High Energy Accelerator Research Organization, Japan
Kazutaka Ikeda received his Ph.D. from Tohoku University in 2006. During his Ph.D. and postdoctoral studies at Institute for Materials Research, Tohoku University, he was also a research fellow for young scientists of the Japan Society for the Promotion of Science. After serving as an assistant Professor at the same institute, he moved to Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK) as a research associate Professor. His current research interests include material design of hydrogen storage materials and structural study by comprehensive use of multi-probes such as high intensity neutrons and synchrotron light.
Aluminum trihydride (AlH3, alane) is one of the potential candidates for hydrogen storage materials because of high gravimetric and volumetric hydrogen densities (10 mass% and 149 kgH2/m3, respectively) and a simple hydrogen desorption reaction (AlH3→Al+3/2H2) at 370-470 K. In-situ microscopic observations combined with thermal, surface and atomic structural analyses confirmed that primary AlH3 particles of size 100 nm-1 μm were covered by an oxide layer of thickness 3-5 nm. Both the precipitation/grain-growth of metallic Al of size 1-50 nm and an increase in boundary space were clearly observed inside the particles, while the morphologies of the particles covered by the layer did not change during the hydrogen desorption reaction. We investigated the structures of AlD3/AlH3 before the hydrogen desorption reaction by high intensity neutron (BL21 high intensity neutron total diffractometer (NOVA) in J-PARC)/X-ray diffraction (BL02B2 in SPring-8) measurements. The presence of χ-Al2O3 on the surface may prevent the deuterium/hydrogen desorption reaction of AlD3/AlH3 to Al at room temperature.