POSITIVE ELECTRODE ACTIVE MATERIAL FOR SECONDARY BATTERY

摘要

The present invention relates to a positive electrode active material for a secondary battery, and specifically the positive electrode active material for a secondary battery according to the present invention contains a sodium transition metal pyrophosphate satisfying Na3.12-x2Ac x1M1 a y1M2 b y2(P2O7)2, has structural stability due to a strong P-O bond in the olivine structured sodium transition metal phosphate, and involves the smooth insertion and removal of sodium ions having a large ion radius, markedly improving the charge and discharge speed and reversibility during charge and discharge.