CHARACTERIZATION OF BOROHYDRIDES AS HYDROGEN STORAGE MATERIALS USING NEUTRON SCATTERING TECHNIQUES

Nina Verdal¹, Michael Hartman², Theodore Baumann³, Adam Gross⁴, John Vajo⁴, John J. Rush^1,5, Terrence J. Udovic¹

¹NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102

²Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109-2104

³Advanced Materials Synthesis Group, Lawrence Livermore National Laboratory

Livermore, California 94550

⁴HRL Laboratories, LLC, 3011 Malibu Canyon Rd, Malibu, CA 90265

⁵Department of Materials Science and Engineering, University of Maryland,
College Park, MD 20742-2115

Materials relevant to hydrogen storage have been characterized using primarily quasielastic and vibrational neutron scattering.  The reorientational mechanism and activation energy have been determined for bulk KBH₄ and NaBH₄.  Quasielastic neutron scattering of bulk and nanoconfined LiBH₄ show that nanoconfinement of these materials lowers the temperature of the onset of reorientational dynamics.  A popular material for nanoconfinement, carbon aerogels have been studied by vibrational spectroscopy and prompt gamma analysis.  The carbon to hydrogen ratio in the aerogels increases as a function of annealing temperature.  This knowledge helps standardize dehydrogenation results of the nanoconfined borohydrides.