Silicon-containing alloys useful as electrodes for lithium-ion batteries
View Patent ↗An electrode composition for a lithium ion battery having the formula Si x Sn q M y C z where q, x, y, and z represent atomic percent values and (a) (q+x)>2y+z; (b) q≧0, (c) z≧0; and (d) M is one or more metals selected from manganese, molybdenum, niobium, tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, or a combination thereof. The Si, Sn, M, and C elements are arranged in the form of a multi-phase microstructure comprising: (a) an amorphous phase comprising silicon; (b) a nanocrystalline phase comprising a metal silicide; and (c) a phase comprising silicon carbide phase when z>0; and (d) an amorphous phase comprising Sn when q>0.
1. An electrode composition for a lithium ion battery having the formula Si x M y C z where x, y, and z represent atomic percent values and
(a) x>2y+z;
(b) x, y and z are greater than 0; and
(c) M is one or more metals selected from manganese, molybdenum, niobium, tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, or combinations thereof,
wherein the Si, M, and C elements are arranged in the form of a multi-phase microstructure comprising:
(i) an amorphous phase comprising silicon;
(ii) a nanocrystalline phase comprising metal silicide; and
(iii) a phase comprising a silicon carbide.
2. An electrode composition according to claim 1 wherein M is one or more metals selected from cobalt, nickel, iron, titanium, molybdenum, tungsten, or combinations thereof.
3. An electrode composition according to claim 1 wherein x≧60.
4. An electrode composition according to claim 1 wherein z≧10.
5. An electrode composition according to claim 1 wherein z≧15.
6. An electrode composition according to claim 1 wherein x≧60 and M is one or more metals selected from cobalt, nickel, iron, titanium, molybdenum, or combinations thereof.
7. An electrode composition according to claim 6 wherein z≧10.
8. An electrode composition according to claim 1 wherein M comprises Co.
9. An electrode composition according to claim 8 wherein x≧60.
10. A lithium ion battery comprising:
an anode;
a cathode; and
an electrolyte,
wherein the anode comprises a composition having the formula Si x M y C z where x, y, and z represent atomic percent values and
(a) x>2y+z;
(b) x, y, and z are greater than 0; and
(c) M is one or more metals selected from manganese, molybdenum, niobium, tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, or combinations thereof,
wherein the Si, M, and C elements are arranged in the form of a multi-phase microstructure comprising:
(i) an amorphous phase comprising silicon;
(ii) a nanocrystalline phase comprising metal silicide; and
(iii) a phase comprising a silicon carbide.
11. A lithium ion battery according to claim 10 wherein M is one or more metals selected from cobalt, nickel, iron, titanium, molybdenum, tungsten, or combinations thereof.
12. A lithium ion battery according to claim 10 wherein x≧60.
13. A lithium ion battery according to claim 10 wherein z≧10.
14. A lithium ion battery according to claim 10 wherein z≧15.
15. A lithium ion battery according to claim 10 wherein x≧60 and M is one or more metals selected from cobalt, nickel, iron, titanium, molybdenum, or combinations thereof.
16. A lithium ion battery according to claim 15 wherein z≧10.
17. A lithium ion battery according to claim 10 wherein M comprises Co.
18. A lithium ion battery according to claim 17 wherein x≧60.
19. A lithium ion battery according to claim 10 wherein the anode further comprises a binder and a conductive diluent.
20. A lithium ion battery according to claim 19 wherein the binder comprises a polyimide.
21. A lithium ion battery according to claim 19 wherein the conductive diluent comprises carbon black.
22. A lithium ion battery according to claim 10 wherein the electrolyte comprises fluoroethylene carbonate.