The electrochemical behaviors of Mg–8Li–0.5Y and Mg–8Li–1Y alloys in sodium chloride solution

Abstract

The electrochemical performances of Mg–8Li–0.5Y and Mg–8Li–1Y electrodes in 0.7 mol L−1 NaCl solution are investigated by methods of potentiodynamic polarization, electrochemical impedance spectroscopy, potentiostatic oxidation and scanning electron microscopy (SEM). Their performances as anodes of Mg–H2O2 semi-fuel cells are also determined. It is found that the Mg–8Li–1Y electrode has higher corrosion resistant ability and electrooxidation activity than that of Mg–8Li–0.5Y electrode in 0.7 mol L−1 NaCl solution. The corrosion potential of Mg–8Li–1Y electrode is 60 mV more positive than that of Mg–8Li–0.5Y electrode. The current density of Mg–8Li–1Y electrode is around 2 mA cm−2 higher than that of Mg–8Li–0.5Y electrode at the discharge potentials of −0.8 V, −1.0 V and −1.2 V, and it is similar to that of Mg–8Li–0.5Y electrode at −1.4 V. The Mg–H2O2 semi-fuel cell with Mg–8Li–1Y anode presents a maximum power density of 59 mW cm−2 at room temperature, which is higher than that of Mg–8Li–0.5Y anode (53 mW cm−2). The content of Y in alloys obviously affects the performance of the alloys and the Y content of 1 wt. % is better than 0.5 wt. %.