摘要储氢材料作为镍氢电池的负极材料，已被广泛的应用。所以在阅读大量文献后，所以确定研究对象为La-Ni-Co系中A5B19型储氢合金。通过 Mg部分替代 La，分析Mg含量对合金微观结构及电化学性能的影响。试验中，采用高频感应熔炼制备La1-xMgxNi2。75Co1。05 (x=0。05，0。07，0。10，0。13，0。15）合金，通过x射线衍射(XRD)对其结构进行表征和物相分析。86872

    相结构分析表明，铸态La1-xMgxNi2。75Co1。05 合金具有多相结构，主要由LaNi5相、Pr5Co19相和Ce5Co19相组成，随着Mg含量x的变化，各相的相丰度发生了变化，而相丰度的变化影响合金的滞后和吸放氢平台压力。

    储氢合金研究者常采用元素替代法来提高贮氢合金电化学综合性能。实验结果表明，Mg的添加，使最大放电容量、高倍率放电性能 HRD都有提高，当x值取0。05、0。07、0。1、0。13、0。15五个值时最大放电容量从254。00mAh/g增加到351。51mAh/g。HRD300由87。79%升高到99。08%，HRD600，HRD900都提高，合金电极的高倍率放电性能主要由合金电极表面的电催化活性所控制。而极限电流密度IL随着Mg的含量增加先增加后减小。

毕业论文关键词： 铸态储氢合金La1-xMgxNi2。75Co1。05   相结构  电化学性能

Abstract    Hydrogen storage materials as anode materials for nickel hydrogen batteries have been widely used。So after reading a lot of literature, so to determine the object of study for the A5B19 La-Ni-Co type hydrogen storage alloys。The effect of Mg content on the microstructure and electrochemical properties of the alloy was analyzed by means of Mg partial substitution of La。In experiment,La1-xMgxNi2。75Co1。05  (x=0。05,0。07,0。10,0。13,0。15) alloy was prepared by high frequency induction melting, and its structure was characterized by X - ray diffraction (XRD)。

    Phase structure analysis showed that cast La1-xMgxNi2。75Co1。05 alloys have multiphase structures, mainly consisted of LaNi5 phase and Pr5Co19 phase and Ce5Co19 phase composition, with the change of Mg content x, of each phase abundance occurred the change, and phase changes in the abundance of the alloy of lag and absorption and desorption plateau pressure。

    Hydrogen storage alloys are often used as an alternative method to improve the electrochemical performance of hydrogen storage alloys。The experimental results show that the Mg is added to make the maximum discharge capacity, and the high rate performance of HRD is improved,The maximum discharge capacity increased from 254。00mAh/g to 351。51mAh/g。HRD300 from 87。79% to 99。08%, HRD600 and HRD900 all increased when the x value of 0。05,0。07,0。1,0。13,0。15 was five,The high rate discharge performance of the alloy electrode is mainly controlled by the electrocatalytic activity of the alloy electrode surface。However the electrochemical cycling stability of the alloy electrode has decreased a litter, and the limiting current density IL increases first and then decreases with the increase of Mg content。

Keywords: As cast hydrogen storage alloyLa1-xMgxNi2。75Co1。05;  phase structure;     Electrochemical properties

目录

第一章   绪  论 1

1。1 引言 1

1。2 储氢合金的研究现状及发展趋势 2

1。2。1 储氢方式 2

1。2。2 储氢合金的发展及研究 2

1。2。3 储氢合金的基本类型 3

1。2。4 元素替代对储氢合金性能的影响