Hydrogen storage in light-metal based systems: A review

Promoting widespread utilization of sustainable and renewable energy sources along with efficient energy storage and conversion technologies is vital to address gargantuan energy and environmental challenges. Hydrogen, working as an eco-friendly and highest mass-energy density clean energy carrier for abundant but fluctuating renewable power, has been recognized as an ideal alternative for fossil fuels in both mobile and stationary applications. To date, the production, storage, and delivery of hydrogen remain a linchpin enabling technologies for the advent of the hydrogen economy community. Herein, an overview is present of recent research progress on hydrogen release and uptake in potential reversible systems with a focus on light-metal hydrogen storage materials, including magnesium (Mg)-based hydrides, metal alanates, borohydrides, and amides. Both Mg-based hydrides and complex hydrides are, however, plagued by unfavorable thermodynamics and/or sluggish kinetics in the dehydrogenation and/or rehydrogenation. To overcome these challenges, recent advances have been driven by tremendous efforts, such as catalysis, nanoscaling, compositing or ionic substitutions, etc. Though great achievements have been attained in light-metal based materials, it is still far from satisfying the requirements of practical automotive applications. Sustainable research efforts are further needed to be made for solving the intrinsic thermodynamic and kinetic barriers.