Methods of forming electrochemical cells
Methods and system for forming electrochemical cells are provided. An electrochemical cell may be formed by providing an electrochemical cell that includes a first electrode and a second electrode, a separator between the first electrode and the second electrode, and an electrolyte, with at least the first electrode is a silicon-dominant electrode. A formation process may then performed, with the formation processing including charging the electrochemical cell by providing a formation charge current at about 1 C or greater to the electrochemical cell, and discharging the electrochemical cell after a rest step between the charging and the discharging.
1. A method of forming an electrochemical cell, the method comprising:
providing an electrochemical cell comprising:
a first electrode and a second electrode, wherein at least the first electrode is a silicon-dominant electrode;
a separator between the first electrode and the second electrode; and
an electrolyte; and
performing a formation process that comprises:
charging the electrochemical cell by providing a formation charge current at about 1 C or greater to the electrochemical cell; and
discharging the electrochemical cell after a rest step between the charging and the discharging.
2. The method of claim 1 , wherein the electrochemical cell has a rated capacity of 1 C.
3. The method of claim 1 , wherein the formation charge current is provided at greater than about 2 C.
4. The method of claim 1 , wherein the formation charge current is provided at less than or equal to about 20 C.
5. The method of claim 1 , wherein providing the formation charge current comprises charging to partial formation.
6. The method of claim 5 , wherein charging to partial formation comprises charging to about 10% to about 90% of total capacity of the electrochemical cell.
7. The method of claim 5 , wherein charging to partial formation comprises charging to about 20% to about 70% of the total capacity of the electrochemical cell.
8. The method of claim 5 , wherein charging to partial formation comprises charging to about 30% to about 50% of the total capacity of the electrochemical cell.
9. The method of claim 1 , wherein providing the formation charge current comprises providing a substantially constant formation charge current.
10. The method of claim 1 , wherein providing the formation charge current comprises providing the formation charge current at a charge voltage from about 3 volts to about 6 volts.
11. The method of claim 1 , wherein the electrochemical cell is a lithium-ion battery and providing the formation charge current comprises providing the formation charge current with substantially no lithium plating.
12. The method of claim 1 , wherein the first electrode is an anode.
13. The method of claim 1 , wherein the first electrode comprises silicon at about 20% to about 99% by weight of silicon.
14. The method of claim 1 , wherein the first electrode comprises silicon at about 30% to about 99% by weight.
15. The method of claim 1 , wherein the first electrode comprises silicon at about 40% to about 99% by weight.
16. The method of claim 1 , wherein the first electrode comprises silicon at about 50% to about 99% by weight.
17. The method of claim 1 , wherein the first electrode comprises silicon at about 60% to about 99% by weight.
18. The method of claim 1 , wherein the first electrode comprises silicon at about 70% to about 99% by weight.
19. The method of claim 1 , wherein the first electrode comprises silicon at about 80% to about 99% by weight.
20. The method of claim 1 , wherein the first electrode further comprises graphite.
21. The method of claim 1 , wherein the first electrode comprises a silicon-carbon composite material film.
22. The method of claim 21 , wherein the composite material film has a self-supported composite structure.
23. The method of claim 1 , wherein providing the formation charge current comprises charging to partial State of Charge (SOC).
24. The method of claim 23 , wherein charging to partial SOC comprises charging to about 30% of the total capacity of the electrochemical cell.
25. The method of claim 1 , wherein the rest step is substantially no more than 5 minutes.