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和Ni对LiNH2体系的晶体、电子结构及解氢性能的影响.负合金形成热与H原子解离能的计算结果表明:金属元素Co、Ni在LiNH2中少量置换固溶时,体系结构稳定性发生变化,合金化增强了体系的解氢能力,其中Ni提高LiNH2体系解氢效果较好.电子态密度(DOS)与电子密度分析结果表明:合金化提高LiNH2解氢能力的主要原因是合金化元素Co、Ni导致LiNH2体系Fermi能级附近能隙值发生变化以及“与N-H之间的成键作用减弱.%The effect of Co, Ni on the crystal, electronic structure and dehydrogenating of LiNH2 system were calculated by first-principles calculation based on the density functional theory. The calculated negative heat of formation and dissociation energy of H atom show that, when a little Co,Ni dissolve into LiNH2 in a small amount of replacement solution, there are some changes on structural stability, alloying elements befit to improve the dehydrogenating properties of the system. After comparing the densities of states (DOS) and the charge distribution, it is found that the catalysis effect of Co, Ni on dehydrogenating kinetics of LiNH2 may attribute to the changes of energy gap near the Fermi level and the weakened bonding between Li and N-H.
展开▼
