Canadian scientists create powerful new lithium battery material Last Updated: Monday, May 18, 2009 | 1:00 PM ET Comments7Recommend14 CBC News
Lithium batteries could deliver more than three times their usual power if they contained a new composite material invented by scientists at the University of Waterloo, a study suggests. The material created by chemistry professor Linda Nazar and her research team contains sulphur, a cheap substance that scientists have been trying to incorporate into rechargeable lithium batteries for a long time, said a news release Monday. The challenge had been to find a way to keep the electrically active sulphur in intimate contact with a conductor such as carbon, Nazar said in a statement. She and her research group described their solution to the problem in a report published Sunday in the advance online edition of Nature Materials. The researchers took mesoporous carbon, a material riddled with extremely fine channels that are about 1/20,000th of the width of a human hair. When it was put in contact with melted sulphur, the hot liquid was drawn by capillary forces into the channels, where it solidified into nanofibres. The new carbon-sulphur composite was used as the cathode, the positive electrode of a test battery, and showed what the researchers called an "impressive capacity." "This composite material can supply up to nearly 80 per cent of the theoretical capacity of sulphur, which is three times the energy density of lithium [traditional] transition metal oxide cathodes," Nazar said in a statement. In addition, the material remained stable when recharged multiple times. Nazar said a patent had been filed for the material and her team is continuing to study the material in an effort to refine the battery's performance.
