Holding the Invisible: Advanced Materials for Hydrogen Storage

Hydrogen storage remains the main barrier to the broader use of hydrogen as an energy carrier, despite hydrogen’s high energy density and clean combustion. This study presents a comparative evaluation of conventional and emerging storage methods, integrating thermodynamic, kinetic, economic, and environmental metrics to assess capacity, efficiency, cost, and reversibility. Physisorption analysis reveals that metal organic frameworks can achieve storage capacities up to 14.0 mmol/g. Chemical storage systems are evaluated, including nanostructured MgH2 (7.6 wt%), catalyzed reversible complex hydrides, liquid organic hydrogen carriers, and clathrate hydrates. Techno-economic analysis shows storage costs from $500–700/kg H2 to $30–50/kg H2 , with energy efficiencies of 50%–90%. Life cycle assessment identifies manufacturing as the primary source of emissions, with carbon footprints varying from 150 to 2057 kg CO2 -eq/kg H2 . Cryo-compressed is the most practical transportation option while metal hydrides suit stationary use. This study provides a quantitative foundation to guide material selection and system design for next-generation hydrogen storage technologies.