Effect of Co substitution for La on hydrogen storage properties and thermal stabilities of amorphous Mg60Ni30La10−xCox (x = 0, 2 and 4) alloys prepared by melt spinning. (February 2014)

• Record Type: Journal Article
• Authors: Lv, P.; Wang, Z.; Zhou, H.; Deng, J.; Yao, Q.; Zhang, H.
• Is Part Of: Materials science and technology. Volume 30:Number 2(2014:Feb.)
• Page Start: 176
• Page End: 182
• Publication Date: 2014-02
• Subjects: Materials science -- Periodicals; Microstructure -- Periodicals; Metallurgy -- Periodicals; 620.1105
• DOI: 10.1179/1743284713Y.0000000339
• Languages: English
• ISSNs: 0267-0836

Abstract

<abstract> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <sec> <p>A comparison of the hydrogen storage properties and thermal properties of amorphous Mg<sub>60</sub>Ni<sub>30</sub>La<sub>10−x</sub>Co<sub>x</sub> hydrogen storage alloys prepared by melt spinning has been investigated. A, B and C were used to represent each alloy composition when <italic>x</italic> = 0, 2 and 4 respectively. Their microstructures, the hydrogen storage properties and the thermal stabilities were analysed by X-ray diffraction (XRD), PCTPro2000 and differential scanning calorimetry (DSC) respectively. After hydrogenation of Mg<sub>60</sub>Ni<sub>30</sub>La<sub>10−x</sub>Co<sub>x</sub> (A, B and C) samples at 573 K under 2 MPa hydrogen pressure, XRD pattern results indicate the formation of new phases of MgH<sub>2</sub> (A, B, C), Mg<sub>2</sub>NiH<sub>4</sub> (A, B, C), La<sub>4</sub>H<sub>12·19</sub> (A, B, C), Mg<sub>2</sub>Ni<sub>0·9</sub>Co<sub>0·1</sub>H<sub>4</sub> (B), Mg<sub>2</sub>NiH<sub>0·26</sub> (C) and Mg<sub>2</sub>CoH<sub>2</sub> (C). It is observed that the experimental data of hydrogen desorption kinetics at 523, 573 and 623 K are well fitted through Avrami–Erofeev equation, and the hydrogen desorption kinetics is in the order of C>B>A. In addition, with increasing Co content, alloy C has the maximum hydrogen absorption capacity of 3·05 wt-% and the maximum hydrogen desorption capacity of 2·85 wt-%. Based on the results of DSC analysis, dehydrogenation activation energies of these alloys are determined to be 98·31±2·82 kJ mol<sup>−1</sup> (A), 96·33±5·61 kJ mol<sup>−1</sup> (B) and 78·99±2·98 kJ mol<sup>−1</sup> (C), which are in accordance with the results of hydrogen desorption kinetics.</p> </sec> </abstract>