Positive active material for rechargeable lithium battery, preparing method thereof and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-12322791-B2
Application number	US-202418603865-A
Country	US
Kind code	B2
Filing date	Mar 13, 2024
Priority date	May 28, 2021
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

Disclosed are a positive active material for a rechargeable lithium battery, a method of preparing the same, and a rechargeable lithium battery including the same. The positive active material includes a first positive active material in a form of secondary particles including a plurality of primary particles that are aggregated together, and a second positive active material having a single particle form, wherein both of the first positive active material and the second positive active material are nickel-based positive active materials, each of the first positive active material and the second positive active material is coated with cobalt, and a maximum roughness of a surface of the second positive active material is greater than or equal to about 15 nm.

First claim

What is claimed is:

1. A positive active material for a rechargeable lithium battery, comprising:
a first positive active material in a form of secondary particles comprising a plurality of primary particles that are aggregated together, and
a second positive active material having a single particle form,
wherein both of the first positive active material and the second positive active material are nickel-based positive active materials,
each of the first positive active material and the second positive active material is coated with cobalt, and
the second positive active material has protrusions and depressions on the surface of the single particle, and
wherein:
a maximum roughness (R max ; peak to peak height) of a surface of the second positive active material is greater than or equal to about 15 nm.

2. The positive active material of claim 1 , wherein cobalt-containing compound is linearly or atypically attached to the surface of the single particle of the second positive active material.

3. The positive active material of claim 1 , wherein:
an average roughness (R a ) of the surface of the second positive active material is greater than or equal to about 1.5 nm, and/or
a root mean square roughness (R q ) of the surface of the second positive active material is greater than or equal to about 2.0 nm.

4. The positive active material of claim 1 , wherein a BET specific surface area of the positive active material including the first positive active material and the second positive active material is about 0.3 m 2 /g to about 0.6 m 2 /g.

5. The positive active material of claim 1 , wherein:
an average particle diameter of the first positive active material is about 7 μm to about 25 μm, and
an average particle diameter of the second positive active material is about 1 μm to about 10 μm.

6. The positive active material of claim 1 , wherein the first positive active material is included in an amount of about 50 wt % to about 90 wt %, and the second positive active material is included in an amount of about 10 wt % to about 50 wt % based on the total amount of the first positive active material and the second positive active material.

7. The positive active material of claim 1 , wherein:
the first positive active material comprises a compound represented by Chemical Formula 1, and
the second positive active material comprises a compound represented by Chemical Formula 11:

wherein, in Chemical Formula 1, 0.9≤a1≤1.8, 0.3≤x1≤1, 0≤y1≤0.7, and M 1 and M 2 are each independently selected from Al, B, Ba, Ca, Ce, Co, Cr, Cu, F, Fe, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr, and a combination thereof,

wherein, in Chemical Formula 11, 0.9≤a11≤1.8, 0.3≤x11≤1, 0≤y11≤0.7, and M 11 and M 12 are each independently selected from Al, B, Ba, Ca, Ce, Co, Cr, Cu, F, Fe, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr, and a combination thereof.

8. A rechargeable lithium battery comprising:
a positive electrode including the positive active material of claim 1 , a negative electrode, and an electrolyte.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Jang Jungsue
• Kil Donghyun
• Kim Minhan
• Kim Jinyoung
• Kim Jinhwa
• Seog Jihyun
• Shim Jaeha
• Ahn Kiyong
• Chang Donggyu
• Chae Youngjoo
• Choi Aram
• Ha Jeuk

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/021

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

• H01M4/505

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

• H01M4/366 Primary

  as layered products · CPC title