Capacity degradation study of AB4-type La-Y-Mg-Ni superlattice structure hydrogen storage alloy
HaiDeng Wang, RuiXuan Zhao, MeiYing Li, GuangBo Shi, ChuBin Wan, Yuting Wang, Xiao‐Yu Hu, Xin Ju, Yuan Wu
Abstract
In this study, an AB 4 -type La 2.5 Y 0.5 MgNi 14 alloy is synthesized by partially substituting La with Y in La-Mg-Ni alloys. The structure, hydrogen storage, and electrochemical properties of the alloys are systematically studied to elucidate capacity degradation mechanisms. The maximum hydrogen storage capacity of all alloys is approximately 1.4 wt%, with reversible hydrogen storage improving as the Y content increases. The AB 4 -type La-Y-Mg-Ni alloy exhibits excellent cycling stability in both hydrogen storage and electrochemical cycling. After 500 electrochemical cycles, its capacity retention is significantly higher than that of other alloys studied. The discharge capacity of all alloys reaches ∼230 mAh g −1 at a current density of 1000 mA g −1 . The AB 4 -type La-Y-Mg-Ni alloy demonstrates superior resistance to pulverization and corrosion. These findings suggest that optimizing Y content and synthesizing high stability AB 4 -type structures can enhance the cycle performance of Re-Mg-Ni-based alloys, making them suitable for long-life Ni/MH battery applications.