摘要
研究了Cr添加量对V_(2.1)Ti Ni_(0.3)Crx(x=0,0.2,0.4,0.6)贮氢合金的结构和电化学性能的影响。结果表明,所有合金均由V基固溶体主相和Ti Ni基第二相组成,且第二相呈网状分布在晶界上,部分呈颗粒状分布于合金主相之中。随着Cr含量增大,合金主相的晶胞体积与合金电极的最大放电容量逐渐减小,而循环稳定性逐渐增加,同时合金电极的动力学性能得到改善。在合金中添加Cr使合金电极的活化性能变差,但添加量的进一步增多对其活化性能影响不大。综合考虑,V_(2.1)Ti Ni_(0.3)Cr_(0.4)合金的电化学性能最好,最大放电容量可达442.20 m Ah·g^(-1),20次充放电循环后容量保持率达81.91%。
The microstructures and electrochemical properties of the V2.1TiNi0.3Crx（x=0, 0.2, 0.4, 0.6） hydrogen storage electrode alloys were investigated. The results showed that all of the alloys were consisted of the V-based solid solution main phase with a body centered cubic（bcc） structure and the Ti Ni-based secondary phases. The secondary phases were mainly in the grain boundaries with network distribution, and some of the secondary phase particles were distributed in the main phase. The cell volumes of the main phase and the maximum discharge capacity of the alloy electrodes decreased with the increase of Chromium（Cr） content, while the cycle stability of the alloy electrodes was gradually increased. At the same time, the kinetic performance of the alloy electrodes improved. The activation performance of the alloy electrodes deteriorated when the Chromium element was added,but further increase of Cr content did not change the activation performance significantly. The V2.1TiNi0.3Cr0.4alloy showed the best electrochemical properties among the investigated alloys. Its maximum discharge capacity reached 442.20 m Ah·g^-1, and its capacity retention ratio after 20 cycles was 81.91%.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2016年第6期975-982,共8页
Chinese Journal of Inorganic Chemistry
基金
四川省科技支撑计划项目(No.2012GZX0089)
四川省科技创新研究团队建设项目(No.2015TD0008)资助
关键词
钒基贮氢合金
镍氢电池
Cr添加
显微结构
电化学性能
V-based hydrogen storage alloy
Ni-MH battery
Cr addition
microstructure
electrochemical property
作者简介
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