Magnesium nickel hydride monocrystalline nanoparticles for reversible hydrogen storage

Although Mg -based hydrides are extensively considered as a prospective material for solid-state hydrogen storage and clean energy carriers, their high operating temperature and slow kinetics are the main challenges for practical application. Here, a Mg -Ni based hydride, Mg 2 NiH 4 nanoparticles (-100 nm), with dual modi fication strategies of nanosizing and alloying is successfully prepared via a gas -solid preparation process. It is demonstrated that Mg 2 NiH 4 nanoparticles form a unique chain -like structure by oriented stacking and exhibit impressive hydrogen storage performance: it starts to release H 2 at -170 degrees C and completes below 230 degrees C with a saturated capacity of 3.32 wt% and desorbs 3.14 wt% H 2 within 1800 s at 200 degrees C. The systematic characterizations of Mg 2 NiH 4 nanoparticles at different states reveal the dehydrogenation behavior and demonstrate the excellent structural and hydrogen storage stabilities during the de/hydrogenated process. This research is believed to provide new insights for optimizing the kinetic performance of metal hydrides and novel perspectives for designing highly active and stable hydrogen storage alloys.