US 12,482,810 B2
Positive electrode active material for lithium secondary battery, method for preparing same, and lithium secondary battery including same
Moon Ho Choi, Chungcheongbuk-do (KR); Seung Hyun Choi, Chungcheongbuk-do (KR); Ra Na Lim, Chungcheongbuk-do (KR); and A Reum Yang, Chungcheongbuk-do (KR)
Assigned to ECOPRO BM CO., LTD., Chungcheongbuk-Do (KR)
Appl. No. 18/247,326
Filed by ECOPRO BM CO., LTD., Chungcheongbuk-do (KR)
PCT Filed Dec. 2, 2021, PCT No. PCT/KR2021/018087
§ 371(c)(1), (2) Date Mar. 30, 2023,
PCT Pub. No. WO2022/119338, PCT Pub. Date Jun. 9, 2022.
Claims priority of application No. 10-2020-0168858 (KR), filed on Dec. 4, 2020; application No. 10-2021-0067237 (KR), filed on May 25, 2021; application No. 10-2021-0080132 (KR), filed on Jun. 21, 2021; and application No. 10-2021-0080133 (KR), filed on Jun. 21, 2021.
Prior Publication US 2023/0387403 A1, Nov. 30, 2023
Int. Cl. H01M 4/505 (2010.01); C01G 53/00 (2025.01); C01G 53/44 (2025.01); H01M 4/36 (2006.01); H01M 4/525 (2010.01); H01M 10/052 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/364 (2013.01) [C01G 53/44 (2013.01); H01M 4/366 (2013.01); H01M 4/505 (2013.01); H01M 4/525 (2013.01); H01M 10/052 (2013.01); C01P 2002/01 (2013.01); C01P 2002/76 (2013.01); C01P 2004/03 (2013.01); C01P 2006/40 (2013.01); H01M 2004/028 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A cathode active material for a secondary battery, comprising a lithium composite oxide represented by Formula 1 below and containing a layered structure of overlithiated oxide,
wherein the lithium composite oxide includes a secondary particle, the secondary particle includes at least one primary particle, and the primary particle includes at least one crystallite; at least one of the secondary particle, the primary particle, or the crystallite comprises a core and a shell occupying at least a part of the surface of the core, and when a crystal structure assigned to a space group C2/m is defined as [C2/m], a crystal structure assigned to a space group R-3m is defined as [R-3m], and the ratio of the crystal structure assigned to the space group C2/m to the crystal structure assigned to the space group R-3m is defined as [C2/m]/[R-3m],
the [C2/m]/[R-3m] in the core of the secondary particle is greater than in the shell of the secondary particle, the [C2/m]/[R-3m] in the core of the primary particle is greater than in the shell of the primary particle, or the [C2/m]/[R-3m] in the core of the crystallite is greater than in the shell of the crystallite, and
at least one of the secondary particle, the primary particle, and the crystallite includes a phase gradient portion in which [C2/m]/([C2/m]+[R-3m]) has a gradient toward the center from the surface of the selected at least one:
rLi2M1O3·(1−r)LiaM2O2  [Formula 1]
where, 0<r<1 and 0<a≤1; M1 is at least one of Mo, Nb, Fe, Cr, V, Co, Cu, Zn, Sn, Mg, Ni, Ru, Al, Ti, Zr, B, Mn, Na, K, Y, P, Ba, Sr, La, Ga, Gd, Sm, W, Ca, Ce, Ta, Sc, In, S, Ge, Si, and Bi; and M2 is at least one of Mo, Nb, Fe, Cr, V, Co, Cu, Zn, Sn, Mg, Ni, Ru, Al, Ti, Zr, B, Mn, Na, K, Y, P, Ba, Sr, La, Ga, Gd, Sm, W, Ca, Ce, Ta, Sc, In, S, Ge, Si, and Bi.