Thermodynamically destabilized hydride formation in “bulk” Mg–AlTi multilayers for hydrogen storage

Abstract

Thermodynamic destabilization of MgH₂ formation through interfacial interactions in free-standing Mg–AlTi multilayers of overall “bulk” (0.5 μm) dimensions with a hydrogen capacity of up to 5.5 wt% is demonstrated. The interfacial energies of Mg–AlTi and Mg–Ti (examined as a baseline) are calculated to be 0.81 and 0.44 J m⁻². The enhanced interfacial energy of AlTi opens the possibility of creating ultrathin alloy interlayers that provide further thermodynamic improvements in metal hydrides.