Hydrogenation properties of amorphous Ni materials prepared by mechanical alloying

Mechanical alloying (MA) process was used to synthesize amorphous 2 Mg + Fe / x wt % Ni hydrogen storage materials. The structure, thermodynamic and electrochemical properties of these materials has been examined. The nickel addition is advantageous for the formation of Mg–Fe amorphous structures and for the improvement of the electrochemical properties of the studied alloys. With the increasing of nickel content, at first cycle, the discharge capacity of the 2Mg–Fe alloys increases first and then decreases reaching a maximum of 155 mAh g - 1 at x = 100 . For all 2 Mg + Fe studied materials, MA with nickel effectively reduced the degradation rate of the studied electrodes. This result indicates that the nickel content does help to inhibit the corrosion of the alloy electrode in the KOH solution. On the other hand, the concentration of hydrogen in produced amorphous 2 Mg + Fe / x wt % Ni alloys strongly decreases with increasing nickel contents. The hydrogen content at 300 ∘ C in these materials was 3.25, 1.55 and 0.35 wt% for x = 0 , 100 and 200, respectively.