Positive electrodes and rechargeable lithium batteries including the same

Patent metadata

Field	Value
Publication number	US-2026011726-A1
Application number	US-202519259511-A
Country	US
Kind code	A1
Filing date	Jul 3, 2025
Priority date	Jul 5, 2024
Publication date	Jan 8, 2026
Grant date	—

Abstract

A positive electrode includes a positive electrode current collector and a positive electrode active material layer located on the positive electrode current collector and including a positive electrode active material and a conductive material. The positive electrode active material includes a layered lithium nickel-manganese-based composite oxide. The positive electrode may derive a reduced amount of a required conductive material using only the information of the positive electrode active material, thereby realizing high capacity and low mixture resistance, thereby enabling the realization of a long cycle-life.

First claim

What is claimed is:

1 . A positive electrode, comprising:
a positive electrode current collector; and a positive electrode active material layer located on the positive electrode current collector and including a positive electrode active material and a conductive material; wherein the positive electrode active material comprises a layered lithium nickel-manganese-based composite oxide, and in the positive electrode active material layer, the positive electrode active material and the conductive material satisfy Equation 1:

y
=

1
.
0

⁢
9
⁢
2
⁢
3
⁢

x
2

+

0
.
1

⁢
0
⁢
2
⁢
x

+

0
.
7

⁢
4
⁢
7
⁢
1

Equation
⁢

1

wherein, in Equation 1, x is a specific surface area of the positive electrode active material, 0.13≤x≤0.63, and
y is a content of the conductive material based on 100 wt % of the positive electrode active material layer.

2 . The positive electrode as claimed in claim 1 , wherein y is in a range of about 0.8 wt % to about 1.2 wt % based on 100 wt % of the positive electrode active material layer.

3 . The positive electrode as claimed in claim 1 , wherein the layered lithium nickel-manganese-based composite oxide has a nickel content in a range of about 60 mol % to about 80 mol %, and a manganese content that is equal to or greater than about 15 mol % based on 100 mol % of a total metal excluding lithium nickel.

4 . The positive electrode as claimed in claim 1 , wherein in the layered lithium nickel-manganese-based composite oxide, a cobalt content is in a range of about 0 mol % to about 0.01 mol % based on 100 mol % of a total metal excluding lithium.

5 . The positive electrode as claimed in claim 1 , wherein the layered lithium nickel-manganese-based composite oxide is represented by Chemical Formula 1:

wherein, in Chemical Formula 1, 0.9≤a1≤1.8, 0.6≤x1≤0.8, 0.1≤y1≤0.4, 0≤z1≤0.03, 0≤w1≤0.3, 0.9≤x1+y1+z1+w1≤1.1, and 0≤b1≤0.1, M 1 comprises one or more of B, Ba, Ca, Ce, Cr, Fe, Mg, Mo, Nb, Si, Sn, Sr, Ti, V, W, Y, Zr, and Zn, and X comprises one or more of F, P, and S.

6 . The positive electrode active material as claimed in claim 1 , wherein the positive electrode active material comprises secondary particles in which a plurality of primary particles are aggregated.

7 . The positive electrode active material as claimed in claim 1 , comprising:
a first positive electrode active material having an average particle diameter (D 50 ) in a range of about 10 μm to 25 μm; and a second positive electrode active material having an average particle diameter (D 50 ) in a range of about 0.1 μm to about 5 μm.

8 . The positive electrode active material as claimed in claim 7 , wherein a weight ratio of the first positive electrode active material to the second positive electrode active material is in a range about 80:20 to about 30:70.

9 . The positive electrode active material as claimed in claim 1 , wherein the positive electrode active material has an average particle diameter (D 50 ) in a range of about 3 μm to about 15 μm.

10 . The positive electrode active material as claimed in claim 1 , wherein the conductive material comprises a linear conductive material and a spherical shape conductive material.

11 . The positive electrode active material as claimed in claim 10 , wherein a weight ratio of the linear conductive material to the spherical shape conductive material is in a range of about 10:90 to about 90:10.

12 . A method for manufacturing a positive electrode, the method comprising:
measuring an average particle diameter (D 50 ) of a positive electrode active material including a layered lithium nickel-manganese-based composite oxide using a particle size analyzer; calculating a specific surface area of the positive electrode active material using an average particle diameter (D 50 ) assuming that the positive electrode active material is spherical; substituting the specific surface area of the positive electrode active material into Equation 1 to obtain a reduced content of the conductive material; and forming a positive electrode active material layer including the positive electrode active material and the reduced content of a conductive material on a positive electrode current collector;

y
=

1
.
0

⁢
9
⁢
2
⁢
3
⁢

x
2

+

0
.
1

⁢
0
⁢
2
⁢
x

+

0
.
7

⁢
4
⁢
7
⁢
1

Equation
⁢

1

wherein, in Equation 1

Assignees

• Samsung Sdi Co Ltd

Inventors

• Park Sejeong
• Kang Younghye
• Lee Minju
• Oh Songyul
• Ko Donghyun
• Choi Kyuhwan
• Lee Boram
• Lee Junsik
• Lee Seongsun

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/021

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

• H01M10/052

  Li-accumulators · CPC title

• H01M4/13915

  containing halogen atoms, e.g. LiCoOxFy · CPC title

• H01M4/1315

  containing halogen atoms, e.g. LiCoOxFy · CPC title