OLi3-decorated Irida-graphene for High-capacity Hydrogen Storage: A First-principles Study

Abstract: Efficient hydrogen storage in solid-state materials is essential for next-generation energy systems, yet achieving a high gravimetric capacity with optimal adsorption characteristics remains a critical challenge. Although Li-decorated irida-graphene (IG) has shown promising hydrogen storage potential, its capacity is limited to $\sim$ 7wt\%, which, despite exceeding the U.S. DOE target, remains inadequate for large-scale applications. Additionally, Li clustering over extended cycles may compromise adsorption efficiency and structural stability. In this study, we employ first-principles calculations to investigate the hydrogen storage potential of IG decorated with superalkali OLi$_3$ clusters, aiming to enhance the adsorption capacity and stability for advanced hydrogen storage technologies. Our findings show that the OLi$_3$ clusters exhibit a significant binding energy of -3.24 eV, which highlights its strong interaction with the IG. OLi$_3$@IG complex can host up to 12H$_2$ molecules, with optimal maximum storage capacity of 10.00 wt\%. Additionally, the release temperature (T$_R$) and \textit{ab initio} molecular dynamics (AIMD) simulations indicate that H$_2$ molecules can be efficiently released at operating temperatures under ambient conditions. These results highlight the potential of OLi$_3$-decorated irida-graphene as a promising candidate for reversible hydrogen storage.