Supercapacitor compositions, devices and related methods
Disclosed are supercapacitor materials comprising compositions having pores that are optimally sized to maximize capacitance. Also disclosed are related methods for fabricating such supercapacitors.
1. A composition, comprising:
a nanoporous material and an ionic liquid,
the ionic liquid comprising a plurality of ions,
the nanoporous material being characterized as comprising a plurality of nanopores having an average characteristic cross-sectional dimension in the range of from about 0.1 nm to about 3 nm, and
the difference between the average characteristic cross-sectional dimension of the nanopores and the average cross-sectional dimension of the plurality of ions being in the range of less than about 0.05 nm.
2. The composition of claim 1 , wherein the nanoporous material is capable of functioning as an electrode.
3. The composition of claim 2 , wherein the nanoporous material comprises a unimodal distribution of pore size.
4. The composition of claim 3 , wherein the nanoporous material comprises a multimodal distribution of pore size.
5. The composition of claim 1 , wherein the plurality of ions are capable of remaining stable when subjected to a voltage.
6. The composition of claim 1 , wherein the ionic liquid comprises cations of ethylmethylimmidazolium, tetraalkylammonium, dialkylimidazolium, trialkylimidazolium, tetraalkylimidazolium, alkylpyridinium, dialkylpyrrolidinium, dialkylpiperidinium, tetraalkylphosphonium, trialkylsulfonium, or a combination thereof.
7. The composition of claim 1 , wherein the ionic liquid comprises an anion of BF 4 , B(CN) 4 , n-C 3 F 7 BF 3 , CH 3 BF 3 , CH 2 CHBF 3 , CF 3 BF 3 , C 2 F 5 BF 3 , n-C 4 F 9 BF 3 , PF 6 , CF 3 CO 2 , CF 3 SO 3 , N(SO 2 CF 3 ) 2 , N(COCF 3 )(SO 2 CF 3 ), N(SO 2 F) 2 N(CN) 2 , C(CN) 3 , SCN, SeCN, CuCl 2 , AlCl 4 , spyro-bipyrrolidinium, or a combination thereof.
8. The composition of claim 1 , wherein the ionic liquid comprises Ethyl-Methyl Immidazolium-Trifluoromethane-Sulfonyl Imide.
9. The composition of claim 1 , wherein the plurality of ions comprises two or more species of ion.
10. The composition of claim 1 , wherein the plurality of ions comprises an average cross-sectional dimension in the range of from about 0.1 nm to about 3 nm.
11. The composition of claim 1 , wherein the nanoporous material comprises carbon.
12. The composition of claim 1 , wherein the nanoporous material comprises a carbide-derived carbon.
13. The composition of claim 12 , wherein the nanoporous material comprises a titanium-carbon carbide derived carbon.
14. The composition of claim 1 , wherein the nanoporous material is characterized as being substantially free of halogens.
15. The composition of claim 1 , wherein the plurality of nanopores is characterized as having an average cross-sectional dimension in the range of from about 0.2 nm and about 2.5 nm.
16. The composition of claim 1 , wherein the plurality of nanopores is characterized as having an average cross-sectional dimension in the range of from about 0.5 nm and about 2.0 nm.
17. The composition of claim 1 , wherein the plurality of nanopores is characterized as having an average cross-sectional dimension in the range of from about 0.7 nm and about 1.0 nm.
18. The composition of claim 1 , wherein the nanoporous material a specific surface area, as determined by the Brunauer Emmett Teller method, in the range of from about 800 m 2 /g to about 3000 m 2 /g.
19. The composition of claim 1 , wherein the nanoporous material comprises a specific surface area, as determined by the Brunauer Emmett Teller method, in the range of from about 1000 m 2 /g to about 2000 m 2 /g.
20. The composition of claim 1 , wherein the nanoporous material comprises an average pore volume in the range of from about 0.4 cc/g to about 0.9 cc/g.
21. The composition of claim 1 , wherein the difference between the average characteristic cross-sectional dimension of the nanopores and the average cross-sectional dimension of the plurality of ions being less than about 0.03 nm.
22. The composition of claim 1 , wherein the composition is characterized as having a normalized capacitance of greater than about 6 μF/cm 2 .
23. The composition of claim 1 , wherein the composition is characterized as having a normalized capacitance of greater than about 8 μF/cm 2 .
24. The composition of claim 1 , wherein the composition is characterized as having a normalized capacitance of greater than about 12 μF/cm 2 .
25. The composition of claim 1 , wherein the composition is characterized as having a specific capacitance of greater than about 90 F/g.
26. The composition of claim 1 , further comprising a binder capable of fixing the composition into a cohesive form.
27. The composition of claim 26 , wherein the binder comprises an adhesive, a polymer, or any combination thereof.
28. The composition of claim 1 , wherein one or more of the plurality of ions is characterized as residing at least partially within one or more pores of the composition.
29. An energy storage device, comprising:
a composition disposed between one or more electrodes, the composition comprising a nanoporous material and an ionic liquid, the ionic liquid comprising a plurality of ions,
the nanoporous material characterized as having a plurality of nanopores having an average characteristic cross-sectional dimension in the range of from about 0.1 nm to about 3 nm, and
the average characteristic cross-sectional dimension of the nanopores being within about 0.05 nm of the average cross-sectional dimension of the plurality of ions.
30. The energy storage device of claim 29 , wherein the composition comprises carbon, a carbide-derived carbon, or any combination thereof.
31. The energy storage device of claim 29 , wherein the plurality of pores is characterized as having an average cross-sectional dimension in the range of from about 0.1 nm to about 3 nm.
32. The energy storage device of claim 29 , wherein the composition further comprises a binder.
33. The energy storage device of claim 32 , wherein the binder is capable of maintaining the nanoporous material in a cohesive form.
34. The energy storage device of claim 32 , wherein the binder comprises an adhesive, a polymer, or any combination thereof.
35. The energy storage device of claim 29 , wherein the binder is characterized as being essentially electrochemically inert.
36. The energy storage device of claim 29 , wherein the binder is characterized as being essentially insoluble in the ionic liquid.
37. The energy storage device of claim 34 , wherein the polymer comprises polytetrafluoroethylene, polyvinylidene fluoride, or any combination thereof.
38. The energy storage device of claim 29 , wherein the plurality of ions comprises cations of ethylmethylimmidazolium, tetraalkylammonium, di alkylimidazolium, trialkylimidazolium, tetraalkylimidazolium, alkylpyridinium, dialkylpyrrolidinium, dialkylpiperidinium, tetraalkylphosphonium, trialkylsulfonium, and anions of: BF 4 , B(CN) 4 , n-C 3 F 7 BF 3 , CH 3 BF 3 , CH 2 CHBF 3 , CF 3 BF 3 , C 2 F 5 BF 3 , n-C 4 F 9 BF 3 , PF 6 , CF 3 CO 2 , CF 3 SO 3 , N(SO 2 CF 3 ) 2 , N(COCF 3 )(SO 2 CF 3 ), N(SO 2 F) 2 N(CN) 2 , C(CN) 3 , SCN, SeCN, CuCl 2 , AlCl 4 , spyro-bipyrrolidinium, or a combination thereof.
39. The energy storage device of claim 29 , wherein the energy storage device comprises at least two electrodes.
40. The energy storage device of claim 29 , wherein at least one of the plurality of ions resides at least partially within a pore of the nanoporous composition.
41. The energy storage device of claim 40 , wherein the at least two electrodes are separated by a porous material.
42. The energy storage device of claim 41 , wherein the porous material comprises a polymer.
43. The energy storage device of claim 42 , wherein the polymer is characterized as chemically inert, ionically conductive, electrically nonconductive, or any combination thereof.
44. The energy storage device of claim 29 , further comprising an electrical connection to an electrical device.
45. The energy storage device of claim 29 , wherein the electrical device comprises a heater, a cooler, a computer, a portable device, a stationary device, a display, battery, fuel cell, turbine or any combination thereof.
46. A method for fabricating a supercapacitor, comprising:
contacting a nanoporous composition comprising a plurality of nanopores with an ionic liquid comprising a plurality of ions,
the difference between the average characteristic cross-sectional dimension of the nanopores and the average cross-sectional dimension of the plurality of ions being less than about 0.05 nm,
the ions being chosen such that at least one ion is capable of residing at least partially within one or more pores of the nanoporous composition.
47. The method of claim 46 , wherein the contacting comprises applying an electric charge so as to give rise to one or more ions migrating at least partially into one or more pores of the nanoporous composition.
48. The method of claim 47 , wherein the migrating of the one or more ions gives rise to essentially overall electrical neutrality.
49. The method of claim 46 , wherein the contacting comprises immersing, spraying, flowing, pouring, dipping, coating, painting, or any combination thereof.
50. The method of claim 46 , wherein the plurality of pores comprises an average cross-sectional dimension in the range of from about 0.1 nm to about 3 nm.
51. The method of claim 46 , wherein the plurality of ions comprises an average cross-sectional dimension in the range of from about 0.1 nm to about 3 nm.
52. The method of claim 46 , further comprising binding the nanoporous composition so as to give rise to a cohesive material.
53. The method of claim 52 , further comprising disposing the bound nanoporous composition onto at least one current collector.
54. The method of claim 53 , further comprising disposing the nanoporous composition adjacent to one or more electrodes.
55. The method of claim 54 , wherein the nanoporous composition is disposed adjacent to the one or more electrodes prior to contacting the nanoporous composition with the plurality of ions.
56. The method of claim 54 , wherein the nanoporous composition is disposed adjacent to the one or more electrodes after contacting the nanoporous composition with the plurality of ions.
57. The method of claim 54 , wherein one or more of the electrodes are charged.
58. The method of claim 54 , wherein one or more of the electrodes are positioned essentially opposite one another.
59. The method of claim 58 , further comprising disposing the plurality of ions such that at least one ion resides partially within a pore of a charged electrode.
60. A supercapacitor made according to the method of claim 46 .