Discharge Behavior of Mg–Sn–Zn–Ag Alloys with Different Sn Contents as Anodes for Mg-air Batteries

Abstract

Controlling the microstructure and discharge performance of Mg-based alloys is of great importance and aimed at optimizing magnesium anode materials to the level required for power source applications. In this study, the microstructure along with discharge properties of extruded Mg-Sn-Zn-Ag alloys with Sn content ranging from 2 wt.% to 8 wt.% are investigated. The results indicate that the Mg-4Sn-1Zn-1Ag alloy exhibits the most negative discharge potential during the half-cell test than the other alloys investigated in this study. Moreover, a Mg-air battery with a Mg-4Sn-1Zn-1Ag alloy as the anode provides a relatively high cell voltage together with power density compared with the counterpart battery. Furthermore, the microscopic mechanism of an anode material exhibiting an excellent discharge performance is systematically discussed in terms of the second phase, dynamic recrystallization, crystal orientation and discharge product film.

Discharge Behavior and Mechanism of Solid-Solution-Treated Alloy Anodes for Magnesium–Air Batteries

“…Crystallographic planes with nonbasal orientation have low bond breaking energy and high surface energy, making them easy to be broken during discharge. The results are similar to studies of Wang et al, the (101̅0)-(100) and (112̅1)-oriented grains are attacked preferentially to the (0001)-oriented grains during the discharge processes. ,, Therefore, PCP corrosion is propagated along a (0001) plane in a grain of Mg alloys and can efficiently react with the aqueous electrolyte and exhibit excellent electrochemical activity. − …”

“…The CPE of ZT23 is apparently lower than those of pure Mg and Mg−2Zn, implying the formation of relatively dense protective films on the anode surface. 57 Therefore, the soluble Zn and Sn may form a dense oxide or hydroxide film to protect Mg matrix self-corrosion and enhance anodic efficiency.…”

Research Progress on Corrosion Resistance of Magnesium Alloys with Bio-inspired Water-repellent Properties: A Review

“…Adding alloy elements may change the chemical components of magnesium alloy directly or indirectly and drive change in its form of organization, and the second phase size and distribution, consequently improving the corrosion resistance behavior of magnesium alloy [90,91] . On the other hand, grain size of magnesium alloy can be reduced by alloying [92] and plastic deformation [93] , so that mechanical properties of alloys can be improved effectively.…”

Electrochemical behaviors and discharge performance of Mg-Sn binary alloys as anodes for Mg-air batteries

“…In order to find a suitable Mg anode and promote the application of Mg-air batteries, alloying is an effective and economical method to improve the discharge performance and suppress the self-corrosion. The common added alloying elements include Al [8,10], Zn [11,12], Pb [7,13,14], Li [15][16][17], Ca [6,8,18], Sn [8,9,19,20], In [21,22], Mn [8,19], rare earths (RE) [7,17,23], etc. Among these elements, Li has been proved can effectively improve the discharge performance of Mg anodes [15,17].…”

“…As an environmentally friendly element, Sn with a high hydrogen evolution overpotential, a large solubility in Mg and low cost, has attracted considerable attention in the field of corrosion and battery discharge [17,18,24]. Gu et al [20] studied the discharge performance of extruded Mg-Sn-Zn-Ag alloys with Sn content between 2 wt% and 8 wt% as anodes for Mg-air batteries. And Mg-4Sn-4Zn-1Ag anode with a high proportion of dynamic recrystallization and the dispersive nanometer-scale Mg 2 Sn phase, promoting the dissolution of the Mg matrix uniformly and providing a relatively high battery voltage and energy density.…”