Method of preparing positive electrode active material

Patent metadata

Field	Value
Publication number	US-12126019-B2
Application number	US-202117799752-A
Country	US
Kind code	B2
Filing date	Jun 14, 2021
Priority date	Jun 15, 2020
Publication date	Oct 22, 2024
Grant date	Oct 22, 2024

Abstract

A method of preparing a positive electrode active material is disclosed herein. In some embodiments, the method includes firing a first mixture at 400° C. to 700° C. to prepare a primary firing product, wherein the first mixture has a positive electrode active material precursor having a specific composition, a first lithium-containing source material, and optionally, an aluminum-containing source material, and firing a second mixture at a temperature above the firing temperature of the first mixture to prepare a positive electrode active material, wherein the second mixture has the primary firing product, a second lithium-containing source material, and a specific doping element M1-containing source material. The method is capable of degrading the cake strength of a primary firing product and providing a positive electrode active material having excellent quality by dividing a firing process into two steps.

First claim

The invention claimed is:

1. A method of preparing a positive electrode active material, comprising:
firing a first mixture at 400° C. to 700° C. to prepare a primary firing product, wherein the first mixture has a positive electrode active material precursor represented by the following Chemical Formula 1 or Chemical Formula 2, and a first lithium-containing source material;
pulverizing the primary firing product;
firing a second mixture at a temperature above the firing temperature of the first mixture to prepare a lithium transition metal oxide, wherein the second mixture has the pulverized primary firing product, a second lithium-containing source material, and a doping element M 1 -containing source material,
wherein the doping element M 1 -containing source material is added for the first time after the firing of the first mixture and prior to the firing of the second mixture,
wherein the doping element M 1 -containing source material contains one or more metal elements selected from among Zr, Mg, Ti, Nb, W, Sc, Si, V, Fe, Y, and Mo:
[Ni a Co b Mn c ](OH) 2   [Chemical Formula 1]

[Ni a Co b Mn c ]O·OH  [Chemical Formula 2]

wherein in Chemical Formula 1 and Chemical Formula 2,
0.6≤a<1, O<b<0.4, 0<c<0.4, and a+b+c=1.

2. The method of claim 1 , wherein the first lithium-containing source material and the second lithium-containing source material include one or more selected from the group consisting of lithium hydroxide hydrate (LiOH·H 2 O), lithium oxide (Li 2 O), lithium peroxide (Li 2 O 2 ), and lithium hydroxide anhydrate (LiOH).

3. The method of claim 1 , wherein the first lithium-containing source material is used in an amount of 70 mol % to 95 mol % with respect to the total number of moles of the first lithium-containing source material and the second lithium-containing source material.

4. The method of claim 1 , wherein the first mixture is fired under an oxygen atmosphere at an oxygen concentration of 80 wt % or more.

5. The method of claim 1 , wherein the first mixture is fired for 8 hours to 12 hours.

6. The method of claim 1 , wherein the primary firing product has a cake strength of 50 N or less.

7. The method of claim 1 , wherein the pulverizing the primary firing product comprises:
pulverizing the primary fired product using a pulverizer at a rotation speed of 800 rpm to 3000 rpm.

8. The method of claim 1 , wherein the second lithium-containing source material is used in an amount of 5 mol % to 30 mol % with respect to the total number of moles of the first lithium-containing source material and the second lithium-containing source material.

9. The method of claim 1 , wherein the second mixture is fired at 700° C. to 1000° C.

10. The method of claim 1 , wherein the second mixture is fired under an oxygen atmosphere at an oxygen concentration of 80 wt % or more.

11. The method of claim 1 , wherein the second mixture is fired for 8 hours to 12 hours.

12. The method of claim 1 , further comprising:
rinsing and drying the lithium transition metal oxide; and
thermally treating the dried lithium transition metal oxide with a coating element-containing source material a to form a coating layer on the lithium transition metal oxide.

13. The method of claim 1 , wherein the first mixture includes an aluminum-containing source material.

Assignees

• Lg Chemical Ltd

Inventors

• Kwak Ick Soon
• Chae Chang Wan
• Choi Sang Soon
• Chae Hwa Seok

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/505

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

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2004/84

  one phase coated with the other · CPC title