Nanotechnology enables paper batteries

Method aims at powering electric or hybrid cars

Professor Yi Cui and his research team at Stanford University (Stanford, CA) are developing a method for storing energy on plain, commercially available paper. By coating the paper with an ink infused with nanomaterials — carbon nanotubes and silver nanowires — the paper becomes highly conductive and could be used to create batteries and supercapacitors that are inexpensive, flexible, and lightweight.

Bing Hu, a post-doctoral fellow, prepares a small square of ordinary paper to with an ink that will deposit nanotubes on the surface which can then be charged with energy to create a battery.

These nanomaterials are one-dimensional structures with very small diameters, which helps the infused ink strongly adhere to the fibrous paper, making the batteries and supercapacitors very durable. Professor Cui notes that nanomaterials make ideal conductors because they can move electricity along much more efficiently than ordinary conductors. After treating the paper with the ink, it is baked and then folded into an electricity-generating source, such as foil, to create the battery.

The possibility for a paper battery or supercapacitor could be beneficial to a number of applications, including electric or hybrid cars, which depend on the quick transfer of electricity. Cui had previously worked to develop similar devices using plastics, but his recent research shows that a paper battery is more durable because the ink adheres more strongly to paper due to its porous texture.

Paper can also be crumpled, folded, even soaked in acidic or basic solutions with no notable degradation of performance. The research team’s work is reported in the paper “Highly Conductive Paper for Energy Storage Devices,” which has been published online in the Proceedings of the National Academy of Sciences .

For more information, visit http://news.stanford.edu/news/2009/december7/nanotubes-ink-paper-120709.html, or view the abstract of the team’s paper at http://tiny.cc/NT3W4.

Christina D’Airo