摘要
研究了Pr替代La对La0.8-xPrxMg0.2Ni3.2Co0.4Al0.2(x=0～0.4)储氢合金相结构与电化学性能的影响。XRD及Rietveld全谱拟合方法分析表明,合金主要由Pr5Co19,Ce5Co19及CaCu5型物相组成。随着Pr含量x值的增加,合金中A5B19型物相(Pr5Co19+Ce5Co19)逐渐增多,同时各物相的晶胞参数(a,c)和晶胞体积(V)均减小。电化学测试表明,x值的增加对合金电极的活化性能影响不大,但可显著提高合金电极的循环稳定性。合金的高倍率放电性能(HRD)随着x的增加呈增加趋势,在x=0.3时存在最大值(HRD900=89.6%);合金电极的HRD主要由合金电极表面的电荷迁移速率所控制。
The structure and electrochemical properties of La0.8-xPrxMg0.2Ni3.2Co0.4Al0.2（X=0～0.4）alloys were investigated systematically. The structure analysis of alloys showed that the alloys were composed of muhiphase, such as Pr5Co19-type phase, Ce5Co19-type phase, and CaCu5-type phase. The abundance of A5B19 phase increased with the increase of x value, increasing the x value also led to the decrease of both the lattice parameters and the cell volume. The electrochemical measurement showed that the activation performance was influenced a little but the cyclic stability of the alloys was improved obviously with the increase of Pr content. In addition, the high rate dischargeability （HRD） of the alloy electrodes increased with the increase of Pr content. When x was equal to 0.3, the alloy showed the best high rate dischargeability （HRD900 = 89. 6%）. The chargetransfer on tor for the alloy surface was mainly controlling fachigh-rate dischargeability
出处
《中国稀土学报》
CAS
CSCD
北大核心
2007年第4期454-460,共7页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金(50171021)资助项目
