Subunit volume control mechanism for dehydrogenation performance of AB3-type superlattice intermetallics.

The relevance of the dehydrogenation performance of AB 3 -type superlattice intermetallics to their subunit volumes has been comprehensively investigated from the view of geometric crystal structure. The theoretical and experimental results reveal a subunit volume control mechanism that hydrogen can completely desorb from hydrogenated [A 2 B 4 ] and [AB 5 ] subunits when their subunit volumes are simultaneously controlled to less than 89.2 Å3 and 88.3 Å3, respectively. Following such subunit volume control mechanism, we have innovatively designed and prepared a Nd 0.33 Er 0.67 Ni 3 intermetallic with appropriate [A 2 B 4 ] subunit volume of 87.9 Å3 and [AB 5 ] subunit volume of 85.5 Å3, achieving more than 90% of capacity retention after 25 cycles. The current work provides a simplified but significant guidance for exploiting new layered superlattice intermetallics with better hydrogen storage performance by theoretical prediction and then experimental investigation. Image 1 • Series of AB 3 -type intermetallics are designed theoretically and experimentally. • Subunit volume control mechanism for dehydrogenation of AB 3 is proposed. • A novel Nd 0.33 Er 0.67 Ni 3 intermetallic is theoretically designed and manufactured. [ABSTRACT FROM AUTHOR]