AZ61 and AZ61-La Alloys as Anodes for Mg-Air Battery

AZ61 and AZ61-0.5La (wt.%) alloys are prepared by the conventional casting method and then, AZ61 and AZ61-0.5La alloy sheets are obtained with multi-pass hot rolling. Microstructures and electrochemical properties of four alloys are investigated, and discharge properties are tested by an assembled Mg-air battery using alloy anode sheets with a dimension of 70x100x2.5mm. Results show that Al11La3 phases are formed in as-cast AZ61-0.5La alloy and promote the grain refinement and the formation of uniform microstructure in as-rolled AZ61-0.5La alloy. As-rolled AZ61-0.5La alloy exhibits a weak self-corrosion tendency but a strong discharge activity. After discharge test for 5h, the Mg-air battery based on the as-rolled AZ61-0.5La sheet can provide the maximum power output of 1.625W, and as-rolled AZ61-0.5La anode can supply the maximum energy density of 1417mWhg(-1). In addition, the relationship between microstructures and discharge properties is sufficiently described and discussed in this paper.