无镨钕高功率La_(1-x)Ce_x(NiCoM)_5贮氢合金电化学性能研究(Ⅱ)  

The electrochemical properties of La_(1-x)Ce_x(NiCoM)_5 hydrogen storage alloys(Ⅱ)

作　　者：黄玲 黄奇书 雷一锋 彭能 张四奇 刘金刚 李杏英 

机构地区：[1]广东省稀有金属研究所,广东广州510650

出　　处：《材料研究与应用》2016年第2期93-99,共7页Materials Research and Application

摘　　要：采用真空快淬熔炼-热处理方法制备了一系列无镨钕高功率La_（1-x）Ce_x（NiCoM）_5贮氢合金,并对其相结构、活化性能及电化学性能进行了研究,考察了其高倍率放电特性.XRD分析结果表明,合金均为单一的CaCu_5型密排六方结构,晶胞体积和晶胞参数随Ce含量的增加而减小.电化学测试结果表明：随Ce含量增加（x=0.09~0.70）,合金活化次数由3次增加至11次;7C放电的初始容量由248.3mA·h/g下降到168.2mA·h/g;电极搁置5d后的自放电率由13.6%增加至46.2%,而高倍率放电性能（HRD）和高倍率充放电循环稳定性均先增加而后下降.当Ce含量为0.45时,合金7C放电的初始容量为233.8mA·h/g、充放电循环寿命为331次、活化次数为5次、HRD为71.23%,其搁置5d后容量损失率为28.17%（自放电率）.A series of Pr and Nd free AB5 rare earth-based hydrogen storage alloys with Ce were synthesized by rapidly quenched melting-heat treatment method. The phase structures,activation property,electrochemical properties and high discharge rate ofLa_（1-x）Ce_x（NiCoM）_5 hydrogen storage alloys were investigated.XRD analyses shows that all the investigated alloys present CaCu5 type hexagonal phase,and the until cell volume and lattice parameter decreases with the increasing of Ce content.With the increase of Ce content（x=0.09-0.70）,the number of activation increase from 3to 13charge-discharge cycles,and 7C discharge capacity decrease from 248.3mAh/g to168.2mAh/g,and self-discharge rate increase from 13.6%to 46.2%in 5days storage;and the high discharge rate and cyclic stability of alloy electrodes increase at first but decrease finally.When added of 0.45 Ce,the high-rate discharge performance of the alloy shows as follows：the 7Cdischarge initial capacity decrease is 233.8mAh/g and cycle life is 331cycles;the number of activation is 5charge-discharge cycles;7Cdischarge properties is 71.23%,and self-discharge rate is 28.17%in 5days storage.

关 键 词：AB5型无镨钕贮氢合金 动力电池 电化学性能 铈 

分 类 号：TG139.7[一般工业技术—材料科学与工程]