Abstract RE–Mg–Ni-based hydrogen storage alloys are new cathode materials of Nickel-metal hydride (Ni-MH) batteries and the improvement of their kinetic performance is meaningful for enhancing the output power of Ni-MH power batteries. In this work, La–Gd–Mg–Ni-based alloys with different type superlattice structures are obtained by a powder sintering method from LaMgNi4 and La0.60Gd0.15Mg0.25Ni3.60 alloys at a temperature of 1203 K. When the precursor ratio (LaMgNi4/La0.60Gd0.15Mg0.25Ni3.60) is 1.00, the alloy sample shows a single-phase Pr5Co19-type structure. The increased LaMgNi4 ratio promotes the formation of [A2B4] subunit, and a Ce2Ni7-type phase structure which is consisted by more [A2B4] subunits compared with the Pr5Co19-type structure emerges. As a consequence, a Ce2Ni7-type single phase is obtained at the ratio of 1.4, and with the further increase of LaMgNi4, a single-phase PuNi3-type structure forms at the ratio of 1.8. Reaction kinetic characterization shows that the exchange current density of the Pr5Co19-type electrode is high to 769 mA g−1 which represents a good charge-transfer rate. Electrochemical measurements show that the discharge capacity of the Pr5Co19-type electrode could reach 200 mAh g−1 at a current density of 1800 mA g−1. Pr5Co19-type RE–Mg–Ni-based alloys are considered prospective materials of high-power Ni-MH batteries.

中文翻译：

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单相PuNi3-、Ce2Ni7-、Pr5Co19型超晶格结构La-Gd-Mg-Ni基储氢合金的制备及动力学性能

摘要 RE-Mg-Ni基储氢合金是镍氢（Ni-MH）电池的新型正极材料，其动力学性能的提高对提高镍氢动力电池的输出功率具有重要意义。在这项工作中，LaMgNi4 和 La0.60Gd0.15Mg0.25Ni3.60 合金在 1203 K 的温度下通过粉末烧结方法获得了具有不同类型超晶格结构的 La-Gd-Mg-Ni 基合金。 (LaMgNi4/La0.60Gd0.15Mg0.25Ni3.60) 为 1.00，合金样品显示单相 Pr5Co19 型结构。增加的LaMgNi4比例促进了[A2B4]亚基的形成，与Pr5Co19型结构相比，出现了由更多[A2B4]亚基组成的Ce2Ni7型相结构。结果，以 1.4 的比率获得 Ce2Ni7 型单相，随着LaMgNi4的进一步增加，以1.8的比例形成单相PuNi3型结构。反应动力学表征表明，Pr5Co19 型电极的交换电流密度高达 769 mA g-1，代表了良好的电荷转移速率。电化学测量表明，Pr5Co19 型电极的放电容量在 1800 mA g-1 的电流密度下可达到 200 mAh g-1。Pr5Co19 型稀土-镁-镍基合金被认为是高功率镍氢电池的潜在材料。电化学测量表明，Pr5Co19 型电极的放电容量在 1800 mA g-1 的电流密度下可达到 200 mAh g-1。Pr5Co19 型稀土-镁-镍基合金被认为是高功率镍氢电池的潜在材料。电化学测量表明，Pr5Co19 型电极的放电容量在 1800 mA g-1 的电流密度下可达到 200 mAh g-1。Pr5Co19 型稀土-镁-镍基合金被认为是高功率镍氢电池的潜在材料。