Effect of Sm Addition on the Electrochemical Behavior and Discharge Performance of Mg-1Sn-1Ca-0.3Mn Alloy as Mg-Air Battery Anodes

Abstract

Sm element is a relatively inexpensive rare Earth element. The effect of Sm content on the microstructure, electrochemical behavior and discharge performance of Mg-1Sn-1Ca-0.3Mn (TX11) alloy was investigated through scanning electron microscopy (SEM), electrochemistry workstation and Mg-air battery tests. Results reveal the addition of Sm does not change second-phase morphology of TX11 alloy, CaMgSn and Mg2Ca phases solidly dissolves Sm elements. The electrochemistry results depict that Sm addition deteriorates the corrosion resistance and electrochemical activity of TX11 alloy, which is attributed to Sm solid solution changing the original second phase properties. In addition, Mg-1Sn-1Ca-0.5Sm-0.3Mn anode presents the highest anodic efficiency and specific capacity among Mg-1Sn-1Ca-xSm-0.3Mn (x = 0. 0.5, 1, 2 wt%) alloys, those value is 60.2% and 1306.801 mA h g−1, respectively, which attribute to the highest dissolution activity and the smoother discharge surface morphology. Micro-Sm alloyed is beneficial for improving the anodic efficiency of TX11 anode.