Enhanced electrochemical properties of ball-milled Mg2Ni electrodes

The characteristics and mechanisms of enhanced electrochemical properties for a Mg2Ni alloy produced by a ball-milling treatment were investigated by electrochemical measurements and XRD analysis. The particle size decreases, the internal strain increases, and the alloy gradually becomes amorphous on ball-milling. With the accompanying increased diffusion rate of hydrogen into the ball-milled Mg2Ni alloy, the limiting current density, icrit, is decreased and the exchange current density, i0, is increased. As a result, the specific discharge capacity is significantly increased compared to that of the as-received Mg2Ni alloy and reaches a maximum for a ball-milling time of 25 h.