Polyelectrolytes are critically important as ion transport media in fuel cell applications and exhibit growing potential in battery technologies. Material properties (e.g., structure, charge transport, mechanical properties) at interfaces and under confinement play a significant role in device performance in these applications. Performance limitations are often characterized as arising from interfacial effects; however, challenges remain in measuring material properties at interfaces (or under confinement) and under device-relevant conditions. This makes it exceedingly difficult to identify and elucidate the molecular, physical, and chemical origins of performance limitations at interfaces. This project focuses on developing new in-situ metrologies and methods to quantify the structural, dynamical, and interfacial and bulk properties of polyelectrolytes that may be the origin(s) for hindered charge transport, durability, and performance in fuel cell and battery technologies. These measurements provide a platform to quantify and validate models for the origins of interfacial (and bulk) performance limitations and could serve as a means for materials, and device, design and development for energy storage and delivery technologies. Investigational methods include, but are not limited to grazing incidence small-angle X-ray and neutron scattering, quasi-elastic neutron scattering, dielectric spectroscopy, environmentally controlled atomic force microscopy, thin film mechanics, infrared reflectance-absorbance spectroscopy, and reflectivity using both x rays and neutrons. This project is an ongoing collaborative effort with close interaction with other government laboratories and industrial researchers.

References

Eastman SA; et al: Macromolecules 45 (19): 7920, 2012

Modestino MA, et al: Macromolecules 45 (11): 4681, 2012