CPC H01M 4/364 (2013.01) [H01M 4/366 (2013.01); H01M 4/505 (2013.01); H01M 4/525 (2013.01); H01M 4/62 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] | 19 Claims |
1. A positive active material for a rechargeable lithium battery, comprising:
a lithium nickel-based composite oxide and a lithium manganese composite oxide, and
a surface-modifying layer comprising lithium fluoride on a surface of the lithium nickel-based composite oxide,
the lithium nickel-based composite oxide comprising a secondary particle in which a plurality of plate-shaped primary particles are agglomerated,
the secondary particle has
a structure having one center with the primary particles arranged radially around the one center, or
a structure having a plurality of centers with the primary particles arranged radially around the plurality of centers, and
(003) planes of the primary particles are oriented normal to an intersecting portion of an outer surface of the secondary particle, and
the lithium manganese composite oxide having two or more types of crystal lattice structures,
wherein the lithium manganese composite oxide is on the surface of the lithium nickel-based composite oxide and is mixed with the surface-modifying layer comprising lithium fluoride into a mixture,
the lithium manganese composite oxide has a cubic crystal lattice structure and a monoclinic crystal lattice structure, and
the lithium manganese composite oxide is included in an amount of 0.4 mol to 1.5 mol based on 100 mol of the lithium nickel-based composite oxide.
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