Influence of Ti super-stoichiometry on the hydrogen storage properties of Ti_(1+)Cr_(1.2)Mn_(0.2)Fe_(0.6) (x = 0-0.1) alloys for hybrid hydrogen storage application

摘要

Ti_(1+x)Cr_(1.2)Mn_(0.2)Fe_(0.6) {x = 0, 0.02, 0.05, 0.1) alloys with high hydrogen desorption plateau pressures for hybrid hydrogen storage vessel application were prepared by induction levitation melting, as well as the effect of Ti super-stoichiometry on the crystallographic characteristics and hydrogen storage proper ties were systematically investigated. The results show that all of the alloys were determined as a single phase of C14-type Laves structure, the unit cell volume expands with increasing Ti content. Compared with the stoichiometric TiCr_(1.2)Mn_(0.2)Fe_(0.6) alloy, the titanium super-stoichiometric Ti_(1+x)Cr_(1.2)Mn_(0.2)Fe_(0.6) (x = 0.02,0.05,0.1) alloys have larger hydrogen storage capacities and lower hydrogen desorption plateau pressures. Among the studied alloys, Ti_(1.02)Cr_(1.2)Mn_(0.2)Fe_(0.6) has the best overall properties for hybrid hydro gen storage application, its hydrogen desorption plateau pressure at 318 K is 37.69 MPa, its hydrogen storage capacity is 1.61 wt.% and its dissociation enthalpy (ΔH_d) is 16.67 kj/mol H_2.