Electrochemical performance of pure Al, Al–Sn, Al–Mg and Al–Mg–Sn anodes for Al-air batteries
By Ren, Jianming; Ma, Jianbo; Zhang, Jiao; Fu, Chaopeng; Sun, Baode
Published in Journal of Alloys and Compounds
2019
Abstract
In this work, pure Al, Al–Sn, Al–Mg, and Al–Mg–Sn alloys have been investigated as anodes for aluminum-air batteries. Effects of Mg and Sn additions on the aluminum anodes for Al-air battery in 4 mol L−1 KOH solution have been evaluated by self-corrosion test, open circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy, cell voltage and galvanostatic discharge as well as ab-initio energy calculation based on density functional theory. The results show that Al alloy anodes show better corrosion resistance and battery performance than the pure Al anodes. The self-corrosion rate of Al alloys increase in the following order: Al > Al–Sn > Al–Mg–Sn > Al–Mg. The Al–Mg alloy shows the smallest self-corrosion rate and largest capacity among the three Al alloy anodes. The Al–Mg–Sn alloy has the best electrochemical performance and battery discharge performance. SEM, EDS and 3D measuring laser microscope analysis of Al alloys are in good agreement with the self-corrosion test and electrochemical characteristics. Furthermore, the ab-initio energy calculation also reveals the positive role of alloying elements in enhancing corrosion and electrochemical performances.