镁基储氢合金材料研究进展

Research Progress of Magnesium-based Hydrogen Storage Alloys

储氢合金主要有稀土镍系的AB5型、锆基/鈦基Laves相系的AB2、钛镍系的AB型及镁基合金4种类型。镁基储氢合金具有储氢容量大、吸放氢可逆性好、成本低、资源丰富等优点,成为近年来的研究热点。但由于高的热力学稳定性和慢的动力学限制了其应用,因此对镁基储氢合金进行改性成为镁基合金的发展方向。将稀土元素引入储氢合金,其特有的4f电子层对改善储氢材料的放氢性能具有独特作用,成为镁基储氢合金采用的重点改性元素。此外,碳负载镁基储氢合金材料、钛修饰的镁基储氢材料以及其他多元镁基合金的研究也取得了一定进展。过渡金属具有优良的结构、电学和磁性能,可作为储氢合金脱氢的催化剂;稀土元素由于其特殊的4f电子结构,在储氢材料改性中占有重要地位;石墨烯在镁基储氢材料中的催化作用、共催化作用和抑制晶粒聚集长大作用值得关注。

Hydrogen storage alloys mainly include AB5 type of RE/nickel system,AB2 type of Zr/Ti Laves phase system,AB type of Ti/Ni system and Mg-based alloy.Mg-based hydrogen storage alloys have become a research hotspot in recent years due to their advantages of large hydrogen storage capacity,good reversibility of hydrogen absorption and discharge,low cost and abundant resources.However,the application of Mg-based hydrogen storage alloys is limited by high thermodynamic stability and slow kinetic rate,so the modification of Mg-based hydrogen storage alloys becomes the development trend of Mg-based alloys.Rare earth elements are introduced into hydrogen storage alloys,and their unique 4f electron layer plays a unique role in improving the hydrogen discharge performance of hydrogen storage materials,so rare earth elements have become the key modification elements used for Mg-based hydrogen storage alloys.In addition,some progresses have been made in the researches on carbon supported Mg-based hydrogen storage alloy material,Ti modified Mg-based hydrogen storage material and other multi-element Mg-based alloys.Transition metals can be used as catalysts for dehydrogenation of hydrogen storage alloys due to their excellent structure,electrical and magnetic properties.Rare earth elements play a very important role in the modification of hydrogen storage materials due to their special 4f electron structure.The catalysis,co-catalysis and inhibition of grain aggregation and growth of graphene in Mg-based hydrogen storage materials deserve attention.