Wedoany.com Report-Nov 25,Electrolytes that convert chemical to electrical energy underly the search for new power sources with zero emissions. Among these new power sources are fuel cells that produce electricity. Fuel cells are often heavy, which is a problem because lighter power sources enable more energy efficient fuel cell-powered vehicles. Therefore, scientists have been hard at work designing lightweight electrolytes—such as polymers that form electrolytic membranes—that are stable under the conditions in which electricity is generated.

By studying a model system using a combination of neutron scattering and computational models, the team of researchers from the Department of Energy’s Oak Ridge National Laboratory and Sandia National Laboratories and Clemson University discovered a way to control the structure of polymeric electrolyte membranes. These findings could enhance the efficiency and longevity of clean energy generating devices.

The team found that when they added ethanol, a solvent and a potential fuel for clean energy generation, they could manipulate the ionic clusters, thus controlling the conductivity and mechanical properties of the polymers.

The unique properties of neutrons allow researchers to identify the changes that occur while electricity is generated as protons and water diffuse across these membranes. Researchers come from all over the world to use neutrons produced at HFIR to better understand materials such as polymeric electrolyte membranes. HFIR provides a steady-state neutron beam and is the strongest reactor-based neutron source in the US.

To obtain their results, the team combined small-angle neutron scattering at HFIR on the GP-SANS instrument with computational studies performed at the National Energy Research Scientific Computing Center (NERSC), located at Lawrence Berkeley National Laboratory. These computations allowed the team to visualize how ethanol changes the ionic clusters. The computations helped determine that the alcohol molecules wrapped around the ions and opened the clusters just enough to allow the material to organize in a more stable way.

This research was funded by DOE’s Office of Science. HFIR and NERSC are DOE Office of Science user facilities.