Positive Electrode Active Material for Lithium Secondary Battery and Method for Producing the Same

Patent metadata

Field	Value
Publication number	US-2022363561-A1
Application number	US-202017773983-A
Country	US
Kind code	A1
Filing date	Nov 12, 2020
Priority date	Nov 13, 2019
Publication date	Nov 17, 2022
Grant date	—

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

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.

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 the oxide represented by Formula 1 belongs to an Immm space group.

4 . 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.

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

6 . 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 .

7 . 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.

8 . 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.

9 . 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.

10 . The method of claim 9 , 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.

11 . The method of claim 10 , 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.

12 . The method of claim 10 , wherein the heat-treatment is performed at a temperature of 200° C. to 600° C.

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

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

Assignees

• Lg Energy Solution Ltd

Inventors

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

Classifications

• H01M4/505

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

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• C01P2004/80

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

• C01P2006/40

  Electric properties · CPC title

• C01P2002/32

  spinel-type (AB2O4) · CPC title