Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9803634 | Journal of Alloys and Compounds | 2005 | 7 Pages |
Abstract
In this paper, the effects of substitution of Zr for La on the structure and electrochemical properties of the La0.7âxZrxMg0.3Ni2.45Mn0.1Co0.75Al0.2 (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)Ni3 phase and a LaNi5 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 I0 always decreases, the limiting current density IL and the hydrogen diffusion coefficient D first increases and then decreases with increasing x from 0 to 0.1.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Hongge Pan, Yuanjian Yue, Mingxia Gao, Xuefeng Wu, Ni Chen, Yongquan Lei, Qidong Wang,