Metal-hydride based hydrogen storage materials have recently been designed for rechargeable batteries where protons serve as charge carriers. However, the metal-hydride materials generally suffer from poor cycling stability during electrochemical hydrogen storage process. Herein, we report, for the first time, a new AB₄-type single-phase La_0.78Mg_0.22Ni_3.67Al_0.10 metal-hydride superlattice compound with excellent electrochemical hydrogen storage properties. This metal-hydride compound is able to deliver a high discharge capacity of 393 mAh g⁻¹, according to its hydrogen gas absorbability (1.50 wt%), and exhibit a superior rate capability of 180 mAh g⁻¹ even at 1.8 A g⁻¹. In addition, the compound retains its crystalline structure when subjects to electrochemical cycling and shows strong anti-oxidation ability in alkaline electrolyte, indicative of excellent cyclability. Our results demonstrate that the AB₄-type superlattice structure metal-hydride can be a promising electrode material for hydrogen storage, and provide a new avenue for the applications of metal-hydride batteries.

基于金属氢化物的储氢材料最近被设计用于可充电电池，其中质子用作电荷载体。但是，金属氢化物材料在电化学储氢过程中通常遭受较差的循环稳定性。在此，我们首次报道了具有优异的电化学储氢性能的新型AB ₄型单相La _0.78 Mg _0.22 Ni _3.67 Al _0.10金属氢化物超晶格化合物。这种金属氢化物化合物根据其氢气吸收能力（1.50 wt％）能够提供393 mAh g ^-1的高放电容量，并展现出180 mAh g ^-1的优异倍率能力即使在1.8 A g ^-1。另外，当进行电化学循环时，该化合物保留其晶体结构，并且在碱性电解质中显示出强的抗氧化能力，这表明优异的循环能力。我们的结果表明，AB ₄型超晶格结构金属氢化物可以作为一种有前途的储氢电极材料，并为金属氢化物电池的应用提供了新的途径。