Methods for prelithiation of silicon containing electrodes
The present application describes a method of forming an energy storage device that directly adds a lithium layer (such as a lithium foil or otherwise deposited lithium) into the cell stack during cell assembly for prelithiating. The method includes providing a silicon-based anode, providing a cathode, positioning a separator between the anode and the cathode, and disposing a lithium layer between the silicon-based anode and the separator, such that the lithium layer is in contact with the anode.
1. A method of forming an energy storage device comprising:
providing a Si-based anode;
providing a cathode;
providing a separator comprising a lithium layer on a surface of the separator;
positioning the separator between the anode and the cathode, such that the lithium layer is in contact with the anode; and
applying a clamping pressure to the energy storage device across the anode, the cathode, and the separator, wherein the clamping pressure is applied for at least 10 hours.
2. The method of claim 1 , wherein the lithium layer comprises lithium deposited on the surface of the separator.
3. The method of claim 2 , wherein the lithium is deposited on the surface of the separator by spraying powder lithium onto the surface or sputtering lithium onto the surface.
4. The method of claim 1 , wherein the lithium layer comprises a lithium foil applied to the surface of the anode.
5. The method of claim 1 , wherein the lithium layer comprises an amount of lithium for 10% to 30% of anode capacity.
6. The method of claim 1 , wherein the separator is resistant to reduction by the lithium.
7. The method of claim 1 , wherein the separator is made of a material selected from the group consisting of polyolefin, cellulose, and combinations thereof.
8. The method of claim 7 , wherein the polyolefin is selected from polyethylene, polypropylene, and combinations thereof.
9. The method of claim 1 , wherein the separator further comprises a surface coating between the surface of the separator and the lithium layer.
10. The method of claim 1 , further comprises forming a safety layer on at least the lithium layer.
11. The method of claim 10 , wherein the safety layer comprises a polymeric material.
12. The method of claim 11 , wherein the polymeric material is selected from the group consisting of polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), styrene butadiene rubber (SBR), poly(acrylic acid) (PAA), poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), and combinations thereof.
13. The method of claim 1 , wherein the clamping pressure is between 20 psi and 160 psi.
14. The method of claim 1 , wherein the anode is a Si-dominant anode.
15. The method of claim 1 , wherein the anode comprises a composite material film comprising:
greater than 0% and less than 90% by weight of silicon particles, and
greater than 0% and less than 90% by weight of one or more types of carbon phases, wherein at least one of the one or more types of carbon phases is to a greater extent continuous phase that holds the composite material film together such that the silicon particles are distributed throughout the composite material film.
16. The method of claim 15 , wherein at least a portion of the composite material film has a self-supported monolithic structure.
17. A method of forming an energy storage device comprising:
providing a Si-based anode;
providing a cathode;
providing a separator comprising a lithium layer on a surface of the separator;
positioning the separator between the anode and the cathode, such that the lithium layer is in contact with the anode; and
applying a clamping pressure to the energy storage device across the anode, the cathode, and the separator, wherein the clamping pressure is applied for at least 3 hours and is no greater than 160 psi.
18. The method of claim 17 , wherein the lithium layer comprises lithium deposited on the surface of the separator.
19. The method of claim 18 , wherein the lithium is deposited on the surface of the separator by spraying powder lithium onto the surface or sputtering lithium onto the surface.
20. The method of claim 17 , wherein the lithium layer comprises a lithium foil applied to the surface of the anode.
21. The method of claim 17 , wherein the lithium layer comprises an amount of lithium for 10% to 30% of anode capacity.
22. The method of claim 17 , wherein the separator is resistant to reduction by the lithium.
23. The method of claim 17 , wherein the separator is made of a material selected from the group consisting of polyolefin, cellulose, and combinations thereof.
24. The method of claim 23 , wherein the polyolefin is selected from polyethylene, polypropylene, and combinations thereof.
25. The method of claim 17 , wherein the separator further comprises a surface coating between the surface of the separator and the lithium layer.
26. The method of claim 17 , further comprises forming a safety layer on at least the lithium layer.
27. The method of claim 26 , wherein the safety layer comprises a polymeric material.
28. The method of claim 27 , wherein the polymeric material is selected from the group consisting of polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), styrene butadiene rubber (SBR), poly(acrylic acid) (PAA), poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), and combinations thereof.
29. The method of claim 17 , wherein the anode is a Si-dominant anode.
30. The method of claim 17 , wherein the anode comprises a composite material film comprising:
greater than 0% and less than 90% by weight of silicon particles, and
greater than 0% and less than 90% by weight of one or more types of carbon phases, wherein at least one of the one or more types of carbon phases is to a greater extent continuous phase that holds the composite material film together such that the silicon particles are distributed throughout the composite material film.
31. The method of claim 30 , wherein at least a portion of the composite material film has self-supported monolithic structure.