Effect of Mg substitution for La on microstructure, hydrogen storage and electrochemical properties of La1−xMgxNi3.5 (x=0.20, 0.23, 0.25at%) alloys

Quantification of Stacking Faults in ANiy (A = Rare Earth or Mg, y = 3.5 and 3.67) Hydrogen Storage Materials

“…In contrast, [ A 2 B 4 ] subunits can store a higher amount of hydrogen, but their stability is poor, which results in the collapse of the crystal structure and, consequently, a fast capacity decay of the alloy . In addition, the interaction between the subunits affects the structural stability of the alloy as well: the volume expansion and contraction between the [ AB 5 ] and [ A 2 B 4 ] subunits during the hydrogenation and dehydrogenation process can be desynchronized, which causes lattice strain inside the crystal structure, leading to the pulverization and loss of discharge capacity of the alloy. − It is also demonstrated that structures with a high [ AB 5 ]:[ A 2 B 4 ] subunit ratio (i.e., a large number of C subunits between the L layers) show better cycling stability when used as electrode materials, , confirming the key role of [ AB 5 ] subunits in improving the cyclability.…”

Recent Advances on Preparation Method of Ti-Based Hydrogen Storage Alloy

“…It is commonly used as solid-state hydrogen storage, Ni-MH rechargeable battery as well as metal hydride compressor [14]. For a long time, Ti-based hydrogen storage alloys was prone to activation difficulty, surface poisoning, be poor kinetic characteristic and low dehydrogenation capacity at room temperature [15] [16]. In recent years, studies have shown that samples undergo mechanical deformation such as high-pressure torsion (HPT), forging, ball milling (BM) and cold rolling (CR), which can boost the first hydrogenation (activation) of metal hydrides by making defects and reducing the size of microcrystal to nanocrystalline [17] [18].…”