Metal Hydrides
Fundamental Research on Metal Hydrides for Hydrogen Storage
Scope
Metal hydrides called ehydrogen-absorbing alloysf have excellent properties of absorbing and desorbing hydrogen under ambient condition between room temperature and ~100 C. The hydrogenation is a chemical reaction including the following steps: hydrogen molecules are dissociated into atoms on the metal surface, they are solved into the metal, and metal and hydrogen atoms make bonding between them (Figure). The reaction is accompanied by lattice expansion and deformation but by no phase separation. Hydrogenation properties strongly depend on estructuref, i.e. arrangement of metal and hydrogen atoms. In this project, structural studies in various scales are conducted for understanding hydrogenation properties and reaction mechanisms, using in situ observation intensively.
Goals
- Establish methods for structural characterization of materials using advanced techniques.
- Find out a direction for understanding essential hydrogenation properties and reaction mechanisms
Techniques to be used
- X-ray diffraction: Crystal structures, variation of metal lattice during hydrogen absorption/desorption
- Neutron diffraction/ total scattering: Crystal and local structures including position of hydrogen atoms
- Positron annihilation: Lattice defects induced by hydrogen absorption/desorption
- Nuclear Magnetic Resonance (NMR): Local structure around interstitial hydrogen atoms, diffusion of hydrogen atoms
- Transmission Electron Microscopy (TEM): Lattice defects and nanoscale structure
Members
- Hydrogen Energy Group, Energy Technology Research Institute, AIST
- Nano-Dynamics Analysis Research Group, Research Institute of Instrumentation Frontier, AIST
- Los Alamos Neutron Science Center (LANSCE), Los Alamos National Laboratory, USA (Neutron powder diffractometer, NPDF)
- International Institute of Carbon-neutral Energy Research, Kyushu University