Patent ID: 9236609
Filing Date: 2016-01-12
CPC Classification: C01G,C01P,H01M,Y02E

Claim Text:
1. A positive active material for a rechargeable lithium battery, comprising a nickel-based composite oxide represented by the following Chemical Formula 1, wherein the nickel-based composite oxide comprises an over lithiated oxide and non-continuous portions of a lithium nickel cobalt manganese oxide on a surface of the over lithiated oxide, wherein an atomic weight ratio of Ni:Mn of the over lithiated oxide is in a range of about 1:1 to about 2:1, wherein an atomic weight ratio of Ni:Mn of the lithium nickel cobalt manganese oxide is in a range of about 3:1 to about 4:1: wherein, 1<a<1.6, 0.1<b<0.7, 0.1<c<0.4, and 0.1<d<0.7, and wherein the manganese and nickel components of the nickel-based composite oxide have a structural concentration gradient such that the nickel-based composite oxide has a higher concentration of nickel at a surface than at an interior.