Effects of substituting Mg with Zr on the electrochemical characteristics of Mg2Ni-type electrode alloys prepared by mechanical alloying

Mg2−xZrxNi (x = 0, 0.15, 0.3, 0.45 and 0.6) electrode alloys were prepared by mechanical alloying (MA). The effects of substituting Mg with Zr on the microstructures and electrochemical performance of the MA alloys were investigated in detail. The results obtained by XRD and TEM show that the substitution of Zr for Mg is favorable for the formation of an amorphous phase. For a fixed milling time, the amorphous phase in the alloy increases with increasing Zr content. The electrochemical measurements indicate that the substitution of Zr can dramatically enhance the discharge capacity with preferable cycle stability, and markedly improve the discharge voltage characteristics of the alloys. The fact that Zr promotes the formation of an amorphous phase is mainly responsible for these effects.