Nanotechnology could improve how hydrogen fuel is stored

The potential of hydrogen as a fuel source in vehicles such as cars and aircraft is widely accepted, but storing it has proved problematic.

The team at Glasgow is working with several other universities and EADS Innovation Works in order to find a better solution than hydrogen gas or liquid hydrogen.

Prof Duncan Gregory, head of the Glasgow University research group looking at hydrogen storage and sustainable energy materials, told The Engineer: ‘Hydrogen gas isn’t particularly safe and it occupies a large volume.

‘If you use liquid then it takes up a smaller volume but you have to use a lot of energy to get it cold enough and compressed enough to be stored.

‘If one can store hydrogen in a solid then potentially you can store the same sort of mass, at a much smaller volume, and it will be far safer.’

Storing hydrogen as a solid involves binding the hydrogen atoms to another substance that would act like a sponge, soaking it up. The hydrogen is then stored until it is needed.

However, the issues of storing hydrogen as a solid are severalfold.

‘The first problem is how to store enough hydrogen within a solid,’ said Gregory. ‘Getting hydrogen in and out reversibly and quick enough for it to be useful is also a challenge.’

Nanomaterials could help scientists overcome these issues for several reasons.

‘With a nanomaterial, we have the potential to get the hydrogen in and out faster because, to some extent, the rate at which hydrogen can pass through a material is governed by the surface area of the material,’ said Gregory.

The scientists are looking at the potential of lithium- and nitrogen-based materials.

‘One can take the dehydrogenated material, which is lithium nitride, and then progressively add more and more hydrogen to make lithium imide and lithium amide, which is a fully hydrogenated material,’ said Gregory.

The team from Glasgow University’s Inorganic Solid State and Materials Research Group has recently been awarded an EPSRC grant of more than £3m to work with the universities of St Andrews, Strathclyde and Newcastle on a four-year project that will develop these materials.

In addition, the team is collaborating with EADS Innovation Works in testing hydrogen technology in aircraft and aiming to build and test a hydrogen fuel-cell system in an unmanned aircraft in 2014.