Nanoconfinement of lithium alanate for hydrogen storage.

LiAlH 4 is considered as a promising material for solid state hydrogen storage. However, the lack of reversibility along with sluggish kinetics hinders its practical application. In this paper, hollow carbon nanospheres (HCNs) were used as a porous scaffold to confine LiAlH 4 via solvent impregnation method. Nanoconfined LiAlH 4 (LiAlH 4 @HCNs) exhibited significant improvements in hydrogen sorption compared to its bulk counterpart. LiAlH 4 @HCNs releases hydrogen sharply at 146 °C with full conversion to LiH within 1.5 h. The desorbed material can also be regenerated back to some extent into LiAlH 4 under 8 MPa H 2 at 150 °C. Measurement of the pressure-composition isotherm suggests an alteration in the equilibrium state upon confinement of LiAlH 4 in voids of a few nanometres and thus altered hydrogen thermodynamic paths. [Display omitted] • LiAlH 4 was confined within hollow carbon spheres by solvent impregnation method. • Nanoconfined LiAlH 4 sharpy released hydrogen at 146 °C. • Rehydrogenation was observed under moderate conditions of 8 MPa H 2 and 150 °C. • The plateau pressure corresponding to each decomposition step was not observed due to an alteration of LiAlH 4 thermodynamics. [ABSTRACT FROM AUTHOR]