LITHIUM RICH CATHOD ACTIVE MATERIAL FOR RECHARGEABLE BATTERIES

摘要

The present invention relates to a cathode active material for a secondary battery and, more specifically, to a new cathode active material for a secondary battery having extremely improved capacity properties and lifetime properties by solving problems of an existing lithium rich cathode active material. The lithium rich cathode active material for secondary battery includes an element having crystal radius of 0.65-9.8 in the outermost portion and in 2 micrometers from the outermost portion, and is represented by chemical formula 1. [Chemical formula 1] Li1+xNiαMnβ-δCoγO2 (In chemical formula 1, x is 0.4-0.7, alpha is 0.05-0.4, beta is 0.5-0.8, and gamma is 0.-0.4).