Strategic integration of metamaterials properties and topology optimization of gyroid metal hydride reactor for high-density hydrogen storage

Metal hydride (MH) is considered to be one of the potential materials for storing hydrogen. It has a substantial limitation to wide use in the mobility sector, which is its low gravimetric hydrogen storage density. A novel canister design utilizing the optimization of gyroid structure for MH-based hydrogen storage is proposed to enhance reactor strength and capacity, increasing the favor of using it outside stationary applications. Topology optimization (TO) of the reactor increases the capacity by 49 % while maintaining the capability of this reactor to sustain 5000 N of bending case. On top of that, changing the metamaterial properties of the gyroid results in a larger chamber size for storing a larger amount of MH by the maximum amount of 30 %. However, increasing the chamber size comes with a cost of a lower charging rate and a considerable area of non-reacted hydride at the same charging time compared to the non-modified structure. By evaluating the MH bed that consists of lanthanum nickel (LaNi5), the topologically optimized reactor design is varied with different chamber offsets of 0, 2, and 4 mm. The results show that using a 2 mm offset in this study case can increase hydrogen storage capacity by 22 % while maintaining the same charging time of less than 4500 s. The combination of both proposed methods can increase the overall MH bed chamber by 66.22 % compared to previous initial research that acts as proof of concept.