Method of Preparing Positive Electrode Active Material for Lithium Secondary Battery and Positive Electrode Active Material Prepared Thereby

Patent metadata

Field	Value
Publication number	US-2024270603-A1
Application number	US-202218573109-A
Country	US
Kind code	A1
Filing date	Nov 2, 2022
Priority date	Nov 24, 2021
Publication date	Aug 15, 2024
Grant date	—

Abstract

The present invention relates to a method of preparing a positive electrode active material for a lithium secondary battery and a positive electrode active material prepared thereby, wherein the preparation method includes a first step of preparing a lithium transition metal oxide by mixing a lithium raw material and a transition metal precursor containing 70 mol % or more of nickel based on the total number of moles of transition metals and sintering the mixture; and a second step of washing the lithium transition metal oxide with hot water of more than 90° C., wherein, after the second step, a result of EELS analysis of a particle surface of the lithium transition metal oxide satisfies Equation 1.

First claim

1 . A method of preparing a positive electrode active material for a lithium secondary battery, comprising:
preparing a lithium transition metal oxide by mixing a lithium raw material and a transition metal precursor containing 70 mol % or more of nickel based on a total number of moles of transition metals to form a mixture, and sintering the mixture to form the lithium transition metal oxide; and washing the lithium transition metal oxide with hot water of more than 90° C., wherein, after the washing the lithium transition metal oxide, a result of EELS analysis of a particle surface of the lithium transition metal oxide satisfies Equation 1:

I
⁡
(

853
⁢

eV

)

/

I
⁡
(

855.5

eV

)

≥
1

[

Equation
⁢

1

]

wherein, in Equation 1,
I(853 eV) is a peak intensity appearing near 853 eV, and
I(855.5 eV) is a peak intensity appearing near 855.5 eV.

2 . The method of claim 1 , wherein the transition metal precursor comprises 80 mol % or more of the nickel based on the total number of moles of transition metals.

3 . The method of claim 1 , wherein the sintering is performed at 750° C. to 830° C.

4 . The method of claim 1 , wherein more Ni 2+ than Ni 3+ is contained on the particle surface of the lithium transition metal oxide after the washing.

5 . The method of claim 1 , wherein a weight of the hot water used in the washing is 1 to 3 times a weight of the lithium transition metal oxide.

6 . The method of claim 1 , wherein the washing is performed for 10 minutes to 30 minutes.

7 . A positive electrode active material for a lithium secondary battery, comprising:
a lithium transition metal oxide containing 70 mol % or more of nickel based on a total number of moles of transition metals, wherein a result of EELS analysis of a particle surface of the lithium transition metal oxide satisfies Equation 1:

I
⁡
(

853
⁢

eV

)

/

I
⁡
(

855.5

eV

)

≥
1

[

Equation
⁢

1

]

wherein, in Equation 1,
I(853 eV) is a peak intensity appearing near 853 eV, and
I(855.5 eV) is a peak intensity appearing near 855.5 eV.

8 . The positive electrode active material of claim 7 , wherein more Ni 2+ than Ni 3+ is contained on the particle surface of the lithium transition metal oxide.

9 . The positive electrode active material of claim 7 , wherein the lithium transition metal oxide is represented by Formula 1:

wherein, in Formula 1,
a, b, c, d, e, and f are respectively 0.8≤a≤1.5, 0.7≤b<1.0, 0<c≤0.25, 0<d≤0.25, 0≤e≤0.1, b+c+d+e=1.0, and −0.1≤f≤1.0, and
Q is at least one selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo.

10 . The positive electrode active material of claim 9 , wherein b, c, d, and e in Formula 1 satisfy 0.8≤b<1.0, 0<c≤0.15, 0<d<0.15, and 0≤e≤0.05, respectively.

11 . A positive electrode comprising a positive electrode active material layer which includes the positive electrode active material of claim 7 .

12 . A lithium secondary battery comprising the positive electrode of claim 11 .

13 . A lithium secondary battery comprising the positive electrode of claim 11 and a negative electrode.

Assignees

• Lg Energy Solution Ltd

Inventors

• Lho Eun Sol
• Han Gi Beom
• Kim Jong Woo
• Jung Wang Mo
• Park Sang Min
• Lee Sang Wook
• Kim Seul Ki
• Kim Hyeong Ll

Classifications

• H01M4/505

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

• H01M2004/028

  Positive electrodes · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M10/052 Primary

  Li-accumulators · 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