Using the first-principles pseudopotential plane-wave method based on density functional theory, the influences and micro-mechanisms of Mg atom vacancy defect on the dehydrogenation properties of MgH2 system were investigated. The results show that the appearance of Mg atom vacancy results in the shrinkage of crystal cell and distortion of MgH2 lattice, which significantly decreases the structural stability and remarkably improves the dehydrogenation kinetics of this system. Further analysis on electronic structures shows that the mico-mechanisms for Mg atom vacancy improving the dehydrogenati...
