Energy Storage: Scientists Observe Transformation of Copper Sulfide Nanorods

[kristopher]

Energy Storage: Scientists Observe Transformation of Copper Sulfide Nanorods
Written by Nancy Lamontagne | 12 July 2011

Researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory have directly observed structural transformations of a single nanocrystal of copper sulfide, a semiconductor expected to play an important role in future batteries for energy storage.

Fast Fourier transform pattern (left) and high resolution TEM images of the low-chalcocite (green) and high-chalcocite (red) domains in a copper sulfide nanorod.
Some solid materials, especially at the nanoscale, can transition between two more different phases in their crystal structure in response to temperature changes. Copper sulfide, for example, can transform from a complex hexagonal structure known as the low-chalcocite phase to a more simple hexagonal structure known as the high-chalcocite phase.

Studying fluctuations in copper sulfide as it transitions between crystal structures is important for understanding how ion transport occurs within electrodes during the charging and discharging of batteries and how the structures of a solid material might change at the interface between an electrode and an electrolyte.

Using TEAM 0.5, one of the world's most powerful transmission electron microscopes, researchers led by Berkeley Lab director Paul Alivisatos, observed structural fluctuations in a copper sulfide nanorod as it transitioned between the low- and high-chalcocite solid-state phases. Their detailed observations showed that the structural transformation dynamics of the nanorod were strongly influenced by defects. The information revealed possible routes for suppressing or assisting transformation in ways could aid in the future design of materials.

TEAM stands for Transmission Electron Aberration-corrected Microscope...

http://www.solarnovus.com/index.php?option=com_content&view=article&id=3189:energy-storage-scientists-observe-transformation-of-copper-sulfide-nanorods&catid=52:applications-tech-research&Itemid=247