Two days of beamtime on GEM will be used to analyse the structure of the fast lithium-ion conductive phases formed by anion doping the hydrogen storage material LiBH4 with bromide. The presence of bromide modifies the temperature dependence of phase transitions observed in LiBH4 and stabilises the high temperature hexagonal phase. We will collect data from these compounds at temperatures up to 300°C in order to characterise them crystallographically for the first time and identify possible mecahnisms for ionic conduction. The beamtime will also provide information on the mechanism of formation of these phases and identify the role of the dopant in manipulating the temperature stability of this structure.