By sussing out an improved process for adding chains of nanoparticles to nanowires, researchers at Stanford think they've found a path to better batteries and solar cells.
The new method, dubbed the sol-flame method according to Stanford University, is better at "decorating" nanowires than earlier techniques, and the simplicity of the new process may make it easier to create batteries with higher density energy storage as well as more efficient solar cells. The secret is in making the surface of the nanowire as full of bumps and valleys as possible to increase surface area, and the addition of these many nanoparticles does just that. And the process which fixes the nanoparticles to the nanowires is fire.
According to Stanford:
Zheng dipped the nanowires in a solvent-based gel of metal and salt, then air-dried them before applying the flame. In her process the solvent burns away in a few seconds, allowing the all-important nanoparticles to crystalize into branch-like structures fanning out from the nanowires.
“We were a little surprised by how well it worked,” said Zheng. “It performed beautifully.”
Zheng and team have dubbed the technique the sol-flame method, for the combination of solvent and flame that yields the nanoparticle structures. The method appears general enough to work with many nanowire and nanoparticle materials and, perhaps more importantly, provides an unprecedented degree of engineering control in creating the nanoparticle decorations.
The hope of the researchers is that this process could improve the techniques used in manufacturing better batteries and solar cells. But it will be a long time, and a lot of testing, before the sol-flame method is widely used.