Multi-cycle formation methods for secondary battery cells

{
  "publication_number": "US2024234841A1",
  "country": "US",
  "kind": "A1",
  "title": "Multi-cycle formation methods for secondary battery cells",
  "abstract": "In some aspects, a method can include applying a charge to a battery at an initial charge rate, the battery including an anode with silicon particles and graphene particles, a cathode, and a separator disposed between the anode and the cathode, the battery having a maximum voltage of V max, allowing the battery to rest for a first resting period, applying a charge to the battery at a first formation charge rate, discharging the battery at a first formation discharge rate, applying a charge to the battery at a second formation charge rate, the second formation charge rate greater than the first formation charge rate, discharging the battery at a second formation discharge rate, and applying a charge to the battery at a third formation charge rate to form the secondary battery, the third formation charge rate greater than or equal to the second formation charge rate.",
  "claims": [
    "1. A method of forming a secondary battery, the method including: applying a charge to a battery at an initial charge rate, the battery including an anode with silicon particles and graphene particles, a cathode, and a separator disposed between the anode and the cathode, the battery having a maximum voltage of V max; allowing the battery to rest for a first resting period; applying a charge to the battery at a first formation charge rate; discharging the battery at a first formation discharge rate; applying a charge to the battery at a second formation charge rate, the second formation charge rate greater than the first formation charge rate; discharging the battery at a second formation discharge rate; and applying a charge to the battery at a third formation charge rate to form the secondary battery, the third formation charge rate greater than or equal to the second formation charge rate. 2. The method of claim 1, wherein the first resting period is between about 10 minutes and about 2 hours. 3. The method of claim 1, wherein the battery is a lithium-ion battery. 4. The method of claim 1, further comprising: after discharging the battery at the first formation discharge rate, allowing the battery to rest for a second resting period, the second resting period between about 30 minutes and about 90 minutes. 5. The method of claim 4, further comprising: after discharging the battery at the second formation discharge rate, allowing the battery to rest for a third resting period, the third resting period between about 30 minutes and about 12 hours. 6. The method of claim 1, wherein applying the charge to the battery at the third discharge rate brings the battery to between about 20% and about 30% state of charge (SOC). 7. The method of claim 1, wherein the initial charge rate is about 0.015 C to about 0.025 C. 8. The method of claim 7, wherein applying the charge to the battery at the initial charge rate is for about 30 minutes to about 90 minutes. 9. The method of claim 1, wherein the first formation charge rate is between about 0.15 C and about 0.25 C. 10. The method of claim 9, wherein applying the charge to the battery at the first formation charge rate brings the battery to a voltage of about 0.96 V max to about 0.98 V max. 11. The method of claim 10, wherein the first formation discharge rate is about 0.15 C to about 0.25 C and discharging the battery at the first formation discharge rate brings the battery to a voltage of about 0.8 V max to about 0.9 V max. 12. The method of claim 11, wherein applying the charge to the battery at the first formation charge rate is for about 50 minutes to about 90 minutes. 13. The method of claim 1, wherein the second formation charge rate is between about 0.4 C and about 0.6 C. 14. The method of claim 12, wherein applying the charge to the battery at the second formation charge rate is for about 30 minutes to about 90 minutes. 15. The method of claim 13, wherein the second formation discharge rate is about 0.4 C to about 0.6 C, and discharging the battery at the second formation discharge rate brings the battery to a voltage of about 0.6 V max to about 0.7 V max. 16. The method of claim 1, wherein the secondary battery retains a capacity of at least about 70% of its initial capacity after 300 charge/discharge duty cycles. 17. A secondary battery, formed from the method of claim 1. 18. A method of forming a secondary battery, the method including: applying a charge to a battery at an initial charge rate, the battery having a maximum voltage of V max, allowing the battery to rest for a first resting period; applying a charge to the battery at a first formation charge rate; discharging the battery at a first formation discharge rate; allowing the battery to rest for a second resting period; applying a charge to the battery at a second formation charge rate, the second formation charge rate greater than the first formation charge rate; discharging the battery at a second formation discharge rate; and applying a charge to the battery at a third formation charge rate to form the secondary battery, the third formation charge rate greater than or equal to the second formation charge rate. 19. The method of claim 18, wherein the initial charge rate is at a rate of about 0.04 C to about 0.06 C. 20. The method of claim 18, wherein the first resting period is between about 1 hour and about 3 hours. 21. The method of claim 18, wherein the first formation charge rate is a variable charge rate, such that the first formation charge rate increases from a first value to a second value. 22. The method of claim 21, wherein the first value is about 0.06 C and the second value is about 0.12 C. 23. The method of claim 18, wherein the second resting period is between about 14 hours and about 16 hours. 24. The method of claim 18, wherein the second formation charge rate includes a constant current charging phase and a constant voltage charging phase. 25. The method of claim 18, wherein discharging the battery at the second formation discharge rate includes discharging the battery to a SOC between about 60% and about 80%. 26. The method of claim 18, wherein the third formation charge rate is between about 0.4 C to about 0.6 C."
  ],
  "cpc": [
    "H01M 10/446",
    "H01M 10/0525",
    "H01M 10/44",
    "H01M 4/0447",
    "H01M 4/133",
    "H01M 4/134",
    "H01M 4/386",
    "H01M 4/587",
    "Y02E 60/10"
  ],
  "assignees": [
    "VoltaXplore Inc"
  ],
  "filing_date": "2024-01-09",
  "publication_date": "2024-07-11",
  "priority_date": "2023-01-10",
  "application_number": "US-202418407666-A",
  "family_id": "91760896"
}