Dual-tuning effect of In on the thermodynamic and kinetic properties of Mg2Ni dehydrogenation

Mg2In0.1Ni solid solution with an Mg2Ni-type structure has been synthesized and its hydrogen storage properties have been investigated. The results showed that the introduction of In into Mg2Ni not only significantly improved the dehydrogenation kinetics but also greatly lowered the thermodynamic stability. The dehydrogenation activation energy (Ea) and enthalpy change (ΔH) decreased from 80 kJ/mol and 64.5 kJ/mol H2 to 28.9 kJ/mol and 38.4 kJ/mol H2, respectively. The obtained results point to a method for improving not only the thermodynamic but also the kinetic properties of hydrogen storage materials.