTi_yO_(2-z)M_z. In chemical formula 1, 0.9