Metal halide-silicon composites using zintl salts for silicon anode batteries
Systems and methods are disclosed that provide for a silicon-carbon composite material that includes nanoparticulate (e.g., nanocrystalline) silicon derived from a reaction between a zintl salt and metal halide. The nanoparticulate silicon-carbon composite material can be used to provide electrode materials (e.g., anode) and cells.
1. A metal halide-nanoparticulate silicon carbon composite material comprising:
microparticulate silicon;
nanoparticulate silicon;
metal halide; and
pyrolyzed carbon.
2. The metal halide-nanoparticulate silicon carbon composite material according to claim 1 , wherein the amount of metal halide in the composite material is from about 0.01% to about 20.0% by weight relative to the amount of the microparticulate silicon.
3. The metal halide-nanoparticulate silicon carbon composite material according to claim 1 , wherein the amount of nanoparticulate silicon in the composite material is from about 0.01% to about 20.0% by weight relative to the amount of the microparticulate silicon.
4. The metal halide-nanoparticulate silicon carbon composite material according to claim 1 , wherein the metal halide comprises MgCl 2 .
5. The metal halide-nanoparticulate silicon carbon composite material according to claim 4 , wherein the MgCl 2 comprises at least 50% beta-MgCl 2 .
6. The metal halide-nanoparticulate silicon carbon composite material according to claim 1 , wherein the microparticulate silicon has a D 50 size distribution greater than about 1.0 um.
7. The metal halide-nanoparticulate silicon carbon composite material according to claim 1 , wherein the nanoparticulate silicon has a D 50 size distribution less than about 200 nm.
8. The metal halide-nanoparticulate silicon carbon composite material according to claim 1 , wherein the composite material further comprises Si x Mg y Cl z , wherein x is greater than 0.2 and less than 0.45, y is greater than 0.25 and less than 0.50, and z is greater than 0.35 and less than 0.60.
9. The metal halide-nanoparticulate silicon carbon composite material according to claim 8 , wherein the amount of Si x Mg y Cl z in the composite material is from about 0.01% to about 20.0% by weight relative to the amount of the microparticulate silicon.
10. A battery, the battery comprising:
a) an anode comprising metal halide-nanoparticulate silicon carbon composite comprising:
microparticulate silicon;
nanoparticulate silicon;
metal halide; and
pyrolyzed carbon;
b) an electrolyte as the medium that transports charge; and
c) a cathode.
11. The battery according to claim 10 , wherein the amount of metal halide in the metal halide-nanoparticulate silicon carbon composite material is from about 0.01% to about 20.0% by weight relative to the amount of the microparticulate silicon.
12. The battery according to claim 10 , wherein the amount of nanoparticulate silicon in the metal halide-nanoparticulate silicon carbon composite material is from about 0.01% to about 20.0% by weight relative to the amount of the microparticulate silicon.
13. The battery according to claim 10 , wherein the anode comprises silicon and a metal selected from the group consisting of lithium, sodium, potassium, magnesium, and combinations thereof.
14. The battery according to claim 10 , wherein the anode comprises 50% to 95% silicon.
15. The battery according to claim 10 , further comprising a separator between the anode and cathode.
16. The battery according to claim 15 , further comprising an electrolyte in the separator, the anode, and the cathode.
17. The battery according to claim 10 , wherein the active ion is lithium.
18. The battery according to claim 10 , wherein the anode comprises metal chlorides, silanes, or chlorosilanes, or combinations thereof.
19. An electrode, the electrode comprising:
metal halide-nanoparticulate silicon carbon composite material comprising:
microparticulate silicon;
nanoparticulate silicon;
metal halide; and
pyrolyzed carbon.
20. The electrode according to claim 19 , wherein the amount of metal halide in the metal halide-nanoparticulate silicon carbon composite material is from about 0.01% to about 20.0% by weight relative to the amount of the microparticulate silicon.
21. The electrode according to claim 19 , wherein the amount of nanoparticulate silicon in the metal halide-nanoparticulate silicon carbon composite material is from about 0.01% to about 20.0% by weight relative to the amount of the microparticulate silicon.
22. The electrode according to claim 19 , wherein the metal halide in the metal halide-nanoparticulate silicon carbon composite material comprises MgCl 2 .
23. The electrode according to claim 22 , wherein the MgCl 2 comprises 50% or more beta-MgCl 2 .
24. The electrode according to claim 19 , wherein the microparticulate silicon in the metal halide-nanoparticulate silicon carbon composite material has a D 50 size distribution greater than about 1.0 um.
25. The electrode according to claim 19 , wherein the nanoparticulate silicon in the metal halide-nanoparticulate silicon carbon composite material has a D 50 size distribution less than about 200 nm.
26. The electrode according to claim 19 , wherein the metal halide-nanoparticulate silicon carbon composite material further comprises Si x Mg y Cl z , wherein x is greater than 0.2 and less than 0.45, y is greater than 0.25 and less than 0.50, and z is greater than 0.35 and less than 0.60.
27. The electrode according to claim 26 , wherein the amount of Si x Mg y Cl z in the composite material is from about 0.01% to about 20.0% by weight relative to the amount of the microparticulate silicon.
28. A method of forming a metal halide-nanoparticulate silicon carbon composite material, the method comprising:
reacting an amount of a silicon zintl salt or a silane, or a combination thereof with an amount of a silicon halide or a metal halide, or a combination thereof under conditions effective to form nanoparticulate silicon;
adding an amount of microparticulate silicon and an amount of binder to the nanoparticulate silicon and mixing to form a slurry;
coating the slurry on to a substrate;
drying the slurry to form a film; and
pyrolyzing the film under conditions effective to form the nanoparticulate silicon carbon composite material.
29. The method according to claim 28 , wherein the amount of silicon zintl salt is from about 0.01% to about 20.0% by weight relative to the amount of the microparticulate silicon.
30. The method according to claim 28 , wherein the silicon zintl salt comprises Mg 2 Si and the metal halide comprises SiCl 4 .