Ecopro Bm Co., Ltd.

Ra Na Lim

A Reum Yang

Hye Bin Kim

Gyun Joong Kim

Kyung Min Lim

Moon Ho Choi

Seung Hyun Choi

A positive electrode active material for a secondary battery comprises a lithium composite oxide represented by chemical formula 1 below and containing a layer-structured lithium excess oxide, wherein the lithium composite oxide comprises a secondary particle; the secondary particle comprises at least one primary particle; the primary particle comprises at least one crystallite; at least any one of the secondary particle, the primary particle, or the crystallite comprises a core and a shell occupying at least a portion of the surface of the core. When the crystal structure of space group C2/m is designated as [C2/m], the crystal structure of space group R-3m is designated as [R-3m], and the ratio of the crystal structure of space group C2/m versus the crystal structure of space group R-3m is designated as [C2/m]/[R-3m], the [C2/m]/[R-3m] of the core differs from that of the shell in the secondary particle: [chemical formula 1] rLiM1O·(1−r)LiM2O.

Positive electrode active material for lithium secondary battery, method for preparing same, and lithium secondary battery including same

The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a positive electrode active material, which includes an overlithiated lithium manganese-based oxide, which is a solid solution with a phase belonging to a C2/m space group and a phase belonging to an R3-m space group and in which stability degradation caused by excessive amounts of lithium and manganese in the lithium manganese-based oxide is mitigated and/or prevented because there are regions with different proportions of the phase belonging to the C2/m space group and the phase belonging to the R3-m space group in the lithium manganese-based oxide, and a lithium secondary battery including the same.

Positive electrode active material and lithium secondary battery including the same

The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a positive electrode active material which includes an overlithiated lithium manganese-based oxide including at least lithium, nickel, manganese and a doping metal, and in which the degradation in stability caused by excessive amounts of lithium and manganese in the lithium manganese-based oxide is mitigated and/or prevented by controlling the concentration of a transition metal in the lithium manganese-based oxide for each region, and a lithium secondary battery including the same.

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Cheongju-si, South Korea

Ra Na Lim