Graphene Energy Inc., an Austin, Texas-based startup formed in December 2008 to commercialize chemically modified graphene (CMG) ultracapacitors has raised $500,000 in seed money from Quercus Trust and 21Ventures.
The company also concluded licensing terms for its technology from the University of Texas at Austin and The College of William and Mary. Graphene Energy says that its technology is the result of the efforts of the Ruoff research group at the University of Texas at Austin.
The surface area of a single graphene sheet is 2,630 m2/g, substantially higher than values derived from BET surface area measurements of activated carbons used in current electrochemical double layer capacitors. The group measured specific capacitances of 135 and 99 F/g in aqueous and organic electrolytes, respectively, in devices using the CMG material.
Professor Rod Ruoff said: Through such a device, electrical charge can be rapidly stored on the graphene sheets, and released from them as well for the delivery of electrical current and, thus, electrical power. There are reasons to think that the ability to store electrical charge can be about double that of current commercially used materials. We are working to see if that prediction will be borne out in the laboratory.
Treehugger noted in the comments to the greencarcongress article:
Double the current capacity of best commercially available ultra-capacitor will be bring you close to 30Wh/Kg which is the value of a Pb battery (but more in practice since you can do full deep discharge on an ultra-capacitor and you cannot on the battery so you are more close to the equivalent of 60Wh/Kg battery in practice)
Meryl D. Stoller, Sungjin Park, Yanwu Zhu, Jinho An, and Rodney S. Ruoff (2008) Graphene-Based Ultracapacitors. ASAP Nano Lett., doi: 10.1021/nl802558y