Electrochemical behaviors and discharge performance of the as-extruded Mg-1.5 wt%Ca alloys as anode for Mg-air battery

The electrochemical behaviors and discharge performance of an as-extruded Mg-1.5 wt%Ca alloy anode were investigated as well as the corrosion behaviors. The as-extruded Mg-1.5 wt%Ca anode exhibits a superior discharge performance than the as-extruded CP Mg anode. It can exhibit high energy density of 1413 mWh·g−1 with a satisfactory specific capacity (1296 mAh·g−1) at 20 mA·cm−2. The fine DRXed grains (15 ± 2 μm) and the active Mg2Ca particles around grain boundaries are responsible for the promoted discharge performance. Furthermore, the fine and dispersive Mg2Ca particles are favor of the uniform consumption of Mg anode during discharge. The detachment of discharge products of Mg-1.5 wt%Ca anode is more difficult than that of CP Mg, resulting an early failure of discharge at 80 mA·cm−2. The corrosion behaviors are also discussed in detail.