Effects of microstructure on the electrochemical discharge behavior of Mg-6wt%Al-1wt%Sn alloy as anode for Mg-air primary battery

• Published in: Journal of alloys and compounds 2017-06, Vol.708, p.652-661
• Main Authors: Xiong, Hanqing, Yu, Kun, Yin, Xiang, Dai, Yilong, Yan, Yang, Zhu, Hualong
• Format: Article
• Language: English
• Subjects: Annealing; Hot extruding; Magnesium anode; Mg-air battery; Microstructure
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.12.172

The discharge performance of Mg-6wt.%Al-1wt.%Sn alloy is enhanced by hot extruding and subsequent annealing treatment. Limited dynamic recrystallization is observed during the hot extruding process and the extruded alloy exhibits the non-uniform microstructure. Subsequently, 200 °C annealing treatment effectively facilitates the precipitation of second phases and spherical Mg2Sn phases with typical sizes of 50–100 nm uniformly distribute in the Mg-Al-Sn alloy. The 200 °C annealed Mg-Al-Sn anode shows the excellent discharge performance in 3.5 wt% NaCl solution, attributed to fine Mg2Sn phases and fully recrystallized microstructure which accelerate the self-peeling of corrosion products. With air battery tests, the 200 °C annealed Mg-Al-Sn alloy is a promising anode for magnesium-air batteries. •Discharge properties of Mg-Al-Sn alloys are studied as anode for Mg-air batteries.•Hot extruding largely improves the discharge performance of the Mg-Al-Sn anode.•The 200 °C annealed alloy shows higher discharge properties than other ones.•The peak power density of 200 °C annealed anode reaches to 94.1 mW cm−2.