Carbon aerogel-based electrode materials and methods of manufacture thereof
Nanoporous carbon-based scaffolds or structures, and specifically carbon aerogels and their manufacture and use thereof are provided. Embodiments include a silicon-doped anode material for a lithium-ion battery, where the anode material includes beads of polyimide-derived carbon aerogel. The carbon aerogel includes silicon particles and accommodates expansion of the silicon particles during lithiation. The anode material provides optimal properties for use within the lithium-ion battery.
1. A carbon composition comprising:
a carbon material comprising a fibrillar morphology, the fibrillar morphology comprising a plurality of interconnected carbon struts, wherein the interconnected carbon struts define a plurality of pores; and
a silicon-based material,
wherein the carbon composition includes greater than about 10% by weight of the silicon-based material, and
wherein the carbon material is characterized by a Young's modulus of at least about 0.2 GPa and a density of less than 0.1 grams/cubic centimeter.
2. The carbon composition of claim 1 , wherein the carbon material has an electrical conductivity of at least about 10 S/cm.
3. The carbon composition of claim 1 , wherein the carbon material comprises a carbon aerogel.
4. The carbon composition of claim 3 , wherein the carbon material comprises a polyimide-derived carbon aerogel.
5. The carbon composition of claim 1 , wherein the carbon material comprises residual nitrogen of at least about 4 wt %.
6. The carbon composition of claim 1 , wherein the carbon composition is in a monolith form.
7. The carbon composition of claim 6 , wherein the monolithic carbon composition is binder-free.
8. The carbon composition of claim 7 , wherein the monolithic carbon composition has a thickness between about 10 micrometers and about 500 micrometers.
9. The carbon composition of claim 1 , wherein the carbon composition is in a particulate form.
10. The carbon composition of claim 9 , wherein the particulate carbon composition has a diameter of about 1 micrometer to about 50 micrometers.
11. The carbon composition of claim 1 , wherein the silicon-based material is present at least partially within a pore of the plurality of pores of the carbon material.
12. The carbon composition of claim 1 , wherein the carbon material includes about 25% to 65% of silicon by weight of the carbon material.
13. The carbon composition of claim 1 , wherein the carbon composition has a capacity of at least about 800 mAh/g.
14. An electrode comprising the carbon composition of claim 1 .
15. An energy storage device comprising the carbon composition of claim 1 .
16. The energy storage device of claim 15 , wherein the energy storage device is a lithium-ion battery.
17. A method of forming a carbon composition, the method comprising:
providing a mixture of a polyimide precursor and a silicon-based material,
imidizing the mixture chemically or thermally;
drying the imidized mixture to yield a porous polyimide silicon composite; and
carbonizing the porous polyimide silicon composite to yield the carbon composition that is greater than about 10% by weight silicon and comprises a fibrillar morphology, wherein the fibrillar morphology comprises a plurality of interconnected carbon struts, wherein the interconnected carbon struts define a plurality of pores, and
wherein the carbon material is characterized by a Young's modulus of at least about 0.2 GPa and a density of less than 0.1 grams/cubic centimeter.
18. The method of claim 17 , wherein the carbon composition comprises a carbon aerogel.
19. The method of claim 17 , wherein the carbon composition is formed as a monolith.
20. The method of claim 17 , further comprising combining the mixture with a medium that is non-miscible with the mixture, thereby forming droplets of the imidized mixture.
21. The method of claim 20 , further comprising drying the droplets to form particles.
22. The method of claim 21 , wherein the particles have a diameter of about 1 micrometers to about 50 micrometers.
23. The method of claim 17 , wherein a maximum carbonizing temperature is between about 750° C. and about 1600° C.
24. The method of claim 17 , wherein the silicon-based material is present at least partially within a pore structure of the carbon composition.
25. The method of claim 17 , wherein the carbon composition has a capacity of at least about 800 mAh/g.
26. The method of claim 17 , wherein the carbon composition has a silicon utilization of at least about 20%.