Hydrogen absorption performance of mechanically alloyed (Mg ₂Ni)_100-xTi_x powder

The hydrogen storage alloy (Mg₂Ni)_100-xTi_x (x = 0, 2.5, 5.0, 7.5 and 10.0at%) powders were synthesized from elemental powder mixture by mechanical alloying (MA) under an Ar atmosphere. The as-milled powders were examined as a function of titanium addition by X-ray diffraction and synchrotron X-ray absorption near-edge structure (XANES) techniques at various milling time. The hydrogen absorption kinetics of the 15 h as-milled powders were evaluated. The maximum hydrogen absorption content of 15 h as-milled Mg₂Ni powders can be improved from 3.14mass% to 3.88mass% when 5.0at% of titanium was added. The hydrogenation rate of the Mg ₂Ni powder was also obviously enhanced by introducing the titanium into Mg₂Ni lattices. More than 20% improvement of hydrogen absorption for Mg₂Ni intermetallic powders was achieved by adding titanium.