Advancing hydrogen storage and exploring the potential of perovskite hydrides and metal hydrides

Abstract Recent notable developments concerning the hydrogen storage materials are summarized in this review, with particular emphasis placed on magnesium hydrides, titanium- and calcium-based hydrides, metal borohydrides, and perovskite-type hydrides. MgH2 performance is greatly improved through nanostructuring and transition metal doping. Calcium hydrides, as well as titanium hydrides have very good hydrogen storage properties in addition to the potential for superconductivity. Single and bimetallic borohydrides have high hydrogen contents, achieving high performance in battery and energy application, but face challenges in regeneration and stability. Many perovskite-type hydrides, including MgX3H8 (X = Sc, Ti, Zr), Li2CaH4, and Li2SrH4, as well as oxide-based hydrides like MgTiO3Hx, CaTiO3Hx, and BaYO3Hx, are emerging as ideal hydrogen storage materials thanks to their stable crystal structure, promising thermodynamics, excellent mechanical properties, and efficient hydrogen cycling. Destabilization of the hydrogen is likely based on analysis of DFT studies of hydrogen binding enthalpy, which supports stability and negative formation enthalpies for MgX3H8 and BaYO3H3 as well as CaTiO3H6 and storage of 4.27 wt% with desorption at ∼821.1 K further strengthens the potential of perovskite hydrides in a variety of hydrogen storage applications.