Method and system for silicon-dominant lithium-ion cells with controlled utilization of silicon
Systems and methods for silicon-dominant lithium-ion cells with controlled utilization of silicon may include a cathode, an electrolyte, and an anode, where the anode has an active material comprising more than 50% silicon. The battery may be charged by lithiating silicon while not lithiating carbon. The active material may comprise more than 70% silicon. A voltage of the anode during discharge of the battery may remain above a minimum voltage at which silicon can be lithiated. The anode may have a specific capacity of greater than 3000 mAh/g. The battery may have a specific capacity of greater than 1000 mAh/g. The anode may have a greater than 90% initial Coulombic efficiency and may be polymer binder free. The battery may be charged at a 10C rate or higher. The battery may be charged at temperatures below freezing without lithium plating. The electrolyte may comprise a liquid, solid, or gel.
1. A battery, the battery comprising:
a cathode, an electrolyte, and an anode, the anode having an active material comprising more than 50% by weight of silicon in the active material,
wherein the battery is chargeable to full charge by lithiating less than 100% of the silicon of the anode, and
wherein the anode is pre-lithiated, with an amount of pre-lithiation set so that a lithiation level of the anode does not decrease below a pre-determined level that is independent of discharge voltage.
2. The battery according to claim 1 , wherein the active material comprises more than 70% by weight of silicon.
3. The battery according to claim 1 , wherein a voltage of the anode during discharge of the battery remains above a minimum voltage at which silicon can be lithiated.
4. The battery according to claim 1 , wherein the anode has a specific capacity of greater than 3000 mAh/g.
5. The battery according to claim 1 , wherein the battery has a specific capacity of greater than 1000 mAh/g.
6. The battery according to claim 1 , wherein the anode has a greater than 90% of initial Coulombic efficiency.
7. The battery according to claim 1 , wherein the active material has no polymer binder.
8. The battery according to claim 1 , wherein the battery is operable to be charged at a 10C rate or higher while retaining at least 50% of 1C rate charge retention to 80% of original capacity of the battery.
9. The battery according to claim 1 , wherein the battery can be charged at temperatures below freezing temperature of water without lithium plating.
10. The battery according to claim 1 , wherein the electrolyte comprises a liquid, solid, or gel.
11. A method of forming and operating a battery, the method comprising:
forming a battery comprising a cathode, an electrolyte, and an anode, the anode having an active material comprising more than 50% by weight of silicon in the active material,
wherein the battery is chargeable to full charge by lithiating less than 100% of the silicon of the anode, and
wherein the forming comprises pre-lithiating the anode, with an amount of pre-lithiation set so that a lithiation level of the anode does not decrease below a pre-determined level that is independent of discharge voltage.
12. The method according to claim 11 , wherein the active material comprises more than 70% by weight of silicon.
13. The method according to claim 11 , comprising configuring a voltage of the anode during discharge of the battery above a minimum voltage at which silicon can be lithiated.
14. The method according to claim 11 , wherein the anode has a specific capacity of greater than 3000 mAh/g.
15. The method according to claim 11 , wherein the battery has a specific capacity of greater than 1000 mAh/g.
16. The method according to claim 11 , wherein the anode has a greater than 90% of initial Coulombic efficiency.
17. The method according to claim 11 , wherein the active material has no polymer binder.
18. The method according to claim 11 , comprising charging the battery at a 10C rate or higher.
19. The method according to claim 11 , comprising charging the battery at temperatures below freezing temperature of water without lithium plating.
20. An anode for use in a battery, the anode comprising an active material comprising more than 50% by weight of silicon in the active material, wherein the anode is chargeable to full charge when in a battery by lithiating less than 100% by weight of the silicon of the anode, and wherein the anode is pre-lithiated, with an amount of pre-lithiation set so that a lithiation level of the anode does not decrease below a pre-determined level that is independent of discharge voltage.
21. The battery according to claim 1 , wherein the battery is configured such that a voltage of the anode during discharge of the battery remains above a graphite lithiation voltage.
22. The method according to claim 11 , wherein the forming comprises selecting or adjusting a composition and/or a structure of one or both of the active material and the anode to ensure that the battery is chargeable to full charge by lithiating less than 100% by weight of the silicon of the anode.
23. The method according to claim 11 , wherein the battery is configured such that a voltage of the anode during discharge of the battery remains above a graphite lithiation voltage.
24. The anode according to claim 20 , wherein a voltage of the anode during discharge of the battery remains above a graphite lithiation voltage.