物理学报2011，Vol.60Issue(11)：515-519,5.
LiNH_2储氢材料中间隙H与掺杂原子交互作用对其释氢性能影响机理研究
Mechanism of the influence of the interaction between interstitial H atom and doped atom on the dehydrogenation performance of LiNH_2
摘要
Abstract
The first-principles plane-wave pseudopotential method based on the density functional theory is used to investigate the mechanism of the influence of interaction between interstitial H atom defect and doped atom on the dehydrogenation performance of LiNH2.We obtain the most stable structure of LiNH2 by geometrical optimization,and calculate the binding-energies,interstitial H atom defect formation energies,densities of states （DOSs）,and electric charge populations for LiNH2 and doped LiNH2.Studies show that the results of binding-energy cannot reflect the dehydrogenating properties of LiNH2 and doped LiNH2.In equilibrium,there are a number of interstitial H atom defects;the formation energy of interstitial H atom defect is reduced by doping Mg and Ti,which increases the concentration of interstitial H atoms.Interstitial H atoms can induce the defect energy level in the gap,which reduces the width of the gap,and improves the dehydrogenation performance of LiNH2.The strength of N—H bond in - is weakened by interstitial H atom,so that hydrogen atoms in LiNH2 is relatively easy to release.The covalent bond between interstitial H atom and N atom of - explains the escape of NH3 from the dehydrogenation reaction of LiNH2 system.The strengths of N—H bonds are not equal in doped LiNH2,a part of N—H bonds are weaker,and other N—H bonds are strong,the hydrogen atoms are easy to release from weaker N—H bonds.关键词
储氢材料/第一性原理/缺陷/释氢机理Key words
hydrogen storage materials/first-principles calculation/defect/dehydrogenation mechanics分类
数理科学引用本文复制引用
路广霞,张辉,张国英,梁婷,李丹,朱圣龙..LiNH_2储氢材料中间隙H与掺杂原子交互作用对其释氢性能影响机理研究[J].物理学报,2011,60(11):515-519,5.基金项目
国家高技术研究发展计划 （）
辽宁省教育厅科学研究计划（批准号：2009S099 2008511）资助的课题 （）
