Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same, and more particularly, to a positive electrode active material which exhibit improved driving characteristics under high-voltage operating conditions through surface modification of a lithium transition metal oxide of a Mid-Ni type having a relatively low nickel content, and to a lithium secondary battery comprising the same.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same, and more particularly, to a positive electrode active material comprising a mid-Ni type lithium transition metal oxide having a relatively low nickel content, wherein the c-axis length of unit particles constituting the lithium transition metal oxide is increased to enhance the efficiency of reversible intercalation/deintercalation of lithium ions, thereby improving electrochemical characteristics, which are relatively insufficient compared to those of a high-Ni type lithium transition metal oxide having a relatively high nickel content, and to a lithium secondary battery comprising the same.

Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same. More specifically, the present invention relates to a positive electrode active material comprising a lithium transition metal oxide of a Mid-Ni type having a relatively low nickel content, in which the content of fine powder in the positive electrode active material is controlled and the particle size distribution of the lithium transition metal oxide included in the positive electrode active material is adjusted, thereby improving capacity and lifetime characteristics and providing enhanced operational properties at high voltage.