Positive impacts of tuning lattice on cyclic performance in ZrCo-based hydrogen isotope storage alloys

Abstract

ZrCo alloy is considered a promising hydrogen isotope storage material used in nuclear fusion reactors, but its large-scale promotion is inhibited by its poor cycling stability induced by disproportionation. To enhance the cycling stability of ZrCo-H systems, tuning lattice by Pd substitution for Co is performed in this work. The prepared ZrCo0.6Pd0.4 alloy mainly consists of the CrB-type orthorhombic phase (B33), sharing an identical lattice structure with its hydrided phase (ZrCoH3); thus, stable homogeneous structural dehydrogenation/hydrogenation reaction is constructed for the first time with remarkably low lattice fluctuation and dehydrogenation activation energy, in favor of restraining disproportionation. Hence, a highest capacity of 1.45 wt% and optimum capacity retention of 96.67% after 50 dehydriding/hydriding cycles is achieved in ZrCo-H systems. Our work proposes the great potential of tuning lattice for improving the cycling performance in hydrogen isotope storage materials.