用于固态储氢的新型储氢合金储氢特性、机理及应用技术研究

针对高安全性低压固态储氢要求储氢材料具有储氢容量高、平衡氢压随温度变化大和循环稳定性好特性，本项目提出利用新型RE-Mg-Ni系储氢合金具有超晶格结构多样性和储氢特性可调整性强等特点，通过研究储氢合金超晶格单元与组成元素原子半径和电负性的匹配关系，调控合金Laves相[A2B4]亚单元及CaCu5相[AB5]亚单元体积，提高合金氢化物的形成速度和稳定性，显著改善合金储氢容量和氢化物分解压力；通过调整合金相结构组成及其丰度，研究介质温度变化对合金吸放氢平台压、热焓以及吸放氢速率等影响关系，分析具有吸放氢平衡压力温度系数大和储氢特性可调整性强的合金结构特点。在揭示新型储氢合金超晶格晶体结构与储氢特性关系及储氢机理基础上，设计和制备具有高储氢容量、吸/放氢平台压力可调控性强以及长寿命的新型储氢合金，并研究合金可用于固态储氢的应用技术，为储氢合金实际应用提供参考数据和理论指导。

Aiming to satisfy the demand of solid hydrogen storage with high security and low pressure that the hydrogen storage materials are with high hydrogen storage capacity, greatly variable equilibrium hydrogen pressure with temperature, and good cycle stability characteristics, this project proposes to study a new type of RE-Mg-Ni-based hydrogen storage alloy with diversity superlattice structure and adjustable hydrogen storage properties. Through elucidating the matching relationship between the superlattice unit of the hydrogen storage alloy and the atomic radius and electronegativity inside elements, we intend to control the volumes of the Laves-type [A2B4] and CaCu5-type [AB5] subunits of the structure to improve the forming speed and stability of the alloy hydride, and significantly improve the hydrogen storage capacity and hydride decomposition pressure of the alloy. By adjusting the phase composition and abundance, the effect of the change of the medium temperature on pressure, enthalpy and the rate for hydrogen absorption and desorption of the alloy will be studied, and the alloy’s structure characteristics with high temperature coefficient for hydrogenation and dehydrogenation and strong adjustability for hydrogen storage performance will be analyzed. Based on the relationship between the superlattice structure and hydrogen storage property of the new type hydrogen storage alloys and its hydrogen storage mechanism, the new type alloy with high hydrogen storage capacity, highly adjustable hydrogenation and dehydrogenation pressure and long life will be design and prepared. The application technology of alloys for solid state hydrogen storage will be studied. The studies of this project will provide data and theoretical guidance for the practical application of hydrogen storage alloy.