Effects of microstructure on the electrode properties of melt–spun Mg-based amorphous alloys

Abstract

Amorphous and nanocrystalline Mg-based alloys (Mg 60Ni 25) 100− x Nd x ( x = 2, 5, 10, 15) were prepared by rapid solidification. The phase structures and the electrochemical properties of the ribbons before and after charge/discharge cycling were characterized by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) analysis and galvanotactic charge–discharge cycle test, respectively. The experimental results showed that the discharge capacities increased with increasing Nd atomic content and the optimum Nd content is between 10 and 15 mol%. The highest discharge capacity reached more than 580 mAh/g at the discharge current densities of 50 mA/g for (Mg 60Ni 25) 90Nd 10 samples. However, the discharge capacity gradually becomes low with the crystallization proceeding of amorphous structure. It was suggested that the amorphous structure was a key factor to achieve high discharge capacity and good cycling stability.