非晶纳米晶PrMg_(12)型合金微观结构及吸放氢热力学与动力学性能  

Microstructure and hydrogenation/dehydrogenation thermodynamic and kinetic properties of PrMg_(12) type alloy with amorphous and nanocrystalline structure

作　　者：段亚楠 胡锋[1] 夏婷 李永治[1] 赵鑫 蔡颖[1] DUAN Yanan;HU Feng;XIA Ting;LI Yongzhi;ZHAO Xin;CAI Ying(Inner Mongolia University of Science and Technology,Baotou 014010,Inner Mongolia Autonomous Region,China)

机构地区：[1]内蒙古科技大学,内蒙古自治区包头014010

出　　处：《储能科学与技术》2022年第10期3151-3160,共10页Energy Storage Science and Technology

基　　金：内蒙古自然科学基金项目(2020LH05024);内蒙古自治区应用技术研究与开发资金项目(2021GG0016;2021GG0017);国家自然科学基金项目(51871125)。

摘　　要：采用机械球磨法制备了非晶纳米晶PrMg_(12)+x%Ni(x=0、10、20、30)合金,系统地研究了镍含量对该合金储氢热力学与动力学的影响。利用X射线衍射(XRD)、高分辨透射电子显微镜(HRTEM)两种方法分析了合金的相组成及微观组织结构。结果表明:PrMg_(12)+x%Ni(x=0、10、20、30)合金的微观结构主要为非晶纳米晶;加入镍前,吸氢前后的主相分别为PrMg_(12)相、MgH_(2)相以及PrH_(2.92)相;加入镍后,吸氢前后的主相分别为Ni相、PrMg_(12)相、MgH_(2)相以及Mg_(2)NiH_(4)相。采用Sieverts装置测定了合金的P-C-T曲线与吸放氢动力学曲线,并结合Van't Hoff方程、JMAK模型和Arrhenius法计算了热力学与动力学参数。结果表明:随着镍含量由0%增加至30%,合金氢化物的放氢焓值由89.881 kJ/mol降低至82.764 kJ/mol,放氢活化能由126 kJ/mol降低至90 kJ/mol,这进一步证明添加镍可以显著改善球磨PrMg_(12)型合金氢化物的释氢热力学和动力学。Amorphous and nanocrystalline PrMg_(12)+x%Ni(x=0,10,20,or 30)alloys were prepared by mechanical milling,and the effects of the nickel content on the thermodynamics and kinetics of hydrogen storage in the alloys were studied systematically.The phase composition and microstructure of the alloy were analyzed by X-ray diffraction(XRD)and highresolution transmission electron microscopy(HRTEM).The PrMg_(12)+x%Ni(x=0,10,20,or 30)alloy was mainly amorphous and nanocrystalline.Before adding nickel,the main phases before and after hydrogen absorption were the PrMg_(12)phase,MgH_(2) phase,and PrH_(2.92) phase,respectively.After adding nickel,the main phases before and after hydrogen absorption were a Ni phase,PrMg_(12)phase,MgH_(2) phase,and Mg_(2)NiH_(4) phase.The P-C-T curves and hydrogen absorption and desorption kinetic curves of the alloy were measured using a Sieverts apparatus,and the thermodynamic and kinetic parameters were calculated by combining the Van't Hoff equation,the JMAK model,and the Arrhenius method.The hydrogen desorption enthalpy of the alloy hydride decreased from 89.881 kJ/mol to 82.764 kJ/mol as the Ni content was increased from 0%to 30%,and the hydrogen desorption activation energy decreased from 126 kJ/mol to 90 kJ/mol.Hence,adding nickel can significantly improve the hydrogen release thermodynamics and kinetics of ball-milled PrMg_(12)-type alloy hydrides.

关 键 词：PrMg_(12)合金 机械球磨法 热力学性能 动力学性能 活化能 

分 类 号：TG139.7[一般工业技术—材料科学与工程]