The effect of substitution of Zr for La on the electrochemical properties of La0.7−xZrxMg0.3Ni2.45Mn0.1Co0.75Al0.2 hydrogen storage electrode alloys
The effect of substitution of Zr for La on the electrochemical properties of La0.7−xZrxMg0.3Ni2.45Mn0.1Co0.75Al0.2 hydrogen storage electrode alloys
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DOI：
10.1016/j.jallcom.2004.12.042
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发表时间：
2005-07
影响因子：
6.2
通讯作者：
H. Pan;Yuanjian Yue;M. Gao;Xue-Xiang Wu;N. Chen;Y. Lei;Qidong Wang
中科院分区：
文献类型：
--
作者：
H. Pan;Yuanjian Yue;M. Gao;Xue-Xiang Wu;N. Chen;Y. Lei;Qidong Wang
本文系统地研究了La掺杂对La{sub0.7-x}Zr{subx}Mg{sub0.3}Ni{sub2.45}Mn{sub0.1}Co{sub0.75}Al{sub0.2}(x=0，0.02，0.04，0.06，0.08，0.1)储氢合金结构和电化学性能的影响。X射线粉末衍射分析表明，所有合金主要由(La，Mg)Ni{sub3}相和LaNi{sub5}相组成。两相的电池容量均随x的增加而减小。电化学研究表明，最大放电容量从364.5 mAh/g(x=0)下降到306.9 mAh/g(x=0.1)。电化学阻抗谱、线性极化、阳极极化和电位阶跃测试表明，随着x的增加，交换电流密度i{sub0}始终减小，极限电流密度i{subL}和氢扩散系数D先增大后减小。
In this paper, the effects of substitution of Zr for La on the structure and electrochemical properties of the La{sub 0.7-x}Zr {sub x}Mg{sub 0.3}Ni{sub 2.45}Mn{sub 0.1}Co{sub 0.75}Al{sub 0.2} (x = 0, 0.02, 0.04, 0.06, 0.08, 0.1) hydrogen storage alloys have been studied systematically. X-ray powder diffraction (XRD) analysis shows that all the alloys mainly consist of a (La, Mg)Ni{sub 3} phase and a LaNi{sub 5} phase. The cell volumes of these two phases decrease with increasing x. Electrochemical studies indicate that the maximum discharge capacity decreases from 364.5 mAh/g (x = 0) to 306.9 mAh/g (x = 0.1). The high rate dischargeability (HRD) first increases and then decreases with increasing x. Electrochemical impedance spectroscopy (EIS), linear polarization, anodic polarization and potential-step measurements showed that the exchange current density I {sub 0} always decreases, the limiting current density I {sub L} and the hydrogen diffusion coefficient D first increases and then decreases with increasing x from 0 to 0.1.