Anodes for Refuelable Magnesium-Air Batteries

The aim of this work was to select a suitable anode and electrolyte combination for the operation of a replaceable anode magnesium‐air battery. Various combinations were considered from the standpoint of cell voltage, parasitic consumption of metal, and the volume of reaction product sludge formed. Packaging materials were also tested to prevent the sludge from falling to the bottom of the cells and to minimize magnesium hydroxide formation on the cathodes. The anode package selected consisted of AZ61 magnesium alloy covered on each surface with Vexar expanded polyethylene and glycerinated cellulose. Sodium chloride solutions, between 7 and 18%, were satisfactory electrolytes, the latter being superior as a result of a lower resistive drop in the electrolyte and a shorter voltage transient on changing current densities.