Objective Metal hydride hydrogen storage reactors serve as core components in solid-state hydrogen storage techniques.During the reversible hydrogen absorption and desorption reactions of metal hydrides, significant heat exchange occurs, leading to uneven temperature distribution within the reactors and resulting in adverse effects on the hydrogen storage performance and service life of the reactors. Therefore, effective thermal management is recognized as one of the key technologies to improve the efficiency and stability of metal hydride hydrogen storage reactors.

Methods This paper aims to review the research progress in the field of thermal management for metal hydride hydrogen storage reactors both in China and abroad. To this end, an extensive investigation of available literature was conducted to summarize the principle of hydrogen absorption-desorption reactions in metal hydrides. The heat transfer process within hydrogen storage reactors was examined, leading to the division of the heat exchange process into three stages: heat transfer in the hydrogen storage materials; heat exchange between the hydrogen storage materials and the wall surface of the hydrogen storage reactors; heat exchange between the wall surface of the hydrogen storage reactors and the ambient environment. Furthermore, thermal management methods that enhance heat exchange efficiency in each stage were categorized.

Results Through an analysis of the heat exchange performance in various thermal management methods, this review presents an overview of the research progress in these approaches, including the use of heat exchange tubes, fins, and phase-change materials. The evaluation of hydrogen absorption and desorption rates as crucial metrics allows for a comparison of their advantages and disadvantages. Additionally, the review summarizes the existing challenges in this field and envisions the prospects for future trends in thermal management for metal hydride hydrogen storage reactors.

Conclusion Different thermal management methods have their pros and cons. Therefore, it is essential to select and optimize specific thermal management methods based on the scale and intentions of metal hydride hydrogen storage reactors, to design efficient and compact thermal management systems. The outcomes of this research lay a foundation for the large-scale and engineering applications of solid-state hydrogen storage techniques.