两步电弧熔炼法制备Ti0.10Zr0.15V0.35Cr0.10Ni0.30 + 5wt% La0.85Mg0.25Ni4.5Co0.35Al0.15复合储氢合金, X射线衍射(XRD)和扫描电镜?能谱(SEM-EDS)显示: 复合储氢合金的主相是体心立方结构的钒基固溶体相和六方结构的C14 Laves相, 复合过程中生成了第二相. 电化学研究表明: 复合过程中存在明显的协同效应; 在303 K时, 复合合金电极的实际最大放电容量为361.8 mAh/g; 在233 K时, 复合合金电极的低温放电能力(LTD)是母体合金电极的4.05倍. 与母体合金电极相比, 复合合金电极的高倍率放电性能(HRD)提高了26.87%, 电荷转移电阻(Rct)减小了37.25 mΩ, 同时交换电流密度(I0)增大了115.45 mA/g, 合金体内氢的扩散系数(D)增大了6.13×10-10 cm2/s.
Composite hydrogen storage alloy Ti0.10Zr0.15V0.35Cr0.10Ni0.30 + 5wt% La0.85Mg0.25Ni4.5Co0.35Al0.15 was prepared by two-step arc melting. X-ray diffractometry (XRD) and scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) show that the main phase of the composite alloy consists of V-based solid solution phase with BCC structure and C14 Laves phase with hexagonal structure, while secondary phase also exists in the composite alloy. Electrochemical studies show that distinct synergetic effect appears during the composite process. The real maximum discharge capacity of the composite alloy electrode is 361.8 mAh/g at 303 K, and the low temperature dischargeability (LTD) of the composite alloy electrode is 4.05 times as high as that of the matrix alloy electrode at 233 K. The high rate dischargeability (HRD), the charge–transfer resistance (Rct) and the exchange current density (I0) of the composite alloy electrode are 26.87 % bigger, 37.25 mΩ lower and 115.45 mA/g higher than that of the matrix alloy electrode, respectively. The hydrogen diffusion coefficient (D) in the bulk of the composite alloy is 6.13×10-10 cm2/s bigger than that of the matrix alloy.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] | |
| [9] | |
| [10] | |
| [11] | Feng F, Geng M, Northwood DO. Electrochemical behaviour of intermetallic-based metal hydrides used in Ni/metal hydride (MH) batteries: a review. Int. J. Hydrogen Energy, 2001, 26(7): 725-734.[2] Liu Y, Wang Y, Xiao L, et al. Study on the structure and electrochemical performance of AB3-type hydrogen storage composite electrode material. Int. J. Hydrogen Energy, 2007, 32(17): 4220-4224.[3] Singh B K, Cho S W, Bartwal K S. Effect on structure and hydrogen storage characteristics of composite alloys Ti0.32Cr0.43V0.25 with LaNi5 and rare-earth elements La, Ce, Y. J. Alloys Compd., 2009, 478(1/2): 785-788.[4] Zhao X, Ma L. Recent progress in hydrogen storage alloys for nickel/metal hydride secondary batteries. Int. J. Hydrogen Energy, 2009, 34(11): 4788-4796.[5] Zhang W, Zhu Y, Yang C, et al. Effects of metal additive on electrochemical performances of Mg-based hydrogen storage materials prepared by hydriding combustion synthesis and subsequent mechanical milling (HCS+MM). Int. J. Hydrogen Energy, 2010, 35(15): 8241-8246.[6] Tsukahara M, Takahashi K, Mishima T, et al. Phase structure of V-based solid solutions containing Ti and Ni and their hydrogen absorption&ndash |
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