That's one of the dilemmas confronting efforts to power cars through re-chargeable battery technologies. In order to hold enough energy to enable a car trip of 300-500 miles before re-charging, current lithium-ion batteries become too big or too expensive.
In the search for the "post-lithium-ion" battery, Associate Professor of Chemistry Dunwei Wang has been developing materials that might one day enable the manufacture of new batteries capable of meeting power demands within the size and cost constraints of car makers and other industries.
In a recent report published in the German journalAngewandt Chemie, Wang and a colleague from the University of Massachusetts Amherst unveiled a new method of stabilizing carbon - a central structural component of any battery - that could pave the way to new performance standards in the hunt for a lithium-ion components.
Central to the search for improved performance is the ability to shed weight and costly chemical components. Researchers pursuing a lithium-air battery have focused on a chemical reaction of lithium and oxygen, which can be pulled from the atmosphere. But the materials used to generate this reaction have shown poor life cycles, lasting through just a few charges.
The culprit, said Wang, is the instability of carbon, an essential structural support to a battery's electrode, a conductor where charges collect and dispense.
"Carbon is used in every battery because it has that combination of low cost, light weight and conductivity," said Wang, whose research is funded in part by the National Science Foundation. "You can't just scrap it."
So Wang and UMass Assistant Professor of Chemical Engineering Wei Fan set to work improving the performance capabilities of a newly engineered form of carbon fabricated by Fan. It's called three-dimensionally ordered mesoporous “3DOm” carbon, valued by scientists for its highly ordered structure.