Destabilisation of the Li–N–H hydrogen storage system with elemental Si

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Authors

Colleges, School and Institutes

External organisations

  • UCL

Abstract

A significant improvement in the dehydrogenation kinetics of the (LiNH2 + LiH) system was obtained upon doping with elemental Si. Whilst, complete dehydrogenation of the (LiNH2 + LiH) system requires more than 2 h, the time required for full dehydrogenation was reduced to less than 30 min by doping with elemental Si. It is observed that Si thermodynamically destabilises the system through the formation of novel intermediate phases resulting from the reaction of Si with both LiNH2 and LiH. Such intermediate phases are also believed to enhance reaction kinetics by providing a path for accelerated dehydrogenation and the rapid release of hydrogen at the early stages of the reaction. It is believed that the dehydrogenation kinetics of the (LiNH2 + LiH) system, which is controlled by the diffusion of H from LiH and H+ from LiNH2, becomes independent of diffusion upon Si addition due to an enhanced concentration gradient in reactive ionic species.

Details

Original languageEnglish
Pages (from-to)17683-17688
Number of pages6
JournalPhysical Chemistry Chemical Physics
Volume13
Issue number39
Early online date7 Sep 2011
Publication statusPublished - 21 Oct 2011