Carbon surface modification for three-volt ultracapacitor
An electric double-layer ultracapacitor configured to maintain desired operation at an operating voltage of three volts, where the capacitor includes a housing component, a first and a second current collector, a positive and a negative electrode electrically coupled to one of the first and second current collectors, and a separator positioned between the positive and the negative electrode. At least one of the positive electrode and the negative electrode can include a treated carbon material, where the treated carbon material includes a reduction in a number of hydrogen-containing functional groups, nitrogen-containing functional groups and/or oxygen-containing functional groups.
1. A method of making an ultracapacitor, comprising:
forming a positive electrode;
forming a negative electrode;
position a separator between the positive electrode and the negative electrode;
inserting the positive electrode, the negative electrode and the separator into a housing component, wherein the housing component comprises an inner surface having a coating; and
adding an electrolyte to the housing component, wherein the positive electrode and the negative electrode are in ionic contact the electrolyte;
wherein the ultracapacitor is configured to operate at 3 volts or greater at 65° C. and maintain greater than 80% of its initial capacitance for over 1500 hours.
2. The method of claim 1 , wherein the housing component comprises an inner surface exposed to the electrolyte and an outer surface, and wherein method further comprises applying the coating along at least a portion of the inner surface.
3. The method of claim 2 , wherein the coating comprises a conductive material.
4. The method of claim 2 , wherein the coating comprises a non-conductive material.
5. The method of claim 4 , wherein the coating comprises a polymeric material.
6. The method of claim 5 , wherein the polymeric material comprises at least one of polyepoxide, polyolefin, polyethylene, polyimide, polyether ether ketone, polyurethane, ethylene propylene rubber, poly(p-xylylene), polytetrafluoroethylene (PTFE), polyvinylidene difluoride (PVDF), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene, and/or copolymers thereof.
7. The method of claim 4 , wherein the coating comprises a ceramic coating.
8. The method of claim 1 , wherein the positive electrode comprises a dry electrode film comprising carbon and binder.
9. The method of claim 1 , wherein the electrolyte comprises acetonitrile.
10. The method of claim 1 , wherein the ultracapacitor is configured to operate at 65° C. with a cycle life of greater than 500 k cycles.
11. A method of making an ultracapacitor, comprising:
forming a positive electrode;
forming a negative electrode;
position a separator between the positive electrode and the negative electrode;
inserting the positive electrode, the negative electrode and the separator into a housing component, wherein the housing component comprises an inner surface having a coating; and
adding an electrolyte to the housing component, wherein the positive electrode and the negative electrode are in ionic contact the electrolyte;
wherein the ultracapacitor is configured to operate at 3 volts or greater at 65° C. and maintain less than 200% of its initial equivalent series resistance for over 1500 hours.
12. The method of claim 11 , wherein the housing component comprises an inner surface exposed to the electrolyte and an outer surface, and wherein method further comprises applying the coating along at least a portion of the inner surface.
13. The method of claim 11 , wherein the coating comprises a conductive material.
14. The method of claim 11 , wherein the coating comprises a non-conductive material.
15. The method of claim 14 , wherein the coating comprises a polymeric material.
16. The method of claim 15 , wherein the polymeric material comprises at least one of polyepoxide, polyolefin, polyethylene, polyimide, polyether ether ketone, polyurethane, ethylene propylene rubber, poly(p-xylylene), polytetrafluoroethylene (PTFE), polyvinylidene difluoride (PVDF), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene, and/or copolymers thereof.
17. The method of claim 14 , wherein the coating comprises a ceramic coating.
18. The method of claim 11 , wherein the positive electrode comprises a dry electrode film comprising carbon and binder.
19. The method of claim 11 , wherein the electrolyte comprises acetonitrile.
20. The method of claim 11 , wherein the ultracapacitor is configured to operate at 65° C. with a cycle life of greater than 500 k cycles.
21. The method of claim 11 , wherein the ultracapacitor is configured to operate at 3 volts or greater at 65° C. and maintain greater than 80% of its initial capacitance for over 1500 hours.