Tailoring the electrochemical behavior and discharge performance of Mg–Al–Ca–Mn anodes for Mg-air batteries by different extrusion ratios
Weiying Huang, Zhen Jiang, Pengfei Wu, Wei Qiu, Wei Chen, Jian Chen
Abstract
This work investigates the electrochemical behavior and discharge performance of Mg–3Al-0.4Ca-0.7Mn alloys with three extrusion ratios (ER) of 10, 16, and 25 as anodes for Mg-air batteries. The results show that the ER16 alloy has the lowest corrosion current density and the highest corrosion resistance. The ER25 slightly reduces the corrosion performance due to excessive discontinuous second phase leading to elevated self-corrosion rate. The alloy exhibits higher discharge voltage and stable discharge process with increasing extrusion ratio. Increasing the extrusion ratio has a homogeneous microstructure, the increase in the area fraction of non-basal oriented grains is conducive to the homogeneous dissolution of the anode and the inhibition of the “chunk effect”. The ER25 alloy showed the highest anode efficiency, specific capacity and energy density of 55.73 %, 1306.67 mA h g-1 and 1635.947 mW h g−1 at 20 mA cm−2, respectively.