Hydrogen storage performance of LiBH4+1/2MgH2 composites improved by Ce-based additives

LiBH₄+1/2MgH₂ is a promising reactive hydride composite for hydrogen storage. In the present study, three Ce-based additives were used as catalysts to enhance the hydrogen storage performance of LiBH₄+1/2MgH₂ composites. The composites with Ce additives demonstrated significantly improved dehydrogenation kinetics and cyclic stability compared with the pure composite. X-ray diffraction and scanning electron microscopy analyses clearly revealed the phase transitions and morphological evolution during the hydriding-dehydriding cycling. The composites with Ce-based additives displayed stable nanostructures, in contrast to the rapid microstructural deterioration in the uncatalyzed composite. The CeB₆ formed in the composites had a particle size of 10 nm after five cycles. It may act as the nucleus for MgB₂ formation during dehydrogenation and thus account for the structural and performance stability of the composites upon cycling.