A_2B_7型贮氢合金表面覆钴及电化学性能研究  

Cobalt microencapsulated A_2B_7 type metal hydride electrodes and its electrochemical properties

作　　者：田晓光 周沛丽 

机构地区：[1]黄河交通学院,河南焦作454950 [2]广东省机械高级技工学校,广东广州512026

出　　处：《电源技术》2015年第7期1452-1454,1468,共4页Chinese Journal of Power Sources

摘　　要：通过研究了表面包覆钴和未包覆的A2B7型贮氢合金La1.5Mg0.5Ni7电极的电化学性能,同时对包覆钴贮氢合金进行低温退火的研究。结果表明:表面包覆钴贮氢合金电极放电容量明显提高,但合金循环寿命并未得到改善;与镀态合金相比,经低温退火处理的合金电极放电容量变化不大,但循环寿命较镀态合金有所改善。SEM结果表明:化学镀Co镀层为晶态,且镀层晶粒细小,经退火处理,晶粒长大,应力减小。The effects of Co-P coatings and annealing on the electrochemical properties of La1.5Mg0.5Ni7 hydrogen storage alloy electrode was studied. The results show： the coated material has a higher capacity compared to the barealloy due to the faradaic reaction of cobalt during discharge, but the cycle life of coated material were not improved compared to the bare alloy. Comparing to coating alloys, When the coating alloys was treated at the low heating temperature ,whose capacity approximated to coating alloys and cycling stability was improved .The Co coated powder electrode is better than bare relectrode in exchange current density l0, limiting current density l0 and hydrogen diffusion coeffient D.SEM and XRD show that electroless plated Co-P alloys coating is crystalline, being a solid solution of phosphors in cobalt matrix with finer grains as plated. When heated, grains growth stress relaxation occur in the coating.

关 键 词：A2B7型贮氢合金 化学镀钴 电化学性能 

分 类 号：TM912.2[电气工程—电力电子与电力传动]