【作者】 黄存可；

【导师】 郭进；

【作者基本信息】 广西大学 ， 理论物理， 2006， 硕士

【摘要】 Mg₂Ni基合金由于贮氢量大、重量轻、价格低和储存量大，是最有前景的贮氢合金之一。本文采用理论计算与实验相结合的方法对Mg₂Ni基贮氢合金进行了较系统的研究。 采用烧结和球磨制备了Mg_2-xSn_xNi（x=0，0.05，0.1，0.15，0.2）合金，并进行了微结构及贮氢和电化学性能的研究。结果发现，Sn掺杂后，合金的结构还保持，但随掺杂量的提高非晶化程度提高。在贮氢性能方面，掺杂后吸放氢温度降低，分解焓数值减少，即氢化物稳定性降低。同时，掺杂后贮氢量明显减少，在PCI图线中出现两个吸放氢平台。在电化学方面，电化学容量有明显提高，并随着掺杂量增大而增大。 将Mg₂Ni与V₂O₅和Ni复合球磨制备多元复合合金，并与单一复合的合金进行对比。发现多元复合的合金在吸放氢动力学性能、电化学放电容量方面得到了改善和提高。 利用第一原理密度泛函理论对Mg₂Ni的电子结构进行了计算，对它们成键特征进行了较为详细的研究。对Sn掺杂Mg₂Ni的电子结构的计算表明，掺杂后晶胞膨胀，晶胞的稳定性下降，同时应力有很大的增加。更多还原

【Abstract】 Mg2Ni-based alloy is one of the most promising hydrogen storage materials due to its high hydrogen storage capacity, lightweight, low price and fundamental reserves. We have systematically studied the hydrogen storage properties of the Mg2Ni-based alloy by both theoretical calculation and experimental research.Mg_2-xSn_xNi （x=0,0.05,0.1,0.15,0.2） alloys were prepared by sinter and ball-mill method. Then the microstructure was studied in XRD, and the experiments about hydrogen storage and electrochemical properties were developed. We found that the crystal structures of the doped alloys remain unchanged, the degree of amorphous increases with the amount of x increasing. For hydrogen storage properties, the hydriding/dehydriding temperature of doped alloys fall down, and the decompose-enthalpies of their hydrides decrease which mean that the stability of the hydrides reduce. At the same time, their hydrogen storage capacity descend, and two hydriding/dehydriding pressure plateaus occur in PCI curves. In the aspect of electrochemistry, the discharge capacity is improved with the amount of更多还原