| Summary: | Rare-earth-based AB<sub>2</sub>-type compounds with Laves phase structure are readily subject to hydrogen-induced amorphization and disproportionation upon hydrogenation. In this work, we conducted the Sc alloying on Y<sub>0.95</sub>Ni<sub>2</sub> to improve its hydrogen storage properties. The results show that the amorphization degree of Y<sub>0.95</sub>Ni<sub>2</sub> deepens with the increasing hydrogenation time, pressure, and temperature. The Y(Sc)<sub>0.95</sub>Ni<sub>2</sub> ternary compounds show a significant improvement in reversibility and dehydriding thermodynamics due to the reduced atomic radius ratio R<sub>A</sub>/R<sub>B</sub> and cell volume. Hydrogen-induced amorphization is fully eliminated in the Y<sub>0.25</sub>Sc<sub>0.7</sub>Ni<sub>2</sub>. The Y<sub>0.25</sub>Sc<sub>0.7</sub>Ni<sub>2</sub> delivers a reversible hydrogen storage capacity of 0.94 wt.% and the dissociation pressure of 0.095 MPa at the minimum dehydrogenation temperature of 100 °C.
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