- News Home
17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
- About Us
Cheap Batteries Designed From Scratch
15 April 1998 7:00 pm
A cheaper, lighter version of the lithium batteries used in laptop computers and cellular phones may soon become available. Researchers have found a way to replace cobalt--the most expensive component of these batteries--with aluminum. The new material, described in today's issue of Nature, is the first of its kind to be designed using theoretical calculations rather than simply by trial and error.
Batteries discharge electricity by sending a stream of electrons from a positive to a negative electrode, thus powering any device that dips into that stream. In lithium batteries, the negative electrodes are made up of an oxide of lithium and cobalt. Cobalt is expensive, but scientists thought that only metals like cobalt could satisfactorily discharge the current. One strategy for finding a replacement electrode would be to fabricate and test countless combinations of lithium-metal oxides. Gerd Ceder and his colleagues at the Massachusetts Institute of Technology wanted to search in a more directed way.
Armed with the basic laws of quantum mechanics, they developed a computer simulation that predicted the properties of different materials. The calculations identified a promising replacement: an oxide made primarily of lithium and aluminum. The team synthesized this new material and experimentally confirmed their predictions. That aluminum works supports a previous finding of theirs that oxygen is more important than cobalt in accepting electrons from the positive electrode.
The work is a "marvelous" example of how theory can point to an experiment, says Didier de Fontaine, a materials scientist at the University of California, Berkeley, who has done pioneering work in calculating the properties of complicated materials from the ground up. Ceder and his colleagues say they have already developed a different material, based on the same approach, that could be ready to use in a battery in less than a year.