【摘要】 研究了Ce2N i7型贮氢合金La1.5Mg0.5N i7-xCux(x=0.1~1.2)的组织结构和电化学性能。当x=0.1-0.6时Cu元素部分替代N i后可形成La2N i7型相,x≥0.9时,合金中则有少量的未知相析出。合金MH电极电化学研究表明,随Cu元素量的增加,合金电极的最大放电容量从380mAh/g(x=0.1)下降至340mAh/g(x=1.2);当x=0.3~0.9时合金电极的循环寿命较x=0.1时有一定的改善,合金电极交换电流密度(I0)和极限电流密度(IL)均以x=0.6为转折点先减小后增大。电极反应的动力学性能依Cu0.1>Cu0.3>Cu1.2>Cu0.9>Cu0.6的次序递减。更多还原

【Abstract】 The structural and electrochemical properties of the La_1.5Mg_0.5Ni_7-xCu_x hydrogen storage alloy with x=0.1-1.2 were investigated.It is found that when x changes from 0.1 to 1.2,La₂Ni₇ type phase is formed with well-distributed structure but a small amount of unknown phase is found in the alloy with x≥0.9.The investigation on electrochemical properties of the MH alloy electrodes indicate that with increasing Cu content in the alloys the discharge capacities decrease from 380mAh/g to 340mAh/g.The cycle stability of the alloys with x from 0.3 to 0.9 is improved in comparison to x=0.1.The high rate discharge ability（HRD）,the exchange current density I₀,and the limiting current density I_L of the alloy electrodes decrease with increasing x from 0.1 to 0.6 and then increase with increasing x from 0.6 to 1.2.The electrochemical kinetic properties of the electrodes decrease in the following order:Cu0.1>Cu0.3>Cu1.2>Cu0.9>Cu0.6.更多还原