Copper wires may also work as batteries, Florida researchers say

By Barbara Liston ORLANDO Fla. (Reuters) - A breakthrough in the way energy is stored could lead to smaller electronics, more trunk space in a hybrid car and eventually clothing that can recharge a cellphone, according to researchers at the University of Central Florida. Nanotechnology scientist Jayan Thomas said in an interview he believes he has discovered a way to store energy in a thin sheath around an ordinary lightweight copper electrical wire. As a result, the same wire that transmits electricity can also store extra energy. "We can just convert those wires into batteries so there is no need of a separate battery," Thomas said. "It has applications everywhere." The work will be the cover story in the June 30 issue of the material science journal Advanced Materials, and is the subject of an article in the current edition of science magazine Nature. Thomas's Ph.D. student Zenan Yu is co-author. Thomas said the process is relatively simple. First, he said, he heated the copper wire to create what he described as fuzzy "nano-whiskers," which are naturally insulated by copper oxide. The microscopic nano-whiskers vastly expand the wire's surface area that can store energy. A second plastic-covered layer of nano-whiskers creates a second electrode, similar to the positive and negative sides of a standard battery, Thomas said. The technique could be used to lighten airplanes and spacecraft, to store excess energy from solar panels, and to further miniaturize small electronics, he said. The technique could also replace high energy-density supercapacitors, sometimes mistaken by hybrid car owners as a second battery, which provide the quick shot of energy that cars and heavy machinery need to start. "You open your trunk and you see a lot of space is taken by your batteries. If you can just use some of the cables along the length of your car, you don't need any of that space for batteries," Thomas said. He plans further research to apply the same technique to fibers woven into clothing along with a flexible solar cell, creating a wearable battery pack. Thomas is a faculty member at the UCF Nanoscience Technology Center with joint appointments in the College of Optics and Photonics and the College of Engineering and Computer Science. (Editing by Kevin Gray)