Superior hydrogen storage kinetics of Mg12YNi alloy with a long-period stacking ordered phase

The hydrogen absorption/desorption kinetics of the Mg12YNi alloy with an 18R-type long-period stacking ordered phase was investigated. It was found that the hydrogen-induced decomposition of the 18R phase with a grain size of 200–300 nm occurs at 573 K, leading to the formation of YH2 and YH3 particles with an average size of 10 nm. In the subsequent hydrogen absorption/desorption process, the fine YH2 and/or YH3 particles act as catalysts that enhance remarkably the hydrogen storage kinetics.