Discharge and corrosion behaviors of the α-Mg and β-Li based Mg alloys for Mg-air batteries at different current densities

Abstract

The discharge and corrosion behaviors of the wrought α-Mg and β-Li based Mg alloys at large current densities were investigated in this work. The β-Li phase strongly promotes the power density of Mg based anodes up to 58.9 mW/cm2 at 80 mA/cm2, due to the dissolvable discharge product. The α-Mg based alloy suffers significant hydrogen gas evolution. The β-Li phase memorably weakens the hydrogen evolution, due to prior dissolution of β-Li phase. The discharged surface becomes fine and dense after the fast and uniform consumption of the anodes at large current density. The corroded phase transform into particle-like clusters. Furthermore, the fine and dense precipitates play important roles in the spalling behavior of β-Li phase and surface film formation process. The corrosion behaviors connecting discharge properties are also discussed in detail. Keywords: Magnesium alloys, Mg-air batteries, Microstructures, Discharge and corrosion behaviors