Ti0．8Zr0．2V1．1Mn0.9-xNi0．4Crx固溶体贮氢合金结构和电化学性能  

Structure and Electrochemical Properties of Ti_(0.8)Zr_(0.2)V_(1.1)Mn_(0.9-x)Ni_(0.4)Cr_x Hydrogen Storage Almoys

作　　者：印文雅[1,2] 赵敏寿[1] 

机构地区：[1]中国科学院长春应用化学研究所稀土化学与物理重点实验室,长春130022 [2]中国科学院研究生院,北京

出　　处：《应用化学》2008年第2期162-168,共7页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金(20171042)资助项目

摘　　要：研究了Ti_(0.8)Zr_(0.2)V_(1.1)Mn_(0.9-x)Ni_(0.4)Cr_x(x为0～0.4)固溶体电极合金的结构和电化学性能。结果表明,Ti_(0.8)Zr_(0.2)V_(1.1)Mn_(0.9-x)Ni_(0.4)Cr_x系列合金是由具有体心立方(BCC)结构的V基固溶体相和C14Laves第二相组成的双相合金。Ti_(0.8)Zr_(0.2)V_(1.1)Mn_(0.9-x)Ni_(0.4)Cr_x系列合金作为镍-氢化物电池负极材料具有良好的活化性能(3次循环可以达到最大放电容量)和倍率放电能力;由于Cr取代Mn抑制了合金中吸氢元素V充放电过程中在电解液中溶解,显著改善了此系列合金电极的循环寿命,20周循环后循环稳定性系数S20从6.4%(x=0)增加到73.8%(x=0.4);合金电极的最大放电容量随Cr取代量的增加从420mA.h/g(x=0)降低到279mA.h/g(x=0.4);高温放电容量随着Cr取代量的增加而降低,333K温度条件下,放电容量从744mA.h/g(x=0)减少到246mA.h/g(x=0.4);Ti_(0.8)Zr_(0.2)V_(1.1)Mn_(0.9-x)Ni_(0.4)Cr_x系列合金电极的交换电流密度和氢扩散系数均随Cr取代量增加而先增大后减小,当x=0.3时最大,分别为275mA/g和5.956×10-10cm2/s。The structure and electrochemical properties of Ti0.8Zr0.2V1.1Mn0.9-xNi0.4Crx（x =0. 0 -0. 4） solid solution electrode alloys were investigated systematically. It was found that these alloys mainly consisted of a solid solution phase with a body centered cubic（bcc） structure and a C14 Laves secondary phase. The solid solution alloys showed easy activation behavior（to reach the maximum capacity within 3 cycles） and favorable rate dischargeability as a negative electrode material in Ni-MH batteries. The cycle stability of the alloy electrodes was improved markedly with the increase of Cr content in the alloys because the substitution of Cr for Mn suppresses vanadium dissolution in the alkali solution. The cycle stability parameter S20 of the alloy electrodes increased from 6.4% to 73.8% with x increasing from 0 to 0. 4. The maximum discharge capacity of the alloy electrodes decreased from 420 mA · h/g to 279 mA · h/g with x changing from 0 to 0. 4. The high temperature discharge capacity of the alloy electrodes decreased from 744 mA · h/g to 246 mA · h/g with x changing from 0 to 0.4 at 333 K. Furthermore, both the exchange current density and the hydrogen diffusion coefficient of the alloy electrode increased first and then decreased with the amount of Mn substituted by Cr increasing, and the maximum values of them were 275 mA/g and 5. 956 × 10^-10 cm^2/s with x =0. 3, respectively.

关 键 词：金属氢化物 固溶体合金 负极材料 电化学性能 

分 类 号：O612.4[理学—无机化学]