Nanoconfined 2LiBH4–MgH2 Prepared by Direct Melt Infiltration into Nanoporous Materials

Nanoconfined 2LiBH4–MgH2 is prepared by direct melt infiltration of bulk 2LiBH4–MgH2 into an inert nanoporous resorcinol–formaldehyde carbon aerogel scaffold material. Scanning electron microscopy (SEM) micrographs and energy dispersive X-ray spectroscopy (EDS) mapping reveal homogeneous dispersion of Mg (from MgH2) and B (from LiBH4) inside the carbon aerogel scaffold. Moreover, nanoconfinement of LiBH4 in the carbon aerogel scaffold is confirmed by differential scanning calorimetry (DSC). The hydrogen desorption kinetics of the nanoconfined 2LiBH4–MgH2 is significantly improved as compared to bulk 2LiBH4–MgH2. For instance, the nanoconfined 2LiBH4–MgH2 releases 90% of the total hydrogen storage capacity within 90 min, whereas the bulk material releases only 34% (at T = 425 °C and p(H2) = 3.4 bar). A reversible gravimetric hydrogen storage capacity of 10.8 wt % H2, calculated with respect to the metal hydride content, is preserved over four hydrogen release and uptake cycles.