Improvement of the LiBH₄ hydrogen desorption by confinement in modified carbon nanotubes

Highlights: • The desorption kinetics for LiBH₄ greatly promoted using melt infiltration method. • The LiBH₄ confined in modified MWCNTs shows the best desorption kinetics. • The crystal structure of MWCNTs and SWCNTs is unchanged after ball milling. • Ball milling introduces a great amount of structural defects in the CNTs. • Nano-confinement is dominant on improving the hydrogen desorption of LiBH₄. - Abstract: The dehydrogenation kinetics of LiBH₄ incorporated within various carbon nanotubes has been studied. It is demonstrated that the desorption kinetics of LiBH₄ could be greatly promoted using a simple melt infiltration method and LiBH₄ confined in modified multi-walled carbon nanotubes (MWCNTs) shows the best desorption kinetics. The structural properties of carbon nanotubes and confined samples are demonstrated by means of transmission electron microscopy, powder X-ray diffraction and Raman spectroscopy. The crystal structure of MWCNTs and single-walled carbon nanotubes (SWCNTs) are almost unchanged after ball milling. But high energy ball milling leads to a decrease in the average nanotube length and introduces a great amount of local disorder and structural defects in the CNTs, which may provide a considerable kinetic improvement