采用中频感应熔炼的方法制备了La_0.8-xCe_xMg_0.2Ni₃Co_0.6储氢合金,研究了不同Ce摩尔分数的退火态La_0.8-xCe_xMg_0.2Ni₃Co_0.6储氢合金的物相组成、微观结构和电化学性能。结果表明,La_0.8-xCe_xMg_0.2Ni₃Co_0.6储氢合金的主要物相都为(La,Mg) Ni₃、(La,Mg)₂Ni₇和LaNi₅相,随着x值从0增加至0.20,La_0.8-xCe_xMg_0.2Ni₃Co_0.6储氢合金的最大放电容量C_max和腐蚀电流密度i逐渐减小,100次充放电的循环寿命S₁₀₀逐渐增加,交换电流密度I₀先增加后减小,氢扩散系数D₀逐渐减小,高倍率放电性能先增加后减小,当x=0.10时La_0.8-xCe_xMg_0.2Ni₃Co_0.6储氢合金取得高倍率放电性能最大值;La_0.8-xCe_xMg_0.2Ni₃Co_0.6储氢合金的高倍率放电性能主要由I₀决定。

La_0.8-xCe_xMg_0.2Ni₃Co_0.6 hydrogen storage alloy is prepared by medium frequency induction melting method.The phase composition,microstructure and electrochemical properties of the annealed La_0.8-xCe_xMg_0.2Ni₃Co_0.6 hydrogen storage alloy with different Ce substitution rates are studied.It is shown that main phases of La_0.8-xCe_xMg_0.2Ni₃Co_0.6 hydrogen storage alloy include (La,Mg)Ni₃,(La,Mg)₂Ni₇ and LaNi₅ phases.As x value rises from 0 to 0.20,both the maximum discharge capacity C_max and corrosion current density(i) of the alloy decrease gradually,the cycle life of S₁₀₀ charge-discharge increases gradually,the exchange current density I₀ increases first and decreases then,the hydrogen diffusion coefficient D₀ decreases gradually,and the high-rate discharge performance increases first and decreases then.The high-rate discharge performance of the alloy reaches the maximum when x=0.10.The high-rate discharge performance of the alloy is mainly determined by I₀.