The invention relates to a
metal hydride heat-storage medium and a preparation method thereof. Through optimization, the heat-storage medium provided by the invention comprises the following components by
mass: 50 to 90% of
magnesium; 0 to 40% of M1, which is at least one selected from the group consisting of iron,
nickel and
cobalt elements; 1 to 5% of M2, which is at least one selected from thegroup consisting of
titanium,
vanadium and
niobium elements; and 3 to 20% of carbon. The heat-storage medium has an
energy storage density of 1000 to 3000 MJ / m3, a
thermal conductivity of 3 to 10 W / m.K and a compactness of 50 to 70%. The preparation method for the heat-storage medium comprises the following steps: preparing
magnesium-based
hydride in a high-pressure
hydrogen atmosphere; then subjecting
metal M2 containing a catalytic element to hydrogenation treatment so as to obtain a catalyst; uniformly mixing the catalyst with the
magnesium-based
hydride, and crushing an obtained mixture toa nanometer grade; and adding a carbon-based
heat transfer agent, carrying out uniform mixing, and carrying out press molding so as to obtain a finished product with a compactness of 50 to 70%. The preparation method provided by the invention is reasonable in component design; and the
metal hydride heat-storage medium prepared by using the preparation method provided by the invention has the advantages of large heat-storage density,
high heat-absorbing rate, controllable heat-releasing rate, excellent cycle performance and long service life.