POSITIVE ELECTRODE ACTIVE MATERIAL AND SECONDARY BATTERY COMPRISING THE SAME

摘要

In the positive electrode active material according to the inventive concept, the amount of residual lithium is decreased although the concentration of nickel is high, and thus the positive electrode active material exhibits excellent cycle-life characteristics and charge and discharge characteristics, has a stabilized crystal structure while having a high capacity, and is structurally stabilized even when being used at a high voltage. In the positive electrode active material, a shell portion in which the concentration of nickel is controlled and the concentrations of other metals are constant is formed on the surface of a core portion having gradients of concentrations of nickel, manganese, and cobalt. Thus, the positive electrode active material exhibits excellent cycle-life characteristics and charge and discharge characteristics, has a stabilized crystal structure while having a high capacity, and is structurally stabilized even when being used at a high voltage.

主权项

1. A positive electrode active material for lithium secondary battery, the positive electrode active material comprising:
a core portion; a concentration gradient portion that is formed on the outside of the core portion and has gradients of concentrations of nickel, manganese, and cobalt; and a shell portion that is formed on the outside of the concentration gradient portion and has constant concentrations of nickel, manganese, and cobalt.