Friday, May 13, 2011
Carbon “sponge” could charge supercapacitors

University of Texas at Austin collaborators Meryl Stoller, Dr. Yanwu Zhu and Dr. Rodney Ruoff stand with a 3-D model of the new carbon material they have created.
The significance of the discovery is the potential it offers for enabling supercapacitors to deliver significantly more charge, opening the doors to many potential unprecedented uses for this type of electrical energy storage device.
Supercapacitors are known as the “sprinters” among electrical energy storage devices, able to deliver energy much faster and more efficiently than batteries, but usually holding much less electrical charge, while batteries are like marathon runners, delivering energy slowly, but steadily.
The findings were made by a research group led by materials science and mechanical engineering Professor Rodney S. Ruoff in the Cockrell School of Engineering and published May 12 by Science in its online publication ScienceXpress.
“We synthesized a new sponge-like carbon that has a surface area of up to 3,100 square meters per gram (two grams has a surface area roughly equivalent to that of a football field). It also has much higher electrical conductivity and, when further optimized, will be superb for thermal management as well,” Ruoff said. “The processes used to make this porous carbon are readily scalable to industrial levels.
“After we realized that we had a new carbon with a highly novel structure that showed superb performance as an electrode, we knew that this direction of research — to create carbon materials that consist of a continuous three-dimensional porous network with single-atom-thick walls — was likely to yield the optimum electrode material for supercapacitors.”
Ruoff’s team at Texas included postdoctoral fellow Dr. Yanwu Zhu and graduate students Shanthi Murali and Meryl Stoller,






