Effect of microstructure on discharge performance of Al-0.8Sn-0.05Ga-0.9Mg-1.0Zn (wt%) alloy as anode for seawater-activated battery

The electrochemical performance and discharge behavior of Al-0.8Sn-0.05Ga-0.9Mg-1.0Zn (wt%) alloys in as-cast, homogenized, and annealed states were investigated through electrochemical means, corrosion rate test, and discharge test in a 3.5 wt% NaCl solution. Results suggest that the discharge performance of this alloy is enhanced by rolling and subsequent annealing treatment. This is attributed to the fact that the microstructure of the alloy is greatly improved through rolling and subsequent annealing treatment. The 400 degrees C-annealed alloy exhibits the most excellent discharge activity than alloys in other states, which is due to more regions being activated by a finer and more uniform Sn-rich phase. Furthermore, the anode efficiency of the 400 degrees C-annealed alloy is higher than that of as-cast and homogeneous alloys due to the more uniform distribution of Sn in the aluminum matrix.