Speaker: Prof. Vidvuds Ozolins
(Dept. of Materials Science and Engineering, Univ. of California)
Title: First-principles design of hydrogen storage materials
Time: 15:30, Tue., March 15, 2011
Venue: Dr. C. T. Chang Memorial Hall (4F), IAMS, AS
Contact: Dr. Jer-Lai Kuo
General adoption of hydrogen as a vehicular fuel depends on the ability to store hydrogen at high volumetric and gravimetric densities, as well as on the ability to extract it at sufficiently rapid rates. Practical requirements for on-board hydrogen storage systems are very challenging and cannot be met with existing technologies, and significant effort has been invested in searching for new materials that could efficiently store hydrogen at near ambient temperatures and pressures. Among the various hydrogen storage options (such as compressed gas, sorbents and metal-organic frameworks, chemical liquid hydrides), solid-state storage in multicomponent complex hydrides has attracted particular attention due to the very high storage densities and favorable thermodynamics that can be achieved in these systems. We will show how first-principles theoretical calculations based on the fundamental physics theories of quantum mechanics and statistical mechanics can be used as a valuable tool for understanding and predicting novel hydrogen storage materials. Recent studies in our group have used density-functional theory (DFT) calculations to (i) predict crystal structures of new solid-state hydrides, (ii) determine phase diagrams and thermodynamically favored reaction pathways in multinary hydrides, and (iii) study microscopic kinetics of diffusion, phase transformations, and hydrogen release.