【摘要】 La1.5Mg0.5Ni7-xCox(x=0~1.8)贮氢合金电极由高频感应熔炼加热处理制备得到。合金结构分析表明,合金主相为Ce2Ni7型结构,Mg原子分布在Ce2Ni7型单胞结构的Laves相单元中,而Co原子则分布在CaCu5单元中。随着合金中Co含量的增多,点阵参数和单胞体积呈增大趋势,氢化物变的更加稳定。合金的吸放氢平台在298K条件下介于1.01×103~1.01×104Pa之间,吸放氢滞后效应较小。合金电极的电化学分析表明合金具有390mAh/g以上的放电容量和良好的活化特性,Co元素不利于合金电极循环稳定性的改善,氢在合金中的扩散是电极反应的控制步骤。La1.5Mg0.5Ni7.0合金电极表现出较好的综合电化学性能。更多还原

【Abstract】 La_1.5Mg_0.5Ni_7-xCo_x（x=0～1.8） hydrogen storage alloys have been prepared by induction melting followed by an annealing treatment.Structure analyses showed that the main phase of alloys belongs to Ce₂Ni₇-type structure,Mg atoms are located only at the laves unit of Ce₂Ni₇-type unit cell,while Co atoms are located only at the CaCu₅ unit.As Co content increased,the lattice parameters and cell volume presents an increase trend and the hydrides become more stable.The absorption/desorption plateau of hydrogen ranges from 1.01×10³～1.01×10⁴Pa,and alloys exhibit a small hysteresis factor.Electrochemical analyses showed that all the alloys have a large discharge capacity（above 390mAh/g） and can be easily activated;The Co element is not beneficial to the development of cyclic stability;The control process of alloy electrode reaction is hydrogen diffusion in bulk of alloy.The La_1.5Mg_0.5Ni_7.0 alloy exhibits better overall electrochemical properties.更多还原