Positive electrode active material and method for preparing the same

Patent metadata

Field	Value
Publication number	US-12315922-B2
Application number	US-202016988024-A
Country	US
Kind code	B2
Filing date	Aug 7, 2020
Priority date	Aug 7, 2020
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A method for preparing a positive electrode active material and a positive electrode active material prepared thereby are provided. The method includes a first step of reacting a coating precursor preparation solution including a metal solution containing metal ions included in a coating layer and a chelating agent to prepare a coating precursor, which is a complex in which the metal ions and the chelating agent are combined, and a second step of dry-mixing particles having a specific composition and the coating precursor, followed by firing the mixture to form a coating layer having a specific composition on surfaces of the particles.

First claim

The invention claimed is:

1. A positive electrode active material comprising:
particles having the composition of Formula 1 below; and
a coating layer formed on surfaces of the particles and having the composition of Formula 3 below:
Li[Co 1-a M 1 a ]O 2   [Formula 1]

wherein, in Formula 1 above,
M 1 is one or more selected from the group consisting of B, Mg, Ca, Al, Ti, V, Cr, Fe, Zn, Ga, Y, Zr, Nb, Mo, Ta, and W, and 0≤a<0.1,
Li[Ni f Co g Mn h M 3 i ]O 2   [Formula 3]

wherein, in Formula 3 above,
M 3 is one or more selected from the group consisting of B, Ca, V, Cr, Fe, Zn, Ga, Y, Nb, Mo, and Ta, and 0<f≤0.4, 0≤g≤0.6, 0≤h≤0.6, 0≤i<0.1, and f+g+h+i=1,
wherein the thickness of the coating layer is 1 nm to 500 nm.

2. The positive electrode active material of claim 1 , wherein the surfaces of the particles are completely surrounded by the coating layer.

3. The positive electrode active material of claim 1 , wherein the thickness of the coating layer is 1 nm to 200 nm.

4. A positive electrode for a lithium secondary battery, the positive electrode comprising the positive electrode active material according to claim 1 .

5. A lithium secondary battery comprising the positive electrode for a lithium secondary battery according to claim 4 .

6. The positive electrode active material of claim 1 , wherein the coating layer consists of the composition of Formula 3.

7. A method for preparing the positive electrode active material of claim 1 , comprising:
reacting a coating precursor preparation solution comprising a metal solution containing metal ions and a chelating agent to prepare a coating precursor, wherein the coating precursor is a complex in which the metal ions and the chelating agent are combined; and
dry-mixing particles having the composition of Formula 1 below and the coating precursor to obtain a mixture, followed by firing the mixture to form a coating layer having the composition of Formula 3 below on surfaces of the particles:
Li[Co 1-a M 1 a ]O 2   [Formula 1]

wherein, in Formula 1 above,
M 1 is one or more selected from the group consisting of B, Mg, Ca, Al, Ti, V, Cr, Fe, Zn, Ga, Y, Zr, Nb, Mo, Ta, and W, and 0≤a<0.1,
Li[Ni f Co g Mn h M 3 i ]O 2   [Formula 3]

wherein, in Formula 3 above, M 3 is one or more selected from the group consisting of B, Mg, Ca, Al, Ti, V, Cr, Fe, Zn, Ga, Y, Zr, Nb, Mo, Ta, and W, and 0<f≤0.4, 0≤g≤0.6, 0≤h≤0.6, 0≤i<0.1, and f+g+h+i=1, and
wherein the thickness of the coating layer is 1 nm to 500 nm.

8. The method of claim 7 , wherein the chelating agent is a Lewis acid compound including a carboxylic acid group or a nitrogen element.

9. The method of claim 8 , wherein the chelating agent is one or more selected from the group consisting of citric acid, polyvinylpyrrolidone, and glycolic acid.

10. The method of claim 7 , wherein the coating precursor preparation solution is prepared by adding the metal solution containing ions and the chelating agent to a solvent, followed by mixing.

11. The method of claim 10 , wherein the solvent is one or more selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 2,3-butanediol.

12. The method of claim 7 , wherein the average particle diameter (D 50 ) of the coating precursor is 1 nm to 500 nm.

13. The method of claim 7 , wherein the reacting the coating precursor preparation solution is performed at 200° C. to 300° C.

14. The method of claim 7 , wherein the firing is performed at a temperature 800° C. to 900° C.

15. The method of claim 14 , wherein the firing is performed after raising the temperature to 800° C. to 900° C. at a rate of 5° C./min to 10° C./min.

Assignees

• Lg Chemical Ltd
• Univ California
• Lg Energy Solution Ltd

Inventors

• Jo Chi Ho
• Jung Wang Mo
• Chung Hyeseung
• Meng Ying Shirley

Classifications

• H01M4/505

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

• H01M10/0525

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

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• C01P2006/40

  Electric properties · CPC title