Electrochemical properties and discharge performance of Mg-3Sn-xCa alloy as a novel anode for Mg-air battery

In this work, Ca was introduced into the Mg-3Sn alloy as an environmentally friendly element. The electrochemical performance and discharge properties of Mg-3Sn-xCa (x = 0, 0.2, 0.6, 1.0 wt%) as an anode for Mg-air battery were investigated. The results revealed that the Mg-3Sn-1.0Ca alloy exhibited the best activity and the optimum discharge performance, reaching a voltage of 1.46 V at 2.5 mA cm−2 and a peak specific energy of 1277 mA h g−1 at 20 mA cm−2. The Ca element increases the activity of Mg-3Sn through phase modulation, which results in the presence of a large number of cracks in the discharge products and facilitates the maintenance of high and stable voltages. In addition, the refined grains increase the grain boundaries and expand the contact area with the cathode phase, which dissolves the Mg matrix sufficiently and reduces the chunk effect.