Cathode active material, cathode for lithium secondary battery, and lithium secondary battery

Patent metadata

Field	Value
Publication number	US-2025233132-A1
Application number	US-202519015464-A
Country	US
Kind code	A1
Filing date	Jan 9, 2025
Priority date	Jan 17, 2024
Publication date	Jul 17, 2025
Grant date	—

Abstract

A cathode active material includes a core containing a first active material, a lithium-rich oxide, and a shell disposed on a surface of the core and containing a second active material having an olivine structure. Weight % of the first active material is greater than or equal to weight % of the second active material based on a total weight of the cathode active material. A cathode for a lithium secondary battery having excellent lifespan performance may be provided.

First claim

What is claimed is:

1 . A cathode active material comprising:
a core containing a first active material, a lithium-rich oxide; and a shell disposed on a surface of the core and containing a second active material having an olivine structure, wherein weight % of the first active material is greater than or equal to weight % of the second active material based on a total weight of the cathode active material.

2 . The cathode active material of claim 1 , wherein the first active material is represented by chemical formula 1: Li a [M x Ni y Mn z ]O b , where M is at least one element selected from the group consisting of Co, Mg, Ti, Al, Fe, Ru, Zr, W, Sn, Nb, Mo, Cu, Zn, Cr, Ga, V and Bi, 0≤x≤0.9, 0≤y≤0.9, x+y>0, 0.1≤z≤0.9, 1.8≤a+x+y+z≤2.2, 1.05≤a/(x+y+z)≤1.95, and 1.8≤b≤2.2.

3 . The cathode active material of claim 1 , wherein the second active material is represented by chemical formula 2: LiMePO 4 , where Me is at least one element selected from the group consisting of Co, Ni, Fe, and Mn.

4 . The cathode active material of claim 1 , wherein the second active material includes a carbon coating layer on a surface thereof.

5 . The cathode active material of claim 1 , wherein a weight ratio of the first active material and the second active material based on the total weight of the cathode active material is 60:40 to 95:5.

6 . The cathode active material of claim 1 , wherein a BET specific surface area of the first active material is 0.9 m 2 /g to 2.0 m 2 /g.

7 . The cathode active material of claim 1 , wherein an average particle diameter D50 of the first active material is equal to or greater than an average particle diameter D50 of the second active material.

8 . The cathode active material of claim 7 , wherein the average particle diameter D50 of the first active material is 5 μm to 12 μm.

9 . The cathode active material of claim 7 , wherein the average particle diameter D50 of the second active material is 0.3 μm to 5 μm.

10 . A cathode for a secondary battery, comprising:
a cathode active material, wherein the cathode active material includes a core containing a first active material which is a lithium-rich oxide; and a shell disposed on a surface of the core and containing a second active material having an olivine structure, and weight % of the first active material is greater than or equal to weight % of the second active material based on a total weight of the cathode active material.

11 . The cathode of claim 10 , wherein the first active material is represented by chemical formula 1: Li a [M x Ni y Mn z ]O b , where M is at least one element selected from the group consisting of Co, Mg, Ti, Al, Fe, Ru, Zr, W, Sn, Nb, Mo, Cu, Zn, Cr, Ga, V and Bi, 0≤x≤0.9, 0≤y≤0.9, x+y>0, 0.1≤z≤0.9, 1.8≤a+x+y+z≤2.2, 1.05≤a/(x+y+z)≤1.95, and 1.8≤b≤2.2.

12 . The cathode of claim 10 , wherein the second active material is represented by chemical formula 2: LiMePO 4 , where Me is at least one element selected from the group consisting of Co, Ni, Fe, and Mn.

13 . The cathode of claim 10 , wherein the second active material includes a carbon coating layer on a surface thereof.

14 . The cathode of claim 10 , wherein a weight ratio of the first active material and the second active material based on the total weight of the cathode active material is 60:40 to 95:5.

15 . The cathode of claim 10 , wherein a BET specific surface area of the first active material is 0.9 m 2 /g to 2.0 m 2 /g.

16 . The cathode of claim 10 , wherein an average particle diameter D50 of the first active material is equal to or greater than an average particle diameter D50 of the second active material.

17 . The cathode of claim 16 , wherein the average particle diameter D50 of the first active material is 5 μm to 12 μm.

18 . The cathode of claim 16 , wherein the average particle diameter D50 of the second active material is 0.3 μm to 5 μm.

19 . A lithium secondary battery comprising the cathode for a lithium secondary battery according to claim 10 .

Assignees

• Sk On Co Ltd

Inventors

• Park Young Uk
• Kang Hyun Sung
• Beak Min Cheol
• Kang Min Suk
• Kim Seung Hyun
• Do Ji Yae

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/1397

  of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title