"Just think how often your fancy new mobile phone or computer has become little more than a paperweight because the battery lost its zeal for doing its job," says John Chmiola, a chemist with the Lawrence Berkeley National Laboratory (Berkeley Lab). "At a time when cellphones can do more than computers could do at the beginning of the Clinton presidancy, it would be an understatement to say that batteries have not been holding up their end of the mobile device bargain."
Chmiola is a staff scientist in the Advanced Energy Technologies Department of Berkeley Lab's Environmental Energy Technologies Division. His research is aimed at addressing this problem of relatively short-lived portable energy storage devices. Chmiola believes he has found a solution in electrochemical capacitors, which are commonly referred to as "supercapacitors" because of their higher energy storage densities than conventional dielectric capacitors and higher abuse tolerance than batteries.
In a paper published in the April 23, 2010 issue of the journal Science, titled "Monolithic Carbide-Derived Carbon Films for Micro-Supercapacitors," Chmiola and Yury Gogotsi of Drexel University, along with other co-authors, describe a unique new technique for integrating high performance micro-sized supercapacitors into a variety of portable electronic devices through common microfabrication techniques.
By etching electrodes made of monolithic carbon film into a conducting substrate of titanium carbide, Chmiola and Gogotsi were able to create micro-supercapacitors featuring an energy storage density that was at least double that of the best supercapacitors now available. When used in combination with microbatteries, the power densities and rapid-fire cycle times of these micro-supercapacitors should substantially boost the performance and longevity of portable electric energy storage devices.
"The prospect of integrating batteries and supercapacitors with
|Contact: Lynn Yarris|
DOE/Lawrence Berkeley National Laboratory