Researchers in the UK have revealed the structure of a compound they say could have a major impact on hydrogen storage.  

Before transport powered by hydrogen fuel-cells can become a reality, materials that can store adequate amounts of hydrogen are needed. Paul Anderson at  the University of Birmingham and co-workers mixed different ratios of lithium amide and lithium borohydride, uncovering a body centred cubic structure identified as Li₄BH₄(NH₂)₃. The researchers say this compound has a high hydrogen gravimetric storage density (11 percent by weight) and when it breaks down it releases hydrogen.  This is in contrast to LiNH₂, which releases ammonia on decomposition.

The structure of the compound plays an important role in the mechanism of hydrogen release, said Anderson. The researchers claim that understanding the crystal structure of this compound will aid the design of future hydrogen storage materials that can release and reabsorb hydrogen under practical operating conditions.

Anderson's team plan to investigate the hydrogen desorption properties of other mixed metal-amide and metal-borohydride compounds, in an attempt to meet the challenge of creating a viable hydrogen storage system for fuel cells.

Rebecca I Gillan