期刊
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
卷 372, 期 1-2, 页码 163-172出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.msea.2003.12.004
关键词
hydrogen storage alloy; La-Mg based electrode metal hydrides; structural characteristics; slectrochemical properties
The effects of Mn content on the structure and the main electrochemical properties of La0.7Mg0.3N4.25-xCo0.75Mnx (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) hydrogen storage alloys were investigated systematically. X-ray powder diffraction (XRD) analysis shows that all the alloys mainly consist of a (La,Mg)Ni-3 phase and a LaNi5 phase. The lattice parameters and the unit cell volumes of the two phases increase with increasing x. P-C-T curves reveal that the plateau pressure decreases progressively and the hydrogen storage capacity increases first and then decreases with an increase in Mn content. Electrochemical studies showed that the maximum discharge capacity and the high rate dischargeability (HRD) of the alloy electrodes increased with increasing x. Electrochemical impedance spectroscopy (EIS), linear polarization, anodic polarization and potential-step measurements, showed that the exchange current density I-0, the limiting current density I-L and the hydrogen diffusion coefficient D all first increase and then decrease with increasing x from 0 to 0.5. Considering the global effect of Mn substitution for Ni on the overall performance of the La0.7Mg0.3Ni4.25-xCo0.75Mnx alloy electrodes, the optimum composition was found to be x = 0.4. (C) 2003 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据