La_(1-x)Ce_x(NiCoMnAl)_5贮氢合金电极的制备及表面改性  

Surface modification and preparation technique for La_(1- x) Ce_x (NiCoMnAl)_5 hydrogen storage alloy electrode

作　　者：于波[1] 朱建新[1] 陈廉[2] 文明芬[2] 宋崇立[1] 

机构地区：[1]清华大学核能设计研究院,北京100084 [2]中国科学院金属研究所氢重点实验室,沈阳110000

出　　处：《清华大学学报（自然科学版）》2001年第6期63-66,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家"八六三"高技术项目 (715 -0 0 4-0 2 3 3 )

摘　　要：制备了 L a1 - x Cex(Ni Co Mn Al) 5 贮氢合金电极 ,研究高温热碱充电和 KBH4还原剂热充电两种新型表面改性方法及其对 L a1 - x Cex(Ni Co Mn Al) 5 贮氢合金电极活化次数、高倍率充放电能力和氢扩散行为的影响。探讨了作用机理。结果发现表面处理法有利于提高合金电极的活化性能和大电流充放电性能。其中 KBH4还原剂热充电法处理后的合金电极在第二次充放电循环时就能完全活化 ;并且在90 0 m A/g的充放电电流密度下 ,其高倍率放电能力达到85 %左右 ;合金电极表面出现大量的微裂纹 ,氢在处理后的合金电极中的扩散系数为 3.2 3× 10 - 9cm2La 1- x Ce x (NiCoMnAl) 5 alloy electrodes were treated by hot charging in alkaline aqueous solution containing potassium borohydride. The activation behavior, hydrogen diffusion coefficient, maximum discharge capacity, high rate discharge capability of these alloy electrodes are then tested. The surface morphology and elemental content were observed using a scanning electron microscope .The results showed that the pre treatments markedly improved the activation behavior and the charging capacity of the alloy electrode. Hot charging of the alloy electrode in alkaline aqueous solution containing potassium borohydride fully activated the electrode after the second charging discharging cycle with a high discharging capability of 85% at 900mA/g. The surface had many micro cracks with a hydrogen diffusion coefficient of about 3.23×10 -9 cm 2/s. The mechanism causing the surface modifications of the alloy electrode is also analyzed.

关 键 词：贮氢合金 表面改性 高温热碱充电法 电池 碱液热充电法 

分 类 号：TM912[电气工程—电力电子与电力传动]