July 6, 2000


Patent Gives Battery Research a Charge

Upton, N.Y. ,Researchers at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have been awarded U.S. Patent Number 6,022,643 for their work in developing a new kind of electrolyte for use in lithium-ion batteries. The new electrolyte is less expensive and more environmentally friendly than those currently used.

Rechargeable lithium-ion batteries now dominate the market for use as a power source in cell phones and many laptop computers. Researchers would like to scale up these batteries for use in electric and hybrid electric vehicles.

One problem, however, is that in today's lithium batteries, the salt component of the electrolyte, the fluid that carries the flow of electricity from the positive cathode to the negative anode, is expensive and toxic, explains Xiao-Qing Yang, one of the Brookhaven scientists. With the large quantities required for vehicle batteries, these drawbacks could become prohibitive.

So, with funding from the DOE's Office of Basic Energy Sciences, BNL's team has been looking at ways to improve the electrical conductivity of electrolytes containing less-expensive, less-toxic salts. In the technique for which they've been awarded a patent, the researchers have designed and synthesized a series of boron-based compounds that, when added to electrolytes, increase their electrical conductivity to a level comparable with those currently used.

"This opens up a new approach in developing electrolytes for lithium-ion batteries," says Hung Sui Lee, the chemist who was in charge of the organic synthesis work.

"There are still some improvements that need to be made," says Yang. Spectroscopy studies the team is conducting at Brookhaven's National Synchrotron Light Source will help. "By understanding how these additives work with the salt and the electrolyte at the molecular level, we can modify their molecular structures to improve their performance," Yang says.

The team, which also included James McBreen of Brookhaven Lab and Caili Xiang, a visiting scientist from China, has already gotten inquiries about licensing the invention, but nothing has been agreed to yet. One company that could benefit is Gould Electronics, Inc., a manufacturer of lithium-ion batteries that entered a Cooperative Research and Development Agreement (CRADA) with BNL last spring.

For more information on this CRADA, go to: http://www.pubaf.bnl.gov/pr/bnlpr031500.html

The U.S. Department of Energy's Brookhaven National Laboratory creates and operates major facilities available to university, industrial and government personnel for basic and applied research in the physical, biomedical and environmental sciences and in selected energy technologies. The Laboratory is operated by Brookhaven Science Associates, a not-for-profit research management company, under contract with the U.S. Department of Energy.


Note to local editors: Hung Sui Lee lives in East Setauket, New York; Xiao-Qing Yang lives in Port Jefferson, New York; James McBreen lives in Bellport, New York; Caili Xiang has returned to China.