Anode slurry and method for preparing the same

Patent metadata

Field	Value
Publication number	US-10431819-B2
Application number	US-201615378031-A
Country	US
Kind code	B2
Filing date	Dec 13, 2016
Priority date	Dec 14, 2015
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

The present invention provides a method for preparing an anode slurry used in a lithium ion battery. The method includes the following steps: providing at least one anode active material, at least one conductive agent, at least one monomer or a prepolymer and at least one solvent. Mixing the anode active material, the conductive agent and the monomer or the prepolymer with the solvent; dispersing uniformly to form a mixture. Adding an initiator into the mixture; polymerizing the monomer or the prepolymer at a certain temperature; and yielding the anode slurry. Besides, the present invention also provides an anode slurry prepared by the above method, and an anode plate prepared by the anode slurry, and a lithium ion battery including the anode plate.

First claim

What is claimed is:

1. A method for preparing an anode slurry used in a lithium ion battery, comprising: providing at least one anode active material, at least one conductive agent, at least one monomer or prepolymer, and at least one solvent; mixing the anode active material, the conductive agent and the monomer or prepolymer with the solvent, dispersing uniformly to form a dispersion; and adding an initiator into the dispersion and therefore inducing a polymerization of the monomer or the prepolymer, thereby yielding an anode slurry; the monomer is at least one selected from the group consisting of acrylic acid, methacrylic acid and itaconic acid; the prepolymer is selected from at least one of acrylic prepolymers, methacrylic acid prepolymer, and itaconic acid prepolymer; wherein said polymerization of the monomer or prepolymer is induced prior to coating onto a current collector.

2. The method of claim 1 , wherein the anode active material comprises silicon, which is at least one selected from the group consisting of silicon powder, nano-silicon particles, and silicon-carbon composite.

3. The method of claim 2 , wherein an average particle diameter of the silicon powder or the nano-silicon particles is between 20 nm and 2000 nm.

4. The method of claim 2 , wherein an average particle diameter of the silicon-carbon composite is between 1 μm and 100 μm.

5. The method of claim 1 , wherein a BET specific surface area of the anode active material is from 1 cm 2 /g to 100 cm 2 /g.

6. The method of claim 1 , wherein an initial coulombic efficiency of the anode active material is greater than 50%.

7. The method of claim 1 , wherein the solvent is water and/or organic solvent, the organic solvent is alcoholic solvent or ketone solvent.

8. The method of claim 7 , wherein the organic solvent is at least one selected from methanol, ethanol and acetone.

9. The method of claim 1 , wherein the conductive agent is at least one selected from the group consisting of carbon power, carbon fiber, conductive carbon black, carbon nanotube, flaky graphite and graphene; a mass of the conductive agent accounts for 0.1% to 5% of the total mass of the anode slurry.

10. The method of claim 1 , wherein the initiator is at least one selected from the group consisting of sodium persulfate, potassium persulfate and ammonium persulfate; a mass of the initiator accounts for 0.1% to 5% of the total mass of the anode slurry.

11. The method of claim 1 , wherein a mass of the anode active material accounts for 5% to 50% of the total mass of the anode slurry.

12. The method of claim 1 , wherein a mass of the monomer or prepolymer accounts for 5% to 50% of the total mass of the anode slurry.

13. The method of claim 1 , wherein a mass of the solvent accounts for 20% to 85% of the total mass of the anode slurry.

14. The method of claim 1 , wherein a temperature of polymerization is between 30° C. to 120° C.

15. The method of claim 14 , wherein the temperature of polymerization is between 50° C. to 100° C.

16. The method of claim 14 , wherein the temperature of polymerization is between 65° C. to 85° C.

17. The method of claim 1 , wherein a reaction time of the polymerization is between 1 to 10 hours.

18. The method of claim 17 , wherein the reaction time of the polymerization is between 2 to 6 hours.

19. The method of claim 17 , wherein the reaction time of the polymerization is between 2 to 4 hours.

20. The method of claim 1 , wherein a viscosity of the anode slurry prepared above is 1000 to 8000 mPa·s.

Assignees

• Microvast Power Systems Co Ltd
• Ochem Chemical Co Ltd

Inventors

• Mattis Wenjuan Liu
• Deng Tianshu
• Hu Ruanbing
• Ning Chaofeng

Classifications

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• C08F2/16

  Aqueous medium · CPC title

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• C08F120/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• H01M10/0525

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