Issue 84, 2015

Effect of LiCl presence on the hydrogen storage performance of the Mg(NH2)2–2LiH composite

Abstract

The Mg(NH2)2–2LiH composite is a promising hydrogen storage material due to its favourable thermodynamics and hydrogen storage reversibility. However, its application is restricted owing to the presence of severe kinetic barriers. In the present work, the Mg(NH2)2–2LiH was synthesized by metathesis reaction of LiNH2 plus MgCl2 and posterior milling with LiH. LiCl is a co-product that operates as a separation phase favouring the nanostructure of the composite. The synthesized material exhibits good dehydrogenation rate and approximately the theoretical hydrogen storage capacity at 200 °C. However, the formation of Li4(NH2)3Cl and the incomplete rehydrogenation of Li2Mg2(NH2)3 are progressively favoured during successive hydrogen cycling, deteriorating the storage properties. Two competitive reactions can simultaneously occur involving LiNH2 as an intermediate phase: the formation of Li4(NH2)3Cl using the co-product LiCl and the complete dehydrogenation of Li2Mg2(NH2)3 leading to the Li2Mg(NH)2 formation. The worst effect of Li4(NH2)3Cl formation was simultaneously demonstrated by kinetics and PCI measurements. The amide-chloride phase was actually the active species for the deterioration of dehydrogenation kinetics and hydrogen storage capacity of the Li–Mg–N–H–Cl system.

Graphical abstract: Effect of LiCl presence on the hydrogen storage performance of the Mg(NH2)2–2LiH composite

Supplementary files

Article information

Article type
Paper
Submitted
25 Jun 2015
Accepted
06 Aug 2015
First published
06 Aug 2015

RSC Adv., 2015,5, 68542-68550

Effect of LiCl presence on the hydrogen storage performance of the Mg(NH2)2–2LiH composite

N. S. Gamba, P. Arneodo Larochette and F. C. Gennari, RSC Adv., 2015, 5, 68542 DOI: 10.1039/C5RA12241D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements