合金化元素的选择及其对(La, Mg)5Ni19 A5B19型相稳定性和电化学储氢性能的影响

项目名称： 合金化元素的选择及其对(La, Mg)5Ni19 A5B19型相稳定性和电化学储氢性能的影响

项目编号： No.U1304522

项目类型： 联合基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 范燕平

作者单位： 河南理工大学

项目金额： 30万元

中文摘要： 镧-镁-镍A5B19型合金因理论比容量高、吸/放氢晶格应力低和耐腐蚀性好而受到广泛关注，但其综合电化学储氢性能有待进一步提高。在保持良好循环稳定性的同时，优化合金电化学储氢性能的关键在于合理选择合金化元素，所选元素应有利于提高A5B19型相稳定性和[A2B4]/[AB5]子单元的匹配性，并降低吸/放氢过程中晶格应力。本项目拟选择La4MgNi19 A5B19型相合金作为基体，采用理论计算与实验研究相结合的方法，明确合金化元素在A5B19型相中的占位及合金化对[A2B4]/[AB5]子单元匹配性和相稳定性的影响；研究合金化后A5B19型相合金的微观结构和储氢性能，揭示合金化对吸/放氢过程中晶格应力和循环稳定性的影响规律；结合相稳定性和循环稳定性，合理选择合金化元素，多元优化La4MgNi19合金的微观结构和储氢性能，以期得到高比容量、低自放电、长寿命的镧-镁-镍基A5B19型相储氢合金。

中文关键词： 储氢合金；电化学性能；相稳定性；循环稳定性；合金化元素

英文摘要： La-Mg-Ni-based A5B19-type alloys have attracted much attention due to high theoretical capacity, good corrosion resistance and low lattice strains in hydrogen absorption/desorption. However, the overall electrochemical hydrogen storage properties are not satisfying. La-Mg-Ni A5B19-type alloys have attracted extensive attentions due to their high theoretical capacity, low lattice strains during hydrogen absorption/desorption and good corrosion resistance. However, the overall electrochemical hydrogen storage properties are yet not satisfying. In fact, selection of alloying elements plays a critical role in improving the overall electrochemical hydrogen storage properties with excellent cycling stability. Proper chosen of alloying element is believed to benefit the phase stability and the matching ability between [A2B4] and [AB5], and can also lower the lattice strains during the hydrogen absorption/desorption. This project aims to take La4MgNi19 A5B19-type phase as research system, study the site occupancy and preference of alloying elements, and clarify their influences on matching ability between [A2B4] and [AB5] and the stability of A5B19-type alloys by both experimental and theoretical methods. At the same time, the microstructures and hydrogen storage performances of the alloyed A5B19-type alloys would be in

英文关键词： Hydrogen storage alloys；Electrochemical performance；Phase stability；Cycling stability；Alloying element