Electrochemical properties of magnesium alloy anodes discharged in seawater
(School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: Magnesium alloys can be developed as anode materials for seawater activated batteries. The electrochemical properties of AZ31, AP65 and Mg-3%Ga-2%Hg alloy anodes discharged in seawater were studied. The potentiodynamic polarization shows that the Mg-3%Ga-2%Hg alloy provides more negative corrosion potentials than AZ31 or AP65 alloy. The galvanostatic discharge results show that the Mg-3%Ga-2%Hg alloy exhibits good electrochemical properties as anodes in seawater. And the EIS studies reveal that the magnesium alloy anode/seawater interfacial process is determined by an activation controlled reaction. The Mg3Hg and Mg21Ga5Hg3 phases in Mg-3%Ga-2%Hg alloy improve its electrochemical properties better than the Mg17(Al,Zn)12 phase in AZ31 and Mg(Pb) solid solution phase in AP65 alloys.
Key words: magnesium alloy; Mg-Ga-Hg alloy; electrochemical properties; seawater activated battery; anode