New York, Sep 14 (IANS) Scientists have created a new battery that uses plastic, not metal, to conduct electrical current.

Brown University engineers Hyun-Kon Song and Tayhas Palmore have created the thin, light flexible and hybrid prototype polymer-based battery packs that deliver more power than a standard alkaline battery and have more storage capacity than a double-layered capacitor, according to a release posted in the university website.

Battery makers are always looking for new ways to more efficiently store and deliver power. NASA and the US Air Force are also exploring polymer-based batteries.

The researchers began to experiment with a new energy-storage system using a substance called polypyrrole, a chemical compound that carries an electrical current.

In their experiments, the researchers took a thin strip of gold-coated plastic film and covered the tip with polypyrrole and a substance that alters its conductive properties. The process was repeated, this time using another kind of conduction-altering chemical.

During performance testing, the new battery performed like a hybrid, too. It had twice the storage capacity of an electric double-layer capacitor. Moreover, it delivered more than 100 times the power of a standard alkaline battery.

But Palmore said the new battery's form, as well as its function, is exciting. In width and height, it is smaller than an iPod Nano.

Palmore said some performance problems - such as decreased storage capacity after repeated recharging - must be overcome before the device is marketable.