Preparation, scale-up and testing of nanoscale, doped amide systems for hydrogen storage

A comparative study of the LiNH2–MgH2 hydrogen storage system has been made, and several additives (LiBH4, KH and ZrCoH3) have been tested as single catalysts and in various combinations in order to study potential synergistic effects.It was verified that LiBH4 and KH significantly improve the de-/rehydrogenation kinetics. However, the addition of KH results in irreversible reactions.Testing of catalyst combinations showed that a system composed of 2 LiNH2–1.1 MgH2–0.1 LiBH4–3 mass% ZrCoH3 shows superior absorption/desorption kinetics, with a reversible capacity of 4.2 mass% H at 180 °C.An optimal milling time of 5 h was found by variation of ball-milling conditions, whereas too long milling durations resulted in a lower capacity and reduced reversibility.Based on optimized conditions, the system was scaled up on semi-industrial milling equipment and kilogramme quantities of material were produced for testing in a tank coupled to a fuel cell.

► The Li–Mg–N–H hydrogen storage system was investigated with addition of dopants.
► Characterization under practical conditions.
► Co-catalysed system with addition of LiBH4 and ZrCoH3 found to be most suitable.
► Optimization of preparation conditions.
► Scale-up on semi-industrial milling equipment to produce a large quantity.