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.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
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
关键词
钒基固溶体合金
相结构
电化学性能
MH-NI电池
V-based solid solution alloy
phase structure
electrochemical performance
MH-Ni secondary battery
