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-2024282928-A1
Application number	US-202218561009-A
Country	US
Kind code	A1
Filing date	Sep 19, 2022
Priority date	Oct 1, 2021
Publication date	Aug 22, 2024
Grant date	—

Abstract

A method of preparing a positive electrode active material for a lithium secondary battery which includes:
(1) mixing a lithium composite transition metal oxide in a form of a single particle or pseudo-single particle with a cobalt-containing raw material and performing a heat treatment to form a cobalt coating layer on a surface of the lithium composite transition metal oxide; and (2) mixing the lithium composite transition metal oxide having the cobalt coating layer formed thereon with a boron-containing raw material and performing a heat treatment to form a boron coating layer on the cobalt coating layer. A positive electrode active material for a lithium secondary battery which is prepared thereby, is also provided.

First claim

1 . A method of preparing a positive electrode active material for a lithium secondary battery, comprising:
(1) mixing a lithium composite transition metal oxide in the form of a single particle or a pseudo-single particle with a cobalt-containing raw material and performing a first heat treatment to form a cobalt coating layer on a surface of the lithium composite transition metal oxide; and (2) mixing the lithium composite transition metal oxide having the cobalt coating layer formed thereon with a boron-containing raw material and performing a second heat treatment to form a boron coating layer on the cobalt coating layer.

2 . The method of claim 1 , wherein the single particle is a particle composed of one primary particle, and
the pseudo-single particle is a particle composed of a secondary particle in which 30 or less primary particles are aggregated.

3 . The method of claim 1 , wherein the cobalt-containing raw material is mixed in an amount of 1 wt % to 5 wt % based on a total amount of the lithium composite transition metal oxide.

4 . The method of claim 1 , wherein the boron-containing raw material is mixed in an amount of 0.03 wt % to 0.08 wt % based on a total amount of the lithium composite transition metal oxide having the cobalt coating layer formed thereon.

5 . The method of claim 1 , wherein the first heat treatment is performed at 600° C. to 800° C.

6 . The method of claim 1 , wherein the second heat treatment is performed at 250° C. to 400° C.

7 . The method of claim 1 , wherein the lithium composite transition metal oxide is represented by Formula 1:

in Formula 1,
1.0≤a≤1.5, 0≤x≤0.2, 0≤y≤0.2, 0≤w≤0.1, and 0≤x+y≤0.4,
M1 is at least one selected from the group consisting of Mn and Al, and
M2 is at least one selected from the group consisting of Ba, Ca, Zr, Ti, Mg, Ta, Nb, and Mo.

8 . The method of claim 47 , wherein x, y, and w of Formula 1 satisfy 0.025≤x≤0.15, 0.025≤y≤0.15, 0≤w≤0.05, and 0.05≤x+y≤0.2, respectively.

9 . A positive electrode active material for a lithium secondary battery, comprising:
a lithium composite transition metal oxide in the form of a single particle or a pseudo-single particle, a cobalt coating layer formed on the lithium composite transition metal oxide, and a boron coating layer formed on the cobalt coating layer.

10 . The positive electrode active material of claim 9 , wherein the single particle is a particle composed of one primary particle, and
the pseudo-single particle is a particle composed of a secondary particle in which 30 or less primary particles are aggregated.

11 . The positive electrode active material of claim 10 , wherein the primary particle has an average particle diameter of 1 μm to 5 μm.

12 . The positive electrode active material of claim 9 , wherein the positive electrode active material has an average particle diameter of 3 μm to 10 μm.

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

wherein, in Formula 1, 1.0≤a≤1.5, 0≤x≤0.2, 0≤y≤0.2, 0≤w≤0.1, and 0<x+y≤0.4,
M1 is at least one selected from the group consisting of Mn and Al, and
M2 is at least one selected from the group consisting of Ba, Ca, Zr, Ti, Mg, Ta, Nb, and Mo.

14 . A positive electrode comprising a positive electrode active material layer which includes the positive electrode active material of claim 9 .

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

16 . A lithium secondary battery comprising the positive electrode of claim 14 and a negative electrode.

Assignees

• Lg Energy Solution Ltd

Inventors

• Jung Hae Jung
• Jung Wang Mo
• Jo Chi Ho
• Yoo Tae Gu
• Hwang Jin Tae
• Heo Jong Wook
• Cho Hyeon Jin

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/62

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

• H01M4/0471

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