The storage of hydrogen as a renewable energy carrier is still a key-challenge in hydrogen-based energy cycles. Metal hydride (MH) technology offers hydrogen storage solutions with highest volumetric hydrogen storage densities (higher than liquid hydrogen) at moderate temperatures and gas pressures [1,2]. Thus, the hazard potential of MH storage solutions is rather low. Various metals and metal alloys readily absorb gaseous hydrogen forming solid metal hydrides. The exothermal absorption is often reversible. Many metal alloys exhibit a very fast intrinsic hydrogenation kinetics, which offers the possibility to build high-dynamic hydrogen storage systems as long as heat and gas transport are sufficiently high. Industrial state-of-the-art metal hydride storage solutions include hydrogen supply for stationary or transportable back-up power systems, fuel cell powered boats and submarines, mining or railed vehicles [3,4]. To allow high-dynamic operation (loading/unloading < 10 min) a special MH composite material is favorable over loose MH power (increased thermal conductivity, reduced porosity). Metal hydride composites (MHC) consist of the hydrogen absorbing alloy and a secondary phase, e.g. graphite or aluminum, which improves the heat transport properties in the reaction bed [5,6,7].
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