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Amorphous MgNi and MgNi0.5Co0.5 composites were prepared by mechanical ball grinding in an argon atmosphere. The electrodes made of these composites are characterized by high electrochemical discharge capacity: 872 mA · h/g for MgNi and 309 mA · h/g for MgNi0.5Co0.5. The cyclic stability (S30) of the MgNi0.5Co0.5 electrode (42%) is somewhat higher compared to MgNi (26%). Reduction in the capacity of electrodes is associated with bulk and corrosion processes. The MgNi0.5Co0.5 electrode increases its capacity to a greater extent than MgNi after deep discharge.

The LaMgNi4–xCox (x = 0, 0.33, 0.67, 1) alloys are prepared by sintering and prolonged heat treatment at 500°C, with the main cubic phase of MgCu4Sn type. The alloy samples ball-milled in an argon atmosphere show the glass-forming ability. Electrochemical experiments of the LaMgNi4–xCox electrodes are performed at charge and discharge current densities of 100 mAh. The maximum discharge capacity is exhibited by the powdered alloys (218–302 mAh/g) compared to the ball-milled ones (92–134 mAh/g). The cobalt content of the LaMgNi4–xCox alloys influences the electrode characteristics. The highest discharge capacity is shown by the powdered alloy with x = 0.33. The ball-milled alloys have slightly higher cyclic stability.

The advantages of reactive ball grinding for preparation of new efficient Mg-based hydrogen storage materials are discussed. Magnesium-based nanocomposites were synthesized with additions of η-Zr4Fe2O0.5 intermetallic compound, which is characterized by enhanced resistance to disproportionation in hydrogen and can prolong the cyclic life of materials. The improvement of hydrogen absorption parameters for Mg–intermetallic composites was observed. It was shown that fourfold increase in the reaction rate during mechanochemical synthesis of MgH2 and decrease in hydrogen desorption temperature by 80°C were induced by catalytic additions.