Nucleation and growth behaviors of hydriding and dehydriding reactions of Mg2Ni
- School of Chemical Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangj 61186 (Korea, Republic of)
- Department of Materials Engineering, Graduate School, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 54896 (Korea, Republic of)
Highlights: • Preparation of Mg{sub 2}Ni by sintering under Ar in a stainless steel crucible at 823 K. • Application of Johnson-Mehl equation for the nucleation and growth mechanism. • Reverse dependences on temperature of initial hydriding rate and quantity of H absorbed for 60 min. • Hydriding and dehydriding reactions progressed by a nucleation and growth mechanism. - Abstract: Mg{sub 2}Ni has drawn attention due to its high reaction rates, good reversibility, and possibility to be applied as a negative electrode in the Ni-MH (metal hydride) batteries. Mg{sub 2}Ni samples were prepared by sintering under Ar in a stainless-steel crucible at 823 K. Johnson-Mehl equation for nucleation and growth mechanism was applied to the behaviors of hydriding and dehydriding reactions of Mg{sub 2}Ni. At 571 K under 30 bar H{sub 2}, the activation of the Mg{sub 2}Ni sample was completed at the number of cycles of three (n = 3). At n = 3, hydrided fractions of the sample were 0.51 (1.92 wt% H) at 0.50 min and 0.90 (3.38 wt% H) at 2.00 min. Reverse temperature dependences of the initial hydriding rate and the quantity of hydrogen absorbed for 60 min appeared from 571 K to 620 K. Hydriding and dehydriding reactions progressed by the nucleation and growth mechanism and could be expressed by the Johnson-Mehl equation.
- OSTI ID:
- 22805424
- Journal Information:
- Materials Research Bulletin, Vol. 99; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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