Use of a material (3) for producing hydrogen or electricity, wherein the material comprises at least 50% by weight of a reagent for hydrolysis upon contact with an aqueous solution to obtain hydrogen. The reagent comprises: a first compound chosen from magnesium metal, magnesium hydride, and mixtures thereof, and a second compound alloyed with the first compound, wherein the second compound is chosen from graphite, carbon fibers, and mixtures thereof. The first compound represents at least 75% by weight of the reagent, while the second compound represents between 1% and 25% by weight of the reagent.Use of a capsule containing the material.Method and corresponding production device.