Effect of adding magnesium to lithium on the performance of discharge and hydrogen evolution of the lithium anode

The present study evaluates the effect of magnesium as an inhibitor on the performance of discharge and hydrogen evolution of lithium anode in alkaline electrolyte with additives. The electrochemical behaviors of lithium and lithium–magnesium alloy are assessed by hydrogen evolution rate, discharge current density, anodic potential, and potentiodynamic polarization. For these conditions, the results show that addition of magnesium to lithium enhances the current efficiency. Addition of 0.07 wt% Mg to lithium has minor effect on discharge current and anodic potential of lithium anode. The chemical composition and the morphology of the anode surfaces were evaluated by X-ray diffraction and scanning electron microscopy. The results show that the slow dissolution of lithium–magnesium alloy generates the formation of LiOH, LiOH·H2O, and Mg(OH)2. After discharge in saturated alkaline electrolyte with additives, the lithium–magnesium surface is less porous than lithium surface. Hydrogen evolution decrease, prompted by adding magnesium to lithium, is related to surface integrity enhanced by Mg(OH)2.