Kazutaka Ikeda received his PhD from Tohoku University in 2006. During his PhD 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.
A high intensity neutron total diffractometer, NOVA, at J-PARC realizes new opportunity to explore structures ofcrystalline, amorphous and liquid materials in a short time, and clarify the structural changes during hydrogen absorption and desorption reactions of the hydrogen storage materials. 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) and a simple hydrogen desorption reaction (AlH3→ Al + 3/2H2) at 370-470 K. We investigated the structures of AlD3/AlH3 before the hydrogen desorption reaction by high intensity neutron (NOVA)/X-ray diffraction (BL02B2 at SPring-8) measurements. The presence of chi-Al2O3 (thickness 3-5 nm) on the surface of AlH3 particles (size 100-1000 nm) may prevent the hydrogen desorption reaction of AlH3 to Al at room temperature. Also, the local structures includingcrystallineand amorphous phase during the thermal decomposition reaction from LiAl(ND2) 4to Li3AlN2 and AlN accompanying ammonia desorption were investigated by PDF (atomic Pair Distribution Function) analysis. Some of recent results for structural study of aluminum-based hydrides on NOVA will be presented. This work was partially supported by the New Energy and Industrial Technology Development Organization (NEDO) under “Advanced Fundamental Research Project on Hydrogen Storage Materials (HydroStar)” and “Feasibility Study on Advanced Hydrogen Storage Materials for Automotive Applications (2012)”, JSPS KAKENHI Grant Numbers 23686101, 24241034, and the Neutron Scattering Program Advisory Committee of IMSS, KEK (Proposal No. 2009S06, 2014S06).