A first-principle study on hydrogen storage of metal atoms (M = Li, Ca, Sc, and Ti) coated B40 fullerene composites

Abstract

By means of density functional calculations, we design four hydrogen storage materials, 6Li@B40, 6Ca@B40, 6Sc@B40, and 6Ti@B40 composites, and perform a comprehensive study on hydrogen adsorption and storage. It is found that 6Ca@B40 is the best candidate for hydrogen storage with moderate adsorption energy of H2. The clustering of Ca on B40 surface is avoided, owing to the strong binding between Ca and B40. 6Ca@B40 can store up to 24 H2 molecules through physical absorption mainly and with an average adsorption energy of 0.170 eV/H2, corresponding to a gravimetric density of 6.66 wt%.