Regulating local chemistry in ZrCo-based orthorhombic hydrides via increasing atomic interference for ultra-stable hydrogen isotopes storage

Abstract

Developing a universal and reliable strategy for the modulation of composition and structure of energy storage materials with stable cycling performance is vital for hydrogen and its isotopes storage advanced system, yet still challenging. Herein, an ultra-stable lattice structure is designed and verified to increase atomic chaos and interference for effectively inhibiting disproportionation reaction and improving cycling stability in ZrCo-based hydrogen isotopes storage alloy. After screening in terms of configuration entropy calculation, we construct Zr1−xNbxCo1−2xCuxNix (x = 0.15, 0.2, 0.25) alloys with increased atomic chaos, and successfully achieve stable isostructural de-/hydrogenation during 100 cycles, whose cycling capacity retentions are above 99%, much higher than 22.4% of pristine ZrCo alloy. Both theoretical analysis and experimental evidences indicate the high thermo-stability of orthorhombic lattice in Zr0.8Nb0.2Co0.6Cu0.2Ni0.2 alloy. Notably, the increased atomic chaos and interference in Zr0.8Nb0.2Co0.6Cu0.2Ni0.2 alloy causes regulation in hydrogen local chemical neighborhood, thereby confusing the hydrogen release order, which effectively eliminates lattice distortion and unlocks an ultra-stable lattice structure. This study provides a new and comprehensive inspiration for hydrogen atoms transport behaviors and intrinsic reason of stable orthorhombic transformation, which can contribute to paving the way for other energy storage materials modulation.