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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 first principle pseudopotential plane wave method based on density functional theory was used to calculate the crystal structure, electron structure and hydrogen desorption performance of Co and Ni doped LiBH4 system. Negative alloy formation heat and H atom dissociation energy calculations found that: the metal element Co, Ni in LiBH4 in a small amount of replacement solution, the stability of the system changes, alloying enhanced the ability of the system of hydrogen, in which Co improve LiBH4 system solution Hydrogen effect is better. The electronic density of states and electron density analysis found that the main reason for the alloying ability of LiBH4 to reduce hydrogen is that Co and Ni reduce the energy gap near the Fermi level of LiBH4 system, BH bond between the weakened.