Particulate composite materials

1. A particulate silicon-carbon composite comprising silicon and carbon, wherein:

A) the carbon comprises:

i) a porous carbon scaffold comprising:

a) amorphous carbon;

b) a pore volume, wherein greater than 70% of the pore volume resides in pores having a diameter less than 2 nm; and

c) a DPv90 less than 50 nm;

B) the silicon comprises:

i) amorphous, nano-sized silicon embedded within the pore volume of the carbon scaffold; and

C) the composite comprises:

i) a surface area less than 30 m 2 /g;

ii) a capacity of greater than 1300 mA/g;

iii) an average Coulombic efficiency of greater than or equal to 0.9980, as measured in a half cell;

iv) a Z of less than 10, wherein Z=1.875×[(M1100−M)/M1100]×100%, wherein M1100 is a mass of the silicon-carbon composite at 1100° C. and M is the minimum mass of the silicon-carbon composite between 800° C. and 1100° C. when the silicon-carbon composite is heated under air from about 25° C. to about 1100° C., as determined by thermogravimetric analysis; and

v) a φ of greater than or equal to 0.15, wherein φ=(Max peak height dQ/dV in Regime I)/(Max peak height dQ/dV in Regime III), wherein dQ/dV is measured in a half-cell coin cell, and Regime I is 0.8V-0.4V and Regime III is 0.15V-0V.

2. The particulate composite of claim 1 , wherein the surface area of the composite is less than 10 m 2 /g.

3. The particulate composite of claim 1 , wherein the composite comprises from 30% to 70% by weight of the silicon.

4. The particulate composite of claim 1 , wherein the composite comprises from 40% to 60% by weight of the silicon.

5. The particulate composite of claim 1 , wherein the Z is less than 5.

6. The particulate composite of claim 1 , wherein the φ is greater than or equal to 0.25.

7. The particulate composite of claim 1 , wherein the average Coulombic efficiency is greater than or equal to 0.9985, as measured in a half cell.

8. The particulate composite of claim 1 , wherein the pore volume of the porous carbon scaffold, in the absence of the embedded silicon, is greater than 0.5 cm 3 /g.

9. The particulate composite of claim 1 , wherein the particulate composite comprises a first cycle efficiency of greater than 75%, as measured in a half cell coin cell cycled from 5 mV to 0.8 V.

10. The particulate composite of claim 1 , having a Dv50 particle size ranging from 2 microns to 20 microns.

11. A particulate silicon-carbon composite; comprising silicon and carbon, wherein:

A) the carbon comprises:

i) a porous carbon scaffold comprising:

a) amorphous carbon;

b) a pore volume of greater than 0.5 cm 3 /g; and

c) greater than 70% of the pore volume residing in pores having a diameter less than 2 nm;

B) the silicon comprises:

i) amorphous, nano-sized silicon embedded within the pore volume of the carbon scaffold; and

C) the composite comprises:

i) a surface area less than 30 m 2 /g;

ii) a capacity of greater than 1300 mA/g;

iii) an average Coulombic efficiency of greater than or equal to 0.9980, as measured in a half cell;

iv) a Z of less than 10, wherein Z=1.875×[(M1100−M)/M1100]×100%, wherein M1100 is a mass of the silicon-carbon composite at 1100° C. and M is the minimum mass of the silicon-carbon composite between 800° C. and 1100° C. when the silicon-carbon composite is heated under air from about 25° C. to about 1100° C., as determined by thermogravimetric analysis; and

v) a φ of greater than or equal to 0.15, wherein φ=(Max peak height dQ/dV in Regime I)/(Max peak height dQ/dV in Regime III), wherein dQ/dV is measured in a half-cell coin cell, and Regime I is 0.8V-0.4V and Regime III is 0.15V-0V.

12. The particulate composite of claim 11 , wherein the surface area of the composite is less than 10 m 2 /g.

13. The particulate composite of claim 11 , wherein the composite comprises from 30% to 70% by weight of the silicon.

14. The particulate composite of claim 11 , wherein the composite comprises from 40% to 60% by weight of the silicon.

15. The particulate composite of claim 11 , wherein the Z is less than 5.

16. The particulate composite of claim 11 , wherein the φ is greater than or equal to 0.25.

17. The particulate composite of claim 11 , wherein the average Coulombic efficiency is greater than or equal to 0.9985, as measured in a half cell.

18. The particulate composite of claim 11 , wherein the pore volume of the porous carbon scaffold, in the absence of the embedded silicon, is greater than 0.7 cm 3 /g.

19. The particulate composite of claim 11 , wherein the particulate composite comprises a first cycle efficiency of greater than 75%, as measured in half cell coin cells cycled from 5 mV to 0.8 V.

20. The particulate composite of claim 11 , having a Dv50 particle size ranging from 2 microns to 20 microns.