There is worldwide interest in the use of hydrogen as the basis for a future sustainable energy system with low carbon emissions. Cars powered by hydrogen-based fuel cells are widely regarded as the first major inroad into the hydrogen economy. However, a suitable material for on-board storage should be able to store a high weight-percent and high volume density of hydrogen and, equally importantly, rapidly discharge and charge this same amount of hydrogen at acceptable temperatures (typically around 50-100°C). This represents a particular challenging set of credentials for an ideal storage material and at present no known material meets these critical requirements. The GEM diffractometer at ISIS has been used in conjunction with the high resolution powder diffractometer, ID31, at the ESRF to determine the crystal structure of a new candidate material for hydrogen storage, Li4BN3H10. Importantly, the high count-rate of GEM enabled the material to be studied without any isotopic enrichment thus accelerating the ability to determine new hydride storage materials.
These ultra-lightweight materials, Li4BN3H10 (left) and LiNH2 (right), under development within the UK Sustainable Hydrogen Energy Consortium (UK-SHEC), offer significant hydrogen storage potential. Amazingly, they contain a higher density of hydrogen (illustrated as white spheres) than liquid hydrogen itself.
PA Chater (University of Birmingham), WIF David (ISIS), SR Johnson, PP Edwards (University of Oxford), PA Anderson (University of Birmingham)
Research date: December 2006
Further information: Prof WIF David, [firstname.lastname@example.org] PA Chater et al., Chem. Comm. 23 (2006) 2439.