A review on design strategies for metal hydrides with enhanced reaction thermodynamics for hydrogen storage applications

Hydrogen is an alternative clean energy carrier that can replace current fossil fuels for vehicular applications. Thus, it is important to develop a method that would enable a high density of hydrogen to be stored safely under the operating conditions of polymer electrolyte membrane fuel cells. Even though metal hydrides are regarded as promising candidates that can safely store a high density of hydrogen, their stable nature makes it difficult for them to release hydrogen at mild temperatures in the range of 50 to 150 degrees C. In this review, 3 primary strategies, namely, introduction of appropriate dopants, particle size control, and design of novel reactant mixtures based on high-throughput screening methods, are briefly described with the aim of evaluating the potential of metal hydrides for hydrogen storage applications. The review suggests that successful development of promising hydrogen storage systems will depend on collaborative introduction of these 3 primary design strategies through the combined utilization of experimental and computational techniques to overcome the major challenges associated with the reaction thermodynamics of metal hydrides.