镁及镁基储氢合金具有储氢容量高、成本低及污染小等优点,被认为是用于车载储氢方面较有前途的材料。然而镁基合金存在吸放氢温度较高,吸放氢速度较慢的缺点,抑制了它的实际应用。研究表明,制备多元镁基合金可明显改善合金的储氢性能。采用氢化燃烧合成(Hydriding Combustion Synthesis-HCS)和机械球磨(Mechanical Milling-MM),即HCS+MM技术复合制备Mg90Ni10-xVx(x=0,2,4,6,8)合金。采用X射线衍射仪、扫描电镜及气体反应控制器研究了HCS+MM产物的相组成、表面形貌以及吸放氢性能。XRD分析表明,不同合金均含有MgH2,Mg2NiH4,Mg2NiH0.3,Mg以及VHy相,随着V含量的增加,VHy的相含量逐渐增加,而Mg2Ni氢化物含量逐渐减少。SEM结果表明,Mg90Ni4V6和Mg90Ni2V8合金的颗粒平均尺寸较小且分布比较均匀。Mg-Ni-V合金的吸氢性能优于二元Mg-Ni合金,Mg90Ni4V6的吸氢性能最好,在373 K,合金的吸氢量达到5.25%,且在50 s内就基本达到饱和吸氢量。V可以细化晶粒,使合金内部晶界增多,有利于氢的扩散;并且当合金中的V与Mg2Ni达到一定比例时,对合金的吸氢具有协同催化作用,改善了合金的吸氢性能。Mg-Ni-V合金的放氢性能不如二元Mg-Ni合金,说明在放氢过程中Mg2Ni的催化作用优于V。 Magnesium and magnesium-based hydrogen storage alloys have the advantages of high hydrogen storage capacity, low cost and small pollution, and are considered as more promising materials for hydrogen storage in vehicles. However, Mg-based alloys have the disadvantages of higher temperature of hydrogen absorption and desorption and slower absorption and desorption, which inhibits its practical application. Studies have shown that the preparation of multiple magnesium-based alloys can significantly improve the hydrogen storage properties of the alloy. The alloy Mg90Ni10-xVx (x = 0, 2, 4, 6, 8) was prepared by Hydriding Combustion Synthesis-HCS and Mechanical Milling-MM. The phase composition, surface morphology and hydrogen storage and desorption properties of HCS + MM were studied by X-ray diffraction, scanning electron microscopy and gas reaction controller. XRD analysis shows that all the alloys contain MgH2, Mg2NiH4, Mg2NiH0.3, Mg and VHy phases. With the increase of V content, the content of VHy gradually increases and the content of Mg2Ni hydride gradually decreases. SEM results show that the average particle size of Mg90Ni4V6 and Mg90Ni2V8 alloy is smaller and more evenly distributed. The hydrogen absorption performance of Mg-Ni-V alloy is better than that of binary Mg-Ni alloy. Mg90Ni4V6 has the best hydrogen absorption performance. At 373 K, the hydrogen absorption capacity reaches 5.25% Hydrogen content. V can refine the grains and increase the grain boundary within the alloy, which is conducive to the diffusion of hydrogen; and when the ratio of V to Mg2Ni in the alloy reaches a certain proportion, the hydrogen absorption of the alloy has synergistic catalysis and the hydrogen absorption performance of the alloy is improved . The desorption performance of Mg-Ni-V alloy is not as good as that of binary Mg-Ni alloy, indicating that the catalytic effect of Mg2Ni is better than that of V during the process of desorption.