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 10 C 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 - 20 . (canceled)
21 . A battery, the battery comprising:
a cathode, an electrolyte, and an anode, the anode having an active material comprising more than 50% 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 a voltage of the anode at full charge of the cell does not drop below a level where graphite is significantly lithiated.
22 . The battery according to claim 21 , wherein the active material comprises more than 70% silicon.
23 . The battery according to claim 21 , wherein a voltage of the anode during discharge of the battery remains above a minimum voltage at which silicon can be lithiated.
24 . The battery according to claim 21 , wherein the anode has a specific capacity of greater than 3000 mAh/g.
25 . The battery according to claim 21 , wherein the battery has a specific capacity of greater than 1000 mAh/g.
26 . The battery according to claim 21 , wherein the anode has a greater than 90% initial Coulombic efficiency.
27 . The battery according to claim 21 , wherein the active material has no polymer binder.
28 . The battery according to claim 21 , wherein the battery is operable to be charged at a 10 C rate or higher while retaining at least 50% of 1 C rate charge retention to 80% of original capacity of the battery.
29 . The battery according to claim 21 , wherein the battery can be charged at temperatures below freezing temperature of water without lithium plating.
30 . The battery according to claim 21 , wherein the electrolyte comprises a liquid, solid, or gel.
31 . 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% silicon in the active material,
wherein the forming comprises providing or configuring the battery such that the battery is chargeable to full charge by lithiating less than 100% of the silicon of the anode, and
wherein the forming comprises providing or configuring the anode such that a voltage of the anode at full charge of the cell does not drop below a level where graphite is significantly lithiated.
32 . The method according to claim 31 , wherein the active material comprises more than 70% silicon.
33 . The method according to claim 31 , comprising configuring a voltage of the anode during discharge of the battery above a minimum voltage at which silicon can be lithiated.
34 . The method according to claim 31 , wherein the anode has a specific capacity of greater than 3000 mAh/g.
35 . The method according to claim 31 , wherein the battery has a specific capacity of greater than 1000 mAh/g.
36 . The method according to claim 31 , wherein the anode has a greater than 90% initial Coulombic efficiency.
37 . The method according to claim 31 , wherein the active material has no polymer binder.
38 . The method according to claim 31 , comprising charging the battery at a 10 C rate or higher.
39 . The method according to claim 31 , comprising charging the battery at temperatures below freezing temperature of water without lithium plating.
40 . The method according to claim 31 , 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% of the silicon of the anode.
41 . An anode for use in a battery, the anode comprising an active material comprising more than 50% silicon in the active material, wherein the anode is configured such that the battery is chargeable to full charge by lithiating less than 100% of the silicon of the anode, and wherein a voltage of the anode at full charge of the cell does not drop below a level where graphite is significantly lithiated.