The superlattice La–Y–Ni-based hydrogen storage alloys have high discharge capacity and are easy to prepare. However, there is still a gap in commercial applications because of the severe corrosion of the alloys in electrolyte and poor high-rate dischargeability (HRD). Therefore, (LaSmY) (NiMnAl)_3.5 alloy was prepared by magnetic levitation induction melting, and then the alloy was coated with different contents (0.1 wt%–1.0 wt%) of nano-carbons by low-temperature sintering with sucrose as the carbon source in this work. The results show that the cyclic stability and HRD of the alloy first increase and then decrease with the increase of carbon contents. The kinetic results show that the electrocatalytic activity and conductivity of the alloy electrodes can be enhanced by carbon coating. The electrochemical properties of the alloy are the best when the carbon coating content is 0.3 wt%. Compared with the uncoated alloy, the maximum discharge capacity (C_max) improves from 354.5 to 359.0 mAh/g, the capacity retention rate after 300 cycles (S₃₀₀) enhances from 73.15% to 80.01%, and the HRD₁₂₀₀ of the alloy enhances from 74.39% to 74.39%.

超晶格La-Y-Ni基储氢合金具有高放电容量且易于制备。然而，由于合金在电解液中的严重腐蚀和较差的高倍率放电能力（HRD），在商业应用中仍然存在差距。因此，(LaSmY) (NiMnAl) _3.5采用磁悬浮感应熔炼法制备合金，然后以蔗糖为碳源，通过低温烧结法在合金中包覆不同含量（0.1 wt%~1.0 wt%）的纳米碳。结果表明，随着碳含量的增加，合金的循环稳定性和HRD先增大后减小。动力学结果表明，碳包覆可以提高合金电极的电催化活性和电导率。当碳涂层含量为0.3 wt%时合金的电化学性能最好。与未涂层合金相比，最大放电容量（_Cmax ）从354.5提高到359.0 mAh/g，循环300次后的容量保持率（S ₃₀₀) 从 73.15% 提高到 80.01%，合金的 HRD ₁₂₀₀从 74.39% 提高到 74.39%。