| Abstract |
| To improve the hydrogen-storage properties of Mg2Ni, LiBH4 was added by milling in hydrogen atmosphere (reactive mechanical milling, RMM). Mg2Ni-10LiBH4 was prepared with a composition of 90 wt% Mg2Ni + 10 wt% LiBH4. The quantity of released hydrogen (Hr) versus temperature T curve for Mg2Ni- 10LiBH4 was obtained by heating at a rate of 4~5 K in 1.0 bar hydrogen. The hydrogen-storage properties of the sample were investigated. The phases formed were examined from the x-ray diffraction (XRD) patterns of the samples after RMM, and after hydrogen-absorption and release cycling. The XRD pattern of Mg2Ni- 10LiBH4 showed that this sample contained Mg2Ni, Mg2NiH4, o-LiBH4, h-LiBH4, Ni, and MgH2. The dHr/dT versus T curve exhibited three peaks at 325 K, 563 K, and 600 K, respectively. The peak at 325 K is for the hydrogen release from o-LiBH4 and h-LiBH4. The peak at 563 K is for the hydrogen release from Mg2NiH4 and the peak at 600 K is for the hydrogen release from Mg2NiH4 and MgH2. The RMM of Mg2Ni with added LiBH4 creates defects and cracks. RMM facilitates nucleation, increases reactivity, and shortens the diffusion distances of hydrogen atoms. Expansion and contraction of lattices due to cycling has effects similar to, but weaker than, the effects of RMM.
(Received 23 November, 2023; Accepted 6 January, 2024) |
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| Key Words |
| hydrogen-storage properties, Mg2Ni, LiBH4, XRD patterns, hydrogen absorption and release curves |
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