Lithium borohydride is currently of great interest as a fast lithium ion conducting material at elevated temperatures. We request one day of beam time on D20 in order to characterize thoroughly a room temperature analogue of the high temperature phase of this compound. Data will be collected between 2-300 K from an isotopically enriched sample of 7Li(11BD4)0.67Br0.33. Data will be analysed by Rietveld refinement and will be able to show for the first time whether the highly conducting hexagonal polymorph can be stabilised to low temperatures or if, like the LiBH4 parent, it undergoes a structural transition to a fully ordered, lower symmetry polymorph. The insights generated from these data will inform the battery community about the behaviour of the borohydride systems and more generally about the role of 'paddlewheel' versus 'percolation' mechanisms for Li+ transport within complex anion lattices.