We apply for beam time on TOSCA to investigate this highly unusual system. Lithium nitride appears unique among storage materials in its ability to take up significant amounts of hydrogen at both extremes of the temperature scale. We propose to perform INS measurements using extremely high dosing pressures of hydrogen, in order to investigate fully the effect of dosing pressure on hydrogen uptake and storage mechanism in this compound. The use of high pressures during dosing mimics conditions for storage applications including transport and should allow thorough exploration of the relationship between dosing pressure and storage capacity at low temperature that has been touched on in previous experiments. We have discovered very unusual sorption kinetics during our previous experiments that appear inexorably linked to the remarkable negative thermal expansion of Li3N.