Discharge properties of ECAP processed AZ31－Ca alloys as anodes for seawater-activated battery

Abstract

The effects of Ca addition and equal channel angular pressing (ECAP) on the microstructure evolution and discharge properties of AZ31-1.0Ca alloy were investigated to develop high-performance anodes for seawater-activated battery. Microscopic observations show that the net-like (Mg, Al)2Ca phase replaces the Mg17Al12 phase and distributes along grain boundaries in AZ31-1.0Ca alloy. 12-pass ECAP effectively refines the grains and crushes the (Mg, Al)2Ca phase into fine particles. The discharge measurements reveal that the 12-pass ECAP processed AZ31-1.0Ca anode exhibits desirable discharge properties with the largest power density of 88.1 mW cm−2 and the highest anodic efficiency of 63.3% at 100 mA cm−2, which are 25.0% and 13.6% higher than that of AZ31 anode, respectively. The enhanced discharge performances can be attributed to the modified microstructure with refined grains, fragmented and dynamically precipitated (Mg, Al)2Ca particles.

Keywords

• Magnesium alloy
• Equal channel angular pressing
• Discharge performance
• Seawater-activated battery