Discharge properties of low-alloyed Mg-Bi-Ca alloys as anode materials for Mg-air batteries: Influence of Ca alloying

In this study, the discharge behaviors of extruded low-alloyed Mg-Bi-Ca alloys in an aqueous electrolyte (3.5 wt% NaCl solution) were investigated using electrochemical techniques. The Mg-1Bi-0.5Ca alloy showed more negative discharge potential and higher anodic efficiency compared with the Mg-1Bi alloy during half-cell testing. Furthermore, the discharge morphologies of the Mg-1Bi-0.5Ca alloy showed loose and thin discharge products, along with numerous cracks, these features promoted diffusion of the NaCl solution into the discharge products, enhancing the discharge activity. The Mg-air battery with a Mg-1Bi-0.5Ca anode showed the higher cell voltage and power density at all current densities. Hence, the Mg-1Bi-0.5Ca alloy has great potential for further development as an anode material for Mgeair battery. (C) 2020 Published by Elsevier B.V.