Mechanical behavior of metal hydrides and hydrogen storage containers: A review

This review article delves into the intricate mechanical behaviors exhibited by metal hydrides within hydrogen storage tanks during hydrogen absorption and release processes. The metal’s crystal structure undergoes expansion upon hydrogen absorption, leading to the liberation of energy—an exothermic phenomenon. Conversely, during hydrogen release, the metal contracts, necessitating an intake of energy from the surroundings—an endothermic occurrence. These cyclic processes give rise to two significant mechanical implications: firstly, the initiation of a decrepitation mechanism; secondly, the material undergoes rhythmic expansion and contraction, often referred to as "hydride breathing." These dual mechanisms collectively contribute to the escalating strain and stress imposed on the walls of the metal hydride container, thereby impacting its structural integrity. This review delves into the comprehensive landscape of experimental studies, measurement techniques, and modeling approaches employed in analyzing stress and strain within metal hydride hydrogen storage tanks. The report encompasses an exploration of the factors amplifying mechanical stresses within the metal hydride bed, alongside proposed strategies for their mitigation and control. Furthermore, the article concludes by presenting pragmatic and experimental recommendations aimed at the development of secure hydrogen storage tanks grounded in metal hydride technology.