Functionalized Nanotube Material for Supercapacitor Electrodes

Abstract

The present teachings are directed towards supercapacitors including an electrode composed of a functionalized carbon nanotube-containing material, and also an organic electrolyte solution. The organic electrolyte solution can contain a non-aqueous solvent and an ionic salt, examples of non-aqueous solvent include propylene carbonate, ethylene carbonate, sulfolane and acetonitrile. The functional groups present on the carbon nanotubes can include hydroxyl groups, carboxyl groups, alkoxyl groups and mixtures thereof.

1 . A supercapacitor comprising
 one or more electrodes comprising a functionalized carbon nanotube-containing material, and   an organic electrolyte solution.   
   
   
       2 . The supercapacitor according to  claim 1 , wherein the organic electrolyte solution comprises a non-aqueous solvent and an ionic salt. 
   
   
       3 . The supercapacitor according to  claim 2 , wherein the non-aqueous solvent comprises at least one member selected from the group consisting of propylene carbonate, ethylene carbonate, sulfolane and acetonitrile. 
   
   
       4 . The supercapacitor according to  claim 2 , wherein the ionic salt comprises at least one member selected from the group consisting of triethylmethylammonium tetrafluoroborate, triethylmethylammonium hexafluorophosphate, tetraethylammonium tetrafluoroborate, tetraethylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, and tetrabutylammonium hexafluorophosphate. 
   
   
       5 . The supercapacitor according to  claim 1 , wherein the functionalized carbon nanotube-containing material comprises carbon nanotubes having functional groups attached thereto. 
   
   
       6 . The supercapacitor according to  claim 5 , wherein the carbon nanotubes are functionalized during oxidation. 
   
   
       7 . The supercapacitor according to  claim 5 , wherein the carbon nanotubes comprise single-walled carbon nanotubes. 
   
   
       8 . The supercapacitor according to  claim 7 , wherein the single-walled carbon nanotubes have average bundle sizes ranging from about 20 nm to about 30 nm. 
   
   
       9 . The supercapacitor according to  claim 7 , wherein the single-walled carbon nanotubes have average lengths ranging from about 50 nm to about 1 mm. 
   
   
       10 . The supercapacitor according to  claim 5 , wherein the functional groups comprise at least one member selected from the group consisting of hydroxyl groups, carboxyl groups, alkoxyl groups and mixtures thereof. 
   
   
       11 . The supercapacitor according to  claim 1 , wherein the functionalized carbon nanotube-containing material comprises a film. 
   
   
       12 . The supercapacitor according to  claim 1 , wherein the functionalized carbon nanotube-containing material is substantially free of binder material. 
   
   
       13 . A capacitor electrode comprising:
 a functionalized carbon nanotube-containing material.   
   
   
       14 . The capacitor electrode according to  claim 13 , wherein the functionalized carbon nanotube-containing material comprises carbon nanotubes having functional groups attached thereto. 
   
   
       15 . The capacitor electrode according to  claim 14 , wherein the carbon nanotubes are functionalized during oxidation. 
   
   
       16 . The capacitor electrode according to  claim 14 , wherein the carbon nanotubes comprise single-walled carbon nanotubes. 
   
   
       17 . The capacitor electrode according to  claim 16 , wherein the single-walled carbon nanotubes have average bundle sizes ranging from about 20 nm to about 30 nm. 
   
   
       18 . The capacitor electrode according to  claim 16 , wherein the single-walled carbon nanotubes have average lengths ranging from about 50 nm to about 1 mm. 
   
   
       19 . The capacitor electrode according to  claim 16 , wherein the functional groups comprise at least one member selected from the group consisting of hydroxyl groups, carboxyl groups, alkoxyl groups and mixtures thereof. 
   
   
       20 . The capacitor electrode according to  claim 13 , wherein the functionalized carbon nanotube-containing material comprises a film. 
   
   
       21 . The capacitor electrode according to  claim 13 , wherein the functionalized carbon nanotube-containing material is substantially free of binder material.