GROUP14 COMPOSITE
Particulate composite materials and devices comprising the same are provided.
1 . A process for preparing Group14 composite particles, the process comprising:
a. providing a polyol and an optional exclusion agent in an aqueous milieu;
b. heating the aqueous milieu at 150 to 250 C to produce a hydrothermal char;
c. heating of the hydrothermal char to 750 C to 1050 C in the presence of an inert gas to produce pyrolyzed carbon particles;
d. heating of the pyrolyzed carbon particles to 750 C to 1050 C in the presence of an activation gas to produce primary activated carbon particles, the primary activated carbon particles comprising a porous carbon framework; and
e. heating the primary activated carbon particles to 350 C to 450 C in the presence of a silicon-containing gas to impregnate silicon within the porous carbon framework,
wherein individual particles of the Group14 composite particles have a sphericity of greater than 0.5.
2 . The process of claim 1 , wherein the aqueous milieu comprises a co-solvent including one or more of: an alcohol, alkanes, ethers, THF, DMSO, DMF, N-methyl pyrrolidone, glycol, and glymp.
3 . The process of claim 1 , wherein the aqueous milieu is heated to a temperature less than or equal to a decomposition temperature of the preferential exclusion agent.
4 . The process of claim 1 , wherein the polyol is sucrose.
5 . The process of claim 1 , wherein the exclusion agent is: Span 80, poly(acrylic acid), Triton X, or a combination thereof.
6 . The process of claim 1 , wherein the ratio of polyol to the exclusion agent is 1000:1 or less.
7 . The process of claim 1 , wherein the inert gas is nitrogen.
8 . The process of claim 1 , wherein the activation gas is carbon dioxide, steam, or combinations thereof.
9 . The process of claim 1 , further comprising stirring the aqueous milieu.
10 . The process of claim 1 , wherein the silicon-containing gas deposits silicon onto at least a portion of a surface of the primary activated carbon particle.
11 . The process of claim 1 , wherein the fraction of silicon not impregnated within the porous carbon framework relative to the fraction of silicon impregnated within the porous carbon framework, Z, is less than 10.
12 . The process of claim 11 , wherein the impregnating silicon within the porous carbon framework comprises the deposit of a silicon nanoparticle within the interior framework of the activated carbon particles.
13 . The process of claim 1 , wherein the Group 14 composite particles further comprise two or more discrete Group 14 particles and wherein the discrete Group 14 particles are not agglomerated.
14 . The process of claim 1 , wherein a pore volume of the primary activated carbon is at least 0.6 cm3/g.
15 . The process of claim 1 , wherein the silicon-containing gas is introduced via chemical vapor infusion (CVI).
16 . The process of claim 1 , wherein the silicon-containing gas is silane.
17 . The process of claim 1 , further comprising casting a slurry comprising the Group 14 composite particles to produce an anode electrode.
18 . A Group14 composite comprising:
(a) a plurality of porous carbon primary particles derived from a polyol, wherein the plurality of porous carbon particles exhibit a spherical morphology;
(b) silicon impregnated within pores of the porous carbon primary particles;
(c) Dv50 is less than or equal to 10 μm;
(d) Z<10; and
(e) phi (φ)≥0.15, 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.
19 - 25 . (canceled)
26 . A Group14 composite comprising:
(a) a plurality of primary particles comprising Group14 elements silicon and carbon, wherein the primary particles have a sphericity of at least 0.5, and wherein each particle comprises a porous carbon scaffold;
(b) 30% to 60% silicon by weight;
(c) Dv50 is less than or equal to 10 μm;
(d) Z<10; and
(e) phi (φ)≥0.15, 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.
27 . A Group14 composite comprising carbon and silicon, wherein:
(a) the carbon comprises a porous carbon scaffold derived from a polyol and further comprising:
(i) amorphous carbon,
(ii) a pore volume, wherein greater than 70% of the pore volume is comprised of pores having a diameter less than 2 nm, and
(iii) a Dv90 less 50 nm;
(b) the silicon comprises:
(i) amorphous, nano-sized silicon embedded within the pore volume of the porous carbon scaffold; and
(c) the Group14 composite further comprises:
(i) 30% to 60% silicon by weight,
(ii) Dv50 is less than or equal to 10 μm,
(iii) Z<10, and
(iv) phi (φ)≥0.15, 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.
28 - 34 . (canceled)
35 . An energy storage device comprising the Group14 composite of claim 26 .
36 . The energy storage device of claim 35 , wherein the energy storage device is a lithium-silicon battery or a lithium-ion battery.