Method of Preparing Positive Electrode Active Material for Lithium Secondary Battery and Positive Electrode Active Material Prepared by the Same

Patent metadata

Field	Value
Publication number	US-2022407077-A1
Application number	US-202017775694-A
Country	US
Kind code	A1
Filing date	Dec 3, 2020
Priority date	Dec 3, 2019
Publication date	Dec 22, 2022
Grant date	—

Abstract

A method of preparing a positive electrode active material includes preparing a lithium transition metal oxide containing nickel in an amount of 60 mol % or more based on a total number of moles of metals excluding lithium, impregnating the lithium transition metal oxide with 300 ppm to 1,000 ppm of moisture based on 100 parts by weight of the lithium transition metal oxide, and performing a heat treatment on the lithium transition metal oxide impregnated with the moisture, wherein a lithium by-product present on a surface of the lithium transition metal oxide and the moisture react to form a passivation layer on the surface of the lithium transition metal oxide. A positive electrode active material prepared by the above-described preparation method, and a positive electrode and a lithium secondary battery which include the positive electrode active material are also provided.

First claim

1 . A method of preparing a positive electrode active material, the method comprising:
preparing a lithium transition metal oxide containing nickel in an amount of 60 mol % or more based on a total number of moles of metals excluding lithium; impregnating the lithium transition metal oxide with 300 ppm to 1,000 ppm of moisture based on 100 parts by weight of the lithium transition metal oxide; and performing a heat treatment on the lithium transition metal oxide impregnated with the moisture, wherein a lithium by-product present on a surface of the lithium transition metal oxide and the moisture react to form a passivation layer on the surface of the lithium transition metal oxide.

2 . The method of claim 1 , wherein the lithium transition metal oxide is impregnated with 300 ppm to 500 ppm of moisture based on 100 parts by weight of the lithium transition metal oxide.

3 . The method of claim 1 , wherein the passivation layer comprises lithium carbonate.

4 . The method of claim 1 , wherein the lithium transition metal oxide is represented by Formula 1:
Li 1+a [Ni 1-x-y-w Co x M 1 y M 2 w ] 1-a O 2   [Formula 1]
wherein, in Formula 1, M 1 comprises at least one of manganese (Mn) or aluminum (Al), M 2 comprises at least one of barium (Ba), calcium (Ca), zirconium (Zr), titanium (Ti), magnesium (Mg), tantalum (Ta), niobium (Nb), or molybdenum (Mo), and 0≤a≤0.5, 0≤x≤0.4, 0≤y≤0.4, and 0≤w≤0.1.

5 . The method of claim 1 , wherein the lithium by-product present on the surface of the lithium transition metal oxide comprises at least one of Li 2 O, LiOH, or Li 2 CO 3 .

6 . The method of claim 1 , wherein the heat treatment is performed in a temperature range of 500° C. to 900° C. for 3 hours to 15 hours.

7 . The method of claim 1 , wherein the passivation layer is changed from a layered structure to a rock salt structure by the heat treatment.

8 . A positive electrode active material comprising:
a lithium transition metal oxide containing nickel in an amount of 60 mol % or more based on a total number of moles of metals excluding lithium; and a passivation layer which is disposed on a surface of the lithium transition metal oxide, has a rock salt structure, and includes lithium carbonate.

9 . The positive electrode active material of claim 8 , wherein the passivation layer has a thickness of 5 nm to 30 nm.

10 . A positive electrode for a lithium secondary battery, the positive electrode comprising the positive electrode active material of claim 8 .

11 . A lithium secondary battery comprising the positive electrode of claim 10 .

12 . The positive electrode active material of claim 8 , wherein the passivation layer is formed by reacting a lithium by-product present on the surface of the lithium transition metal oxide and moisture impregnated in the surface of the lithium transition metal oxide.

Assignees

• Lg Energy Solution Ltd

Inventors

• Han Jung Min
• Han Gi Beom
• Lee Sang Wook
• Kim Hak Yoon
• Baek So Ra
• Jung Wang Mo

Classifications

• H01M4/505

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

• C01P2004/03

  obtained by SEM · 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

• C01P2004/80

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

• H01M4/628 Primary

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title