Improved hydrogen desorption from lithium hydrazide by alkali metal hydride

• LiH can dramatically improve the hydrogen desorption properties of LiNHNH2.
• KH doping had positive effect in promoting the hydrogen desorption properties of LiNHNH2–LiH mixture.
• The reaction mechanism between LiNHNH2 and LiH was studied and discussed.

Lithium hydrazide (LiNHNH2), which is a white solid with 8.0 mass% of theoretical hydrogen content, was synthesized from a reaction between anhydrous hydrazine and n-butyllithium in diethyl ether. The thermodynamic properties of this compound and its detailed decomposition pathways had been investigated in our previous work. However, a number of undesired gaseous products such as hydrazine (N2H4) and ammonia (NH3) were generated during the thermal decomposition of LiNHNH2. In this work, alkali metal hydride was used to suppress the impurities in the desorbed hydrogen and improved the hydrogen desorption properties. The reaction mechanism between LiNHNH2 and LiH was also studied and discussed in this paper.