Anode compositions having an elastomeric binder and an adhesion promoter
An anode composition that includes an elastomeric polymer binder, a plurality of electrochemically active metal particles dispersed in the binder, an electrically conductive diluent, and an adhesion promoter that promotes adhesion among the particles, the diluent, and the binder. Also featured are lithium ion batteries featuring anodes made from these compositions.
1. A lithium ion battery comprising:
(A) an anode comprising:
(a) an elastomeric polymer binder;
(b) an electrically conductive diluent dispersed in said binder;
(c) a plurality of electrochemically active metal particles dispersed in said binder; and
(d) an adhesion promoter that promotes adhesion among said particles, said electrically conductive diluent, and said binder;
(B) a cathode; and
(C) an electrolyte separating said electrode and said cathode.
2. A lithium ion battery according to claim 1 , wherein said elastomeric binder comprises a fluoroelastomer binder.
3. A lithium ion battery according to claim 2 , wherein said fluoroelastomer binder comprises units derived from monomers selected from the group consisting of olefins, fluoroolefins, perfluorolefins, perfluoroalkyl vinyl ethers, perfluoroalkoxy vinyl ethers, and combinations thereof.
4. A lithium ion battery according to claim 2 , wherein said fluoroelastomer binder comprises units derived from monomers selected from the group consisting of vinylidene fluoride, hexafluoropropylene, ethylene, propylene, and combinations thereof.
5. A lithium ion battery according to claim 1 , wherein said binder comprises the reaction product of polymerizable reactants that include a crosslinking agent.
6. A lithium ion battery according to claim 1 , wherein said adhesion promoter coats the surface of said electrochemically active metal particles.
7. A lithium ion battery according to claim 1 , wherein said adhesion promoter is selected from the group consisting of silanes, titanates, phosphonates, and combinations thereof.
8. A lithium ion battery according to claim 1 , wherein said electrochemically active metal particles comprise an electrochemically active metal selected from the group consisting of silver, aluminum, silicon, tin, antimony, lead, germanium, magnesium, zinc, cadmium, bismuth, and indium.
9. A lithium ion battery according to claim 8 , wherein said electrochemically active metal particles comprise silicon.
10. A lithium ion battery according to claim 9 , wherein said electrochemically active particles comprise amorphous silicon.
11. A lithium ion battery according to claim 1 , wherein said electrochemically active metal particles further comprise an electrochemically inactive metal.
12. A lithium ion battery according to claim 11 , wherein said electrochemically inactive metal is selected from the group consisting of molybdenum, niobium, tungsten, tantalum, iron, nickel, manganese, and copper.
13. A lithium ion battery according to claim 1 , wherein said electrochemically active metal particles consist essentially of at least one electrochemically inactive metal and at least one electrochemically active metal in the form of an amorphous mixture at ambient temperature that remains amorphous when said anode composition is incorporated into a lithium battery and cycled though at least one full charge-discharge cycle at ambient temperature.
14. A lithium ion battery according to claim 1 , wherein each of said electrochemically active metal particles includes an electrically conductive layer partially covering said particle.
15. A lithium ion battery according to claim 14 , wherein said layer is present in an amount no greater than about 75 vol. % of said particle.
16. A lithium ion battery according to claim 14 , wherein said layer is present in an amount no greater than about 75 wt. % of said particle.
17. A lithium ion battery according to claim 14 , wherein said layer is porous.
18. A lithium ion battery according to claim 17 , wherein said layer has a porosity of about 90%.
19. A lithium ion battery according to claim 14 , wherein said layer comprises a metal.
20. A lithium ion battery according to claim 19 , wherein said metal is selected from the group consisting of copper, chromium, nickel, silver, and combinations thereof.
21. A lithium ion battery according to claim 1 , wherein said electrically conductive diluent comprises carbon black.
22. A lithium ion battery comprising:
(A) an anode comprising:
(a) a fluoroelastomer binder;
(b) an electrically conductive diluent dispersed in said binder; and
(c) a plurality of electroehemically active metal particles dispersed in said binder,
said particles consisting essentially of (i) at least one electrochemically inactive metal and at least one electrochemically active metal in the form of an amorphous mixture at ambient temperature that remains amorphous when said anode composition is incorporated into a lithium battery and cycled through at least one full charge-discharge cycle at ambient temperature, and (ii) an electrically conductive layer partially covering each of said particles, said particles having a surface treated with an adhesion promoter that promotes adhesion among said particles, said electrically conductive diluent, and said binder;
(B) a cathode; and
(C) an electrolyte separating said anode and said cathode.