Sn对稀土系贮氢合金性能的影响

来源期刊：中国有色金属学报2000年第1期

论文作者：赵爽 林勤 朱大建 陈宁 袁永文

文章页码：73 - 76

关键词：贮氢合金；稀土金属；锡

Key words：hydrogen storage alloys; rare earth; tin

摘    要：研究了Sn替代贮氢合金LaNi₅和MlNi₅(Ml=富镧混合稀土)中部分Ni对合金的结构、吸氢容量和平衡氢压等性能的影响。用X射线衍射进行物相分析，测试了298K，313 K，333 K温度下合金的吸、放氢 p-c-T 曲线。结果表明，MlNi_5-xSn_x合金(x=0，0.1)为六方晶体结构的单相组织。以Sn部分取代Ni，使平台压力降低，吸、放氢滞后减小，而吸氢能力降低很小。利用电负性、电子浓度及原子尺寸等参数的半经验模型，计算的ΔH^θ与实验值符合较好，因此，少量Sn替代Ni时，影响合金热力学性质的主要因素是外层电子数的变化。

Abstract: The effect of partial substitution of tin for nickel in hydrogen storage alloys LaNi₅ and MlNi₅(Ml=lanthanum-rich mischmetal) on structure, hydrogen content, hydrogen absorption capability and hydrogen equilibrium pressure of those hydrogen storage alloys was investigated. The phase structure was studied by X-ray diffraction analysis . The hydrogen absorption and desorption pressure-composition isotherms were measured under t he temperature of 298 K, 313 K and 333 K. The results indicate that the MlNi_5-xSn_x(x=0～0.1 ) alloys have a single phase and hexagonal structure. The partial substitution of tin for nickel in MlNi₅ results in low hydrogen equilibrium pressure and hysteresis. There is little decrease in hydrogen capability when a small amount of tin is added.