Graphene electrode, energy storage device employing the same, and method for fabricating the same

Abstract

The disclosure provides a graphene electrode, an energy storage device employing the same, and a method for fabricating the same. The graphene electrode includes a metal foil, a non-doped graphene layer, and a hetero-atom doped graphene layer. Particularly, the hetero-atom doped graphene layer is separated from the metal foil by the non-doped graphene layer.

What is claimed is: 
     
         1 . A graphene electrode, comprising:
 a metal foil;   a non-doped graphene layer; and   a hetero-atom doped graphene layer, wherein the hetero-atom doped graphene layer is separated from the metal foil by the non-doped graphene layer.   
     
     
         2 . The graphene electrode as claimed in  claim 1 , wherein the hetero-atoms doped in the hetero-atom doped graphene layer comprise nitrogen atoms, phosphorous atoms, boron atoms, or combinations thereof. 
     
     
         3 . The graphene electrode as claimed in  claim 1 , wherein the doped amount of hetero-atoms in the hetero-atom doped graphene layer is from 0.1 to 3 atom %, based on the total atomic amount of the hetero-atom doped graphene layer. 
     
     
         4 . The graphene electrode as claimed in  claim 1 , wherein the non-doped graphene layer is a single-layer graphene, or graphene nanosheets. 
     
     
         5 . The graphene electrode as claimed in  claim 1 , wherein the hetero-atom doped graphene layer is a single-layer hetero-atom doped graphene, or hetero-atom doped graphene nanosheets. 
     
     
         6 . A method for fabricating a graphene electrode, comprising:
 providing the metal foil;   forming the graphene layer on the metal foil; and   subjecting the graphene layer to a dry-process surface modification treatment, thereby doping the hetero-atoms into the graphene layer surface.   
     
     
         7 . The method as claimed in  claim 6 , wherein the hetero-atoms comprise nitrogen atoms, phosphorous atoms, boron atoms, or combinations thereof. 
     
     
         8 . The method as claimed in  claim 6 , wherein the hetero-atoms are doped into the surface of the graphene layer, forming the hetero-atom doped graphene layer. 
     
     
         9 . The method as claimed in  claim 6 , wherein the graphene layer has a portion which is not doped with the hetero-atoms. 
     
     
         10 . The method as claimed in  claim 9 , wherein the portion, which is not doped with the hetero-atoms, of the graphene layer is defined as the non-doped graphene layer. 
     
     
         11 . The method as claimed in  claim 6 , wherein the steps for forming the graphene layer comprise:
 forming the coating on the metal foil, wherein the coating is formed from a graphene-containing composition; and   subjecting the coating to a drying process, obtaining the graphene layer.   
     
     
         12 . The method as claimed in  claim 11 , wherein the graphene-containing composition comprises:
 a graphene; and   a binder.   
     
     
         13 . The method as claimed in  claim 12 , wherein the binder comprises an aqueous-based binder, an organic-based binder, or combinations thereof. 
     
     
         14 . The method as claimed in  claim 12 , wherein the graphene-containing composition further comprises a conducting agent. 
     
     
         15 . The method as claimed in  claim 14 , wherein the conducting agent comprises graphite, carbon black, or combinations thereof. 
     
     
         16 . The method as claimed in  claim 6 , wherein the dry-process surface modification treatment comprises a plasma modification process. 
     
     
         17 . The method as claimed in  claim 16 , wherein a reactive gas is introduced during the plasma modification process, and the reactive gas comprises nitrogen gas, ammonia gas, air, or combinations thereof. 
     
     
         18 . The method as claimed in  claim 17 , wherein the reactive gas further comprises argon gas, hydrogen gas, oxygen gas, or combinations thereof. 
     
     
         19 . The method as claimed in  claim 17 , wherein a carrier gas is introduced during the plasma modification process, and the carrier gas comprises helium gas, argon gas, nitrogen gas, neon gas, or combinations thereof. 
     
     
         20 . An energy storage device, comprising:
 a first electrode, wherein the first electrode is the graphene electrode as claimed in  claim 1 ;   a second electrode; and   an isolation membrane disposed between the first electrode and the second electrode.   
     
     
         21 . The energy storage device as claimed in  claim 20 , wherein the energy storage device is a lithium ion battery, supercapacitor or a fuel cell.