Si composite electrode with Li metal doping for advanced lithium-ion battery
View Patent ↗A silicon electrode is described, formed by combining silicon powder, a conductive binder, and SLMP™ powder from FMC Corporation to make a hybrid electrode system, useful in lithium-ion batteries. In one embodiment the binder is a conductive polymer such as described in PCT Published Application WO 2010/135248 A1.
1. A composition of matter comprising:
an active electrode material selected from the group comprising silicon, or tin;
a conductive binder; and,
a stabilized lithium metal powder, wherein the conductive binder comprises a polymeric composition having repeating units of the formula:
wherein 0<x, x′, y and z<1, x+x′+y+z=1, R 1 and R 2 is (CH 2 ) n CH 3 where n=0-8, R 3 and R 4 is (CH 2 ) n COOH where n=0-8, and R 5 and R 6 is any combination of H, COOH and COOCH 3 .
2. The composition of matter of claim 1 wherein the composition is deposited onto a copper foil.
3. The composition of matter of claim 2 wherein the composition is deposited onto the copper foil to form a film laminate.
4. The composition of matter of claim 3 wherein an exposed side of said film laminate includes a carbonate stabilizer.
5. The composition of matter of claim 4 wherein the carbonate stabilizer is ethylene carbonate.
6. The composition of matter of claim 4 wherein said carbonate stabilizer is an alkylene carbonate.
7. The composition of matter of claim 6 where said carbonate stabilizer is a vinylene carbonate.
8. The composition of matter of claim 1 where the active electrode material is silicon.
9. The composition of matter of claim 1 wherein the ratio of silicon/SLMP/conductive binder is 2/7/1 by weight.
10. An electrode for use in a lithium-ion battery including the composition of matter of claim 1 .
11. A lithium ion battery having a negative electrode, wherein said electrode comprises a laminate of the composition of matter of claim 1 in combination with a current collector.
12. The lithium ion battery of claim 11 wherein the laminate comprises a copper foil current collector in electrical contact with a covering layer of the composition of matter of claim 1 .
13. A method of forming the laminate of claim 12 wherein silicon in powder form is combined with SLMP in powder form and the conductive binder, the three components mixed in an organic solvent to form a slurry, the slurry then deposited onto the copper foil current collector, followed by drying.
14. The method of claim 13 wherein, after formation, the exposed surface of the laminate is brought into contact with an alkylene carbonate to further stabilize the exposed surface.
15. The method of claim 14 wherein the carbonate is added to the electrolyte of the lithium ion battery to bring it into contact with the exposed surface of the laminate.