Ordinary paper could one day be used as a lightweight battery to power the devices that are now enabling the printed word to be eclipsed by e-mail, e-books and online news.

Scientists at Stanford University in California report they have successfully turned paper coated with ink made of silver and carbon nanomaterials into a "paper battery" that holds promise for new types of lightweight, high-performance energy storage.

The same feature that helps ink adhere to paper allows it to hold onto the single-walled carbon nanotubes and silver nanowire films.

Earlier research found that silicon nanowires could be used to make batteries 10 times as powerful as lithium-ion batteries now used to power devices such as laptop computers.

"Taking advantage of the mature paper technology, low cost, light and high-performance energy-storage are realised by using conductive paper as current collectors and electrodes," the scientists said in research published in the Proceedings of the National Academy of Sciences.

This type of battery could be useful in powering electric or hybrid vehicles, would make electronics lighter weight and longer lasting, and might even lead someday to paper electronics, the scientists said. Battery weight and life have been an obstacle to commercial viability of electric-powered cars and trucks.

"Society really needs a low-cost, high-performance energy storage device, such as batteries and simple supercapacitors," Stanford assistant professor of materials science and engineering and paper co-author Yi Cui said.

Professor Cui said in an email that in addition to being useful for portable electronics and wearable electronics: "Our paper supercapacitors can be used for all kinds of applications that require instant high power."

"Since our paper batteries and supercapacitors can be very low cost, they are also good for grid-connected energy storage," he said.

Peidong Yang, professor of chemistry at the University of California-Berkeley, said the technology could be commercialised within a short time.

- Reuters