表面包覆处理对A2B7型贮氢电极性能影响研究

以A2B7型贮氢合金La1.5Mg0.5Ni6.5Co0.5为对象,在不同反应温度下对合金粉末进行化学镀镍,系统研究了未包覆以及表面包覆镍后对La1.5Mg0.5Ni6.5Co0.5合金电极电化学性能的影响。结果表明,与未包覆相比,包覆后合金电极的活化性能、高倍率放电性能、交换电流密度和氢的扩散速率均得到明显的提高,且随着反应温度的升高而增大。合金电极循环寿命也在一定程度均好于未包覆的,但是改善不明显,这表明化学镀镍能有效地提高贮氢合金电极电化学性能。

Effect of surface treatment on electrochemical performance of A_2B_7 type hydrogen storage alloy

Taking A2B7-type hydrogen storage alloy La1.5Mg0.5Ni6.5Co0.5 as an investigation object,the electrochemical properties of the alloy electrode with Ni-P coating and without coating under the different reaction temperatures were studied.The results show that the nickel microencapsulated hydrogen storage alloy electrodes reveal better performance in activation property,high-rate discharge ability,exchange current density and diffusing coefficient Dα of hydrogen in α-phase of hydride with increasing reaction temperature.The Ni surface microencapsulating has a little effect on the cyclic stability.All of the above indicate that the technique of Ni-P coating by chemical plating can effectively improve the electrochemical performance of hydrogen storage alloy electrodes.