Method to increase the capacitance of electrochemical carbon nanotube capacitors by conformal deposition of nanoparticles

Abstract

A method of increasing the area of carbon nanotubes used in fabricating capacitors is described. The method involves reacting carbon nanotubes with electrically conductive ions, molecules or nanoparticles that increase the surface area of the nanotubes. The capacitance and the energy stored in the capacitor can be increased by such treatment. Devices constructed from such treated materials and their properties are described.

What is claimed is: 
     
         1 . A method of modifying an area of an electrical energy storage device element, comprising the steps of:
 providing an electrically conductive material having a surface that has an intrinsic area, and having an electrical terminal;   reacting said electrically conductive material with a plurality of electrically conductive particles; and   forming an electrical energy storage device element comprising said electrically conductive material having attached thereto at least some of said plurality of electrically conductive particles, thereby providing said electrical energy storage device element having an area that is increased relative to said intrinsic area of said electrically conductive material prior to said reacting step.   
     
     
         2 . The method of modifying an area of an electrical energy storage device element of  claim 1 , wherein said electrically conductive material comprises carbon nanotubes. 
     
     
         3 . The method of modifying an area of an electrical energy storage device element of  claim 1 , wherein said electrically conductive material comprises graphene. 
     
     
         4 . The method of modifying an area of an electrical energy storage device element of  claim 1 , wherein said plurality of electrically conductive particles comprises fullerene moieties. 
     
     
         5 . The method of modifying an area of an electrical energy storage device element of  claim 1 , wherein said plurality of electrically conductive particles comprises particles selected from the group of particles consisting of electrically conductive ions, electrically conductive molecules, and electrically conductive nanoparticles. 
     
     
         6 . The method of modifying an area of an electrical energy storage device element of  claim 1 , wherein said plurality of electrically conductive particles and said electrically conductive material having a surface are attached with covalent forces. 
     
     
         7 . The method of modifying an area of an electrical energy storage device element of  claim 1 , wherein said plurality of electrically conductive particles and said electrically conductive material having a surface are attached with non-covalent n-n bonds. 
     
     
         8 . The method of modifying an area of an electrical energy storage device element of  claim 1 , wherein said plurality of electrically conductive particles is provided in a liquid carrier. 
     
     
         9 . The method of modifying an area of an electrical energy storage device element of  claim 8 , further comprising the step of sonicating said electrically conductive particles with a solvent to form a reagent for reaction with said electrically conductive material. 
     
     
         10 . The method of modifying an area of an electrical energy storage device element of  claim 8 , further comprising the step of attaching said electrically conductive particles to said electrically conductive material via a sol-gel method. 
     
     
         11 . The method of modifying an area of an electrical energy storage device element of  claim 8 , further comprising the step of attaching said electrically conductive particles to said electrically conductive material via a plating method. 
     
     
         12 . The method of modifying an area of an electrical energy storage device element of  claim 1 , wherein said plurality of electrically conductive particles is provided in a gaseous carrier. 
     
     
         13 . The method of modifying an area of an electrical energy storage device element of  claim 12 , further comprising the step of physical vapor deposition of said plurality of electrically conductive particles onto said electrically conductive material. 
     
     
         14 . The method of modifying an area of an electrical energy storage device element of  claim 12 , further comprising the step of chemical vapor deposition of said plurality of electrically conductive particles onto said electrically conductive material.