Positive electrode active material and lithium secondary battery comprising the same

Patent metadata

Field	Value
Publication number	US-2025140809-A1
Application number	US-202418904857-A
Country	US
Kind code	A1
Filing date	Oct 2, 2024
Priority date	Oct 25, 2023
Publication date	May 1, 2025
Grant date	—

Abstract

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 including an overlithiated lithium manganese-based oxide, wherein through surface modification of the lithium manganese-based oxide, the surface resistance of the lithium manganese-based oxide is reduced, thereby improving the lifetime characteristics of the lithium secondary battery, which uses the lithium manganese-based oxide as a positive electrode active material, and a lithium secondary battery including the same.

First claim

What is claimed is:

1 . A positive electrode active material comprising a lithium manganese-based oxide in which a phase belonging to the C2/m space group and a phase belonging to the R3-m space group are dissolved,
wherein the lithium manganese-based oxide further includes a spinel phase belonging to the Fd-3m space group, in X-ray diffraction analysis of the positive electrode active material using Cu-Kα rays, the intensity ratio between the diffraction peaks of the (003) plane and the (104) plane satisfies Equation 1 below, and the intensity ratio between the diffraction peaks of the (018) plane and the (110) plane satisfies Equation 2 below:

1.59
≤

I
(
003
)

/

I
(
104
)

≤
2.6

,

[

Equation
⁢

1

]

1.15
≤

I
(
018
)

/

I
(
110
)

≤

1.55
.

[

Equation
⁢

2

]

2 . The positive electrode active material of claim 1 , wherein in X-ray diffraction analysis of the positive electrode active material using Cu-Kα rays, the full width at half maximum (FWHM) of the (104) plane diffraction peak is 0.27 to 0.50.

3 . The positive electrode active material of claim 1 , wherein the lithium manganese-based oxide is represented by Chemical Formula 1 below,

r
⁢
Li

2

⁢

MnO

3
-
c

⁢

X
c
′

·

(

1
-
r

)

⁢

Li
a

⁢
M
⁢

1
x

⁢
M
⁢

2
y

⁢

O

2
-
b

⁢

X
b

[

Chemical
⁢

Formula
⁢

1

]

wherein, M1 is at least one selected from Ni and Mn,
M2 is at least one selected from Ni, Mn, Co, Al, P, Nb, B, Si, Ti, Zr, Ba, K, Mo, Fe, Cu, Cr, Zn, Na, Ca, Mg, Pt, Au, Eu, Sm, W, Ce, V, Ta, Sn, Hf, Gd, Y, Ru, Ge, and Nd,
M2 does not overlap M1,
X and X′ each are independently halogens capable of substituting at least some of the oxygen in the lithium manganese-based oxide, and
0<r≤0.7, 0<a≤1, 0≤b≤0.1, 0≤c≤0.1, 0<x≤1, 0≤y<1, and 0<x+y≤1 are satisfied.

4 . The positive electrode active material of claim 1 , wherein the lithium manganese-based oxide is a solid solution of a phase belonging to the C2/m space group, a phase belonging to the R3-m space group, and a spinel phase belonging to the Fd-3m space group.

5 . The positive electrode active material of claim 4 , wherein the lithium manganese-based oxide is represented by Chemical Formula 2 below,
(1 −z ){ r Li 2 MnO 3-c X′ c ·(1 −r )Li a M1 x M2 y O 2-b X b }·z Li(Li d Mn 2-d-e M3 e )O 4-g X″ g   [Chemical Formula 2]
wherein, M1 is at least one selected from Ni and Mn, M2 is at least one selected from Ni, Mn, Co, Al, P, Nb, B, Si, Ti, Zr, Ba, K, Mo, Fe, Cu, Cr, Zn, Na, Ca, Mg, Pt, Au, Eu, Sm, W, Ce, V, Ta, Sn, Hf, Gd, Y, Ru, Ge, and Nd, M2 does not overlap M1, M3 is at least one selected from Ni, Co, Al, P, Nb, B, Si, Ti, Zr, Ba, K, Mo, Fe, Cu, Cr, Zn, Na, Ca, Mg, Pt, Au, Eu, Sm, W, Ce, V, Ta, Sn, Hf, Gd, Y, Ru, Ge, and Nd, X, X′, and X″ each are independently halogens capable of substituting at least some of the oxygen in the lithium manganese-based oxide, and 0<r≤0.7, 0<a≤1, 0≤b≤0.1, 0≤c≤0.1, 0<x≤1, 0≤y<1, 0<x+y≤1, 0<z≤0.5, 0≤d≤1, 0<e≤1, and 0≤g≤0.1 are satisfied.

6 . The positive electrode active material of claim 5 , wherein the spinel phase is represented by LiMn 1.5 Ni 0.5 O 4 .

7 . The positive electrode active material of claim 1 , wherein the lithium manganese-based oxide includes a core portion in which a phase belonging to the C2/m space group and a phase belonging to the R3-m space group are dissolved, and a shell portion, which is present on at least a portion of the surface of the core portion and has a spinel phase belonging to the Fd-3m space group, and the core portion and the shell portion are dissolved core-shell particles.

8 . The positive electrode active material of claim 7 , wherein the core portion is a secondar

Assignees

• Ecopro Bm Co Ltd

Inventors

• Jeon Se Hyeon
• Jung Hyun Su
• Lim Ra Na

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/505 Primary

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title