Graphene fiber and method for manufacturing same

Abstract

The present invention relates to a method for manufacturing a graphene fiber and a graphene fiber manufactured thereby, comprising the following steps: a) preparing a dispersion liquid by dispersing graphene with a surfactant in a solvent; b) preparing a composite fiber by mixing the dispersion liquid with a polymer solution, wet spinning and drying same; and c) removing polymers by heat-treating or treating the composite fiber with strong acid. The graphene fiber manufactured by the method has superior electric and mechanical properties, is flexible, and can be utilized as a storage medium for energy, hydrogen, etc. due to porosity from having a wrinkled structure.

1 . A method for producing a graphene fiber, comprising
 a) dispersing graphene and a surfactant in a solvent to prepare a dispersion,   b) incorporating the dispersion into a polymer solution, wet spinning the resulting solution, followed by drying to produce a composite fiber, and   c) annealing the composite fiber or treating the composite fiber with a strong acid to remove the polymer.   
     
     
         2 . The method according to  claim 1 , wherein the graphene is chemically reduced graphene or graphene oxide. 
     
     
         3 . The method according to  claim 2 , wherein the chemically reduced graphene is prepared by reducing an aqueous dispersion of graphene with hydrazine at 90 to 100° C. for 1 to 24 hours. 
     
     
         4 . The method according to  claim 1 , wherein the annealing is performed at a temperature of 300 to 1000° C. 
     
     
         5 . The method according to  claim 1 , wherein the strong acid is selected from hydrochloric acid, sulfuric acid, a piranha solution consisting of a mixture of sulfuric acid and hydrogen peroxide, a mixture of sulfuric acid and oleum, and mixtures thereof. 
     
     
         6 . The method according to  claim 1 , wherein the graphene is 100 to 1000 nm in length. 
     
     
         7 . The method according to  claim 1 , wherein the surfactant is selected from sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfonate (SDS), Triton X-100, and cetyltrimethylammonium bromide (CTAB). 
     
     
         8 . The method according to  claim 1 , wherein the polymer is selected from polyvinyl alcohol (PVA) and poly(methyl methacrylate) (PMMA). 
     
     
         9 . The method according to  claim 1 , wherein the contents of the graphene and the polymer in the graphene composite fiber are from 20 to 90% by weight and from 10 to 80% by weight, respectively. 
     
     
         10 . A porous graphene fiber comprising graphene whose wrinkled structure is maintained. 
     
     
         11 . The graphene fiber according to  claim 10 , wherein the graphene fiber has an electrical conductivity of 10 to 100 S/cm. 
     
     
         12 . The graphene fiber according to  claim 10 , wherein the graphene fiber has an electrochemical capacitance of 100 to 300 F/g. 
     
     
         13 . The graphene fiber according to  claim 10 , wherein the graphene fiber has a porosity of 1000 to 2000 m 2 /g. 
     
     
         14 . The graphene fiber according to  claim 10 , wherein the graphene fiber is flexible. 
     
     
         15 . The graphene fiber according to  claim 10 , wherein the porous graphene fiber is capable of being formed into knot and spring structures and being woven into a fabric. 
     
     
         16 . A supercapacitor comprising the graphene fiber according to  claim 10 . 
     
     
         17 . An energy or hydrogen storage medium comprising the graphene fiber according to  claim 10 .