Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5148463 | International Journal of Hydrogen Energy | 2017 | 7 Pages |
Abstract
NaMgH3 hydride is a potential candidate for hydrogen storage due to its high gravimetric and volumetric H densities (6Â wt. % and 88Â kg/m3). Perovskite-type NaMgH3 and Na0.9K0.1MgH3 hydrides have been synthesized by a high-energy ball milling method in this work. The replacement of Na by 10Â at.% of K results in a slight increase of lattice parameters of NaMgH3 phase and the decrease of activation energy of decomposition reactions. In comparison with NaMgH3 hydride, Na0.9K0.1MgH3 hydride presented better dehydriding kinetic properties, the onset desorption-temperature of which is greatly decreased from 581Â K to 430Â K, the hydrogen-desorbed amount is about 3.0Â wt. % within 6Â min at 638Â K, and the maximum amount is 5.25Â wt. % (about 87.5% of the theoretical value) after 40Â min. Further theoretical calculations, based on DFT, suggest that higher formation enthalpy and s-p-d hybridized orbitals (instead of s-p hybridized orbitals) in Na0.9K0.1MgH3 hydride maybe contribute to the improved dehydriding properties by reducing its structure stability.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Song Tao, Zhong-min Wang, Zhen-zhen Wan, Jian-qiu Deng, Huaiying Zhou, Qingrong Yao,