添加稀土元素对Ti_(0.26)Zr_(0.07)V_(0.24)Mn_(0.1)Ni_(0.33)储氢合金微观结构和电化学性能的影响  

Effect of Rare Earth Elements on Microstructure and Electrochemical Characteristics of Ti_(0.26)Zr_(0.07)V_(0.24)Mn_(0.1)Ni_(0.33) Alloy

作　　者：刘妍[1] 赵敏寿[1] 李书存[1] 王艳芝[1] 马琳[1] 宋杰[1] 

机构地区：[1]燕山大学环境与化学工程学院,河北秦皇岛066004

出　　处：《中国稀土学报》2008年第2期188-194,共7页Journal of the Chinese Society of Rare Earths

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(REL200601)

摘　　要：研究了添加5种稀土元素对Ti0.26Zr0.07V0.24Mn0.1Ni0.33合金的微观结构和电化学性能的影响。结果表明,Ti0.26Zr0.07V0.24Mn0.1Ni0.33和Ti0.26Zr0.07V0.24Mn0.1Ni0.33RE0.01(RE=La,Ce,Pr,Nd,Gd)合金均由体心立方结构的BCC主相和少量六方结构的C14型Laves相组成;在合金中加入稀土元素,会使合金中两相的晶胞体积同时增大。添加5种稀土元素都可以改善合金电极的活化性能,而对合金电极其他性能的影响则各有不同,其中添加铈和镨可以提高合金电极的最大放电容量,而添加钕和钆能改善合金电极的循环稳定性。工作温度对合金电极的放电容量影响较大,过高的温度使其循环容量衰减加剧;而含稀土元素的合金电极在333 K温度下放电容量达到最大值。稀土对合金电极的荷电保持率产生一定影响;镧、铈、镨的添加能够改善合金电极的倍率放电性能。The effects of five rare earth elements addition on microstructure and electrochemical properties of Ti0.26Zr0.07V0.24Mn0.1Ni0.33 alloys were studied. It was found that all the Ti0.26Zr0.07V0.24Mn0.1Ni0.33 and Ti0.26Zr0.07V0.24Mn0.1Ni0.33RE0.01 （RE = La, Ce, Pr, Nd, Gd） alloys consisted of V-based solid solution with bee structure as main phase and C14 Laves phase with hexagonal structure. The cell volumes of both phases were swelled after rare earth elements were added into the alloy. The addition of five kinds of rare-earth elements could improve the activation performance of the electrodes alloy and affected the other characteristics of the alloy. However, with different rare-earth elements the effect on other performance ofelectrode alloy was different. Cerium and praseodymium addition could enhance the maximum discharge capacity of the electrode alloy, and neodymium and gadolinium addition could improve the cycle stability of the electrode alloy. The temperature had obvious in fluence on discharge capacity of the ahoy, and the excessively high temperature made the capacity of the electrode alloy degrade rapidly. The discharge capacity of the electrode alloy which contained rare-earth element reached its maximum at 333 K. The rare earth had certain influence on the charge retention of the electrode alloy, and the addition of La, Ce and Pr could improve the high-rate dischargeability of the electrode alloy, respectively.

关 键 词：钒基固溶体合金 电化学性能 MH—Ni电池 稀土 

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]