The Future of Energy Storage: Printable, Moldable Batteries Made From Paper
Those who are quick to dismiss paper as old-fashioned should hold off on the trash talk. Scientists have made batteries and supercapacitors with little more than ordinary office paper and some carbon and silver nanomaterials. The research, published online December 7 in Proceedings of the National Academy of Sciences, brings scientists closer to lightweight printable batteries that may one day be molded into computers, cell phones or solar panels.
"Power storage is one of the very important aspects of solving the energy issue," comments Robert Linhardt of Rensselaer Polytechnic Institute in Troy, N.Y. The paper-based devices show excellent performance.
That performance is largely due to paper’s porous nature: at the nano scale, paper is a tangled matrix of fibers. This vast surface area helps inks stick, says Yi Cui of Stanford University, coauthor of the new work. This holds true for carbon nanotube ink as well. When carbon-nanotube ink touches paper, the nanotubes "get caught very tightly to the cellulose," says Cui, probably just via good old electrostatic forces.
The paper acts as a scaffold, and the carbon nanotubes act as electrodes that electrolytes in solution react with. This nanotube-paper combination offers a lightweight alternative to traditional energy storage devices that rely on metals.
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Image: A carbon nanotube.
Photo: A c