Mn元素对储氢合金(La_(0.78)Mg_(0.22))(Ni_((0.9-x))Co_(0.1)Mn_x)_(3.5)的结构及电化学性能的影响  

EFFECT OF Mn CONTENT ON THE STRUCTURE AND ELECTROCHEMICAL CHARACTERISTICS OF(La_(0.78)Mg_(0.22))(Ni_((0.9-x))Co_(0.1)Mn_x)_(3.5) HYDROGEN STORAGE ALLOYS

作　　者：张灏[1] 汪保国[1] 王丹[1] 眭艳辉[1] 何丹农[1] 夏保佳[2] 

机构地区：[1]纳米技术及应用国家工程研究中心,上海200241 [2]中国科学院上海微系统与信息技术研究所

出　　处：《上海金属》2010年第2期16-19,共4页Shanghai Metals

基　　金：上海市科委科研计划项目基金资助(06 JC 4028和06dz11001)

摘　　要：感应熔炼法制备了(La_(0.78)Mg_(0.22))(Ni_((0.9-x))Co_(0.1)Mn_x)_(3.5)(x=0.00,0.01,0.03,0.05,0.07)合金,并在氩气气氛下,以1 173 K温度退火处理。XRD相结构分析表明,合金具有多相结构,随着Mn含量的不同分别含有:La_2Ni_7相、LaNi_5相和LaNi_3相。P-C-T性能测试表明,合金在3 MPa压力和298 K温度下的吸氢量高达1.6 wt.%。电化学测试表明,合金放电容量随着Mn含量的增大而减小,由x=0时的394.2 mAh/g下降到x=0.07时的363.3 mAh/g,充放电循环性能是先下降,后上升,再下降。合金的倍率性能随着Mn含量的增加先上升,后下降,然后又上升。当放电电流密度为3 000 mA/g时,高倍率性能由x=0时的201.6 mAh/g变为x=0.07时的182.9 mAh/g。研究表明当x=0.03时合金具有比较好的综合性能。The effect of Mn content on the crystal structure, thermodynamics and electro- chemical properties of （La0.78Mg0.22）（Ni（0.9-x）Co0.1Mnx）3.5 （ x = 0.00, 0.01, 0.03, 0.05 and 0.07） alloys was studied systematically. The phase structures identified by X-ray diffraction （XRD） showed that the alloys consisted of three phases, La2 NiT, LaNi5 and LaNi3 phase, depending on the different amount of Mn, The properties of hydrogen absorption and desorption were determined by Pressure Composition Temperature （P-C-T）. The results revealed that the test alloy absorbed about 1.61 wt. % H2 at 3 MPa H2 and 298 K. The electrochemical analysis showed that the discharge ca- pacity decreased with the increasing of Mn content, but the cycle stability and high discharge rate property were improved by some degree with the increasing of Mn content. It was showed that the per- formance of alloys was best when x = 0.03.

关 键 词：储氢合金 La2Ni7相 LaNi5相 P-C—T 电化学性能 

分 类 号：TG139.7[一般工业技术—材料科学与工程]