Enhancing Hydrogen Storage Performance of Metal Hydrides in Ships: A Review

Some metals and metal alloys can store gaseous hydrogen (GH₂), making the storage of hydrogen in metal hydrides (MHs) possible. The present work aims to explore the development of marine MHs and technologies for enhancing hydrogen storage performance while identifying future research priorities. First, the mechanism of MHs hydrogen storage is summarized and its applications in the maritime field are introduced. Subsequently, the technical and economic feasibility of utilizing MHs hydrogen storage technology in ships is analyzed along with the application scenarios and requirements of ship-based MHs. Furthermore, to meet the target requirements for hydrogen storage properties in ship power systems, this review focuses on several aspects: the hydrogen storage materials, reactor structural parameters, hydrogen storage operating conditions, and thermal management optimization. The factors influencing the performance of MHs hydrogen storage systems and their impacts are summarized. Strategies to enhance the performance of MHs hydrogen storage are proposed and technologies for heat transfer enhancement in MHs hydrogen storage, along with the corresponding thermal management systems, are introduced. Finally, future research directions for ship-based MHs hydrogen storage are outlined: developing new synthesis routes for novel MH hydrogen storage materials; creating microchannel hydrogen storage reactors with excellent hydrogen storage and heat transfer performance and conducting combined optimization analyses of multiple reactor structural parameters and operational parameters; coupling phase change materials (PCMs) to enhance the energy utilization efficiency of the hydrogen absorption and desorption process; reasonably regulating the kinetics of the hydrogen storage system to ensure the dynamic stability coupled with hydrogen fuel cells; and constructing intelligent hydrogen storage systems based on deep learning methods to improve the predictive and decision-making capabilities for hydrogen storage performance and thermal management. Through exploring these research directions, MHs hydrogen storage technology is anticipated to achieve greater efficiency and wider applications in the future.