The layer-by-layer fabrication technique used to make the 3-micrometer-thick carbon nanotube electrode described in the published paper was an extremely time-consuming process. For each layer of nanotubes, a sample had to be dipped into a solution awash with nanotubes.
Then, covered in the solution, the sample had to be left out for 15 to 20 minutes as gravity slowly pulled the nanotubes down through the liquid and onto the sample surface. This procedure had to be repeated about 400 times in order to pile up enough layers to reach a thickness of 3 micrometers.
To bring the layering process up to reasonable, commercially viable speeds, Hammond is appropriating an automatic spray technique she developed for producing layers of polymer materials.
"The spray method is 40 to 100 times faster," she said, taking only seconds to lay down each new layer of nanotubes rather than the 15 to 20 minutes it normally takes. The true test will come once much thicker electrodes are tested.
Other battery research from Shao-Horn's group has been highlighted in other ClimateWire stories.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500