稀土对Ti_(0.25)V_(0.34)Cr_(0.2)Ni_(0.2)合金相结构和电化学性能的影响  

Effects of Rare Earth on Phase Structure and Electrochemical Properties of Ti_(0.25)V_(0.34)Cr_(0.2)Ni_(0.2) Alloys

作　　者：李佳[1] 赵敏寿[1] 侯春平[1] 黄亮[1] 朱新坚[2] 曹广益[2] 

机构地区：[1]燕山大学环境与化学工程学院,河北秦皇岛066004 [2]上海交通大学燃料电池研究所,上海200030

出　　处：《稀有金属》2007年第6期772-777,共6页Chinese Journal of Rare Metals

基　　金：中国科学院稀土化学与物理重点实验室基金资助项目

摘　　要：通过XRD,SEM-EDS等方法及电化学测试研究了稀土对Ti0.25V0.34Cr0.2Ni0.2合金的微观结构和电化学性能的影响。结果表明,Ti0.25V0.34Cr0.2Ni0.2和Ti0.25V0.34Cr0.2Ni0.2RE0.01(RE分别代表La,Ce,Pr,Nd和混合稀土)合金均由主相为体心立方结构的钒基固溶体相和少量TiNi基第二相组成。稀土元素加入后,合金bcc相的晶格参数略有增加;镧在合金中发生偏析,形成新相。添加稀土元素能够加速合金的活化。303 K温度下基准合金和含Pr合金电极实际测定的理论放电容量大致相等,约为364 mAh.g-1。合金的放电容量对温度的变化比较敏感,高温有利于合金放电。稀土对合金电极的荷电保持率产生不利影响;混合稀土的添加能够改善合金的倍率放电性能。The effects of rare earth addition on microstructure and electrochemical properties of Ti0.25V0.34Cr0.2Ni0.2 alloy were studied by using XRD,SEM-EDS and electrochemical testing.It was found that these alloys were all consisted of V-based solid solution with bcc structure as a main phase and TiNi-based alloy as a secondary phase.The lattice parameters of bcc phase were enlarged slightly,with addition of rare earth elements to the alloys.In the alloy,La deposited to form a new phase.The addition of rare earth elements could improve the activation characteristics of the alloy electrodes.At 303 K the theoretical discharge capacities of the reference alloy electrode and the one with Pr-addition were measured,both of which were similarly approximate to 364 mAh·g-1. Discharge capacities of the alloy electrodes were sensitive to temperature.The charge retention was adversely affected by rare earth addition,although the addition of mischmetal could enhance the high rate dischargeability（HRD） of the alloy electrodes.

关 键 词：钒基固溶体合金 相结构 电化学性能 MH-NI电池 

分 类 号：TG146.4[一般工业技术—材料科学与工程] O611.61[金属学及工艺—金属材料]