Discharge properties of ECAP processed AZ31－Ca alloys as anodes for seawater-activated battery
Qiuyuan Xie, Aibin Ma, Jinghua Jiang, Huan Liu, Bassiouny Saleh
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.