Positive electrode active material for secondary battery, method of preparing the same, and lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-12308415-B2
Application number	US-201916979401-A
Country	US
Kind code	B2
Filing date	May 15, 2019
Priority date	May 17, 2018
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

The present invention relates to a positive electrode active material for a secondary battery which includes a lithium composite transition metal oxide including nickel (Ni), cobalt (Co), and manganese (Mn), wherein the lithium composite transition metal oxide includes the nickel (Ni) in an amount of 65 mol % or more and the manganese (Mn) in an amount of 5 mol % or more based on a total amount of transition metals, and wherein the electrode positive active material is composed of a single particle, having a crystallite size of 180 nm or more.

First claim

The invention claimed is:

1. A positive electrode active material for a secondary battery, the positive electrode active material comprising:
a lithium composite transition metal oxide including nickel (Ni), cobalt (Co), and manganese (Mn),
wherein the lithium composite transition metal oxide comprises the nickel (Ni) in an amount of 65 mol % or more and the manganese (Mn) in an amount of 5 mol % or more based on a total amount of transition metals,
wherein the positive electrode active material comprises a single particle having a crystallite size of 180 nm or more, wherein the single particle is polycrystalline and wherein the single particle is a primary particle,
wherein the positive electrode active material contains an amount of a chlorine (Cl) impurity of 20 ppm or less, and
wherein the positive active material has an average particle diameter (D 50 ) of from 3 μm to 7 μm.

2. The positive electrode active material claim 1 , wherein the positive electrode active material contains an amount of residual lithium by-products of 0.5 wt % or less based on a total weight of the positive electrode active material.

3. The positive electrode active material claim 1 , wherein the positive electrode active material produces a main peak with a maximum heat flow at 235° C. or more when the positive electrode active material is thermally analyzed by differential scanning calorimetry (DSC).

4. A method of preparing the positive electrode active material of claim 1 , the method comprising:
preparing a precursor including nickel (Ni), cobalt (Co), and manganese (Mn) in which an amount of the nickel (Ni) is 65 mol % or more and an amount of the manganese (Mn) is 5 mol % or more based on a total amount of transition metals;
pre-sintering the precursor at 600° C. to 800° C. to form a pre-sintered precursor; and
forming a mixture of the pre-sintered precursor with a lithium raw material and performing secondary sintering on the mixture at a temperature of 850° C. or more to form the lithium composite transition metal oxide.

5. The method of claim 4 , wherein the pre-sintering is performed for 4 hours to 8 hours.

6. The method of claim 4 , wherein the precursor is a secondary particle which is formed by aggregation of primary particles, and the secondary particle has an average particle diameter (D 50 ) of 3 μm to 6 μm.

7. The method of claim 4 , wherein the secondary sintering is performed at 880° C. to 980° C.

8. The method of claim 4 , wherein the lithium raw material is mixed with the pre-sintered precursor such that a molar ratio (Li/M) of lithium (Li) to total metallic elements (M) excluding lithium of the lithium composite transition metal oxide is in a range of 0.98 to 1.05.

9. The method of claim 4 , wherein the secondary sintering is performed after mixing the pre-sintered precursor and the lithium raw material with a particle growth promoter including at least one particle growth-promoting element selected from the group consisting of: strontium (Sr), zirconium (Zr), magnesium (Mg), yttrium (Y), and aluminum (Al).

10. The method of claim 9 , wherein the particle growth-promoting element is included in the positive electrode active material in an amount of 500 ppm to 2,000 ppm based on a total weight of the positive electrode active material.

11. The method of claim 4 , wherein primary particles of the positive electrode active material have an average particle diameter (D 50 ) of 2 μm to 10 μm.

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

Assignees

• Lg Chemical Ltd
• Lg Energy Solution Ltd

Inventors

• Park Sung Bin
• Lee Dong Hun
• Cho Hyung Man
• Han Jung Min
• Hwang Jin Tae
• Jung Wang Mo

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/505

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

• H01M4/364

  as mixtures · CPC title