稀土镍镁储氢材料的相结构研究概况

本文系统介绍稀土合金系列储氢合金：AB（A=稀土元素;B=Ni,Mg,Co）2∶1;1∶2;1∶3;2∶7;1∶5;2∶17以及近期研究的5∶19型合金的制备、相结构和储氢性能。通过性能与结构的关系的研究表明：储氢性能与材料的相组成和相结构密切相关,稀土原子和金属镁原子与氢原子之间存在很强的亲和力,同时镁原子在合金中的占位导致晶格畸变,诱发晶胞内空隙变大,为合金吸氢提供空间,有利于提高储氢能力。另外,多相之间共格性较好是决定贮氢合金贮氢能力的微观原因。

Progress on Phase Structure of Rare Earth Nickel Magnesium Based Hydrogen Storage Materials

The synthesis technology and phase relations as well as hydrogen storage properties of hydrogen storage alloys with normal compositions： AB（A=rare earth element;B=Ni,Mg,Co） 2∶1;1∶2;1∶3;2∶7;1∶5;2∶17 and 5∶19 have been systemically commented.It reveals that the hydrogen storage properties are very sensitive to the phase constructions and phase contents due to the strong bonding force between the rare earth element Mg and H atoms.The lattice distortions caused by Mg doping in rare earth intermetallics is benefit for enhancing the vacancy spaces in unit cell,it supplies enough space for the occupations of H atoms and increases the H absorption ability.In addition,the lattice coherency on the interface among the phases is also regarded to improve the hydrogen storage ability.