Hydrogen storage properties of LiNH2-LiH system with MgH2, CaH2 and TiH2 added

作者：Amica G; Arneodo Larochette P; Gennari F C^*

来源：International Journal of Hydrogen Energy, 2015, 40(30): 9335-9346.

DOI：10.1016/j.ijhydene.2015.05.091

• Lithium amide
• Ball milling
• Calcium hydride
• Magnesium hydride
• Kinetics

The addition of different metal hydrides to Li-N-H system offers a possible way to modify its thermodynamic properties and/or the dehydrogenation/hydrogenation kinetics. In this paper we report the hydrogen storage properties of LiNH2-LiH system with MH2 added (M = Mg, Ca, Ti) and clarify the chemical interactions occurring during hydrogen cycling. Detailed structural investigations reveal that during heating under hydrogen, MH2 (M = Mg, Ca) reacts with LiNH2 to form Li2Mg(NH)(2) and 2CaNH-Ca(NH2)(2) solid solution, with simultaneous hydrogen release. Formation of the Li2NH-CaNH mixture after dehydrogenation of the LiNH2-LiH with CaH2 added is proved by XRPD and FTIR, providing a new reversible pathway for hydrogen storage in the Li-Ca-N-H system. Notable improvement in the dehydrogenation temperature and kinetics was observed for LiNH2-LiH system with CaH2 and MgH2 added, without clear effects in the case of TiH2. The kinetic analysis reveals that dehydrogenation process is diffusion-controlled and the beneficial effect of MgH2 and CaH2 is due to the enhancement of Li+ mobility.

• 出版日期2015-8-10