MgH₂ is one of promising hydrogen storage materials due to its high hydrogen capacity of 7.6 wt%. However, MgH₂ nanocrystallites easily grow up during hydrogen absorption―desorption cycling, leading to deterioration of hydrogen storage properties. To clarify the growth kinetics of MgH₂ crystallites, the growth characteristics of MgH₂ nanocrystallites are investigated in this work. The growth exponents of MgH₂ nanocrystallites in pure MgH₂ and MgH₂―10 wt% Pr₃Al₁₁ samples are evaluated to be n = 5 and n = 6, respectively. Meanwhile, their activation energies for crystallite growth are also determined to be 109.2 and 144.2 kJ/mol, respectively. The increase of growth exponent and rise of activation energy for crystallite growth in MgH₂―10 wt% Pr₃Al₁₁ composite are ascribed to the presence of nano-sized Pr₃Al₁₁ phase.

MgH ₂由于其高的7.6 wt％的氢容量而成为有前途的储氢材料之一。但是，MgH ₂纳米晶体在氢吸收-解吸循环中容易长大，导致储氢性能下降。为了阐明MgH ₂晶体的生长动力学，在这项工作中研究了MgH ₂纳米晶体的生长特性。在纯MgH ₂和MgH ₂ ―10 wt％Pr ₃ Al ₁₁样品中，MgH ₂纳米晶体的生长指数被评估为n = 5和n= 6。同时，它们用于微晶生长的活化能也分别确定为109.2和144.2 kJ / mol。MgH ₂ -10 wt％Pr ₃ Al ₁₁复合材料中微晶生长的增长指数的增加和活化能的增加归因于纳米级Pr ₃ Al ₁₁相的存在。