IGERT Story
Researchers develop graphene supercapacitor holding promise for portable electronics
Description
Electrochemical capacitors (ECs), also known as supercapacitors or ultracapacitors, differ from regular capacitors that you would find in your TV or computer in that they store substantially higher amounts of charges. They have garnered attention as energy storage devices as they charge and discharge faster than batteries, yet they are still limited by low energy densities, only a fraction of the energy density of batteries. An EC that combines the power performance of capacitors with the high energy density of batteries would represent a significant advance in energy storage technology. This requires new electrodes that not only maintain high conductivity but also provide higher and more accessible surface area than conventional ECs that use activated carbon electrodes.
Now researchers at UCLA have used a standard LightScribe DVD optical drive to produce such electrodes. The electrodes are composed of an expanded network of graphene — a one-atom-thick layer of graphitic carbon — that shows excellent mechanical and electrical properties as well as exceptionally high surface area.
UCLA researchers from the Department of Chemistry and Biochemistry, the Department of Materials Science and Engineering, and the California NanoSystems Institute demonstrate high-performance graphene-based electrochemical capacitors that maintain excellent electrochemical attributes under high mechanical stress. The paper is published in the journal Science.
“Our study demonstrates that our new graphene-based supercapacitors store as much charge as conventional batteries, but can be charged and discharged a hundred to a thousand times faster,” said Richard B. Kaner, professor of chemistry & materials science and engineering.
“Here, we present a strategy for the production of high-performance graphene-based ECs through a simple all solid-state approach that avoids the restacking of graphene sheets,” said Maher F. El-Kady, the lead author of the study and a graduate student in Kaner’s lab.
