Investigation of structural, electronic, mechanical, optical and hydrogen storage properties of cobalt-based hydride-perovskites XCoH3 (X = In, Mn, Sr, Sn, Cd) for hydrogen storage application

In the current study, the physical and hydrogen storage properties of XCoH3 (X = In, Mn, Sr, Sn, Cd) are studied by using first principles calculations. The bandgap and lattice parameters of the studied materials match well with the previous studies involving cobalt-based hydride perovskites. All the compounds are found stable and possess metallic behavior with zero band gap. All the materials are found ductile except MnCoH3 and SrCoH3 which have brittle nature. The Bulk, Shear, and Youngs modulus suggest that CdCoH3 is harder than the other materials. The anisotropic factor suggests that all the materials possess anisotropic nature. The absorption coefficient shows that SrCoH3 is briskly in absorbing the incident photons. The reflectivity shows that SnCoH3 is an effective material for bouncing back the incident radiations. The other optical parameters such as refractive index, extinction coefficient, dielectric function, conductivity and loss function are also investigated in detail. The gravimetric hydrogen storage is found 1.71%, 2.59%, 2.03%, 1.68%, and 1.74 wt% for InCoH3, MnCoH3, SrCoH3, SnCoH3 and CdCoH3, respectively. Due to the higher gravimetric ratio, MnCoH3 is suggested as the most favorable material for storing hydrogen.