Lower pyrolysis temperature binder for silicon-dominant anodes

Patent metadata

Field	Value
Publication number	US-11296311-B2
Application number	US-202016745404-A
Country	US
Kind code	B2
Filing date	Jan 17, 2020
Priority date	Nov 12, 2019
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

Systems and methods are provided for carbon additives for direct coating of silicon-dominant anodes. An example composition for use in directly coated anodes may include a silicon-dominated anode active material, a carbon-based binder, and a carbon-based additive, with the composition being configured for low-temperature pyrolysis. The low-temperature pyrolysis may be conducted at <600° C. An anode may be formed using a direct coating process of the composition on a current collector. The anode active material yields silicon constituting between 86% and 97% of weight of the formed anode after pyrolysis. The carbon-based additive yields carbon constituting between 2% and 6% of weight of the formed anode after pyrolysis.

First claim

What is claimed is:

1. A method of forming an anode of a battery, the method comprising:
mixing a composition comprising a silicon-dominated anode active material, a carbon-based binder, and a carbon-based additive;
coating a conductive foil with the composition; and
subjecting the coated conductive foil to a pyrolysis process in a temperature range that is greater than 500° C. and less than 600° C., wherein the pyrolysis process pyrolyzes the composition coated on the conductive foil resulting in the silicon-dominated anode active material of the pyrolyzed composition comprising at least 86% by weight of the formed anode.

2. The method according to claim 1 , comprising forming a lithium ion battery using the formed anode comprising the pyrolyzed composition.

3. The method according to claim 1 , wherein the carbon-based binder comprises polyamide-imide (PAI).

4. The method according to claim 1 , wherein an onset of pyrolysis of the composition on the conductive foil occurs below 500° C.

5. The method according to claim 1 , wherein carbonization of the composition on the conductive foil occurs at less than 600° C.

6. The method according to claim 1 , wherein the silicon-dominated anode active material comprises up to 97% by weight of the formed anode.

7. The method according to claim 1 , wherein the carbon-based binder of the pyrolyzed composition comprises between 4% and 5% by weight of the formed anode.

8. The method according to claim 1 , wherein the carbon-based additive of the pyrolyzed composition comprises between 2% and 6% by weight of the formed anode.

9. The method according to claim 1 , wherein the carbon-based additive comprises at least one of ECP, ECP600, Super-P, and SLP.

10. A method of forming an anode of a battery, the method comprising:
mixing a composition comprising an active material comprising silicon, and a binder that pyrolyzes at a temperature of 500° C. and higher;
coating a conductive foil with the composition; and
pyrolyzing the binder by subjecting the coated conductive foil to a temperature that is greater than 500° C. and less than 600° C., wherein, after pyrolyzing the binder, the silicon in the active material comprises at least 86% by weight of the formed anode.

11. The method according to claim 10 , comprising forming a lithium ion battery using the formed anode comprising the pyrolyzed binder.

12. The method according to claim 10 , wherein the binder comprises polyamide-imide (PAI).

13. The method according to claim 10 , wherein an onset of pyrolysis of the binder occurs below 500° C.

14. The method according to claim 10 , wherein carbonization of the binder occurs at less than 600° C.

15. The method according to claim 10 , wherein the silicon comprises up to 97% by weight of the formed anode.

16. The method according to claim 10 , wherein the pyrolyzed binder comprises carbon between 4% and 5% by weight of the formed anode.

17. The method according to claim 10 , wherein the composition includes a carbon-based additive and the carbon-based additive comprises between 2% and 6% of weight of the formed anode.

18. The method to claim 17 , wherein the carbon-based additive comprises at least one of ECP, ECP600, Super-P, and SLP.

Assignees

• Enevate Corp

Inventors

• Chhorng Monika
• Lee David J
• Kamath Rahul

Classifications

• 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

• H01M4/622 Primary

  being polymers · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title