Positive electrode active material for lithium secondary battery and method for producing the same

Patent metadata

Field	Value
Publication number	US-12304834-B2
Application number	US-202017773983-A
Country	US
Kind code	B2
Filing date	Nov 12, 2020
Priority date	Nov 13, 2019
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

A positive electrode active material includes a lithium transition metal oxide having a spinel crystal structure, and a coating layer positioned on the surface of the lithium transition metal oxide, wherein the coating layer has an orthorhombic structure, and includes an oxide represented by Formula 1. A method for producing the positive electrode active material, a positive electrode including the positive electrode active material, and a lithium secondary battery, the positive electrode active material.

First claim

The invention claimed is:

1. A positive electrode active material comprising:
a lithium transition metal oxide having a spinel crystal structure; and
a coating layer positioned on a surface of the lithium transition metal oxide,
wherein the coating layer has an orthorhombic structure, and includes an oxide represented by Formula 1 below:
Li 2+x Ni 1−y M1 y O 2+z   [Formula 1]

wherein in Formula 1 above, 0≤x≤0.2, 0<y≤0.5, and 0≤z≤0.2, and M1 includes one or more selected from the group consisting of Cu, Mg, Pt, Al, Co, P, and B, and wherein
the oxide represented by Formula 1 belongs to an Immm space group.

2. The positive electrode active material of claim 1 , wherein the coating layer has a thickness of 1 nm to 20 nm.

3. The positive electrode active material of claim 1 , wherein, in the Formula 1, 0≤x≤0.1, 0.3≤y≤0.5, and 0≤z≤0.05.

4. The positive electrode active material of claim 1 , wherein M1 comprises copper.

5. The positive electrode active material of claim 1 , wherein the oxide represented by Formula 1 is Li 2 Cu 0.5 Ni 0.5 O 2 .

6. The positive electrode active material of claim 1 , wherein the oxide represented by Formula 1 has lattice parameters of 3.7 Å<a<3.8 Å, 2.6 Å<b<2.8 Å, and 9.0 Å<c<9.3 Å.

7. The positive electrode active material of claim 1 , wherein the lithium transition metal oxide is represented by Formula 2 below:
Li 1+a1 Mn 2−x1 M 2 x1 O 4−y1 A y1   [Formula 2]

wherein in Formula 2 above, M 2 is one or more elements selected from the group consisting of Ni, Co, and Al, A is one or more elements selected from the group consisting of F, Cl, Br, I, At, and S, and 0≤a1≤0.2, 0≤x1≤0.5, and 0≤y1≤0.1.

8. A method for producing a positive electrode active material, the method comprising:
preparing a lithium transition metal oxide having a spinel crystal structure; and
forming a coating layer, which has an orthorhombic structure and includes an oxide represented by Formula 1 below, on a surface of the lithium transition metal oxide in a wet manner:
Li 2+x Ni 1−y M1 y O 2+z   [Formula 1]

wherein in Formula 1 above, 0≤x≤0.2, 0<y≤0.5, and 0≤z≤0.2, and M1 includes one or more selected from the group consisting of Cu, Mg, Pt, Al, Co, P, and B, and wherein the oxide represented by Formula 1 belongs to an Immm space group.

9. The method of claim 8 , wherein the forming of the coating layer is performed by mixing the lithium transition metal oxide and the oxide represented by Formula 1 in a solvent, followed by removing the solvent and then performing heat-treatment.

10. The method of claim 9 , wherein the lithium transition metal oxide and the oxide represented by Formula 1 are mixed at a weight ratio of 100:1 to 100:10.

11. The method of claim 9 , wherein the heat-treatment is performed at a temperature of 200° C. to 600° C.

12. A positive electrode for a lithium secondary battery comprising the positive electrode active material of claim 1 .

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

Assignees

• Lg Energy Solution Ltd

Inventors

• Lim Sung Chul
• Jang Min Chul
• Kim Il Hong
• Uhm In Sung
• Jung Byoung Hyo

Classifications

• C01P2006/40

  Electric properties · CPC title

• C01P2002/32

  spinel-type (AB2O4) · CPC title

• C01G53/42 Primary

  containing alkali metals, e.g. LiNiO2 · CPC title

• C01G45/1242

  of the type (Mn2O4)-, e.g. LiMn2O4 or Li(MxMn2-x)O4 · CPC title

• C01P2004/80

  Particles consisting of a mixture of two or more inorganic phases · CPC title