摘要
采用基于密度泛函理论的第一原理赝势平面波方法,计算了Co、Ni掺杂LiBH4体系的晶体与电子结构及解氢性能的影响。负合金形成热与H原子解离能的计算发现:金属元素Co、Ni在LiBH4中少量置换固溶时,体系结构稳定性发生变化,合金化增强了体系解氢能力,其中Co提高LiBH4体系解氢效果较好。电子态密度与电子密度分析发现:合金化提高LiBH4解氢能力的主要原因是Co、Ni导致LiBH4体系Fermi能级附近能隙减小,BH键的键长增长和重叠布局数减小及Li与BH之间的成键作用减弱。
The crystal, electronic structure and dehydrogenating of Co and Ni for LiBH4 system were calculated by first-principles based on density functional theory. The calculated negative heat of formation and dissociation energy of H atom show that when a little Co and Ni dissolve into LiBH4 in a small amount of replacement solution, there are some changes on structural stability. Alloying elements can improve the dehydrogenating properties of the system. After analyzing the density of states （DOS） and charge distribution, it is found that the catalysis effect of Co and Ni on the dehydrogenating kinetics of LiBH4 may attribute to the reduction of energy gap near Fermi level, the growth of bonding length and the reductions of overlap population with BH bonding and the weakened bonding between Li and BH.
出处
《热加工工艺》
CSCD
北大核心
2013年第12期58-62,共5页
Hot Working Technology
基金
国家自然科学基金资助项目(51071065)
湖南大学汽车车身先进设计制造国家重点实验室自主研究课题项目(71075003)
湖南省张家界航空工业职业技术学院创新基金资助项目(ZHKT2010-020)
关键词
LiBH4
合金形成热
电子结构
解氢性能
H原子解离能
LiBH4
alloy heat formation
electronic structure
dehydrogenation properties
H atom dissociation energy
