Hydrogen storage behavior in C15 Laves phase compound TiCr2 by first principles
2009 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 105, no 4Article in journal (Refereed) Published
Hydrogen storage in TiCr2 alloy of AB(2) type with C15 Laves phase structure has been studied using density functional theory and plane-wave pseudopotential technique. The H atom interacts stronger with Cr atoms than with Ti and tends to occupy the g (2A2B) site due to the largest interstitial space. The g sites together with e (1A3B) sites form a three-dimensional clathratelike network, providing a diffusion pathway for H atoms, and the energy barriers for the H diffusion along these paths were computed. Interaction between two interstitial H atoms inside the TiCr2 lattice can be considered as a screened Coulomb repulsion, which seems to control the maximum hydrogen content in the metal hydrides. The absorption energies and electronic structures of metal hydrides TiCr2Hx with x=0.5-12 have been computed, and the theoretical maximum hydrogen storage capacity (between 2.6 and 3.8 wt %) agrees with experiments. The effects of the lattice expansion due to hydrogen absorption of different amounts have also been investigated.
Place, publisher, year, edition, pages
2009. Vol. 105, no 4
ab initio calculations, density functional theory, diffusion, electronic structure, hydrogen storage, interstitials, pseudopotential, methods, titanium compounds, mh rechargeable batteries, crystal-structure, electronic-structure, electrochemical properties, thermodynamic properties, intermetallic, compounds, mathematical-models, annealing treatment, population, analysis, hydride electrodes
IdentifiersURN: urn:nbn:se:kth:diva-18213DOI: 10.1063/1.3081636ISI: 000263803300042ScopusID: 2-s2.0-61449202924OAI: oai:DiVA.org:kth-18213DiVA: diva2:336259
QC 201005252010-08-052010-08-052011-01-31Bibliographically approved