Method and system for thermal gradient during electrode pyrolysis

Patent metadata

Field	Value
Publication number	US-11600809-B2
Application number	US-202117562390-A
Country	US
Kind code	B2
Filing date	Dec 27, 2021
Priority date	Nov 8, 2019
Publication date	Mar 7, 2023
Grant date	Mar 7, 2023

Abstract

Systems and methods for thermal gradient during electrode pyrolysis may include fabricating the battery electrode by pyrolyzing an active material on a metal current collector, wherein the active material comprises silicon particles in a binder material, the binder material being pyrolyzed such that a resistance at an inner surface of the active material in contact with the current collector is at least 50% higher than a resistance at an outer surface of the active material. The active material may be pyrolyzed by electromagnetic radiation, which may be provided by one or more lasers, which may include one or more CO 2 lasers. The electromagnetic radiation may be provided by one or more infrared lamps. An outer edge of the current collector may be gripped using a thermal transfer block that removes heat from the current collector during pyrolysis of the active material and subsequent cool down.

First claim

The invention claimed is:

1. A battery electrode, the electrode comprising:
a metal current collector and active material formed on one or more surfaces of the current collector, wherein the active material comprises silicon particles in a binder material, the binder material being pyrolyzed such that a density of the pyrolyzed binder at an inner surface of the active material in contact with the current collector is higher than a density of the pyrolyzed binder at an outer surface of the active material.

2. The electrode according to claim 1 , wherein the active material is pyrolyzed by electromagnetic radiation.

3. The electrode according to claim 2 , wherein the electromagnetic radiation is supplied by one or more lasers.

4. The electrode according to claim 3 , wherein the one or more lasers comprises one or more CO 2 lasers.

5. The electrode according to claim 2 , wherein the electromagnetic radiation is supplied by one or more infrared lamps.

6. The electrode according to claim 2 , wherein the electromagnetic radiation is microwave radiation.

7. The electrode according to claim 1 , wherein a thermal transfer block grips an outer edge of the current collector and removes heat from the current collector during pyrolysis of the active material and subsequent cool down.

8. The electrode according to claim 1 , wherein heat transfer plates, sheets, or foils are placed on or adjacent to the active material during pyrolysis.

9. The electrode according to claim 8 , wherein the electrode and heat transfer plates, sheets, or foils are wound into a spiral.

10. The electrode according to claim 1 , wherein the metal current collector comprises one or more of: copper, nickel, and aluminum.

11. The electrode according to claim 1 , wherein the active material comprises more than 50% silicon.

12. The system according to claim 1 , wherein the density of the pyrolyzed binder is 50% higher at the inner surface compared to the outer surface.

13. A method of forming a battery electrode, the method comprising:
fabricating the battery electrode by pyrolyzing an active material on a metal current collector, wherein the active material comprises silicon particles in a binder material, the binder material being pyrolyzed such that a density of the pyrolyzed binder at an inner surface of the active material in contact with the current collector is greater than a density of the pyrolyzed binder at an outer surface of the active material.

14. The method according to claim 13 , comprising pyrolyzing the active material using electromagnetic radiation.

15. The method according to claim 14 , comprising providing the electromagnetic radiation using one or more lasers.

16. The method according to claim 15 , wherein the one or more lasers comprises one or more CO 2 lasers.

17. The method according to claim 14 , comprising providing the electromagnetic radiation using one or more infrared lamps.

18. The method according to claim 14 , wherein the electromagnetic radiation is microwave radiation.

19. The method according to claim 13 , comprising gripping an outer edge of the current collector using a thermal transfer block that removes heat from the current collector during pyrolysis of the active material and subsequent cool down.

20. The method according to claim 13 , comprising placing heat transfer plates, sheets, or foils on or adjacent to the active material during pyrolysis.

21. The method according to claim 20 , wherein the electrode and heat transfer plates, sheets, or foils are wound into a spiral.

22. The method according to claim 13 , wherein the metal current collector comprises one or more of: copper, nickel, and aluminum.

23. The method according to claim 13 , wherein the active material comprises more than 50% silicon.

24. The method according to claim 13 , wherein the density of the pyrolyzed binder is 50% higher at the inner surface compared to the outer surface.

25. A method of forming a battery electrode, the method comprising:
heat treating an active material on a metal current collector, wherein the active material comprises silicon particles in a binder material, the active material being at least twice as dense at an inner surface in contact with the metal current collector than at an outer surface of the active material; and
cooling the current collector by gripping an outer edge of the current collector using a thermal transfer block that removes heat from the current collector during heat treatment of the active material and subsequent cool down.

Assignees

• Enevate Corp

Inventors

• Pestana Jill Renee
• Park Benjamin
• Buet Michael
• Canton Giulia

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/0471 Primary

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/622

  being polymers · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title