Solid-State Hydriding Mechanism in the LiBH4 + MgH2 System

Journal Article · Thu May 06 04:00:00 EDT 2010 · Journal of Physical Chemistry C, 114(17):8089-8098

DOI:https://doi.org/10.1021/jp1003837· OSTI ID:979846

Shaw, Leon L; Wan, Xuefei; Hu, Jian Z; Kwak, Ja Hun; Yang, Zhenguo

The LiBH4+MgH2 system has great potential in reversible hydrogen storage for fuel cell vehicles. However, it has always been dehydrogenated and re-hydrogenated in the liquid state until recently. The solid-state hydriding and dehydriding are necessary in order to achieve hydrogen uptake and release near the ambient temperature. In this study, the solid-state hydriding mechanism of 2LiH+MgB2 mixtures has been investigated for the first time. It is found that the solid-state hydriding proceeds in two elementary steps. The first step is the ion exchange between the Mg2+ and Li+ ions in the MgB2 crystal to form an intermediate compound (Mg1-xLi2x)B2. The second step is the continuous ion exchange and simultaneous hydrogenation of (Mg1-xLi2x)B2 to form LiBH4 and MgH2. This finding is consistent with the observed diffusion-controlled hydriding kinetics.*

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 979846
• Report Number(s): PNNL-SA-71617; 30406
• Journal Information: Journal of Physical Chemistry C, 114(17):8089-8098, Journal Name: Journal of Physical Chemistry C, 114(17):8089-8098 Journal Issue: 17 Vol. 114; ISSN 1932-7447
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
30 DIRECT ENERGY CONVERSION
AMBIENT TEMPERATURE
Environmental Molecular Sciences Laboratory
FUEL CELLS
HYDROGEN
HYDROGEN STORAGE
HYDROGENATION
ION EXCHANGE
KINETICS
MIXTURES