The YMg₂Ni₉ hydrogen storage alloy in-situ coated with Ni₃S₂ was successfully prepared by hydrothermal sulfurization treatment and investigated as the anode material in nickel-metal hydride (Ni-MH) batteries for the first time. Owing to the high electronic conductivity and electrocatalytic activity of Ni₃S₂ nanoflake coating, the electrochemical performance of the YMg₂Ni₉ alloy electrode is significantly enhanced. The alloy electrode treated in 0.3 M Na₂S solution exhibits the highest discharge capacity of 230.8 mAh/g and superior cycling stability, maintaining a capacity retention rate of 85.1% after 100 cycles. The increase in the discharge capacity of the electrode is credited to the Ni₃S₂ coating on the surface of the alloy, which possesses a nanoflake structure, facilitating the surface electrochemical reaction and providing more channels for hydrogen diffusion. In addition, Ni₃S₂ nanoflakes wrapped around the surface of the alloy can stabilize the reaction interface between the alloy and the electrolyte and slow down the alkali erosion, thus improving the cycle life of the electrode. The present study offers beneficial information for investigating a potential anode material for Ni-MH batteries.

中文翻译：

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YMg2Ni9 原位涂覆 Ni3S2 储氢电极合金的电化学性能


采用水热硫化处理成功制备了原位涂覆 Ni₃S₂ 的 YMg₂Ni₉ 储氢合金，并首次作为负极材料在镍氢 （Ni-MH） 电池中进行了研究。由于 Ni₃S₂ 纳米片涂层的高电子导电性和电催化活性，YMg₂Ni₉ 合金电极的电化学性能得到显着增强。在 0.3M Na₂S 溶液中处理的合金电极表现出最高的放电容量 230.8mAh/g 和优异的循环稳定性，在 100 次循环后保持 85.1% 的容量保持率。电极放电容量的增加归功于合金表面的 Ni₃S₂ 涂层，该涂层具有纳米片状结构，促进了表面电化学反应并为氢扩散提供了更多通道。此外，包裹在合金表面的 Ni₃S₂ 纳米薄片可以稳定合金与电解质之间的反应界面，减缓碱蚀，从而提高电极的循环寿命。本研究为研究镍氢电池的潜在负极材料提供了有益的信息。