Highlighting the electrochemical performance of AB ₄ ‐type single‐phase La _0.60 Sm _0.22 Mg _0.18 Ni _4.09 Al _0.09 Mn _0.10 hydrogen storage alloy for nickel metal hydride batte

Abstract Rare earth–Mg–Ni‐based superlattice structure alloys have garnered recognition as promising materials for hydrogen storage. However, their application is impeded by suboptimal cycling longevity. The novel AB 4 ‐type alloy emerges as an attractive candidate, distinguished by its good structure stability, high rate capability, and long‐term durability. Herein, we designed an AB 4 ‐type La 0.60 Sm 0.22 Mg 0.18 Ni 4.09 Al 0.09 Mn 0.10 alloy that manifests superior electrochemical performance. The obtained AB 4 ‐type single‐phase alloy delivers a high discharge capacity of 375.2 mAh·g −1 and features outstanding discharge ability at high rates, maintaining 121 mAh·g −1 even at a discharge rate of 6C. The excellent high‐rate discharge performance can be attributed to its fast charge transfer and hydrogen diffusion kinetics. Moreover, the AB 4 ‐type alloy maintains a capacity retention of 84.5% after 200 cycles and retains 55.7% of its capacity retention even after 500 cycles. This work provides a good alternative to hydrogen storage alloy with high power and long cycling durability performance for nickel metal hydride batteries.