Positive electrode active material, preparation method thereof, positive electrode, rechargeable lithium batteries and all-solid-state rechargeable batteries

Patent metadata

Field	Value
Publication number	US-2025026663-A1
Application number	US-202418766791-A
Country	US
Kind code	A1
Filing date	Jul 9, 2024
Priority date	Jul 21, 2023
Publication date	Jan 23, 2025
Grant date	—

Abstract

A positive electrode active material, including a first positive electrode active material including secondary particles including a lithium nickel-cobalt-aluminum composite oxide, wherein the secondary particles include an agglomeration of a plurality of primary particles and at least a portion of the plurality of primary particles are oriented radially, and a coating layer on a surface of the secondary particles, the coating layer including ZrO2 and Li6Zr2O7; and a second positive electrode active material including secondary particles including a lithium nickel-cobalt-aluminum-manganese composite oxide, wherein the secondary particles include an agglomeration of a plurality of primary particles, and a coating layer on a surface of the secondary particles, the coating layer including ZrO2 and Li6Zr2O7, wherein an average particle diameter of the secondary particles of the first positive electrode active material is larger than an average particle diameter of the secondary particles of the second positive electrode active material.

First claim

What is claimed is:

1 . A positive electrode active material, comprising:
a first positive electrode active material including:
secondary particles including a lithium nickel-cobalt-aluminum composite oxide, wherein the secondary particles include an agglomeration of a plurality of primary particles and at least a portion of the plurality of primary particles are oriented radially, and
a coating layer on a surface of the secondary particles, the coating layer including ZrO 2 and Li 6 Zr 2 O 7 ; and
a second positive electrode active material including:
secondary particles including a lithium nickel-cobalt-aluminum-manganese composite oxide, wherein the secondary particles include an agglomeration of a plurality of primary particles, and
a coating layer on a surface of the secondary particles, the coating layer including ZrO 2 and Li 6 Zr 2 O 7 ,
wherein an average particle diameter of the secondary particles of the first positive electrode active material is larger than an average particle diameter of the secondary particles of the second positive electrode active material.

2 . The positive electrode active material as claimed in claim 1 , wherein:
the average particle diameter of the secondary particles of the first positive electrode active material is about 9 μm to about 25 μm, and the average particle diameter of the secondary particles of the second positive electrode active material is about 2 μm to about 8 μm.

3 . The positive electrode active material as claimed in claim 1 , wherein, based on a total weight of the first positive electrode active material and the second positive electrode active material, the first positive electrode active material is included in an amount of about 60 wt % to about 95 wt %, and the second positive electrode active material is included in an amount of about 5 wt % to about 40 wt %.

4 . The positive electrode active material as claimed in claim 1 , wherein the coating layer of the first positive electrode active material and the coating layer of the second positive electrode active material include a ZrO 2 crystalline phase, a Li 6 Zr 2 O 7 crystalline phase, and a Zr-containing amorphous region, respectively.

5 . The positive electrode active material as claimed in claim 1 , wherein the coating layer of the first positive electrode active material and the coating layer of the second positive electrode active material are in a form of a continuous film or in a form of an island.

6 . The positive electrode active material as claimed in claim 1 , wherein a thickness of each of the coating layer of the first positive electrode active material and the coating layer of the second positive electrode active material is about 5 nm to about 300 nm.

7 . The positive electrode active material as claimed in claim 1 , wherein a total Zr content of the coating layer of the first positive electrode active material and the coating layer of the second positive electrode active material is about 0.1 parts by mole to about 0.6 parts by mole, based on 100 parts by mole of total metal excluding lithium in the lithium nickel-cobalt-aluminum composite oxide of the first positive electrode active material and the lithium nickel-cobalt-aluminum-manganese composite oxide of the second positive electrode active material.

8 . The positive electrode active material as claimed in claim 1 , wherein a total Zr content of the coating layer of the first positive electrode active material and the coating layer of the second positive electrode active material is about 0.1 wt % to about 6 wt %, based on a total weight of the positive electrode active material.

9 . The positive electrode active material as claimed in claim 1 , wherein:
the lithium nickel-cobalt-aluminum composite oxide of the first positive electrode active material is represented by Chemical Formula 1:
[Chemical Formula 1]
Li a1 Ni x1 Co y1 Al z1 M 1 w1 O 2-b1 X b1

in Chemical Formula 1, 0.9≤a1≤1.2, 0.7≤x1<1, 0<y1<0.3, 0<z1<0.3, 0≤w1<0.3, 0.9≤x1+y1+z1+w1≤1.1, 0≤b1<0.1, M 1 is B, Ba, Ca, Ce, Cr, Cu, Fe, Mg, Mo, Nb, Si, Sr, Sn, Ti, V, W, or Zr, and X is F, P, or S.

10 . The positive electrode active material as claimed in claim 1 , wherein the average particle diameter of the plurality of primary particles constituting the secondary particles of the first positive electrode active material is less than about 200 nm.

11 . The positive electrode active material as claimed in claim 1 , wherein the secondary particle of the first positive electrode active material includes an internal portion having an irregular porous structure and an external portion having a radially oriented structure as a region surrounding the internal portion.

12 . The positive electrode active material as claimed in claim 1 , wherein:
at least a portion of the plurality of primary particles constituting the secondary particles in the first positive electrode active material have a plate shape, and the secondary particles include open pores on the surface, and the open pores are formed by a space between plate-shaped primary particles oriented radially and the pores are connected from the surface of the secondary particle toward a center.

13 . The positive electrode active material as claimed in claim 1 , wherein:
the lithium nickel-cobalt-aluminum-manganese composite oxide of the second positive electrode active material is represented by Chemical Formula 2:
[Chemical Formula 2]
Li a2 Ni x2 Co y2 Al z2 Mn w2 M 2 v2 O 2-b2 X b2

in Chemical Formula 2, 0.9≤a2≤1.2, 0.7≤x2<1, 0<y2<0.3,0<z2<0.3, 0<w2<0.3, 0≤v2<0.3, 0.95x2+y2+z2+w2+v2≤1.1, 0≤b2≤0.1, M 2 is B, Ba, Ca, Ce, Cr, Cu, Fe, Mg, Mo, Nb, Si, Sr, Sn, Ti, V, W, or Zr, and X is F, P, or S.

14 . The positive electrode active material as claimed in claim 1 , wherein:
the second positive electrode active material has a higher aluminum content in a surface layer of the secondary particles than the aluminum content in an internal portion of the secondary particles, and the internal portion is a region from a center of the secondary particle to about 70 length % of a radius of the secondary particle, and the surface layer is a region surrounding the internal portion and is a region from an outermost surface of the secondary particle to a depth corresponding to about 30 length % of the radius of the secondary particle.

15 . The positive electrode active material as claimed in claim 14 , wherein:
an Al content in the surface layer of the secondary particles of the second positive electrode active material is about 0.2 at % to about 2.0 at %, based on 100 at % of total metal excluding lithium in the second positive electrode active material, and an Al content in the internal portion of the secondary particles of the second positive electrode active material is about 0 at % to about 0.6 at %, based on 100 at % of total metal excluding lithium in the second positive electrode active material.

16 . The positive electrode active material as claimed in claim 14 , wherein:
the surface layer of the secondary particles of the second positive electrode active material includes a high-concentration Al region and a low-concentration Al region, an Al content in the high-concentration Al region is about 0.8 at % to about 2.0at %, based on 100 at % of total metal excluding lithium in the second positive electrode active material, and an Al content in the low-concentration Al region is less than about 0.8 at %, based on 100 at % of total metal excluding lithium in the second positive electrode active material.

17 .

Assignees

• Samsung Sdi Co Ltd

Inventors

• Yun Pilsang
• Kim Saehwan
• Kim Do-Yu
• Kamata Yasutaka
• Byeon Pilgyu

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2300/0068

  inorganic · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• C01G53/42

  containing alkali metals, e.g. LiNiO2 · CPC title

• H01M10/0562

  Solid materials · CPC title