| Abstract |
| Used was a sample with a composition of 86 wt% MgH2+10 wt% Ni+2 wt% NaAlH4+2 wt% Ti prepared by milling under H2 (reactive mechanical grinding) and then kept in a glove box for two months. The variations of its hydrogen-storage characteristics with hydriding-dehydriding cycling were investigated and compared with those of a sample just after reactive mechanical grinding. The hydriding-dehydriding cycling was performed between hydriding (at 593 K under 12 bar H2) and dehydriding (at 623 K in vacuum). The quantities of hydrogen absorbed for 2.5, 5, 10, and 60 min increased rapidly as the number of cycles, n, increased from n=1 to n=3. This is believed to be due to the predominance of the removal of the adsorbed gases and the destruction of oxide layers among the effects of hydriding-dehydriding cycling. From n=3 to n=15, Ha (2.5 min) and Ha (5 min) increased slowly and Ha (10 min) and Ha (60 min) decreased slowly. (Received July 15, 2014) |
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| Key Words |
| hydrogen absorbing materials, mechanical alloying/milling, microstructure, scanning electron microscopy, SEM, transition metals and sodium alanate-added MgH2 |
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