Granted Patent B2

US 12,438,151 · App. 17/371,231 · Granted Oct 7, 2025

Inventors: Qian Liu (Ningde, CN); Yongsheng Guo (Ningde, CN); Chengdu Liang (ningde, CN); Wenguang Lin (Ningde, CN)

Assignee: Contemporary Amperex Technology (Hong Kong) Limited

H01M4/505H01M4/0471H01M4/525H01M10/054H01M2004/021H01M2004/028

Abstract

Claims (31)

1. A positive electrode active material, satisfying a chemical formula Na 2+x Cu h Mn k M l O 7-y , wherein Mis one or more selected from Li, B, Mg, Al, K, Ca, Ti, V, Cr, Fe, Co, Ni, Zn, Ga, Sr, Y, Nb, Mo, Sn, Ba and W, 0≤x≤0.5, 0.1<h≤2, 1≤k≤3, 0≤l≤0.5, and 0≤y≤1, 3.0≤h+k+l≤3.1, and 0.7≤(2+x)/(h+k+l)≤0.73, and

wherein the positive electrode active material has a powder resistivity of from 10 Ω·cm to 3kΩ·cm at a pressure of 12 MPa,

wherein the positive electrode active material has a specific surface area of from 0.01 m 2 /g to 3 m 2 /g; and,

wherein the positive electrode active material has a mean particle size D V 50 of from 7 μm to 25 μm.

2. The positive electrode active material according to claim 1 , wherein in the chemical formula, 0.5≤h≤1.5, 1.5≤k≤2.5.

3. The positive electrode active material according to claim 1 , wherein in the chemical formula, k/(h+l)≥1.4.

4. The positive electrode active material according to claim 1 , wherein the positive electrode active material is of a triclinic phase crystal structure or a hexagonal phase crystal structure.

5. The positive electrode active material according to claim 4 , wherein the positive electrode active material comprises a first diffraction peak at an X-ray diffraction angle 2θ of from 15.8° to 16.0° and a second diffraction peak at an X-ray diffraction angle 2θ of from 32.0° to 32.2°, and an intensity ratio of the first diffraction peak to the second diffraction peak is from 5 to 30, the first diffraction peak has a full width at half maxima of from 0.02° to 0.5°, and the second diffraction peak has a full width at half maxima of from 0.02° to 0.5°.

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

the positive electrode active material has a tap density of from 0.5 g/cm 3 to 3.5 g/cm 3 ; and/or,

the positive electrode active material has a compaction density of from 2.5 g/cm 3 to 4.5 g/cm 3 at a pressure of 8 tons.

7. The positive electrode active material according to claim 1 , wherein the positive electrode active material has a first discharge voltage plateau of from 3.8V to 4.1V and a second discharge voltage plateau of from 3.4V to 3.7V.

8. The positive electrode active material according to claim 7 , wherein the positive electrode active material has a discharge capacity of Q 1 at the first discharge voltage plateau, a discharge capacity of Q 2 at the second discharge voltage plateau, and a full discharge capacity of Q, and Q 1 , Q 2 and Q satisfy:

30%≤( Q 1 +Q 2 )/ Q× 100%≤90%.

9. A method for preparing a positive electrode active material, comprising the following steps:

providing a mixed solution, wherein the mixed solution comprises copper salts and manganese salts, and salts containing an M element are present in the mixed solution in an amount of 0 or more;

adding a precipitant and a complexing agent into the mixed solution, and then subjecting it to coprecipitation to obtain a precursor; and

mixing the precursor and a sodium source to obtain a mixture and sintering the mixture to obtain the positive electrode active material,

wherein the positive electrode active material satisfies a chemical formula Na 2+x Cu h Mn k M l O 7-y , wherein M is one or more selected from of Li, B, Mg, Al, K, Ca, Ti, V, Cr, Fe, Co, Ni, Zn, Ga, Sr, Y, Nb, Mo, Sn, Ba and W; 0≤x≤0.5, 0.1<h≤2, 1≤k≤3, 0≤l≤0.5, 0≤y≤1, 3.0≤h+k+l≤3.1, and 0.7≤(2+x)/(h+k+l)≤0.73, and

wherein the positive electrode active material has a powder resistivity of from 10 Ω·cm to 3 kΩ·cm at a pressure of 12 MPa,

wherein the positive electrode active material has a specific surface area of from 0.01 m 2 /g to 3 m 2 /g; and,

wherein the positive electrode active material has a mean particle size D V 50 of from 7 μm to 25 μm.

10. A sodium-ion battery, comprising a positive electrode plate, wherein the positive electrode plate comprises a positive electrode active material satisfying a chemical formula Na 2+x Cu h Mn k M l O 7-y , wherein M is one or more selected from Li, B, Mg, Al, K, Ca, Ti, V, Cr, Fe, Co, Ni, Zn, Ga, Sr, Y, Nb, Mo, Sn, Ba and W, 0≤x≤0.5, 0.1<h≤2, 1≤k≤3, 0≤l≤0.5, and 0≤y≤1, 3.0≤h+k+l≤3.1, and 0.7≤(2+x)/(h+k+l)≤0.73, and

wherein the positive electrode active material has a powder resistivity of from 10 Ω·cm to 3kΩ·cm at a pressure of 12 MPa,

wherein the positive electrode active material has a specific surface area of from 0.01 m 2 /g to 3 m 2 /g; and,

wherein the positive electrode active material has a mean particle size D V 50 of from 7 μm to 25 μm.

11. The sodium-ion battery according to claim 10 , wherein in the chemical formula, 0.5≤h≤1.5, 1.5≤k≤2.5.

12. The sodium-ion battery according to claim 10 , wherein in the chemical formula, k/(h+l)≥1.4.

13. The sodium-ion battery according to claim 10 , wherein the positive electrode active material is of a triclinic phase crystal structure or a hexagonal phase crystal structure.

14. The sodium-ion battery according to claim 13 , wherein the positive electrode active material comprises a first diffraction peak at an X-ray diffraction angle 2θ of from 15.8° to 16.0° and a second diffraction peak at an X-ray diffraction angle 2θ of from 32.0° to 32.2°, and an intensity ratio of the first diffraction peak to the second diffraction peak is from 5 to 30, the first diffraction peak has a full width at half maxima of from 0.02° to 0.5°, and the second diffraction peak has a full width at half maxima of from 0.02° to 0.5°.

15. The sodium-ion battery according to claim 10 , wherein the positive electrode active material has a first discharge voltage plateau of from 3.8V to 4.1V and a second discharge voltage plateau of from 3.4V to 3.7V.

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (25)