Increasing the density of hydrogen storage under ambient conditions is a critical requirement for the widespread introduction of low-carbon hydrogen vehicles. Ammonia borane (AB) is one of the most promising hydrogen storage materials. We have developed a core-shell electrospinning technique than nanostructures and encapsulates the AB in a one step process. The nanostructuring lowers the hydrogen release temperature and time allowing this material to meet 2010 Department of Energy targets. The fibres are a nanostructured 3 phase system of polystyrene, ammonia borane and voids. We intend to use SANS with isotopic substitution to measure the size and shape of each part of the nanostructure. These results will be coupled with hydrogen desorption measurements which will allow us to fully understand and tune the fibre nanostructure for optimum hydrogen desorption characteristics.