Microstructure and electrochemical properties of as-rolled Mg-Hg-Ga anode materials

In this work, the effects of Hg and Ga additions on the microstructure and electrochemical properties of as -rolled Mg-Hg-Ga alloys are investigated. It can be concluded that the Mg-Hg-Ga alloys are composed of ix -Mg and Mg5Ga2 phases. The addition of the Hg element not only facilitates the precipitation of Mg5Ga2 phases, but also facilitates the distribution of the Ga element in second phases. During rolling, the main soft mechanism in the Mg-1.5Hg-1.5Ga alloy is dynamic recovery, while that of the Mg-1.5Hg-2.0Ga alloy is dynamic recrystallization. The electrochemical tests reveal that the Mg-1.5Hg-2.0Ga alloy has the best corrosion resistance with the smallest corrosion current density of 0.057 mA cm-2. The Mg-2.0Hg-2.0Ga alloy is discovered to exhibit the most negative discharge potential of - 1.976 V and - 1.967 V (vs. SCE) at current densities of 80 mA cm-2 and 180 mA cm-2, respectively. It can be attributed to the fact that the increasing Hg content greatly increases the proportion of deformed grains as well as the volume fraction of Mg5Ga2 phases in the grains, improving the discharge activity of the Mg-2.0Hg-2.0Ga alloy. It also refines the grains of the alloy and forms many anodic dissolution areas, further promoting the discharge activity of the Mg-2.0Hg-2.0Ga alloy.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, the effects of Hg and Ga additions on the microstructure and electrochemical properties of as-rolled Mg-Hg-Ga alloys were investigated. It was observed that the addition of Hg facilitated the precipitation of Mg5Ga2 phases and the distribution of the Ga element. Electrochemical tests revealed that the alloy with 2.0Hg and 2.0Ga exhibited the best corrosion resistance and discharge activity.