Rose madder a natural plant dye once prized throughout the Old World to make fiery red textiles has found a second life as the basis for a new "green" battery.
Chemists from The City College of New York teamed with researchers from Rice University and the U.S. Army Research Laboratory to develop a non-toxic and sustainable lithium-ion battery powered by purpurin, a dye extracted from the roots of the madder plant (Rubia species).
More than 3500 years ago, civilizations in Asia and the Middle East first boiled madder roots to color fabrics in vivid oranges, reds and pinks. In its latest technological incarnation, the climbing herb could lay the foundation for an eco-friendly alternative to traditional lithium-ion (Li-ion) batteries. These batteries charge everything from your mobile phone to electric vehicles, but carry with them risks to the environment during production, recycling and disposal.
"Purpurin," on the other hand, said team member and City College Professor of Chemistry George John, "comes from nature and it will go back to nature." The team reports their results in the journal Nature's online and open access publication, Scientific Reports, on December 11, 2012.
Most Li-ion batteries today rely on finite supplies of mined metal ores, such as cobalt. "Thirty percent of globally produced cobalt is fed into battery technology," noted Dr. Leela Reddy, lead author and a research scientist in Professor Ajayan's lab in the Department of Mechanical Engineering and Material Science at Rice University. The cobalt salt and lithium are combined at high temperatures to make a battery's cathode, the electrode through which the electric current flows.
Mining cobalt metal and transforming it, however, is expensive, he explained. Fabricating and recycling standard Li-ion batteries demands high temperatures, guzzling costly energy, especially during recycling. "In 2010, almost 10 billion lithium-i
|Contact: Jessa Netting |
City College of New York