Co-packed metal hydride and phase change pellets enable rapid hydrogen storage and release

Abstract

Solid-state magnesium-based hydrides provide a promising route toward high-density, safe, and reversible hydrogen storage. However, their practical application is severely limited by inefficient thermal management: heat accumulation during exothermic hydrogenation suppresses reaction kinetics, while continuous external heat input is required to drive endothermic dehydrogenation. Here, we present a simple co-packed strategy that integrates metal hydride and phase change pellets to enable rapid hydrogen storage and release. The phase change pellets dynamically absorb and release latent heat, effectively removing excess heat during hydrogenation and supplying heat during dehydrogenation. As a result, the co-packed system exhibits markedly accelerated hydrogen uptake and release kinetics, with total storage and release time reduced by 39% and 33%, respectively, compared with conventional packed beds. More notably, at 90% conversion, the hydrogen storage and release rates are enhanced by 600% and 400%, respectively. Mechanistic studies reveal that particle-level thermal coupling shortens heat transfer pathways and enables rapid thermal response, thereby accelerating reaction kinetics. This work establishes a simple but effective strategy to mitigate thermal limitations in solid-state hydrogen storage, enabling rapid hydrogen storage and release.