Dual-Ion Substitution-Induced Unique Electronic Modulation to Stabilize an Orthorhombic Lattice towards Reversible Hydrogen Isotope Storage

Abstract

ZrCo-based alloys have attracted wide attention as hydrogen isotopes (deuterium and tritium) storage materials used in the International Thermonuclear Experimental Reactor (ITER); however, the capacity attenuation resulting from disproportionation reaction compromises their development. Herein, a dual-ion substitution strategy to construct a unique orthorhombic intermediate (B33′) during the dehydrogenation of Zr 1−x Nb x Co 0.8 Cu 0.2 -H (x = 0.1−0.3) via Nb/Cu substitutions for Zr/Co is proposed, and isostructural de-/hydrogenation reactions between an isostructural B33′ phase and a ZrCoH 3 phase with superior cycling stability are constructed for the first time, which enable the suppression of disproportionation reaction. As the hydrogen isotope storage material, ultrafast hydriding kinetics at room temperature and a high reversible capacity of 1.57 wt % with a capacity retention of 98.1% after 50 cycles can be obtained among the best ZrCo-based alloys reported. The theoretical calculation reveals that unique electronic interaction modulation, including a stronger bond combination of Nb atoms and weaker regulation effects of reversible desorption of Cu atoms for local H atoms, leads to the formation of a stable orthorhombic B33′ phase with remarkably decreased hydrogen trapping capacity, instrumental in cycling capacity improvement. This work highlights the significance of reasonable modulation of metal−H electronic interaction in realizing reversible hydrogen isotope storage operation in ITER.

Dynamically Staged Phase Transformation Mechanism of Co-Containing Rare Earth-Based Metal Hydrides with Unexpected Hysteresis Amelioration

“…According to the principle of minimum energy, the optimal models of La 0.3 Ce 0.5 Ca 0.2 Ni 5– x Co x H 6 with total formation of A 10 B 50 H 60 were obtained and labeled as H-60 (Table S6 and Figure S9). Then, in the light of the bader atomic charge-based hydrogen electronic interaction, − models of A 10 B 50 H 35 (H-35) and A 10 B 50 (H-0) with different Co content were then optimized (Table S6 and Figures S10–S11).…”

Isotope engineering achieved by local coordination design in Ti-Pd co-doped ZrCo-based alloys

“…More importantly, T 1 bar and T cr show strong sensitivity with the local environment of interstitial isotopes, directly linked to the interstitial coordination atoms. Element substitution, therefore, stands out as a facile strategy for tailoring interstitial coordination environment among modification methods including nanostructuring, surface treatment and mechanical ball-milling [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] . Although a myriad of efforts have been devoted to reducing the hydrogen isotope effect, the trial-and-error strategy still dominates the alloy development.…”