Co含量对La_(0.55)Pr_(0.05)Nd_(0.15)Mg_(0.25)Ni_(3.5-x)Co_xAl_(0.25)(x=0～0.4)储氢合金电极性能的影响  

Effect of Co content on electrochemical properties of La_(0.55)Pr_(0.05)Nd_(0.15)Mg_(0.25)Ni_(3.5-x)Co_xAl_(0.25)(x=0～0.4) hydrogen storage alloy

作　　者：覃铭[1] 何兵[1] 卿培林[1] 卢照[2] 刘奕新[2] 郭进[2] 

机构地区：[1]百色学院物理与电信工程系,百色533000 [2]广西大学物理科学与工程技术学院,南宁530004

出　　处：《粉末冶金材料科学与工程》2012年第2期160-165,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51071054);广西自然科学基金资助项目(2011GXNSFA018034);广州大学百色学院科研基金资助项目(GBK2010008)

摘　　要：采用电磁感应悬浮炉制备La0.55Pr0.05Nd0.15Mg0.25Ni3.5-xCoxAl0.25(x=0,0.1,0.2,0.3,0.4)系列合金,研究Co含量对合金的相结构、吸放氢性能和电化学性能的影响。研究结果表明,该系列合金主要由LaNi5、Nd2Ni7相组成。当Co含量大于0.2时,合金中出现La2Ni7相。压强-吸氢量-温度(Pressure-Content-Temprature)测试显示在303 K温度下,合金具有良好的吸氢性能,当x=0.4时合金的最大吸氢量为1.29(质量分数,%)。电化学测试表明:随x值变化,合金电极的最大放电容量分别为340.0(x=0.0)、346.6(x=0.1)、370.0(x=0.2)、320.0(x=0.3)和346.6(mA.h)/g(x=0.4);随Co含量增加,合金电极容量保持率不断增加,高倍率放电性能先增加后减小,循环伏安曲线、氢在合金体中的扩散系数D共同反映了合金电极的动力学特性。La0.55Pr0.05Nd0.15Mg0.25Ni3.5-xCoxAl0.25（x=0.0,0.1,0.2,0.3,0.4） alloys were prepared by magnetic levitation melting method.The XRD results show that the alloy is mainly composed of LaNi5 and Nd2Ni7 phase,La2Ni7 phase appeared when x0.2.The PCT（pressure-content for hydrogen absorption-temperature） curves show that the alloy has the maximun hydrogen storage capacity 1.29%（mass fraction） at 303 K when x=0.4.The electrochemical measurements indicate that the maximun discharge capacities of the alloy electrodes are 340.0（x=0.0）,346.6（x=0.1）,370.0（x=0.2）,320.0（x=0.3） and 346.6（mA-h）/g（x=0.4）,respectively.With the increase of Co content,the discharge capacity retention increase and the high rate dischargeability first increase then decrease.The cyclic voltammetry curve and the diffusion coefficient of hydrogen in the alloy reflect the electrochemical kinetics of the alloy electrodes.

关 键 词：MH/Ni二次电池 储氢合金 电化学特性 

分 类 号：TG139.7[一般工业技术—材料科学与工程]