Preformed silicon-based negative electrode and method for its manufacture
The present invention relates to a method for manufacturing a silicon-based negative electrode, a method for manufacturing a lithium-ion battery from a preformed silicon-based negative electrode, and a lithium-ion battery thus obtained.
1. A method for manufacturing at least one silicon-based negative electrode, wherein the method comprises the following method steps:
a) providing at least one silicon-based negative electrode precursor, an electrolyte, and at least one lithium-based counter electrode,
b) applying at least three successive constant voltages of 1.2 V-1.8 V, 400 mV-800 mV, and 200 mV-390 mV, respectively, between the at least one silicon-based negative electrode precursor and the at least one lithium-based counter electrode for a period of at least 35 minutes in each case, and
c) obtaining the silicon-based negative electrode.
2. The method according to claim 1 , wherein the three successive, constant voltages are 1.5 V, 600 mV, and 300 mV, respectively.
3. The method according to claim 1 , wherein the lithium-based counter electrode is made of metallic lithium.
4. The method according to claim 1 , wherein the respective successive, constant voltages in method step b) are applied for a period of 35 minutes to 14 hours in each case.
5. The method according to claim 1 , wherein the three successive, constant voltages in method step b) are each applied for the same or different periods of time.
6. The method according to claim 5 , wherein the successive, constant voltages in method step b) are each applied for exactly two hours.
7. The method according to claim 1 , wherein the applied current corresponds to a C-rate of C/5 to C/20.
8. The method according to claim 7 , wherein the applied current corresponds to a C-rate of C/10.
9. The method according to claim 1 , wherein the silicon-based negative electrode precursor is a precursor of a silicon-based negative composite electrode.
10. The method according to claim 1 , wherein the electrode material of the silicon-based negative electrode precursor contains active material and at least one binder.
11. The method according to claim 1 , wherein the active material of the silicon-based negative electrode precursor contains or is made of silicon and graphite.
12. The method according to claim 1 , wherein in method step c) the silicon-based negative electrode is obtained after washing with an organic wash solution and drying.
13. A silicon-based negative electrode that is manufacturable according to the method of claim 1 .
14. A lithium-ion battery comprising at least one silicon-based negative electrode that is manufacturable according to the method of claim 1 .
15. A device comprising at least one lithium-ion battery according to claim 14 .