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-2021135187-A1
Application number	US-201916979401-A
Country	US
Kind code	A1
Filing date	May 15, 2019
Priority date	May 17, 2018
Publication date	May 6, 2021
Grant date	—

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

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, and wherein the positive electrode active material is composed of a single particle having a crystallite size of 180 nm or more.

2 . The positive electrode active material of claim 1 , wherein the positive electrode active material contains an amount of a chlorine (Cl) impurity of 20 ppm or less.

3 . 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.

4 . 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).

5 . A method of preparing a positive electrode active material for a secondary battery, 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.; and mixing 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 a lithium composite transition metal oxide composed of a single particle.

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

7 . The method of claim 5 , 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.

8 . The method of claim 5 , wherein the secondary sintering is performed at 880° C. to 980° C.

9 . The method of claim 5 , 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.

10 . The method of claim 5 , 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).

11 . The method of claim 10 , 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.

12 . The method of claim 5 , wherein primary particles of the positive electrode active material have an average particle diameter (D 50 ) of 2 μm to 10 μm.

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

Assignees

• Lg Chemical 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

• C01G53/82 Primary

  Compounds containing nickel, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01P2006/12

  Surface area · CPC title

• C01P2004/03

  obtained by SEM · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title