Advanced metal hydride reactor design using multi-domain triply periodic minimal surface for enhanced volumetric and absorption performance of hydrogen storage

Metal hydrides (MHs) have attracted considerable attention as hydrogen storage materials owing to their inherent safety and high volumetric density. Nevertheless, their sluggish absorption kinetics and limited gravimetric capacity still pose significant challenges for practical applications. To address these challenges, previous studies have developed and optimized metal hydride reactors (MHRs) incorporating triply periodic minimal surface (TPMS) structures. Nevertheless, achieving both high absorption rates and large storage capacities simultaneously has remained difficult. In this study, a multi-domain TPMS-based MHR, in which the internal space was divided into three and five domains, was proposed to overcome this challenge, and its performance was evaluated through numerical analysis. The results revealed that the five-domain Gyroid achieved hydrogen absorption of 1.2 wt% within approximately 310 s, reducing absorption time by 55.3% and increasing MH volume by 17.6% compared to the conventional Gyroid MHR. Similarly, the five-domain Diamond achieved 1.2 wt% hydrogen absorption in about 290 s, reducing absorption time by 47.6% and increasing MH volume by 21.5% compared with the conventional Diamond MHR. Additionally, mechanical strength evaluations under bending, torsion, and compression—representative load conditions for mobility integrations show that multi-domain MHRs experience slight reductions in stiffness, with maximum displacements remaining below 0.15 mm. These results demonstrate that the proposed multi-domain design is an effective approach for simultaneously enhancing hydrogen storage capacity and absorption performance in TPMS-based MHRs. • Multi-domain TPMS-based MHRs were proposed to enhance hydrogen storage capacity and absorption rate simultaneously. • Numerical simulations assessed the mechanical strength and hydrogen absorption/desorption performance of the MHR. • Five-domain Gyroid reactors increased MH chamber volume by up to 17.6% while reducing hydrogen absorption time by up to 55.3%. • Five-domain Diamond reactors increased MH chamber volume by up to 21.5% while reducing hydrogen absorption time by up to 47.6%. • All reactors endured bending, torsion, and compression, with displacements not exceeding 0.15 mm.