Applications for alliform carbon
This invention relates to novel applications for alliform carbon, useful in conductors and energy storage devices, including electrical double layer capacitor devices and articles incorporating such conductors and devices. Said alliform carbon particles are in the range of 2 to about 20 percent by weight, relative to the weight of the entire electrode. Said novel applications include supercapacitors and associated electrode devices, batteries, bandages and wound healing, and thin-film devices, including display devices.
1. An energy storage device comprising:
a. A first and a second electrode, each electrode comprising a body in electrical communication with a current collector; and
b. an electrolyte;
wherein at least one body comprises a three-dimensionally porous matrix of alliform carbon particles, the alliform carbon particles comprising at least one concentric graphitic shell having at least 25% of the shell comprising sp2 carbon, the alliform carbon particles being substantially spherical in shape, without carbon nanotube appendages, and substantially physically connected;
said alliform carbon particles having a substantially unimodal size distribution with a mean particle diameter as measured by TEM photomicrograph image analysis of in a range of from 2 to 30 nanometers and
said alliform carbon particles having a mean specific surface area in the range of 250 to 750 m2g-1;
wherein the electrolyte physically contacts and is in electrical communication with said three-dimensionally porous matrix of alliform carbon particles; and
wherein the energy storage device exhibits capacitance when a voltage polarity is applied across the first and second electrodes.
2. The energy storage device of claim 1 , wherein the three-dimensionally porous matrix is substantially free of organic binder and has a mean pore size in a range of from 1 nm to 50 nm.
3. The energy storage device of claim 1 , wherein the thickness of each body of three-dimensionally porous matrix of alliform carbon particles is independently in the range of 1 to 20 microns.
4. The energy storage device of claim 1 , wherein the electrolyte is contained within aqueous based solution.
5. The energy storage device of claim 1 , wherein the electrolyte is contained within a polar organic solvent comprising acetonitrile, γ-butyl lactone, dimethylformamide, 1,2-dimethoxyethane, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethylene carbonate, nitromethane, propylene carbonate, or sulfalone.
6. The energy storage device of claim 1 , wherein the electrolyte comprises an anion-cation pair comprising a cation and an anion, wherein the cation comprises an alkali metal, an alkaline earth metal, a lanthanide, a tetraalkyl ammonium cation, aluminum or zinc and the anion comprises OH − , PF 6 − , ClO 4 − , BF 4 − , CF 3 SO 3 − , or SbF 6 − .
7. The energy storage device of claim 1 , wherein the first and second electrodes are superposed on a substrate and arranged in a planar array, with the electrolyte interposed between and physically separating said first and second electrodes, wherein said planar array is characterized as occupying a lateral planar area and having a vertical depth; and wherein the current collector of at least one electrode is positioned adjacent to the corresponding body of three-dimensionally porous matrix of alliform carbon particles.
8. The energy storage device of claim 7 , wherein the first and second electrodes are arranged in an interdigital arrangement, wherein each electrode comprises a plurality of interdigital electrode fingers, said interdigital electrode fingers each characterized as having a length, width, and vertical distance, and said interdigital arrangement characterized as having an interdigital spacing between said interdigital electrode fingers; wherein the widths of the interdigital electrode fingers of each electrode are independently in a range of from 20 nm to 10 millimeters.
9. The energy storage device of claim 1 , wherein the energy storage device:
(a) maintains more than 95% of its original capacitance when the polarity of the electrodes is cycled more than 10,000 times; or
(b) exhibits a near-linear relationship between discharge current and scan rate up to a scan rate of at least 175 Vs −1 ; or
(c) exhibits a linear relationship between discharge current and scan rate up to and including scan rates which exceed 100 Vs −1 ; or
(d) a combination of (a), (b), and (c).
10. The energy storage device of claim 8 , wherein the widths of the interdigital electrode fingers of each electrode are in a range of from 100 nanometers micron to 1000 microns.
11. The energy storage device of claim 8 , wherein the widths of the interdigital electrode fingers of each electrode are in a range of from 100 micron to 500 microns.
12. The energy storage device of claim 9 , wherein the energy storage device maintains more than 95% of its original capacitance when the polarity of the electrodes is cycled more than 10,000 times.
13. The energy storage device of claim 9 , wherein the energy storage device exhibits a near-linear relationship between discharge current and scan rate up to a scan rate of at least 175 Vs −1 .
14. The energy storage device of claim 9 , wherein the energy storage device exhibits a linear relationship between discharge current and scan rate up to and including scan rates which exceed 100 Vs −1 .