Composites of porous nano-featured silicon materials and carbon materials
Composites of porous nano-featured silicon and various materials, such as carbon, are provided. The composites find utility in various applications, such as electrical energy storage electrodes and devices comprising the same.
1 . A method for producing a composite material comprising carbon and porous silicon comprising:
a) suspending particles of a silicon alloy in a liquid medium containing a dissolved acid;
b) storing the suspended particles for a period of time at sufficient temperature to allow for etching away of metal cations from the silicon alloy to yield porous silicon particles with nano-sized features;
c) removing the liquid medium to yield dried porous silicon particles with nano-sized features;
d) blending a mixture of polymer precursors with the dried porous silicon particles with nano-sized features;
e) storing the mixture of polymer precursors and the dried porous silicon particles with nano-sized features for a period of time at sufficient temperature to allow for impregnation and polymerization of the polymer precursors within the dried porous silicon particles with nano-sized features to yield polymer-impregnated silicon particles with nano-sized features; and
f) carbonization of the polymer-impregnated silicon particles to yield a composite silicon-carbon material comprising a porous silicon material with nano-sized features.
2 . The method of claim 1 , further comprising chemical vapor deposition of an additional carbon layer covering the composite silicon-carbon material to yield a composite material comprising porous nano-featured silicon and carbon.
3 . The method of claim 1 , wherein the particles of the silicon alloy comprise a silicon-aluminum alloy.
4 . The method of claim 3 , wherein the silicon-aluminum alloy particles comprise a Dv50 between 1 μm and 20 um.
5 . The method of claim 1 , wherein the liquid medium comprises aqueous hydrochloric acid, and the sufficient temperature is between 25° C. and 100° C.
6 . The method of claim 1 , wherein the liquid removal is accomplished by subjecting the porous silicon particles to centrifugation, vacuum, or elevated temperature, or combinations thereof.
7 . The method of claim 1 , wherein the mixture of polymer precursors comprises a sugar, and acid, and a carbamate compound.
8 . The method of claim 7 , wherein the sugar is sucrose, the acid is citric acid, and the carbamate compound is urea.
9 . The method of claim 1 , wherein the mixture of polymer precursors comprises an acid and a carbamate compound.
10 . The method of claim 9 , wherein the acid is citric acid and the carbamate compound is urea.
11 . The method of claim 1 , wherein the mixture of polymer precursors comprises an epoxy resin and phosphoric acid.
12 . A method for producing a composite material comprising carbon and porous nano-sized silicon comprising:
a) suspending particles of a silicon alloy in a liquid medium containing a dissolved acid;
b) storing the suspended particles for a period of time at sufficient temperature to allow for erosion of metal cations from the silicon alloy into the liquid medium to yield highly friable silicon material with nano-sized features;
c) removing the liquid medium to yield dried highly friable silicon material with nano-sized features;
d) particle size reduction of the dried highly friable silicon material with nano-sized features to yield nano-sized silicon particles with nano-sized features;
e) blending a mixture of polymer precursors with the nano-sized silicon particles with nano-sized features;
f) storing the mixture of polymer precursors and the nano-sized silicon particles with nano-sized features for a period of time at sufficient temperature to allow for impregnation and polymerization of the polymer precursors within the nano-sized silicon particles with nano-sized features to yield polymer-impregnated nano-sized silicon particles with nano-sized features; and
g) carbonization of the polymer-impregnated nano-sized silicon particles to yield a composite silicon-carbon material comprising a nano-sized silicon material with nano-sized features.
13 . The method of claim 12 , wherein the erosion of metal cations is conducted in a continuous feed reactor.
14 . The method of claim 12 , wherein the erosion of metal cations is conducted in a dunk tank.
15 . A method for producing a composite material comprising carbon and porous nano-featured silicon, the method comprising:
a) suspending particles of a silicon alloy in a liquid medium containing a dissolved acid;
b) storing the suspended particles for a period of time at sufficient temperature to allow for etching away of metal cations from the silicon alloy to yield porous silicon particles with nano-sized features;
c) removing the liquid medium to yield dried porous silicon particles with nano-sized features;
d) blending a mixture of polymer precursors with the dried porous silicon particles with nano-sized features;
e) storing the mixture of polymer precursors and the dried porous silicon particles with nano-sized features for a period of time at sufficient temperature to allow for impregnation and polymerization of the polymer precursors within the porous silicon particles with nano-sized features to yield polymer-impregnated silicon particles with nano-sized features;
f) carbonization of the polymer-impregnated silicon particles with nano-sized features to yield a composite silicon-carbon material comprising a porous silicon material with nano-sized features;
g) suspending the composite silicon-carbon material in a solution of a conductive polymer dissolved in a solvent, or blending a solid conductive polymer with the composite silicon-carbon material; and
h) optionally pyrolyzing the product of step g) at a temperature ranging from 350° C. to 1050° C.
16 . The method of claim 15 , wherein the particles of the silicon alloy comprise a silicon-aluminum alloy.
17 . The method of claim 16 , wherein the silicon-aluminum alloy particles comprise a Dv50 between 1 μm and 20 um.
18 . The method of claim 15 , wherein the liquid medium comprises aqueous hydrochloric acid, and the sufficient temperature is between 25° C. and 100° C.
19 . The method of claim 15 , wherein the liquid removal is accomplished by subjecting the porous silicon particles to centrifugation, vacuum, or elevated temperature, or combinations thereof.
20 . The method of claim 15 , wherein the mixture of polymer precursors comprise a sugar, and acid, and a carbamate compound.
21 . The method of claim 20 , wherein the sugar is sucrose, the acid is citric acid, and the carbamate compound is urea.
22 . The method of claim 15 , wherein the polymer precursors comprise an acid and a carbamate compound.
23 . A method for producing a composite material comprising carbon and porous silicon comprising:
a) suspending particles of a silicon alloy in a liquid medium containing a dissolved acid;
b) storing the suspended particles for a period of time at sufficient temperature to allow for etching away of metal cations from the silicon alloy to yield porous silicon particles with nano-sized features;
c) removing the liquid medium to yield dried porous silicon particles with nano-sized features;
d) blending a mixture of polymer precursors with the dried porous silicon particles with nano-sized features;
e) storing the mixture of polymer precursors and the dried porous silicon particles with nano-sized features for a period of time at sufficient temperature to allow for impregnation and polymerization of the polymer precursors within the porous silicon particles with nano-sized features to yield polymer-impregnated silicon particles with nano-sized features; and
f) carbonization of the polymer-impregnated silicon particles with nano-sized features to yield a composite silicon-carbon material comprising a porous silicon material with nano-sized features.
24 . A method for producing a composite a material comprising carbon and porous nano-sized silicon comprising:
a) suspending particles of a silicon alloy in a liquid medium containing a dissolved acid;
b) storing the suspended particles for a period of time at sufficient temperature to allow for erosion of metal cations from the silicon alloy into the liquid medium to yield highly friable silicon material with nano-sized features;
c) removing the liquid medium to yield dried highly friable silicon material with nano-sized features;
d) particle size reduction of the dried highly friable silicon material with nano-sized features to yield nano-sized silicon particles with nano-sized features;
e) blending a mixture of polymer precursors with the nano-sized silicon particles with nano-sized features;
f) storing the mixture of polymer precursors and the nano-sized silicon particles with nano-sized features for a period of time at sufficient temperature to allow for impregnation and polymerization of the polymer precursors within the nano-sized silicon particles with nano-sized features to yield polymer-impregnated nano-sized silicon particles with nano-sized features;
g) carbonization of the polymer-impregnated nano-sized silicon particles to yield a composite silicon-carbon material comprising a nano-sized silicon material with nano-sized features; and
h) subjecting the composite silicon-carbon material to chemical vapor deposition to create an additional carbon layer covering the composite silicon-carbon material to yield a carbon coated composite material comprising porous nano-featured silicon and carbon.