Cathode material, and electrochemical device including the same

Patent metadata

Field	Value
Publication number	US-11936042-B2
Application number	US-202017252144-A
Country	US
Kind code	B2
Filing date	Mar 31, 2020
Priority date	Jul 19, 2019
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

A cathode material includes: a plurality of first particles. Each first particle includes a secondary particle composed of a plurality of third particles, and the first particle includes a first lithium-containing transition metal oxide; and a plurality of second particles. The second particle includes a fourth particle and/or a secondary particle composed of a plurality of fourth particles, and the second particle includes a second lithium-containing transition metal oxide. The electrochemical device including the cathode material is significantly improved in the aspects of energy density, capacity attenuation and service life.

First claim

What is claimed is:

1. A cathode material, comprising:
a plurality of first particles, wherein each first particle comprises a secondary particle composed of a plurality of third particles, each third particle is a first primary particle, the plurality of first particles have an average particle diameter of 8 μm to 20 μm, the plurality of third particles have an average particle diameter of 200 nm to 700 nm, and the first particle comprises a first lithium-containing transition metal oxide; and
a plurality of second particles, wherein each second particle comprises a fourth particle and/or a secondary particle composed of a plurality of fourth particles, the fourth particle is a second primary particle, the second particle has an average particle diameter of 3 μm to 5 μm, the fourth particle has an average particle diameter of 800 nm to 5 μm, and the second particle comprises a second lithium-containing transition metal oxide,
wherein a ratio of the average particle diameter of the plurality of first particles to the average particle diameter of the plurality of third particles is 20 to 50; and
wherein a ratio D s /D p is 0.15 to 0.7, D s is an average particle diameter of the plurality of second particles, and D p is an average particle diameter of the plurality of first particles.

2. The cathode material according to claim 1 , wherein the first particle comprises 150 to 2000 third particles, the second particle is a secondary particle, and the second particle comprises 2 to 100 fourth particles.

3. The cathode material according to claim 1 , wherein a mass percentage of the second particles in the cathode material is 5% to 50%.

4. The cathode material according to claim 1 , wherein a peak intensity ratio of the (003) diffraction peak of the X-ray diffraction of the second particles to that of the first particles is 1.03 to 1.6, a difference between full width at half maximum of the (003) diffraction peak of the X-ray diffraction of the first particles and that of the second particles being 0.003° to 0.008°.

5. The cathode material according to claim 1 , wherein the first particles have a specific surface area of 0.10 m 2 /g to 1.50 m 2 /g, and the second particles have a specific surface area of 0.30 m 2 /g to 2.50 m 2 /g.

6. The cathode material according to claim 1 , wherein the first lithium-containing transition metal oxide has the general formula of Li α Ni x Co y M1 z N1 β O 2 , wherein 0.95≤α≤1.05, 0.5≤x<1, 0<y<0.4, 0<z<0.4, 0≤β≤0.05, and x+y+z+β=1, M1 is selected from at least one of Mn or Al, and N1 is selected from at least one of Mg, Ti, Zr, Nb, Y, Cr, V, Ge, Mo or Sr.

7. The cathode material according to claim 6 , wherein a surface of the first lithium-containing transition metal oxide further comprises a first coating element and a boron element, the first coating element is selected from at least one of Al, La, Y, Zr, Ti, Ce or F, and based on the total molar amount of the transition metal elements in the first lithium-containing transition metal oxide, a molar percentage of the first coating element is 0.1% to 0.5%, and a molar percentage of the boron element is 0.1% to 0.5%.

8. The cathode material according to claim 1 , wherein the second lithium-containing transition metal oxide has the general formula of Li n Ni a Co b M2 c N2 d O 2 , wherein 0.95≤a≤1.05, 0.5≤a<1, 0<b<0.4, 0<c<0.4, 0≤d≤0.02 and a+b+c+d=1, M2 is selected from at least one of Mn or Al, and N2 is selected from at least one of Mg, Ti, Zr, Nb, Y, Cr, V, Ge, Mo or Sr.

9. The cathode material according to claim 8 , wherein a surface of the second lithium-containing transition metal oxide further comprises a boron element, and based on the total molar amount of the transition metal elements in the second lithium-containing transition metal oxide, a molar percentage of the boron element is 0.1% to 0.5%.

10. An electrochemical device, comprising a cathode, wherein the cathode comprises a cathode material, wherein the cathode material comprises:
a plurality of first particles, wherein each first particle comprises a secondary particle composed of a plurality of third particles, each third particle is a first primary particle, the plurality of first particles have an average particle diameter of 8 μm to 20 μm, the plurality of third particles have an average particle diameter of 200 nm to 700 nm, and the first particle comprises a first lithium-containing transition metal oxide; and
a plurality of second particles, wherein each second particle comprises a fourth particles and/or a secondary particle composed of a plurality of fourth particles, the fourth particle is a second primary particle, the second particle has an average particle diameter of 3 μm to 5 μm, the fourth particle has an average particle diameter of 800 nm to 5 μm, and the second particle comprises a second lithium-containing transition metal oxide,
wherein a ratio of the average particle diameter of the plurality of first particles to the average particle diameter of the plurality of third particles is 20 to 50; and
wherein a ratio D s /D p is 0.15 to 0.7, D s is an average particle diameter of the plurality of second particles, and D p is an average particle diameter of the plurality of first particles.

11. The electrochemical device according to claim 10 , wherein the first particle comprises 150 to 2000 third particles, the second particle is a secondary particle, and the second particle comprises 2 to 100 fourth particles.

12. The electrochemical device according to claim 10 , wherein a mass percentage of the second particles in the cathode material is 5% to 50%.

13. The electrochemical device according to claim 10 , wherein a peak intensity ratio of the (003) diffraction peak of the X-ray diffraction of the second particles to that of the first particles is 1.03 to 1.6, a difference between full width at half maximum of the (003) diffraction peak of the X-ray diffraction of the first particles and that of the second particles being 0.003° to 0.008°.

14. The electrochemical device according to claim 10 , wherein the first particles have a specific surface area of 0.10 m 2 /g to 1.50 m 2 /g, and the second particles have a specific surface area of 0.30 m 2 /g to 2.50 m 2 /g.

15. The electrochemical device according to claim 10 , wherein the first lithium-containing transition metal oxide has the general formula of Li α Ni x Co y M1 z N1 β O 2 , wherein 0.95≤α≤1.05, 0.5≤x<1, 0<y<0.4, 0<z<0.4, 0β≤0.05, and x+y+z+β=1, M1 is selected from at least one of Mn or Al, and N1 is selected from at least one of Mg, Ti, Zr, Nb, Y, Cr, V, Ge, Mo or Sr, a surface of the first lithium-containing transition metal oxide further comprises a first coating element and a boron element, the first coating element is selected from at least one of Al, La, Y, Zr, Ti, Ce or F, and based on the total molar amount of the transition metal elements in the first lithium-containing transition metal oxide, a molar percentage of the first coating element is 0.1% to 0.5%, and a molar percentage of the boron element is 0.1% to 0.5%.

16. The electrochemical device according to claim 15 , wherein the second lithium-containing transition metal oxide has the general formula of Li n Ni a Co b M2 c N2 d O 2 , wherein 0.95≤n≤1.05, 0.5≤a<1, 0<b<0.4, 0<c<0.4, 0≤d≤0.02, and a+b+c+d=1, M2 is selected from at least one of Mn or Al, and N2 is selected from at least one of Mg, Ti, Zr, Nb, Y, Cr, V, Ge, Mo or Sr, a surface of the second lithium-containing transition metal oxide further comprises a boron element, and based on the total molar amount of the transition metal elements in the second lithium-contain

Assignees

• Ningde Amperex Technology Ltd

Inventors

• Liu Wenyuan
• Peng Gang
• Lang Ye
• Xu Leimin

Classifications

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/364 Primary

  as mixtures · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title