Method and system for thermal gradient during electrode pyrolysis
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 more than 75% at an outer surface and less than 50% at an inner surface in contact with the current collector. 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. Heat transfer plates may be placed on or adjacent to the active material during pyrolysis.
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 more than 75% at an outer surface of the active material and less than 50% at an inner surface of the active material in contact with the current collector.
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 electrode according to claim 1 , wherein the active material is more than 50% more resistive at the inner surface than at the outer surface.
13. The system according to claim 1 , wherein a density of the pyrolyzed binder is 50% higher at the inner surface compared to the outer surface.
14. 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 more than 75% at an outer surface of the active material and less than 50% at an inner surface of the active material in contact with the current collector.
15. The method according to claim 14 , comprising pyrolyzing the active material using electromagnetic radiation.
16. The method according to claim 15 , comprising providing the electromagnetic radiation using one or more lasers.
17. The method according to claim 16 , wherein the one or more lasers comprises one or more CO 2 lasers.
18. The method according to claim 15 , comprising providing the electromagnetic radiation using one or more infrared lamps.
19. The method according to claim 15 , wherein the electromagnetic radiation is microwave radiation.
20. The method according to claim 14 , 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.
21. The method according to claim 14 , comprising placing heat transfer plates, sheets, or foils on or adjacent to the active material during pyrolysis.
22. The method according to claim 21 , wherein the electrode and heat transfer plates, sheets, or foils are wound into a spiral.
23. The method according to claim 14 , wherein the metal current collector comprises one or more of: copper, nickel, and aluminum.
24. The method according to claim 14 , wherein the active material comprises more than 50% silicon.
25. The method according to claim 14 , active material is more than 50% more resistive at the inner surface than at the outer surface.
26. The method according to claim 14 , wherein a density of the pyrolyzed binder is 50% higher at the inner surface compared to the outer surface.
27. 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 more than 50% more resistive at an inner surface in contact with the metal current collector than 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.