Improved hydrogen storage properties of LiBH4 by mechanical milling with various carbon additives

Various LiBH₄/carbon (graphite (G), purified single-walled carbon nanotubes (SWNTs) and activated carbon (AC)) composites were prepared by mechanical milling method and further examined with respect to their hydrogen storage properties. It was found that all the carbon additives can improve the H-exchange kinetics and H-capacity of LiBH₄ to some extents. Compared with G, SWNTs and AC exhibited better promoting effect on the hydrogen storage properties of LiBH₄. Based on combined property/phase/structure analysis results, the promoting effect of the carbon additives was largely attributed to their heterogeneous nucleation and micro-confinement effect on the reversible dehydrogenation of LiBH₄.