Silicon-based anode material, preparation method therefor and use thereof in lithium-ion battery

Patent metadata

Field	Value
Publication number	US-12406984-B2
Application number	US-202218048812-A
Country	US
Kind code	B2
Filing date	Oct 21, 2022
Priority date	Dec 12, 2017
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

A silicon-based anode material, a preparation method therefor and a use thereof in a lithium-ion battery. The silicon-based anode material comprises a silicon-based active material and a composite layer that coats the surface of the silicon-based active material, wherein the composite layer comprises a flexible polymer, flake graphite and a conductive material. The preparation method according to the present application is simple, low cost, easy to be industrialized. The prepared silicon-based anode material has excellent electrochemical cycle performance and expansion inhibition and allows prolonged service life of lithium ion batteries.

First claim

The invention claimed is:

1. A silicon-based anode material, comprising a silicon-based active material and a composite layer coated on the surface of the silicon-based active material, wherein the composite layer comprises a flexible polymer and a conductive material, wherein, the conductive material comprises flake graphite and a nano-carbon based material, wherein the flake graphite is integrally attached to the surface of the silicon-based active material, and the nano-carbon based material fills the region on the surface of the silicon-based active material that is not attached by the flake graphite, and wherein, a contact angle of the silicon-based anode material is ≤60°, wherein the contact angle is tested by the Washburn method.

2. A silicon-based anode material, comprising a silicon-based active material, a conductive material and a flexible polymer, wherein the conductive material and the flexible polymer coat on the surface of the silicon-based active material, and wherein the conductive material comprises flake graphite and a nano-carbon based material, wherein the flake graphite is integrally attached to the surface of the silicon-based active material, and the nano-carbon based material fills the region on the surface of the silicon-based active material that is not attached by the flake graphite, and wherein, a contact angle of the silicon-based anode material is ≤60°, wherein the contact angle is tested by the Washburn method.

3. A silicon-based anode material, comprising a silicon-based active material, a conductive material and a flexible polymer, wherein the conductive material comprises flake graphite and a nano-carbon based material;
the surface of the silicon-based active material attaches with the flake graphite and the nano-carbon based material;
the flexible polymer is bonded between the flake graphite and the nano-carbon based material and/or the flexible polymer is coated on the surface of the flake graphite,
wherein the flake graphite is integrally attached to the surface of the silicon-based active material, and the nano-carbon based material fills the region on the surface of the silicon-based active material that is not attached by the flake graphite, and
wherein, a contact angle of the silicon-based anode material is ≤60°, wherein the contact angle is tested by the Washburn method.

4. The silicon-based anode material according to claim 1 , wherein, the flake graphite is uniformly distributed on the surface of the silicon-based active material; and/or
the flake graphite, the nano-carbon based material and the flexible polymer form a continuous coating layer.

5. The silicon-based anode material according to claim 1 , wherein, the silicon-based active material has a particle size of 0.5 μm to 100 μm; and/or
the silicon-based active material comprises any one of Si, SiO x , or a silicon alloy, or a combination of at least two thereof, wherein 0<x≤2.

6. The silicon-based anode material according to claim 1 , wherein, the flexible polymer comprises a natural flexible polymer and/or a synthetic flexible polymer; and/or
the flexible polymer comprises any one of polyolefin and derivatives thereof, polyvinyl alcohol and derivatives thereof, polyacrylic acid and derivatives thereof, polyamide and derivatives thereof, carboxymethyl cellulose and derivatives thereof, or alginic acid and derivatives thereof, or a combination of at least two thereof, and optionally polyolefin and derivatives thereof, a combination of polyolefin and derivatives thereof with alginic acid and derivatives thereof; and/or
the flexible polymer has a weight average molecular weight of 2,000-1,000,000; and/or the flexible polymer contains a crosslinking functional group, and the crosslinking functional group comprises any one of epoxy group, carboxyl group, hydroxyl group, amino group, double bond or triple bond, or a combination of at least two thereof; and/or
the flexible polymer contains a thermal crosslinking functional group, and the thermal crosslinking functional group comprises any one of epoxy, carboxyl, hydroxyl, amino, double bond or triple bond, or a combination of at least two thereof.

7. The silicon-based anode material according to claim 1 , wherein, the flake graphite comprises natural flake graphite and/or synthetic flake graphite; and/or
the nano-carbon based material comprises any one of conductive graphite, graphene, carbon nanotubes or carbon nanofibers, or a combination of at least two thereof.

8. The silicon-based anode material according to claim 1 , wherein, based on the total mass of the silicon-based active material being 100%, the flexible polymer is present in an amount of 0-10% by mass, exclusive of 0; and/or
based on the total mass of the silicon-based active material being 100%, the flake graphite is present in an amount of 0-20% by mass, exclusive of 0; and/or
based on the total mass of the silicon-based active material being 100%, the nano-carbon based material is present in an amount of 0-5% by mass, exclusive of 0.

9. The silicon-based anode material according to claim 2 , wherein, the silicon-based active material has a particle size of 0.5 μm to 100 μm; and/or
the silicon-based active material comprises any one of Si, SiO x , or a silicon alloy, or a combination of at least two thereof, wherein 0<x≤2.

10. The silicon-based anode material according to claim 2 , wherein, the flexible polymer comprises a natural flexible polymer and/or a synthetic flexible polymer; and/or
the flexible polymer comprises any one of polyolefin and derivatives thereof, polyvinyl alcohol and derivatives thereof, polyacrylic acid and derivatives thereof, polyamide and derivatives thereof, carboxymethyl cellulose and derivatives thereof, or alginic acid and derivatives thereof, or a combination of at least two thereof, and optionally polyolefin and derivatives thereof, a combination of polyolefin and derivatives thereof with alginic acid and derivatives thereof; and/or
the flexible polymer has a weight average molecular weight of 2,000-1,000,000; and/or the flexible polymer contains a crosslinking functional group, and the crosslinking functional group comprises any one of epoxy group, carboxyl group, hydroxyl group, amino group, double bond or triple bond, or a combination of at least two thereof; and/or
the flexible polymer contains a thermal crosslinking functional group, and the thermal crosslinking functional group comprises any one of epoxy, carboxyl, hydroxyl, amino, double bond or triple bond, or a combination of at least two thereof.

11. The silicon-based anode material according to claim 2 , wherein, the flake graphite comprises natural flake graphite and/or synthetic flake graphite; and/or
the nano-carbon based material comprises any one of conductive graphite, graphene, carbon nanotubes or carbon nanofibers, or a combination of at least two thereof.

12. The silicon-based anode material according to claim 2 , wherein, based on the total mass of the silicon-based active material being 100%, the flexible polymer is present in an amount of 0-10% by mass, exclusive of 0; and/or
based on the total mass of the silicon-based active material being 100%, the flake graphite is present in an amount of 0-20% by mass, exclusive of 0; and/or
based on the total mass of the silicon-based active material being 100%, the nano-carbon based material is present in an amount of 0-5% by mass, exclusive of 0.

13. The silicon-based anode material according to claim 3 , wherein, the silicon-based active material has a particle size of 0.5 μm to 100 μm; and/or
the silicon-based active material comprises any one of Si, SiO x , or a silicon alloy, or a com

Assignees

• Btr New Mat Group Co Ltd
• Dingyuan New Energy Tech Co Ltd

Inventors

• Deng Zhiqiang
• Pang Chunlei
• Ren Jianguo
• Huang Youyuan

Classifications

• H01M4/622

  being polymers · CPC title

• H01M2004/021

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

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0525

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

• H01M4/625

  Carbon or graphite · CPC title