CHEMICAL VAPOR INFILTRATION OF AGGREGATED SCAFFOLDING MATERIALS TO PRODUCE COMPOSITE PARTICULATE MATERIALS
Silicon-carbon composite materials and related processes that overcome the challenges for providing amorphous nano-sized silicon entrained within porous carbon. Agglomerated porous carbon is used during a composite creation process.
1 . A process for preparing silicon-carbon composite particles comprising:
providing a porous carbon material comprising a pore volume, wherein the pore volume comprises greater than 70% microporosity;
agglomerating the porous carbon material with an agglomerant to produce an agglomerated carbon material;
heating the agglomerated carbon material to a temperature from 350° C. to 550° C.; and
contacting the agglomerated carbon material with a silane feedstock gas to produce the silicon-carbon composite particles.
2 . The process of claim 1 , wherein a Dv50 for the agglomerated porous carbon material is greater than a Dv50 of the provided porous carbon material.
3 . The process of claim 2 , wherein the agglomerated porous carbon material comprises volume average particle size (Dv50) of less than 1 cm.
4 . The process of claim 1 , wherein agglomerating comprises:
mixing an immiscible binder with a liquid to produce the agglomerant; and
combining the porous carbon material with the agglomerant to produce the agglomerated carbon material.
5 . The process of claim 4 , wherein the immiscible binder comprises carboxymethylcellulose (CMC).
6 . The process of claim 1 , wherein agglomerating comprises:
dissolving a pre-agglomerant in a liquid to produce the agglomerant; and
combining the porous carbon material with the agglomerant to produce the agglomerated carbon material.
7 . The process of claim 6 , wherein the pre-agglomerant comprises acetone, methanol, benzene, or polyacrylic acid (PAA) and the liquid comprises water or isopropyl alcohol (IPA).
8 . The process of claim 1 , wherein:
the agglomerant is a friction-increasing liquid; and
agglomerating comprises combining the porous carbon material with the friction-increasing liquid to produce the agglomerated carbon material.
9 . The process of claim 8 , wherein the friction-increasing liquid comprises water or isopropyl alcohol.
10 . The process of claim 1 , wherein:
the agglomerant is in liquid form; and
agglomerating comprises combining the porous carbon material with the agglomerant to produce the agglomerated carbon material.
11 . The process of claim 10 , wherein the liquid agglomerant comprises novolac polyethylene glycol (PEG) having a molecular weight below 1000.
12 . The process of claim 1 , wherein the agglomerant is in at least one of a solid form or has less than a predefined moisture content; and
further comprising combining the porous carbon material with the agglomerant to produce the agglomerated carbon material.
13 . The process of claim 12 , wherein agglomerant comprises polytetrafluoroethylene (PTFE).
14 . The process of claim 1 , further comprising:
applying a passivation coating over at least a portion of the silicon-carbon composite particles.
15 . The process of claim 1 , further comprising:
diminuting the silicon-carbon composite particles to produce silicon-carbon composite particles within a specified size range.
16 . A system for producing silicon-carbon composite particles comprising:
an agglomerating device configured to agglomerate activated porous carbon material with an agglomerant to produce an agglomerated carbon material; and
a kiln configured to heat the agglomerated carbon material to a temperature from 350° C. to 550° C. while introducing a silane feedstock gas to perform a chemical vapor infiltration process that produces silicon-carbon composite particles.
17 . The system of claim 16 , wherein the kiln comprises one of a vibro-thermal assisted (VTA) reactor, a convection-thermal assisted (CTA) reactor, a rotating kiln, hearth furnace, belt furnace, or a fluidized bed (FB) reactor.
18 . The system of claim 17 , wherein the kiln is further configured to perform a batch process between 1 to 6 hours.
19 . The system of claim 17 , wherein the kiln is further configured to perform a continuous process.
20 . The system of claim 16 , wherein the kiln is further configured to apply a passivation coating over at least a portion of the silicon-carbon composite particles.
21 . The system of claim 16 , further comprising:
a diminution device configured to diminute the silicon-carbon composite particles to produce silicon-carbon composite particles within a specified size range.