Microwave-assisted smelting to improve the corrosion and discharge performance of Al-anodes in Al-air batteries

Aluminum anodes with fine grain have stronger electrochemical activity and higher corrosion resistance, but the microwave-smelted aluminum alloy anode can be prepared with fine grain. In this work, microwave smelting has been used to refine grain size and optimize the precipitated phase in an aluminum alloy anode. The results show that microwave can not only refine the grain and improve the corrosion resistance of aluminum anode, but also the distribution of precipitated phase is more uniform. The fine grain reduces the potential difference inside the aluminum anode, thus activating the electrochemical activity of the anode and improving the corrosion resistance. The corrosion form is also changed from the conventional pit corrosion to uniform corrosion, so as to improve the utilization rate of anode. The capacity density and energy density of 1000 W microwave-smelted aluminum anode were 1554.404 mAh/g and 1955.181 Wh/kg, respectively. Compared with conventional aluminum anode, the energy density and capacity density increased by 92.7% and 64.5%, respectively. Therefore, microwave technology can improve electrochemical performance and battery performance by optimizing microstructure uniformity and refining grain size.