中国物理B ›› 2011, Vol. 20 ›› Issue (3): 38801-038801.doi: 10.1088/1674-1056/20/3/038801

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

The role of vacancy, impurity, impurity–vacancy complex in the kinetics of LiNH2 complex hydrides: a first-principles study

刘贵立1, 张国英2, 张辉2, 朱圣龙3   

  1. (1)College of Constructional Engineering, Shenyang University of Technology, Shenyang 110023, China; (2)College of Physics Science and Technology, Shenyang Normal University, Shenyang 110034, China; (3)State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • 收稿日期:2010-05-31 修回日期:2010-10-11 出版日期:2011-03-15 发布日期:2011-03-15
  • 基金资助:
    Project supported by the National High Technology Research and Development Program of China (Grant No. 2009AA05Z105), and the Natural Science Foundation of Liaoning Province of China (Grant No. 20102173).

The role of vacancy, impurity, impurity–vacancy complex in the kinetics of LiNH2 complex hydrides: a first-principles study

Liu Gui-Li(刘贵立)a)† , Zhang Guo-Ying(张国英)b), Zhang Hui(张辉)b), and Zhu Sheng-Long(朱圣龙)c)   

  1. a College of Constructional Engineering, Shenyang University of Technology, Shenyang 110023, China; b College of Physics Science and Technology, Shenyang Normal University, Shenyang 110034, China; c State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2010-05-31 Revised:2010-10-11 Online:2011-03-15 Published:2011-03-15
  • Supported by:
    Project supported by the National High Technology Research and Development Program of China (Grant No. 2009AA05Z105), and the Natural Science Foundation of Liaoning Province of China (Grant No. 20102173).

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摘要： This paper studies first-principles plane-wave pseudopotential based on density functional theory of hydrogen vacancy, metal impurity, impurity--vacancy complex in LiNH2, a promising material for hydrogen storage. It finds easy formation of H vacancy in the form of impurity--vacancy complex, and the rate-limiting step to the H diffusion. Based on the analysis of the density of states, it finds that the improvement of the dehydrogenating kinetics of LiNH2 by Ti catalysts and Mg substitution is due to the weak bonding of N--H and the new system metal-like, which makes H atom diffuse easily. The mulliken overlap population analysis shows that H vacancy leads to the H local diffusion, whereas impurity--vacancy complexes result from H nonlocal diffusion, which plays a dominant role in the process of dehydrogenation reaction of LiNH2.

Abstract: This paper studies first-principles plane-wave pseudopotential based on density functional theory of hydrogen vacancy, metal impurity, impurity–vacancy complex in LiNH2, a promising material for hydrogen storage. It finds easy formation of H vacancy in the form of impurity–vacancy complex, and the rate-limiting step to the H diffusion. Based on the analysis of the density of states, it finds that the improvement of the dehydrogenating kinetics of LiNH2 by Ti catalysts and Mg substitution is due to the weak bonding of N–H and the new system metal-like, which makes H atom diffuse easily. The mulliken overlap population analysis shows that H vacancy leads to the H local diffusion, whereas impurity–vacancy complexes result from H nonlocal diffusion, which plays a dominant role in the process of dehydrogenation reaction of LiNH2.

Key words: LiNH2, first-principles calculation, impurity–vacancy complexes, dehydrogenating properties

中图分类号: 

  • 88.30R-
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections)