Flexible paper batteries could meet the energy demands of the next generation of gadgets, says a team of researchers.
They have produced a sample slightly larger than a postage stamp that can store enough energy to illuminate a small light bulb.
But the ambition is to produce reams of paper that could one day power a car.
Professor Robert Linhardt, of the Rensselaer Polytechnic Institute, said the paper battery was a glimpse into the future of power storage.
The team behind the versatile paper, which stores energy like a conventional battery, says it can also double as a capacitor capable of releasing sudden energy bursts for high-power applications.