The influence of samarium (Sm) on the discharge and electrochemical behaviors of the magnesium alloy AZ80 as an anode for the Mg-air battery

• Published in: Electrochimica acta Vol. 348; p. 136315
• Main Authors: Chen, Xingrui, Liao, Qiyu, Le, Qichi, Zou, Qi, Wang, Henan, Atrens, Andrej
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 10.07.2020; Elsevier BV
• Subjects: Anodes; Corrosion rate; Discharge; Discharge performance; Electrochemical analysis; Electrochemical behaviors; Magnesium alloy; Magnesium base alloys; Metal air batteries; Mg-air batteries; Morphology; RE element; Samarium; Mg-air batteries; Discharge performance; Magnesium alloy; Electrochemical behaviors; RE element
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2020.136315

The influence of Sm on the microstructure, electrochemical properties, and discharge performance of cast AZ80 as the anode for Mg-air battery are investigated. AZ80 containing Sm has refined α-Mg grains and contains the Al2Sm phase. With increasing Sm content, the number and size of the Mg17Al12 phase particles are reduced. The AZ80-xSm anodes have higher electrochemical activity and lower self-corrosion rates than AZ80. The AZ80-xSm anodes also have a high discharge performance and a stable discharge voltage, which is attributed to the refined structure and Al2Sm particles. The AZ80-3Sm anode has the best discharge capacity of 1439 mAh g−1 and the best anode efficiency of 65% at 40 mA cm−2, which are 17% and 20% higher than for the AZ80 anode. This anode has an output peak energy of 1719 mWh g−1 at both 10 and 20 mA cm−2, compared with 1510 mWh g−1 for AZ80 at only 20 mA cm−2. The AZ80-xSm anodes have smoother discharge surface morphology, which is beneficial to the exfoliation of discharge products.