中文摘要：

本文系统研究分析了La0.7-xPrxMg0.3Ni2.45Co0.75Mn0.1Al0.2（x=0．00—0．25）贮氢电极合金的电化学性能。电化学研究发现，随着x值的增大，合金电极的最大放电容量逐渐减小，但是合金的循环稳定性会有一定的提高。高倍率放电性能研究结果显示，随着X值的增大，合金电极的高倍率性能先提高后降。同时，电化学阻抗谱、交换电流密度Ⅰ0、极限电流密度ⅠL以及氢在合金中的扩散系数D的研究也表明，随着x值的增加，合金电极的电化学反应动力学性能首先增加，达到一个最大值后，其动力学性能又会随着x值的增大而有所下降。

英文摘要：

In this paper, the effects of substitution of Pr for La on electrochemical properties of the La0.7-x PrxMg0.3 Ni2.45 Co0.75 Mn0.1Al0. 2 （ x = 0. 00 - 0. 25 ） hydrogen storage alloys had been studied systematically. The electrochemical studies showed that the maximum discharge capacity decreased when x increased from 0. 00 to 0. 25. However, the cycling stability of the alloy electrodes was improved with the increase of Pr content. Moreover, the high rate dischargeability （HRD） , the exchange current density Ⅰ0 and the limiting current density ⅠL of the alloy electrodes all increased first and then decreased with increasing x, which indicated that the kinetics of hydriding/dehydriding of the La0. 7 - x Prx Mg0. 3 Ni2.45 Co0. 75 Mn0.1 Al0. 2 （ x = 0. 00 - 0. 25 ） hydrogen storage alloys increased first up to x =0. 15 and then decreased with further increasing x.