Mg-Y-Ni储氢合金吸放氢动力学性能的研究  

Absorption and Desorption Hydrogen Kinetic of Mg-Y-Ni Based Hydrogen Storage Alloy

作　　者：雍辉 季燕全 胡季帆 赵栋梁[3] 王帅[1] Yong Hui;Ji Yanquan;Hu Jifan;Zhao Dongliang;Wang Shuai(School of Materials Science&Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China;Beijing Sinohytec Co.,Ltd.,Beijing 100192,China;Department of Functional Material Research,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]太原科技大学材料科学与工程学院,山西太原030024 [2]北京亿通华科技股份有限公司,北京100192 [3]钢铁研究总院功能材料研究所,北京100081

出　　处：《稀有金属》2022年第8期1021-1030,共10页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51761032,51871125);来晋优秀博士奖励资金(20212042)资助。

摘　　要：针对镁基储氢合金吸放氢动力学缓慢的问题,构建Mg-Y-Ni储氢合金体系,预通过Y元素和Ni元素引入催化基团,以获得改善其动力学性能的途径。通过真空感应熔炼制备了Mg_(95-x)Y_(5)Ni_(x)(x=5,10,15)合金,并采用X射线衍射(XRD)对其不同状态下的相组成进行分析,并采用扫描电镜(SEM)和透射电镜(TEM)分析合金微观结构和晶体状态。同时,采用Sievert等体积方法测试了试样在不同温度下的等温吸放氢动力学性能。结果表明,氢化后的试样是由MgH_(2),Mg_(2)NiH_(4)和YH_(3)相组成的纳米晶结构,然而在放氢后,仅有MgH_(2)和Mg_(2)NiH_(4)相发生分解反应,生成相应的Mg和Mg_(2)Ni相并放出氢气。原位生成的YH_(3)相没有发生分解,并弥散分布在母合金中,且扮演积极的催化效应。此外,随着Ni含量的增加,合金吸放氢动力学均明显改善,特别是对于Mg_(80)Y_(5)Ni_(15)合金,其最佳吸氢温度被降低至200℃,且在1 min内便可吸收最大储氢容量的90%。同时,其放氢活化能也被降至67.0 kJ·mol^(-1),且能在320℃下仅需要5 min便可完全释放氢气。其综合储氢性能优越,能为促进镁基储氢合金的实际应用提供了科学途径。With the advent of a new round of industrial revolution,the profound changes had taken place in energy development and utilization technologies,and the green and low-carbon had become the general trend of global energy development.Therefore,the hydrogen energy became a clean and renewable energy for human sustainable development in the 21st century.In large-scale application of hydrogen energy,Mg-based hydrides were one of the most promising hydrogen storage materials because of their relatively high storage capacity,abundance,and low cost.However,overly stable thermodynamics and sluggish kinetics hindered the practical applications of Mg-based hydrogen storage alloys.In views of this,the Mg-Y-Ni system was constructed in order to solve the puzzle of slow hydrogen absorption and desorption kinetics of Mg-based hydrogen storage alloy by introducing Y and Ni catalytic elements.The as-cast Mg_(95-x)Y_(5)Ni_(x)(x=5,10,15)alloy were prepared by vacuum induction melting.X-ray diffraction analysis(XRD)was used to analytical phase composition of the as-cast,hydrogenation,dehydrogenation alloy,respectively.Besides,scanning electron microscope(SEM)and transmission electron microscope(TEM)were also used to characterize the microstructure and crystalline state of these samples.Meanwhile,the kinetic properties of isothermal hydrogen adsorption and desorption at different temperatures also were tested by the semi-automatic pressure-capacity-temperature(PCT)device which used the Sievert isometric volume method.In addition,the dehydrogenated activation energy was calculated based on combining the Jonhson-Mehl-Avrami-Kolmogorov(JMAK)model and the Arrhenius equation.The results indicated that the as-cast Mg-Y-Ni samples was a polyphase structure composed of Mg,Mg_(2)Ni and YNi3.Besides,with the increase of Ni content,Mg_(2)Ni and YNi3phases which evenly dispersed in Mg gradually increased and became more and more fine.This was conducive to dividing large area Mg into smaller blocks and obtaining more phase boundaries,which provide

关 键 词：储氢材料 镁基合金 动力学 氢化反应 

分 类 号：TG139.7[一般工业技术—材料科学与工程]