La_(0.7)Mg_(0.3)Ni_(2.65)Co_(0.75-x)Mn_(0.1)Si_x储氢电极合金的结构和电化学性能  

Structure and Electrochemical Properties of La_(0.7)Mg_(0.3)Ni_(2.65)Co_(0.75-x)Mn_(0.1)Si_x Hydrogen Storage Electrode Alloys

作　　者：李瑞[1] 胡泽忠 刘永锋[1] 高明霞[1] 潘洪革[1] 

机构地区：[1]硅材料国家重点实验室,浙江省电池新材料及应用技术重点实验室,浙江大学材料科学与工程系,浙江杭州310027 [2]东风本田汽车有限公司,湖北省武汉市430056

出　　处：《材料科学与工程学报》2013年第3期372-375,460,共5页Journal of Materials Science and Engineering

基　　金：浙江省科技创新团队资助项目(2010R50013);浙江省“钱江人才计划”资助项目(20111R10017);国家自然科学基金资助项目(51171170,51222101);中央高校基本科研业务费资助项目(2012XZZX003-8)

摘　　要：系统研究了Si部分替代Co对La0.7Mg0.3Ni2.65Co0.75Mn0.1储氢电极合金结构和电化学性能的影响。XRD结果显示,随着Si替代量的增加,合金中(La,Mg)Ni3相的丰度逐渐降低,而LaNi5相的丰度逐渐增加,且含Si合金中出现了La2Ni7相。电化学测试表明,Si部分替代Co降低了合金的放电容量,但显著提高了其循环稳定性,改善了其高倍率放电性能。其中Si替代量x=0.15时合金的综合性能较好,合金最大放电容量323mAh/g,75次循环后的容量保持率约为71.9%,1250mA/g电流放电时的HRD可达55%。Effects of the partial substitution of Si for Co on the structure and electrochemical properties of La0.7 Mg0.3 Ni2.65 Coo. 75 Mn0.1 hydrogen storage electrode alloys were systematically investigated. XRD results show that the abundance of （La, Mg）Ni3 phase decreases while LaNi5 phase increases with increasing Si content. Moreover, the La2Ni7 phase was detected in the alloys containing the Si. Electrochemical examination revealed that the partial substitution of Si for Co enhanced significantly the cycling stability of the La0. TMg0.3 Ni2.Coo. 7 Mn0.1 alloy, and improved its high rate dischargeability although the maximum discharge capacity was lowered. The x： 0.15 alloy exhibits the optimized overall electrochemical performance as its maximum discharge capacity is 323 mAh/g, the capacity retention is about 71.9 after 75 cycles, and the value of HRD1250 is about 55%.

关 键 词：MH Ni电池 储氢电极合金 元素替代 结构 电化学性能 

分 类 号：TB34[一般工业技术—材料科学与工程]