The optimization of the ball milling parameters resulted in the synthesis with a milling duration equal to 10 hours of amorphous MgNi having an initial discharge capacity over 520 mAh/g. Further milling results in a partial crystallization of amorphous MgNi into nanocrystalline MgNi2 and Mg2Ni, which decreases significantly the electrode performance. This study also shows that it is possible to obtain an amorphous and electroactive material in large scale (I kg of alloy per batch) using an industrial high-energy attritor. In addition, it was demonstrated that the carbon added at the beginning of the milling to avoid powder welding, in spite of its small proportion (1 wt.%), has a notable influence on the performance of the material. This study also confirms the major loss of activity during cycles. However, the partial substitution of Ti for Mg leads to a remarkable improvement of the cycle lifetime of the alloy.