The use of magnesium instead of zinc as an anode in batteries is now being developed. These batteries have important advantages. In particular the shelf life of magnesium dry batteries is better than that of zinc batteries. However, magnesium batteries exhibit a power delay which is especially troublesome during use under certain condition. This phenomenon, which was first described by Kirk and Fry ~, can last for several seconds and cause the battery voltage to drop to less than half its initial value.
Up to the present time studies on the magnesium anode have essentially been aimed at improving battery performances by lowering the rate of open circuit corrosion and the transient amplitude and duration. Factors which have been considered are the composition of the electrolyte and electrode and the effect of corrosion inhibitors. Among the few electrolytes studied, emphasis has been placed on MgC12, MgBr2, MgAc2 and Mg(C104)2. More recently other electrolytes containing no magnesium, such as NaIO4 / and NaCI 3 have been investigated. The electrode studies were mostly concerned with the use of Mg alloys, and directed towards those alloys of magnesium containing zinc and aluminium (AZ alloys). Many organics and some inorganics, such as chromate, have been tried as open circuit corrosion inhibitors. Useful results have been obtained in these studies leading to a great improvement in shelf life at temperatures as high as 40 or 50ยฐC, and greatly reducing the delay phenomenon 4'5.
Few fundamental studies have so far been carried out to elucidate the phenomena associated with the magnesium electrode, and these have almost exclusively dealt with AZ alloys. The long galvanostatic pulse technique has been employed in most cases and has shown that the anode potential changes with time for different electrolytes and temperatures 6,v. Some potentiostatic pulse experiments have also been made in a similar manner and some polarization curves have been obtained, mostly from corrosion current determination 8-~2. Owing to the small number of experiments which have been conducted to date major trends in electrode behavior have not yet become apparent. EXPERIMENTAL Pure magnesium; the spectroscopic analysis of which indicates a level of impurities of less than 0.03~ has been studied in various 2 N aqueous solutions. The electrode was a wire of 1.45 mm diameter and had an active area of about 20 mm 2. The