Granted Patent B2

US 12,244,004 · App. 17/614,285 · Granted Mar 4, 2025

Inventors: Yi Pan (Shenzhen, CN); Rong Hao (Shenzhen, CN); Na Chen (Shenzhen, CN); Xiaotao Yuan (Shenzhen, CN)

Assignee: BYD COMPANY LIMITED

H01M4/366H01M4/505H01M4/525H01M10/0525H01M2004/021H01M2004/028H01M2220/20

Abstract

Claims (20)

1. A composite cathode material for a lithium-ion battery, wherein a core of the cathode material is a lithium-nickel-cobalt-manganese oxide material, a surface layer of the cathode material is a lithium-nickel-cobalt oxide material doped with an element E, there is a transition layer between the core and the surface layer, the transition layer is a lithium-nickel-cobalt-manganese oxide material doped with the element E, and a content of the element E in the transition layer shows a decreasing trend in a direction from the surface layer of the cathode material to the core;

a general formula for the composition of the transition layer is Li 1+m Ni 1-x-y-z Co x Mn y E z O 2 , wherein 0≤m≤0.1, 0.01≤x≤0.1, 0.01≤y≤0.1, and 0.01≤z≤0.1;

E is one or more of Al, Zr, Ti, Y, Ba, and Sr; and

wherein with the total weight of the cathode material as a reference, the content of the transition layer accounts for 0.5% to 12% by weight.

2. The cathode material according to claim 1 , wherein the cathode material is a single crystal material.

3. The cathode material according to claim 1 , wherein a content of the element E in the surface layer accounts for 0.5% to 8% by weight of a total weight of the cathode material, and the content of the element E in the transition layer accounts for 0.05% to 5% by weight of the total weight of the cathode material.

4. The cathode material according to claim 1 , wherein a thickness of the transition layer is 5 nm to 200 nm.

5. The cathode material according to claim 1 , wherein a general formula for the composition of the core is Li 1+m Ni 1-x-y Co x Mn y O 2 , where 0≤m≤0.1, 0.01≤x≤0.1, and 0.01≤y≤0.1.

6. The cathode material according to claim 1 , wherein a molar content of nickel in the core accounts for not less than 80% of the total moles of the core.

7. The cathode material according to claim 1 , wherein the core has an average particle size of 1.5 μm to 2.5 μm.

8. The cathode material according to claim 1 , wherein with the total weight of the cathode material as a reference, a content of the core accounts for 80% to 98% by weight.

9. The cathode material according to claim 1 , wherein with the total weight of the cathode material as a reference, the content of the core accounts for 90% to 98% by weight.

10. The cathode material according to claim 1 , wherein a general formula for the composition of the surface layer is Li 1+m Ni 1-x-y1 Co x E y1 O 2 , wherein 0.01≤y1≤0.15.

11. The cathode material according to claim 1 , wherein a thickness of the surface layer is 5 nm to 50 nm.

12. The cathode material according to claim 1 , wherein with the total weight of the cathode material as a reference, a content of the surface layer accounts for at most 8% by weight.

13. The cathode material according to claim 1 , wherein the element E is Al.

14. A lithium-ion battery, wherein the lithium-ion battery comprises a cathode and an anode, and the cathode is prepared by using the cathode material according to claim 1 .

15. A vehicle, comprising the lithium-ion battery according to claim 14 .

16. The cathode material according to claim 2 , wherein a content of the element E in the surface layer accounts for 0.5% to 8% by weight of a total weight of the cathode material, and the content of the element E in the transition layer accounts for 0.05% to 5% by weight of the total weight of the cathode material.

17. The cathode material according to claim 16 , wherein a thickness of the transition layer is 5 nm to 200 nm.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (39)