Cathode material and manufacturing method thereof, lithium ion battery, and vehicle

Patent metadata

Field	Value
Publication number	US-12145860-B2
Application number	US-201917259106-A
Country	US
Kind code	B2
Filing date	Jul 10, 2019
Priority date	Jul 10, 2018
Publication date	Nov 19, 2024
Grant date	Nov 19, 2024

Abstract

A cathode material, a preparation method thereof, a lithium ion battery and a vehicle are provided. The cathode material comprises elemental sulfur and secondary particles formed by packing primary particles, wherein the secondary particles have a hollow structure, and the elemental sulfur fills in gaps among the primary particles and in the hollow structure. The primary particles comprise a lithium oxide, wherein the lithium oxide comprises δLiNi m Co n X (1-m-n) O 2 :(1−δ)Li 2 MO 3 , 0≤δ≤1, X comprises at least one selected from Mn, Al, Nb, and Fe, M comprises at least one of Mn, Al, Nb, Fe, Co, and Ni, 0≤m<1, 0≤n<1, and 0≤m+n<1.

First claim

What is claimed is:

1. A cathode material, comprising elemental sulfur and secondary particles, wherein
each of the secondary particles is formed by packing primary particles and has a hollow structure and gaps among the primary particles, a coating is formed on an outer surface of each of the secondary particles, and the coating comprises titanium dioxide,
the elemental sulfur fills in the gaps among the primary particles and in the hollow structure of each of the secondary particles, wherein a content of elemental sulfur in the hollow structure is higher than a content of elemental sulfur in the gaps among the primary particles, and
the primary particles comprise a lithium oxide, wherein the primary particles are selected from at least one of rod-shaped lithium oxide and bulk lithium oxide, the primary particles have a length of 0.5-2 μm, a width of 200-500 nm, and an aspect ratio of 2-40, a weight ratio of the lithium oxide, the elemental sulfur of the cathode material, and the titanium dioxide is (90-45):(5-50):(2-8), the lithium oxide comprises δLiNi m Co n X (1-m-n) O 2 ·(1−δ)Li 2 MO 3 , X comprises at least one selected from Mn, Al, Nb, and Fe, M comprises at least one of Mn, Al, Nb, Fe, Co, and Ni, 0<δ≤1, 0≤m<1, 0≤n<1, and 0<m+n<1.

2. The cathode material according to claim 1 , wherein the secondary particles have an average particle size of 5-50 μm, and the hollow structure has an average pore size of 2-10 μm.

3. The cathode material according to claim 1 , wherein the secondary particles comprise a shell layer for defining the hollow structure, and the shell layer is formed by packing the primary particles and has an average thickness of 1-10 μm.

4. The cathode material according to claim 1 , wherein based on a total weight of the cathode material, the content of elemental sulfur in the hollow structure is 5-40 wt %, and the content of elemental sulfur in the gaps among the primary particles is 0-15 wt %.

5. The cathode material according to claim 1 , wherein the gaps among the primary particles have a length of 0.02-1 μm.

6. The cathode material according to claim 1 , wherein the secondary particles are at least one of a spherical, rhombic and ellipsoidal shape.

7. The cathode material according to claim 1 , wherein the secondary particles have a porosity of 20-30%.

8. The cathode material according to claim 1 , wherein based on a total weight of the cathode material, a content of the coating is 0.1 to 10 wt %.

9. The cathode material according to claim 1 , wherein the coating further comprises at least one of carbon, tin dioxide, manganese dioxide, tricobalt tetraoxide, vanadium pentoxide, iron disulfide, copper disulfide, cobalt disulfide, or bismuth trisulfide.

10. A method for preparing a cathode material, comprising:
stirring and adding a solution containing metal ions, a complexing agent, and a precipitating agent to a reactor, co-precipitating at a pH of 11-12 to form a primary particle precursor, forming a core precursor by packing the primary particle precursor, and forming a secondary particle precursor by further packing the primary particle precursor at a pH of 9-10.5;
mixing the secondary particle precursor with a lithium source, and baking to obtain secondary particles having a hollow structure; and
mixing the secondary particles with a sulfur source, melting and solidifying, to fill elemental sulfur into the hollow structure, wherein
the secondary particles have a shell layer for defining the hollow structure, and the shell layer is formed by packing the primary particles, and
the primary particles comprise lithium oxide comprising δLiNi m Co n X (1-m-n) O 2 :(1−δ)Li 2 MO 3 , in which, X comprises at least one selected from Mn, Al, Nb, and Fe, M comprises at least one selected from Mn, Al, Nb, Fe, Co, and Ni, 0<δ≤1, 0<m<1, 0≤n<1, and 0<m+n<1;
wherein the solution containing metal ions comprises one or more of a solution containing Mn ions, a solution containing Al ions, a solution containing Nb ions, a solution containing Fe ions, a solution containing Co ions, and a solution containing Ni ions;
the complexing agent comprises aqueous ammonia; and
the precipitating agent comprises one or two of potassium hydroxide and sodium hydroxide.

11. The method according to claim 10 , wherein a time for co-precipitation at a pH of 11-12 is 2-6 hours, and a time for packing at a pH of 9-10.5 is 10-25 hours.

12. The method according to claim 10 , wherein the secondary particles and the sulfur source are mixed at a weight ratio of (8-12):(0.5-2), a temperature for the melting and solidification is 120° C.-180° C., and a time for the melting and solidification is 10-15 hours.

13. A lithium ion battery, comprising a cathode material comprising elemental sulfur and secondary particles, wherein
each of the secondary particles is formed by packing primary particles and has a hollow structure and gaps among the primary particles, a coating is formed on an outer surface of each of the secondary particles, and the coating comprises titanium dioxide,
the elemental sulfur is filled in the gaps among the primary particles and in the hollow structure of each of the secondary particles, wherein a content of elemental sulfur in the hollow structure is higher than a content of elemental sulfur in the gaps among the primary particles, and
the primary particles comprise a lithium oxide, wherein the primary particles are selected from at least one of rod-shaped lithium oxide and bulk lithium oxide, the primary particles have a length of 0.5-2 μm, a width of 200-500 nm, and an aspect ratio of 2-40, a weight ratio of the lithium oxide, the elemental sulfur of the cathode material, and the titanium dioxide is (90-45):(5-50):(2-8), the lithium oxide comprises δLiNi m Co n X (1-m-n) O 2 ·(1−δ)Li 2 MO 3 , X comprises at least one selected from Mn, Al, Nb, and Fe, M comprises at least one of Mn, Al, Nb, Fe, Co, and Ni, Fe, Co, and Ni, 0<δ≤1, 0<m<1, 0≤n<1, and 0<m+n<1.

14. The lithium ion battery according to claim 13 , wherein the secondary particles have an average particle size of 5-50 μm, and the hollow structure has an average pore size of 2-10 μm.

15. The lithium ion battery according to claim 13 , wherein the secondary particles comprise a shell layer for defining the hollow structure, and the shell layer is formed by packing the primary particles and has an average thickness of 1−10 μm.

16. The lithium ion battery according to claim 13 , wherein based on a total weight of the cathode material, the content of elemental sulfur in the hollow structure is 5-40 wt %, and the content of elemental sulfur in the gaps among the primary particles is 0-15 wt %.

17. The lithium ion battery according to claim 13 , wherein the gaps among the primary particles have a length of 0.02-1 μm.

18. The lithium ion battery according to claim 13 , wherein the secondary particles are at least one of a spherical, rhombic and ellipsoidal shape.

19. The lithium ion battery according to claim 13 , wherein the secondary particles have a porosity of 20-30%.

20. The lithium ion battery according to claim 13 , wherein based on a total weight of the cathode material, a content of the coating is 0.1 to 10 wt %.

Assignees

• Byd Co Ltd

Inventors

• Hu Dongjie
• Wei Hao

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M10/0525

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

• H01M4/525

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