Granted Patent B2

US 12,391,575 · App. 17/683,570 · Granted Aug 19, 2025

Inventors: Shushi Dou (Ningde, CN); Chunhua Hu (Ningde, CN); Yao Jiang (Ningde, CN); Qi Wu (Ningde, CN); Jinhua He (Ningde, CN); Bin Deng (Ningde, CN)

Assignee: CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED

C01G53/50H01M10/0525C01P2002/54C01P2004/61C01P2006/10C01P2006/11C01P2006/12C01P2006/40

Abstract

Claims (24)

1. A positive electrode active material, comprising secondary particles formed by agglomeration of primary particles, wherein the primary particles comprise a layered nickel-containing lithium composite oxide, and the nickel-containing lithium composite oxide comprises a doping element; and

when the positive electrode active material is charged from an 11% delithiated state to a 78% delithiated state at a rate of 0.1 C, a lattice of the primary particles has a maximum shrinkage rate satisfying Δa max ≤3.00% in an a-axis direction, and a maximum swelling rate satisfying Δc max ≤3.02% in a c-axis direction;

wherein a relative deviation of a local mass concentration of the doping element in the secondary particles is less than 30%; and

wherein a true doping concentration φ of the positive electrode active material satisfies 2300 μg/cm 3 ≤φ≤49000 μg/cm 3 .

2. The positive electrode active material according to claim 1 , wherein a molar percentage of nickel in elements at a transition metal site of the nickel-containing lithium composite oxide is 50% to 95%.

3. The positive electrode active material according to claim 1 , wherein

when a molar percentage of nickel in elements at a transition metal site of the nickel-containing, lithium composite oxide is 50% to 60% and the positive electrode active material is charged from an 11% delithiated state to a 78% delithiated state at a rate of 0.1 C, a lattice of the primary particles has a maximum shrinkage rate satisfying Δa max ≤2.69% in an a-axis direction, and a maximum swelling rate satisfying Δc max ≤2.75% in a c-axis direction; or

when a molar percentage of nickel in elements at a transition metal site of the nickel-containing, lithium composite oxide is greater than 60% and less than or equal to 90% and the positive electrode active material is charged from an 11% delithiated state to a 78% delithiated state at a rate of 0.1 C, a lattice of the primary particles has a maximum shrinkage rate satisfying Δa max ≤2.85% in an a-axis direction, and a maximum swelling rate satisfying Δc max ≤2.93% in a c-axis direction.

4. The positive electrode active material according to claim 1 , wherein the doping element comprises a first doping element doping the transition metal site of the nickel-containing lithium composite oxide; and

when the positive electrode active material is in the 78% delithiated state, the first doping element has a valence higher than or equal to +3.

5. The positive, electrode active material according to claim 4 , wherein the first doping element is selected from one or more of Si, Ti, V, Ge, Se, Zr, Nb, Ru, Pd, Rh, Sb, Te, Ce, and W.

6. The positive electrode active material according to claim 1 , wherein the doping element comprises a second doping element doping an oxygen site of the nickel-containing lithium composite oxide, and the second doping element is selected from one or more of F, N, P, and S.

7. The positive electrode active material according to claim 1 , wherein a deviation ε of a mass concentration of the doping element in the positive electrode active material relative to an average mass concentration of the doping element in the secondary particles satisfies ε<50%.

8. The positive electrode active material according, to claim 1 , wherein a true density ρ true of the positive electrode active material satisfies 4.6 g/cm 3 ≤ρ true ≤4.9 g/cm 3 .

9. The positive electrode active material according to claim 1 , wherein the positive electrode active material also satisfies one or more of the following requirements (1) to (4):

(1) a volume average particle size D v 50 of the positive electrode active material is 5 μm to 20 μm;

(2) a specific surface area of the positive electrode active material is 0.2 m 2 /g to 1.5 m 2 /g,

(3) tap density of the positive electrode active material is 2.3 g/cm 3 to 2.8 g/cm 3 ; and

(4) compacted density of the positive electrode active material under a pressure of 5 tons (equivalent to 49 kN) is 3.1 g/cm 3 to 3.8 g/cm 3 .

10. The positive electrode active material according to claim 1 , wherein

the nickel-containing lithium composite oxide satisfies a chemical formula Li 1+m [Ni x Co y Mn z M p ]O 2−q X q , wherein M and X are the doping elements, M is selected from one or more of Si, Ti, V, Ge, Se, Zr, Nb, Ru, Pd, Rh, Sb, Te, Ce, and W, X is selected from one or more of F, N, P, and S, 0.5≤x≤1, 0≤y<0.3, 0≤z<0.3, −0.1≤m<0.2, 0≤p<0.3, 0≤q<0.2, x+y+z+p=1, and p and q are not 0 simultaneously; or

the nickel-containing lithium composite oxide satisfies a chemical formula Li 1+n [Ni r−d Co s Mn t M′ d ]O 2−v X′ v , wherein M′ and X′ are the doping elements, M′ is selected from one or more of Si, Ti, Ge, Se, Zr, Nb, Ru, Pd, Rh, Sb, Te, Ce, and W, X′ is selected from one or more of F, N, P, and S, 0.5≤r−d<1, 0≤s<0.3, 0≤t<0.3, −0.1≤n<0.2, 0≤d<0.3, 0≤v<0.2, r+s+t=1, and d and v are not 0 simultaneously.

11. A positive electrode plate, comprising a positive electrode current collector and a positive electrode active substance layer disposed on the positive electrode current collector, wherein the positive electrode active substance layer comprises the positive electrode active material according to claim 1 .

12. A lithium-ion secondary battery, comprising the positive electrode plate according to claim 11 .

Assignments (2)

Priority Claims (1)

Continuity (2)

References Cited (22)