Valence electron structure and hydrogen storage property of LaNi_-4Co

Lei Zhang^1,2，Shi-Chun Li³

1. School of Electromechanical Automobile Engineering, Yantai University2. Key Laboratory of Advanced Manufacturing and Control Technology in Universities of Shandong3. Materials Department, College of Electromechanical Engineering, China University of Petroleum

摘 要：In the present study, two models of atom occupation in 4 Co were put forward and corresponding valence electron structures（VESs） of these two models were investigated according to empirical electron theory（EET） of solids and molecules. Results demonstrate that the VES-concerned hardness factor（FH） of LaNi4 Co is lower than that of LaNi5, so LaNi4 Co has lower hardness,higher plasticity and improved anti-pulverization ability. In the mean time, the difference of the equilibrium hydrogen pressure between LaNi4 Co and LaNi5 was analyzed in the electronic level. The analysis shows that the strength of the weakest bond net in octahedron lattice interstices of LaNi4 Co is much lower than that in LaNi5; consequently,LaNi4Co’s bond net easily deforms to accommodate hydrogen so that LaNi4 Co has lower equilibrium hydrogen pressure in comparison with LaNi5. The results can provide some theory guide on the design of hydrogen storage alloys.

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