Graphene-based ultracapacitors.
The surface area of a single graphene sheet is 2630 m(2)/g, substantially higher than values derived from BET surface area measurements of activated carbons used in current electrochemical double layer capacitors. Our group has pioneered a new carbon material that we call chemically modified graphene (CMG). CMG materials are made from 1-atom thick sheets of carbon, functionalized as needed, and here we demonstrate in an ultracapacitor cell their performance. Specific capacitances of 135 and 99 F/g in aqueous and organic electrolytes, respectively, have been measured. In addition, high electrical conductivity gives these materials consistently good performance over a wide range of voltage scan rates. These encouraging results illustrate the exciting potential for high performance, electrical energy storage devices based on this new class of carbon material.
Stoller
Meryl D
MD
Department of Mechanical Engineering and Texas Materials Institute, University of Texas at Austin, One University Station C2200, Austin, Texas 78712-0292, USA.
Park
Sungjin
S
Zhu
Yanwu
Y
An
Jinho
J
Ruoff
Rodney S
RS
D002244:Carbon / Q000737:chemistry; D003460:Crystallization / Q000379:methods; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods; D004573:Electrolytes; D006108:Graphite / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D013499:Surface Properties
D004573:Electrolytes; D037742:Nanotubes, Carbon; D010087:Oxides; D002244:Carbon; D006108:Graphite